221 results on '"Argon atmosphere"'
Search Results
2. New Composite Materials Based on Nanoporous Glasses Containing Manganese Oxides
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L. N. Kurylenko, O. A. Pshenko, Tatiana Antropova, and M. Yu. Arsentiev
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Materials science ,Aqueous solution ,Nanoporous ,Oxalic acid ,chemistry.chemical_element ,Manganese ,Porous glass ,Condensed Matter Physics ,chemistry.chemical_compound ,chemistry ,Phase composition ,Materials Chemistry ,Ceramics and Composites ,Composite material ,Chemical composition ,Argon atmosphere - Abstract
A technique is developed and new composite materials containing manganese oxides MnxOy (x = 1, 2, 3; y = 2, 3, 4) are synthesized based on high-silica nanoporous glasses (NPGs). The synthesis is carried out by successive impregnation of porous glass plates in aqueous solutions of manganese chloride (MnCl2) and oxalic acid (H2C2O4), followed by heat treatment of the samples in an argon atmosphere to decompose the reaction product (MnC2O4). The chemical composition and phase composition of the obtained composites are investigated.
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- 2021
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3. Effect of Electropulsing Treatment on the Formation of MnS Inclusions in SUS303
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Danbin Jia, Liangcai Zhong, Chen Tian, Zhaoyang Liu, Lei Yuan, Wenbin Dai, and Jingkun Yu
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Materials science ,Mechanics of Materials ,Metallic materials ,Metallurgy ,Materials Chemistry ,Metals and Alloys ,Nucleation ,Molten steel ,Inclusion (mineral) ,Condensed Matter Physics ,Supercooling ,Argon atmosphere - Abstract
Electropulsing treatment was imposed on SUS303 free-cutting steels to analyze the evolution of MnS inclusions. SUS303 steels were treated in argon atmosphere under various conditions: before the formation of MnS inclusions (1773 K), at the beginning of the formation of MnS inclusions (1678 K), and after the formation and growth of MnS inclusions (1583 K). The results show that the sizes of globular MnS inclusions decrease with an increase of current density when the electropulsing treatment is treated in the melting stage. Meanwhile, electropulsing treatment restrains the growth of inclusions due to the different conductivities between the molten steel and MnS inclusions when electropulsing treatment is treated in the solidification process. However, the number of fine rodlike MnS inclusions increases with the increase of current density in the samples treated in the inclusion nucleation stage and solidification stage because the reduction in chemical potential produced by electropulsing treatment will require less undercooling. Experimental data demonstrate that the application of electropulsing treatment is a fantastic new method to control the morphology and size of MnS inclusions in the melting stage.
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- 2021
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4. Synthesis of graphene nanosheets by the electrical explosion of graphite powder confined in a tube
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Liu Qiuhua, Hui Zhou, Xudong Wang, Liang Zhu, and Yupeng Wei
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010302 applied physics ,Materials science ,Explosive material ,Graphene ,Process Chemistry and Technology ,02 engineering and technology ,Liquid medium ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Rod ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,law ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,Tube (fluid conveyance) ,Graphite ,Composite material ,0210 nano-technology ,Argon atmosphere - Abstract
The electrical explosion method, due to its simplicity and high efficiency, has attracted significant attention in graphene synthesis. Generally, graphite rods and carbon fibers are used to form graphene by electrical explosions in a liquid medium. In the present work, the preparation of graphene from graphite powder in a tube by electrical explosions was proposed. A certain amount of graphite powder was confined in a tube and electrically exploded in an argon atmosphere. The diameter of the constraint tube affected the microstructure of the as-prepared products (graphite nanosheets and few-layer graphene) under the charging voltage of 14 kV. When the diameter of the constraint tube was 3 mm, explosive products were mainly composed of few-layer graphene. The collision degree between graphite powder particles and the diameter of the constraint tube were the key factors to form graphene by electrical explosions. The underlying mechanism governing the generation of graphene was carefully illustrated. Moreover, a self-designed device for electrical explosions was developed.
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- 2021
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5. Efficient destruction of sodium cyanide by thermal decomposition with addition of ferric oxide
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Wei Wang, Yong-feng Chang, Feng Xie, Chunlin Chen, Xiao-wei Gu, and Kaiwei Dong
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inorganic chemicals ,010302 applied physics ,Argon ,Cyanide ,Thermal decomposition ,Inorganic chemistry ,Metals and Alloys ,Oxide ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Geotechnical Engineering and Engineering Geology ,Condensed Matter Physics ,01 natural sciences ,chemistry.chemical_compound ,chemistry ,0103 physical sciences ,Materials Chemistry ,medicine ,Ferric ,0210 nano-technology ,NOx ,Argon atmosphere ,Sodium cyanide ,medicine.drug - Abstract
Efficient destruction of cyanide by thermal decomposition with ferric oxide addition was proposed. The mechanism of destruction of sodium cyanide with or without ferric oxide addition under various conditions was examined by XRD, DSC−TG, and chemical analysis technologies. In the absence of ferric oxide, sodium cyanide decomposes at 587.4 °C in air and 879.2 °C in argon atmosphere. In the presence of ferric oxide, about 60% of sodium cyanide decomposes at 350 °C for 30 min in argon, while almost all sodium cyanide decomposes within 30 min in air or O2 with mass ratio of ferric oxide to sodium cyanide of 1:1. The increase of ferric oxide addition, temperature, and heating time facilitates the destruction of sodium cyanide. It is believed that with ferric oxide addition, NaCN reacts with Fe2O3 to form Na4Fe(CN)6, Na2CO3, NaNO2 and Fe3O4 in argon. NaCN decomposes into NaCNO, Na4Fe(CN)6, minor NaNO2, and the formed NaCNO and Na4Fe(CN)6 further decompose into Na2CO3, CO2, N2, FeOx, and minor NOx in air or O2.
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- 2021
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6. Sulfur Removal from Spent Ladle Refining Furnace Slag at High Temperature
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Liushun Wu, Yuanchi Dong, Wei Xu, Kunlong Liu, Hai Chuan Wang, and Jue Wang
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Ladle ,Structural material ,Materials science ,Metallurgy ,Metals and Alloys ,Slag ,chemistry.chemical_element ,Condensed Matter Physics ,Sulfur ,Flue-gas desulfurization ,chemistry ,Mechanics of Materials ,visual_art ,Reagent ,Materials Chemistry ,visual_art.visual_art_medium ,Argon atmosphere ,Refining (metallurgy) - Abstract
To develop an effective method for removing sulfur from spent refining slag at high temperature, the slag was treated in argon atmosphere using desulfurization ash as desulfurization reagent. Experimental results revealed that at 1773 K, molar ratio of CaS to CaSO4 + CaSO3 of 3:1, and reaction time of 2 hours, sulfur removal efficiency reached a maximum of 67.9 pct. The optimal ratio indicates the reaction of CaS and CaSO4 + CaSO3 to generate S2 may predominante during processing.
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- 2021
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7. A novel high-entropy monoboride (Mo0.2Ta0.2Ni0.2Cr0.2W0.2)B with superhardness and low thermal conductivity
- Author
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Bingbing Fan, Yilin Zhang, Hailong Wang, Yanchun Zhou, Mingliang Li, Pengbo Zhao, Rui Zhang, Gang Shao, Hongxia Lu, Jinpeng Zhu, Hongliang Xu, and Wen Liu
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010302 applied physics ,Materials science ,Process Chemistry and Technology ,High density ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Microstructure ,Hot pressing ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Thermal conductivity ,Electrical resistivity and conductivity ,visual_art ,0103 physical sciences ,Superhard material ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Ceramic ,Composite material ,0210 nano-technology ,Argon atmosphere - Abstract
A new high-entropy monoboride (Mo0.2Ta0.2Ni0.2Cr0.2W0.2)B ceramic with a WB-type orthogonal structure was designed and synthesised by in-situ reactive hot pressing at 2000 °C and 30 MPa for 1.5 h under an argon atmosphere. The microstructure of the sintered samples was comprehensively characterised, and the formation of a high-entropy monoboride (Mo0.2Ta0.2Ni0.2Cr0.2W0.2)B ceramic was confirmed. Owing to the high density of the dislocations and strengthening metal-boron bonds, the high-entropy (Mo0.2Ta0.2Ni0.2Cr0.2W0.2)B ceramic exhibited a hardness of 48.51 ± 4.07 GPa, which enabled it to be classed as a new superhard material. In addition, the thermal conductivity (2.05 ± 0.10 W/(m·K) at 400 °C) and electric conductivity (132.30 S/cm) were determined.
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- 2020
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8. Mechanical and tribological properties of TiB2-SiC and TiB2-SiC-GNPs ceramic composites
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Ján Dusza, Erika Mudra, Dávid Medveď, Zdeněk Chlup, Richard Sedlák, Alexandra Kovalčíková, and Peter Tatarko
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010302 applied physics ,Materials science ,Sintering ,02 engineering and technology ,Tribology ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Fracture toughness ,Flexural strength ,visual_art ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Ceramic ,Composite material ,0210 nano-technology ,Elastic modulus ,Argon atmosphere - Abstract
TiB2-SiC and TiB2-SiC-graphene nanoplatelets (GNPs) composites were prepared using field-assisted sintering technology at 2100 °C in argon atmosphere, and the influence of the SiC and different GNPs addition on microstructure development, mechanical and tribological properties has been investigated. Instrumented hardness, bending strength, chevron-notched fracture toughness and ball-on-flat tribological tests were used for the testing and characterization of the composites. The addition of SiC significantly improved the bending strength and elastic modulus with values of 601 MPa and 474 GPa, respectively, but decreased the fracture toughness with a value of 4.8 MPa.m1/2. The addition of GNPs has a positive effect on fracture toughness and flexural strength but a negative one on the hardness. The increasing amount of both GNPs has a positive influence on wear characteristics of the composites thanks to the described wear mechanisms.
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- 2020
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9. Preparation and application of ZrB2-SiCw composite powder for corrosion resistance improvement in Al2O3–ZrO2–C slide plate materials
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Long Feng, Jinjin Ban, Junhua Hu, Xinhong Liu, Chaojie Zhou, and Quanli Jia
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010302 applied physics ,Thermal shock ,Slide plate ,Materials science ,Process Chemistry and Technology ,Composite number ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Corrosion ,Boric acid ,chemistry.chemical_compound ,chemistry ,0103 physical sciences ,Heating temperature ,Materials Chemistry ,Ceramics and Composites ,medicine ,Composite material ,0210 nano-technology ,Argon atmosphere ,Activated carbon ,medicine.drug - Abstract
ZrB2-SiCw (w-whisker) composite powders were synthesized by a microwave-assisted carbo/borothermal reduction method under argon atmosphere using zircon, boric acid, and activated carbon as starting materials. The optimized ZrB2-SiCw composite powder was obtained by adjusting heating temperature and amounts of boric acid and activated carbon. Further, the effect of the optimized ZrB2-SiCw composite powder addition on corrosion resistance of the Al2O3–ZrO2–C slide plate material against O2 and Ca-treated steel was investigated. The results showed that the relative content of ZrB2-SiCw increased with increasing temperature. The excess of boric acid favored the formation of the ZrB2-SiCw, and the optimum amount of boric acid was overdosed to 30–45 wt%. The corrosion resistance and thermo-mechanical properties of Al2O3–ZrO2–C slide plate material could be improved effectively with 6 wt% ZrB2-SiCw composite powder addition, which was attributed to the excellent oxidation and corrosion resistance of ZrB2-SiCw composite powder. In addition, ZrB2-SiCw could confer excellent thermal shock resistance and reduce the generation of cracks, ultimately preventing corrosive media from infiltrating into slide plates, further increasing corrosion resistance of the plates.
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- 2020
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10. Kinetics of extracting magnesium from prefabricated pellets by silicothermic process under flowing argon atmosphere
- Author
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Zhi-He Dou, Fu Daxue, Guo Junhua, Zonghui Ji, Han Jibiao, and Ting-an Zhang
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lcsh:TN1-997 ,Materials science ,Magnesium ,diffusion ,Kinetics ,Metallurgy ,Metals and Alloys ,Pellets ,chemistry.chemical_element ,Geotechnical Engineering and Engineering Geology ,flowing argon ,silicothermic process ,chemistry ,Mechanics of Materials ,Scientific method ,Materials Chemistry ,prefabricated pellet ,isothermal kinetics ,lcsh:Mining engineering. Metallurgy ,Argon atmosphere - Abstract
The Pidgeon process is the main extraction method of magnesium, but its continuous production cannot be achieved due to the switch between vacuum and atmospheric pressure. Therefore, it is vital to realize continuous extraction of magnesium under atmospheric pressure. In this paper, the process of extracting magnesium from prefabricated pellets in flowing argon was proposed. The isothermal kinetic analysis of the reduction process was carried out. The results showed that the reduction process was controlled by diffusion process in 1 h, and the apparent activation energy of extracting magnesium from prefabricated pellets in flowing argon was 218.75 kJ/mol. Then the influence of experimental factors on the reduction rate was explored, including briquetting pressure, carrier gas flow rate, ferrosilicon content, reaction temperature and time. Through analysis and calculation, it was concluded that the main control step of diffusion process was silicon diffusion.
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- 2020
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11. Improving the properties of 2D titanium carbide films by thermal treatment
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Jing Sun, Yina Yang, Ranran Wang, and Hao Tang
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Flexibility (engineering) ,Titanium carbide ,Materials science ,General Chemistry ,Thermal treatment ,Microstructure ,Engineering physics ,Energy storage ,Flexible electronics ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Electromagnetic interference shielding ,Argon atmosphere - Abstract
As a star of the MXene materials, 2D titanium carbide (Ti3C2Tx) has attracted broad interest from worldwide researchers in view of its potential application in energy storage, chemical sensing, electromagnetic interference shielding and flexible electronics. In order to further improve performances and satisfy the needs of emerging flexible applications, there is an urgent need to increase the electronic conductivity, environmental stability and flexibility of Ti3C2Tx film. Herein, a two-stage thermal treatment process in an argon atmosphere at low temperature (300 °C) is proposed to address this challenge. The resulting Ti3C2Tx film shows a 16-fold increase in electronic conductivity, while its environmental stability and flexibility are also greatly enhanced. Furthermore, systematic investigation into the microstructure and variations of Ti3C2Tx films before and after thermal treatment shed light on the underlying mechanism, which contributes to a deeper understanding of MXene properties and offers general guidance for improving the performance of MXene films.
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- 2020
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12. Lead-bismuth liquid metal: Lubrication behaviors
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Weimin Liu, Jun Yang, Jun Cheng, Hui Tan, Yuan Yu, and Shengyu Zhu
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Liquid metal ,Materials science ,02 engineering and technology ,Surfaces and Interfaces ,Nuclear reactor ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Surfaces, Coatings and Films ,law.invention ,Coolant ,020303 mechanical engineering & transports ,Lubricity ,0203 mechanical engineering ,Mechanics of Materials ,law ,Materials Chemistry ,Lubrication ,Composite material ,0210 nano-technology ,Argon atmosphere ,Lead bismuth ,Eutectic system - Abstract
Lead-bismuth eutectic liquid metal (LBE) is the primary coolant for the advanced liquid-metal nuclear reactor, and clarification of its lubrication behavior and mechanism at elevated temperature is of importance. In this paper, a self-mated high-temperature steel sliding-pair and a pin-on-disc configuration are selected to evaluate the lubrication behaviors of LBE at 250 °C and 400 °C under argon atmosphere. It is found that LBE possesses an excellent lubricity proofed by the low friction coefficient of 0.1 and the wear rate of 10−6 mm3/Nm for the steel discs. Close inspection on the friction interfaces indicates that the worn surfaces of the steel discs are covered by a smooth tribo-film consisting of Bi, Pb7Bi3 and the related oxides.
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- 2019
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13. Kinetics Study of the Thermal Decomposition of Post-consumer Poly(Ethylene Terephthalate) in an Argon Atmosphere
- Author
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Nasrollah Hamidi
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Materials science ,Ethylene ,Polymers and Plastics ,Thermal decomposition ,Kinetics ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Water bottle ,chemistry.chemical_compound ,020401 chemical engineering ,Chemical engineering ,chemistry ,Materials Chemistry ,0204 chemical engineering ,0210 nano-technology ,Argon atmosphere ,Poly ethylene - Abstract
The thermal decomposition of post-consumer samples of a carbonated water bottle made of poly(ethylene terephthalate), PC-PET, was examined by linear temperature programing under an argon atmosphere...
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- 2019
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14. Crystal structure and hydrogen storage properties of (La,Ce)Ni5−xMx (M = Al, Fe, or Co) alloys
- Author
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Toru Kimura, Wan-liang Mi, Atsunori Kamegawa, Zhao-sen Liu, and Hai-liang Wang
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Materials science ,Mechanical Engineering ,Enthalpy ,0211 other engineering and technologies ,Metals and Alloys ,Analytical chemistry ,02 engineering and technology ,Crystal structure ,Vacuum arc ,Partial substitution ,021001 nanoscience & nanotechnology ,Hydrogen storage ,Plateau pressure ,Lattice constant ,Geochemistry and Petrology ,Mechanics of Materials ,Materials Chemistry ,0210 nano-technology ,Argon atmosphere ,021102 mining & metallurgy - Abstract
The effects of partial substitution of La by Ce and Ni by Al, Fe, or Co in LaNi5-based alloys on hydrogen storage performance were systematically studied. All samples were prepared using vacuum arc melting in an argon atmosphere. The results showed that for La-Ni5−xMx (M = Al, Fe, or Co) alloys, the lattice constants and unit cell volumes increased with an increasing amount of Al and Fe. On the other hand, these parameters decreased upon partial substitution of La by Ce. In addition, the lattice constant remained almost constant in the La0.6Ce0.4Ni5–xCox alloys regardless of the value of x (x = 0.3, 0.6, or 0.9), as Ce might enhance the homogeneity of the CaCu5-type phase in Co-containing alloys. The hydrogen storage properties of the alloys were investigated using pressure, composition, and temperature isotherms. The experimental results showed that the plateau pressure decreased with an increasing content of Al, Fe, or Co, but it increased with Ce addition. Furthermore, the plateau pressures of all Co-containing alloys were almost identical upon substitution with Ce. Finally, the enthalpy (ΔH) and entropy (ΔS) values for all alloys were calculated using van’t Hoff plots. The relationship between the lattice parameters and enthalpy changes for hydrogenation will be discussed.
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- 2019
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15. Effect of CaO addition on phase formation in the Fe-Fe2O3-V2O3 system
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Fanyue Meng, Feng Gao, Xinsheng Li, Duoqiang Liang, Xiongxin Dong, and Yuezhou Wei
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Diffraction ,Materials science ,Scanning electron microscope ,Mechanical Engineering ,Metals and Alloys ,Energy-dispersive X-ray spectroscopy ,Analytical chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Phase formation ,0104 chemical sciences ,Differential scanning calorimetry ,Mechanics of Materials ,Materials Chemistry ,0210 nano-technology ,Argon atmosphere - Abstract
Effect of CaO addition on phase formation in the Fe-Fe2O3-V2O3 system under argon atmosphere was investigated by x-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy and differential scanning calorimetry. The results showed that the major phases were Fe2VO4, Fe3O4, and FexO4 (2.8
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- 2019
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16. Specific Features of Temperature Dependence of Graphene Oxide Resistance
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V. S. Levitskii, A. A. Babaev, Sergey V. Tkachev, M. E. Zobov, D. Yu. Kornilov, and E. I. Terukov
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Materials science ,Graphene ,020209 energy ,Organic Chemistry ,Metals and Alloys ,Analytical chemistry ,Oxide ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Surfaces, Coatings and Films ,law.invention ,symbols.namesake ,chemistry.chemical_compound ,chemistry ,law ,Metallic materials ,0202 electrical engineering, electronic engineering, information engineering ,Materials Chemistry ,symbols ,0210 nano-technology ,Raman spectroscopy ,Constant (mathematics) ,Argon atmosphere - Abstract
Temperature dependence of graphene oxide resistance during continuous heating and cooling under argon atmosphere at 300–550 K and Raman spectra were studied. Resistance is constant within 300–370 K during cooling. It is thermostable under further heating. Temperature dependence of resistance changes according to activation law within 370–550 K. The decrease of resistance at the increase is related to the removal of functional oxygen-containing groups, which is proved by the results of Raman spectra.
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- 2019
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17. Physical and Mechanical Properties of Hot-Pressed Materials of the ZrB2–TaC–SiC System
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A. S. Lysenkov, I. D. Shabalkin, S. S. Ordan’yan, and D. D. Nesmelov
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Lattice constant ,Materials science ,Flexural strength ,Phase composition ,Vickers hardness test ,Materials Chemistry ,Ceramics and Composites ,Relative density ,Composite material ,Hot pressing ,Microstructure ,Argon atmosphere - Abstract
High-density (with a relative density of up to 98.8%) ultra-high-temperature ceramic materials (UHTCs) based on the ZrB2–TaC–SiC system were obtained by hot pressing for 15 min at 2000°C 30 MPa of pressure in an argon atmosphere. Phase composition, lattice parameters, microstructure, flexural strength, Vickers hardness and crack resistance were studied. The maximum values of strength, hardness and crack resistance were 440 MPa, 20.3 GPa and 5.3 MPa·m1/2, respectively. The effect of the ZrB2/TaC ratio on the lattice constants and the mechanical properties of the material is established.
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- 2019
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18. The effect of aging processes on tribo-metallurgy properties of al based ternary alloys product by p/m technique
- Author
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Yavuz Kaplan, Serkan Özsoy, Hakan Ada, Sinan Aksöz, and Emre Ince
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Friction coefficient ,Aging ,Materials science ,Ternary Alloys, Tribology ,Metallurgy ,Alloy ,ternary alloys ,Metals and Alloys ,Sintering ,Solution treatment ,engineering.material ,lcsh:Chemical technology ,Condensed Matter Physics ,Wear resistance ,Wear ,Powder metallurgy ,tribology ,Materials Chemistry ,Ceramics and Composites ,engineering ,lcsh:TP1-1185 ,Ternary operation ,Argon atmosphere - Abstract
In this study, Al matrix composites consisting of different amounts of Zn, Cu, and Mg were produced using the powder metallurgy technique. In the alloying, powders were ball milled for 120 min via mechanical alloying. After alloying process, the powders were pressed at 800 MPa at room temperature. Sintering (2 h at 600 °C in argon atmosphere), solution treatment (2 h at 480 °C), and aging processes (3, 6, 9, and 12 h, respectively, at 120 °C) were applied to the samples. The hardness and tribo-metallurgy properties of the products were investigated. After sintering, the hardness values of the three alloys were close to each other; however, the solution treatment after sintering caused the hardness values to increase significantly. It was determined that the Al-2Zn-5Cu-4Mg alloy had the highest hardness increase with the 6-h aging heat treatment. The wear resistance of the materials in all the compositions had increased. The highest wear resistance and lowest friction coefficient were obtained for the Al-2Zn-5Cu-4Mg alloy with the 6-h aging heat treatment. © 2020 Authors. Published by association for ETRAN Society.
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- 2020
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19. Synthesis of holey reduced graphene oxide covered in the FeCo@SiO2 and their enhanced electromagnetic absorption properties
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Meng Zong, Na Zhang, Suping Li, and Ying Huang
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Materials science ,Electromagnetic absorption ,Graphene ,Mechanical Engineering ,Oxide ,02 engineering and technology ,Oxide composite ,021001 nanoscience & nanotechnology ,Redox ,law.invention ,chemistry.chemical_compound ,020303 mechanical engineering & transports ,0203 mechanical engineering ,chemistry ,Mechanics of Materials ,law ,Materials Chemistry ,Ceramics and Composites ,Calcination ,Composite material ,0210 nano-technology ,Argon atmosphere - Abstract
The FeCo@SiO2/holey reduced graphene oxide composite was successfully prepared by combining liquid-phase reduction reaction in argon atmosphere with high-temperature calcination. The FeCo@SiO2/holey reduced graphene oxide composite was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, vibrating sample magnetometer, Fourier transform infrared spectroscopy, Raman spectroscopy, transmission electron microscopy and scanning electron microscopy analysis and exhibit excellent electromagnetic wave absorption properties. The maximum reflection loss of FeCo@SiO2/holey reduced graphene oxide composite reaches –46.28 dB at 16.16 GHz with the thickness of 1.5 mm and the absorption bandwidth with the reflection loss below –10 dB was up to 3.92 GHz (from 14.08 GHz to 18 GHz) with the thickness of 1.5 mm. The absorption bandwidth with RL below –10 dB is up to 12.64 GHz. It is believed that the FeCo@SiO2/holey reduced graphene oxide composite can serve as an excellent microwave absorber.
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- 2018
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20. High-temperature fatigue behavior of 15CrNbTi ferritic stainless steel
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Hongyun Bi, Xin Che, Tianlong Liu, and Li-jia Chen
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010302 applied physics ,Cyclic stress ,Materials science ,fungi ,technology, industry, and agriculture ,0211 other engineering and technologies ,Metals and Alloys ,02 engineering and technology ,01 natural sciences ,Fatigue limit ,Mechanics of Materials ,Phase (matter) ,Free surface ,0103 physical sciences ,Materials Chemistry ,Fracture (geology) ,Dislocation ,Deformation (engineering) ,Composite material ,Argon atmosphere ,021102 mining & metallurgy - Abstract
In order to investigate the high-temperature fatigue and fatigue–creep behavior of 15CrNbTi ferritic stainless steel at 800 °C, fatigue tests without holding time in laboratory air and with 10 s holding time induced at maximum cyclic stress under argon atmosphere were conducted on an electrohydraulic servo fatigue testing machine. In addition, the morphologies of fatigue fracture surfaces were observed, and the precipitates and dislocation substructures were characterized. The experimental results show that the fatigue limit of 15CrNbTi ferritic stainless steel is 30 MPa at 800 °C. The fatigue life of the experimental steel obviously decreases if holding time of 10 s is introduced at maximum cyclic stress. Under two test conditions, the fatigue cracks transgranularly initiate at the free surface of fatigue specimens and then propagate in a transgranular mode. It is demonstrated that three kinds of precipitates including (Nb, Ti)C phase, Fe2Nb phase and Fe3Nb3C phase can be observed in 15CrNbTi ferritic stainless steel, and the Fe2Nb and Fe3Nb3C phases are mainly precipitated during the fatigue tests. In the fatigue deformation area, both dislocation tangles and dislocation arrays are observed. Furthermore, the sub-grains which form during the cycling deformation with holding time of 10 s are also found. Moreover, the formation of sub-grains leads to the deterioration of the fatigue life of 15CrNbTi steel.
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- 2018
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21. Phase equilibria of CaO-SiO2-Gd2O3 system and the feasibility of rare-earth recovery
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Tian Yang, Wenke Zhi, Tao Qu, Yong Deng, Bin Yang, Yang Hongwei, and Fei Wang
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Computer Science::Computer Science and Game Theory ,Ternary numeral system ,Materials science ,Process Chemistry and Technology ,Rare earth ,Slag ,Thermodynamics ,02 engineering and technology ,Electron microprobe ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Isothermal process ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Phase (matter) ,visual_art ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,0210 nano-technology ,Argon atmosphere ,Phase diagram - Abstract
Phase equilibria of the CaO-Gd2O3-SiO2 slag system at 1773 K and 1873 K were investigated by characterizing equilibrated samples with electron probe microanalysis (EPMA). Four three-phase equilibria and five two-phase equilibria are formed in the CaO-Gd2O3-SiO2 ternary system at 1773 K in argon atmosphere. While three three-phase equilibria, six two-phase equilibria and one liquid phase are presented in the system at 1873 K. The isothermal section of the phase diagram is thereafter constructed based on the experimental results. The feasibility of the rare earth recovery is also discussed based on the phase relations.
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- 2018
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22. Rapid Identification of Calcium Aluminate Inclusions in Steels Using Cathodoluminescence Analysis
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Kazuaki Wagatsuma and Susumu Imashuku
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Materials science ,Aluminate ,Metals and Alloys ,Analytical chemistry ,chemistry.chemical_element ,Cathodoluminescence ,02 engineering and technology ,Calcium ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Rapid detection ,Spectral line ,020501 mining & metallurgy ,Rapid identification ,Continuous casting ,chemistry.chemical_compound ,0205 materials engineering ,chemistry ,Mechanics of Materials ,Materials Chemistry ,0210 nano-technology ,Argon atmosphere - Abstract
We propose a method to identify calcium aluminate inclusions in calcium-treated aluminum-killed steels (Ca12Al14O33, CaAl4O7, CaAl12O19, and Al2O3) using cathodoluminescence (CL) analysis. Such inclusions result in nozzle clogging and melting of the stopper rod during continuous casting. We obtain CL images and CL spectra of calcium aluminate inclusions in model samples of calcium-treated aluminum-killed steel. The model samples are prepared by heating mixtures of Fe powder, Al powder, and Ca shot at 1550 °C in an argon atmosphere. On the basis of the CL colors and CL spectra of the calcium aluminate inclusions, we demonstrate that it is possible to distinguish Ca12Al14O33, CaAl4O7, CaAl12O19, and Al2O3 inclusions from CaAl2O4 and Ca3Al10O18 inclusions, which do not cause nozzle clogging and melting of the stopper rod, by comparing CL images obtained using digital cameras with and without a built-in filter. The acquisition times for the CL images are less than 10 seconds. Thus, the method we present here can be applied for the rapid detection of harmful calcium aluminate inclusions during continuous casting. The CL spectra also provide basic information to specify compositions in agglomerated calcium aluminate inclusions.
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- 2018
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23. Prediction of alloy composition and microhardness by random forest in maraging stainless steels based on a cluster formula
- Author
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Huan He, Donghui Wen, Yue Ma, Qing Wang, Zhen Li, Rui Tang, Ruiqian Zhang, and Guo-qing Chen
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010302 applied physics ,Materials science ,Alloy ,Metallurgy ,Metals and Alloys ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,Alloy composition ,01 natural sciences ,Indentation hardness ,Rod ,Mechanics of Materials ,0103 physical sciences ,Metallic materials ,Materials Chemistry ,Cluster (physics) ,engineering ,0210 nano-technology ,Valence electron ,Argon atmosphere - Abstract
Fe–Ni–Cr-based super-high-strength maraging stainless steels were generally realized by multiple-element alloying under a given heat treatment processing. A series of alloy compositions were designed with a uniform cluster formula of [Ni16Fe192](Cr32(Ni16–x–y–z–m–nMoxTiyNbzAlmVn)) (at.%) that was developed out of a unique alloy design tool, a cluster-plus-glue-atom model. Alloy rods with a diameter of 6 mm were prepared by copper-mold suction-cast processing under the argon atmosphere. These alloy samples were solid-solutioned at 1273 K for 1 h, followed by water-quenching, and then aged at 783 K for 3 h. The effect of the valence electron concentration, characterized with the number of valence electrons per unit cluster (VE/uc) formula of 16 atoms, on microhardness of these designed maraging stainless steels at both solid-solutioned and aged states was investigated. The relationship between alloy compositions and microhardness in maraging stainless steels was firstly established by the random forest (RF, a kind of machine learning methods) based on the experimental results. It was found that not only the microhardness of any given composition alloy within the frame of cluster formula, but also the alloy composition with a maximum microhardness for any given VE/uc, could be predicted in good agreement with the guidance of the relationship by RF. The contributions of minor-alloying elements to the microhardness of the aged alloys were also discussed.
- Published
- 2018
- Full Text
- View/download PDF
24. Microstructural evolution and interdiffusion behavior of Mo-Si-B coating on Nb-Si based alloy
- Author
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Jinliang Pi, Chungen Zhou, and Wei Shao
- Subjects
Microstructural evolution ,Materials science ,Annealing (metallurgy) ,020502 materials ,Mechanical Engineering ,Alloy ,Metals and Alloys ,Analytical chemistry ,Modified method ,02 engineering and technology ,General Chemistry ,Rate equation ,engineering.material ,021001 nanoscience & nanotechnology ,0205 materials engineering ,Coating ,Mechanics of Materials ,Cementation (metallurgy) ,Materials Chemistry ,engineering ,0210 nano-technology ,Argon atmosphere - Abstract
A Mo-Si-B coating was prepared on an Nb-Si based alloy by detonation-gun spraying of Mo followed by co-deposition of Si and B via pack cementation. The microstructural evolution and interdiffusion behavior of the coating/substrate system were investigated by annealing for different times at 1250 °C in argon atmosphere. The results show that the interdiffusion zone has a two-layer structure consisting of (Mo, X′)5Si3 (X’ = Nb, Ti, Cr, Hf) and (Nb, X)5Si3 (X = Ti, Cr, Hf), respectively. The growth of the transitional layer, which obeys a parabolic rate law, is dominated by the inward diffusion of Si from the outer layer to the substrate. The interdiffusion coefficients of Si in the transitional layers are calculated using a modified method based on the Boltzmann-Matano analysis.
- Published
- 2018
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25. Effect of Sintering Atmospheres on the Processing of SiC/AlN Ceramic Composites
- Author
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Emad M.M. Ewais, Denis Kuznetsov, Yasser M. Z. Ahmed, Dina H.A. Besisa, Thomas Fend, and F. I. El-Hosiny
- Subjects
010302 applied physics ,Argon ,Materials science ,Sintering ,chemistry.chemical_element ,02 engineering and technology ,Nitride ,021001 nanoscience & nanotechnology ,01 natural sciences ,Nitrogen ,Carbide ,chemistry ,visual_art ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Ceramic ,Composite material ,0210 nano-technology ,Yttria-stabilized zirconia ,Argon atmosphere - Abstract
In an attempt to provide a new advanced carbide/nitride ceramic material with high sinterability and density for high-temperature and solar energy applications, this work inspected the effect of different sintering atmospheres on the processing of near-fully dense SiC/AlN ceramic composites. Several SiC/AlN (0 – 40 wt.%) composites were produced by pressureless sintering at a temperature of 2080°C for 2 hrs using a sintering additive of 2.5% yttria + alumina. Influences of argon/vacuum and nitrogen/vacuum atmospheres on the reaction response and the densification behavior of SiC/AlN composites were examined and analyzed. Results show that sintering of SiC/AlN ceramics in a nitrogen atmosphere increases mass loss of the different composites during sintering and leads to a decrease in their densification parameters. However, sintering in an argon atmosphere promotes both the sintering and densification processes, making argon atmosphere more convenient for sintering SiC/AlN ceramics. The use of SiC/AlN composites prepared by pressureless sintering is suitable for high-temperature applications.
- Published
- 2018
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26. Corrosion behavior of MgZnFeCuCo alloys in the presence of coumarin
- Author
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Adi Noer Syahid, Andi Mulya Ashari, Eddy Agus Basuki, Talitha Asmaria, Franciska Pramuji Lestari, Ika Kartika, and Yudi Nugraha Thaha
- Subjects
Materials science ,High entropy alloys ,Potentiodynamic polarization ,Sintering ,Coumarin ,Corrosion ,Dielectric spectroscopy ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,Mechanics of Materials ,Materials Chemistry ,General Materials Science ,Corrosion behavior ,Argon atmosphere - Abstract
Mg-11Zn-26Fe-7Cu-4Co, Mg-11Zn-6Fe-0.2Cu-0.3Co, and Mg-19Zn-17Fe-28Cu-18Co are produced by using a powder metallurgical process followed by sintering in an argon atmosphere. Potentiodynamic polarization and electrochemical impedance spectroscopy are applied to study the corrosion behavior and corrosion inhibition by coumarin of Mg-11Zn-26Fe-7Cu-4Co, Mg-11Zn-6Fe-0.2Cu-0.3Co, and Mg-19Zn-17Fe-28Cu-18Co in Hanks’ solution. Potentiodynamic polarization and electrochemical impedance spectroscopy characterization reveal that Mg-19Zn-17Fe-28Cu-18Co high entropy alloys exhibit better corrosion resistance than Mg-11Zn-26Fe-7Cu-4Co, and Mg-11Zn-6Fe-0.2Cu-0.3Co in Hanks’ solution. The addition of coumarin effectively inhibits corrosion of Mg-11Zn-26Fe-7Cu-4Co, Mg-11Zn-6Fe-0.2Cu-0.3Co, and Mg-19Zn-17Fe-28Cu-18Co high entropy alloys in Hanks’ solution.
- Published
- 2021
- Full Text
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27. A new method for manufacturing graded refractories by localized hot uniaxial pressing
- Author
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Johannes Solarek, Christos G. Aneziris, and Horst Biermann
- Subjects
010302 applied physics ,Pressing ,Materials science ,Process Chemistry and Technology ,Modulus ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Microstructure ,Compression (physics) ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Cylinder (engine) ,law.invention ,law ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,Composite material ,0210 nano-technology ,Porosity ,Argon atmosphere - Abstract
In this study, a cylinder of fine-grained carbon-bonded alumina was pressed uniaxially at high temperatures in an argon atmosphere. The resulting changes in mechanical properties, physical properties and microstructure were described with various techniques. The porosity of the material was found to have decreased significantly, leading to higher density, higher dynamic Young's modulus, higher strength and increased hardness. Additionally, gradients in porosity and hardness were observed that resulted from inhomogeneous temperature distribution during compression. Possibilities and conditions for the production of graded refractory materials can be deduced from the results.
- Published
- 2017
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28. Effects of processing parameters and rare earths additions on preparation of Al2O3-SiC composite powders from coal ash
- Author
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Qiang Zhu, Xinming Ren, Lei Yuan, Ma Beiyue, Jingkun Yu, Guangqiang Li, Yin Yue, Zhan Zhang, and Zhiqiang Li
- Subjects
010302 applied physics ,Materials science ,Process Chemistry and Technology ,Composite number ,Metallurgy ,02 engineering and technology ,Raw material ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Reaction temperature ,Carbothermic reaction ,Phase (matter) ,Fly ash ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,0210 nano-technology ,Argon atmosphere - Abstract
Al 2 O 3 -SiC composite powders were successfully fabricated from coal ash by carbothermal reduction reaction (CRR) method in argon atmosphere. The effects of raw materials ratio, reaction temperature, La 2 O 3 and Sm 2 O 3 additions on the synthesis process were investigated in detail. Phase compositions and microstructures of Al 2 O 3 -SiC composite powders were characterized by XRD and SEM. Proper processing parameters and rare earths addition amounts were determined, and the formation process of Al 2 O 3 -SiC powders was also discussed.
- Published
- 2017
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29. Influence of mechanical alloying and heat treatment processing on the Ni 2 MnSn Heusler alloy structure
- Author
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Ionel Chicinaş, H.F. Chicinaş, Traian Florin Marinca, and Florin Popa
- Subjects
010302 applied physics ,Diffraction ,Materials science ,Annealing (metallurgy) ,Mechanical Engineering ,Metallurgy ,Alloy ,Metals and Alloys ,Solid-state ,Analytical chemistry ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,01 natural sciences ,Nanocrystalline material ,Mechanics of Materials ,0103 physical sciences ,Materials Chemistry ,engineering ,Thermal stability ,0210 nano-technology ,Ball mill ,Argon atmosphere - Abstract
Formation of the Ni2MnSn Heusler alloy by solid state reaction from elemental powders was investigated. The solid state reaction was conducted in a planetary ball mill under argon atmosphere up to 28 h of milling. During the milling, after selected intervals samples were collected and studied by X-ray diffraction to record phase changes. After 16 h of milling a two phase mixture (Ni2MnSn with B2 structure and NiMnSn with C1b structure) was found. Further, the thermal stability of the samples was investigated, and phase precipitation was found. The formed phases are ordered Full Heusler (L21) and Ni3Sn2. The formation temperature and their amount evolution versus temperature and milling time is discussed. An inversion of the formation temperature was found for the L21 and Ni3Sn2 phase, during the DSC study, in relation with the milling time. For the B2 compound a stability range on temperature was identified (from 25 to 300 °C), as well as for the L21 and Ni3Sn2 phases (from 400 to 600 °C) in the case of 28 h milled sample. The milled and annealed sample exhibit nanocrystalline state, formation mechanism under temperature was concluded to be by precipitation.
- Published
- 2017
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30. Influence of firing conditions and production methods on fracture strength of titanium-based metal ceramic crowns
- Author
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Martin Andersson, P. Vult Von Steyern, Per Haag, and F. Khan
- Subjects
Dental ceramics ,Materials science ,Argon ,Bond strength ,0206 medical engineering ,Metallurgy ,chemistry.chemical_element ,030206 dentistry ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,020601 biomedical engineering ,Metal ceramic ,Surfaces, Coatings and Films ,03 medical and health sciences ,0302 clinical medicine ,Dental porcelain ,Flexural strength ,chemistry ,Mechanics of Materials ,Materials Chemistry ,Composite material ,Argon atmosphere ,Titanium - Abstract
Objectives: This study evaluated the effect of argon atmosphere compared with vacuum during porcelain firing on the fracture strength of crowns made of porcelain and electron beam melted (E...
- Published
- 2017
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31. High transparency Cr,Nd:LuAG ceramics prepared with MgO additive
- Author
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Pande Zhang, Xiaojian Mao, Shuilin Chen, Jintai Fan, Baoyan Chai, Benxue Jiang, Yiguang Jiang, Qijun Gan, and Long Zhang
- Subjects
010302 applied physics ,Materials science ,Metallurgy ,Sintering ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Vacuum sintering ,01 natural sciences ,Hot isostatic pressing ,visual_art ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Transmittance ,Grain boundary ,Ceramic ,0210 nano-technology ,Argon atmosphere - Abstract
Cr (0.2 at.%) and Nd (0.8 at.%) co-doped Lu3Al5O12 ceramics were fabricated with MgO as the sintering additive. The addition of a small amount of MgO can affect the grain boundary mobility and influence the number and location of micropores in ceramics during the sintering process. The results show that when the MgO content is 0.02 wt.%, high-transparency Cr,Nd:LuAG ceramics can be obtained by vacuum sintering at 1670 °C for 5 h followed by hot isostatic pressing (HIP) post-sintering at 1750 °C in an argon atmosphere (P = 200 MPa) for 5 h. The optimum in-line transmittance of the HIPed Cr,Nd:LuAG ceramics (3 mm thick) is 83.5% at a wavelength of 840 nm and 84.0% at 710 nm.
- Published
- 2017
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32. Thermoelectric properties improvement in Mg2Sn thin films by structural modification
- Author
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Nicolas Martin, Mohammad Arab Pour Yazdi, Frédéric Chérioux, Alain Billard, Frank Palmino, Mahsasadat Safavi, Vincent Linseis, Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), and Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph] ,Materials science ,Annealing (metallurgy) ,Mechanical Engineering ,Metals and Alloys ,Analytical chemistry ,02 engineering and technology ,Sputter deposition ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,[SPI.MAT]Engineering Sciences [physics]/Materials ,Mechanics of Materials ,Metastability ,Thermoelectric effect ,Materials Chemistry ,Figure of merit ,Orthorhombic crystal system ,Thin film ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,0210 nano-technology ,Argon atmosphere - Abstract
International audience; Mg-Sn thin films (21 ≤ at. % Sn ≤ 42.5) were deposited by magnetron sputtering in the argon atmosphere. The structure and morphology of the films were characterized as a function of the composition. Mg2Sn structure was changed from stable face-centered cubic to metastable orthorhombic structure while the content of Sn in the films increased. The influence of this structural modification on thermoelectric properties was discussed in a wide range of temperatures (30–200 °C). The film carrier concentration and mobility were measured to explain the electronic transport behavior as a function of the film structural modifications. The maximum figure of merit ZT ≈ 0.26 at 200 °C was reached for the film with 36 at. % Sn while a mixture of cubic and orthorhombic Mg2Sn structures coexisted. An annealing treatment was performed under vacuum (∼10−4 Pa) at different temperatures (up to 600 °C) to determine the limit of structural and morphological stability of this film.
- Published
- 2019
33. Tri-arc growth and characterization of U3Si2 and U3Si5 single crystals
- Author
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J. Bárta, E. Kardoulaki, Kenneth J. McClellan, and Darrin D. Byler
- Subjects
010302 applied physics ,Materials science ,Analytical chemistry ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Rotation ,01 natural sciences ,Characterization (materials science) ,Inorganic Chemistry ,Arc (geometry) ,Crystal ,Cracking ,Quality (physics) ,0103 physical sciences ,Materials Chemistry ,0210 nano-technology ,Argon atmosphere ,Stoichiometry - Abstract
Single crystals of U3Si2 and U3Si5 were grown using the modified Czochralski tri-arc growth technique in a gettered argon atmosphere. A variety of growth parameters including seed pull rate, seed rotation rate, crystal size, charge size and stoichiometry were evaluated to determine the best growth conditions in an effort to produce high quality single crystals for property measurements and basic studies. The crystals were characterized for quality, phase purity, density, and axial variations in chemistry. Near phase-pure, single crystals 5 mm in diameter and 35 mm in length were grown with minimal variation in stoichiometry and limited cracking using a crystal rotation rate of 30 rpm, a hearth rotation rate of 22 rpm, and a pull rate of 16 mm/h up to solidified fraction of g = 0.75.
- Published
- 2021
- Full Text
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34. Bias effects on AlMgB thin films prepared by magnetron sputtering
- Author
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Fuwen Qin, S. Jing, J. Xiao, and Yizhen Bai
- Subjects
010302 applied physics ,Materials science ,Silicon ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,Surfaces and Interfaces ,Substrate (electronics) ,Sputter deposition ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,01 natural sciences ,Surfaces, Coatings and Films ,Amorphous solid ,chemistry ,0103 physical sciences ,Materials Chemistry ,Thin film ,Composite material ,0210 nano-technology ,Argon atmosphere ,Voltage - Abstract
AlMgB thin films were deposited on silicon (100) substrate using a three-target magnetron sputtering system in argon atmosphere. The influence of negative bias voltage on the thickness, morphology, microstructure, local bonding and hardness of the deposited films was investigated. Experimental results show that all films are X-ray amorphous, and the properties of the deposited films have a strong dependence on the applied substrate's negative bias voltage. Deposited at high negative bias voltage, the AlMgB thin films are found to be generally dense, having a smooth surface and containing more well-formed B12 icosahedra, which consequently increase the hardness of the deposited films. However, deposited at low negative bias voltage, the AlMgB thin films exhibit loose structure, coarse surface and contain few B12 icosahedra. It is shown that the hardness of the dense and smooth AlMgB thin films can reach 22 GPa at the negative bias voltage of 400 V.
- Published
- 2016
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35. Studies on evolution of nano SiC ceramics from allylborosiloxane
- Author
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Deepthi Thomas, T.S. Sasikala, and Deepa Devapal
- Subjects
Materials science ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Oligomer ,chemistry.chemical_compound ,Residue (chemistry) ,Nano ,Materials Chemistry ,Organic chemistry ,Ceramic ,Inert gas ,Process Chemistry and Technology ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Monomer ,chemistry ,Chemical engineering ,visual_art ,Ceramics and Composites ,visual_art.visual_art_medium ,0210 nano-technology ,Argon atmosphere ,Boronic acid - Abstract
Allylborosiloxane preceramic oligomers with ceramic residue in the range 75–84% (at 900 °C) were synthesized through the condensation of phenyl boronic acid (PBA) with allyltriethoxysilane (ALTEOS) in three different monomer feed ratios. The oligomers were characterized by GPC, IR, viscosity, TGA and TG–MS techniques. There is an increase in ceramic residue with increase in ALTEOS and maximum residue of 84% was obtained for the oligomer synthesized from PBA and ALTEOS in 1:2 ratio. The oligomers were pyrolysed at 900 °C followed by heat treatment at 1500 °C and 1650 °C in inert atmosphere and were characterized by spectroscopic techniques. Even though SiC formation is observed at 1500 °C, conversion of SiBOC/SiOC to SiC is not complete at 1500 °C and the presence of silica and carbon phases are found in the ceramics. Spectral studies reveals that β-SiC with trace amount of α-SiC is formed when oligomers are heated at 1650 °C in argon atmosphere.
- Published
- 2016
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36. Interfacial reactions between ZrSnNb and FeCrAl alloy during diffusion bonding, hot-rolling and annealing
- Author
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Gang Li, Xun Dai, Jing Chen, Shaoqiang Liu, Huiqun Liu, Gaoyong Lin, and Ruiqian Zhang
- Subjects
Materials science ,Annealing (metallurgy) ,Mechanical Engineering ,Alloy ,Metals and Alloys ,02 engineering and technology ,Electron microprobe ,Electron ,Nuclear reactor ,engineering.material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,Diffusion layer ,Mechanics of Materials ,law ,Materials Chemistry ,engineering ,Composite material ,0210 nano-technology ,Diffusion bonding ,Argon atmosphere - Abstract
The clad plate between ZrSnNb and FeCrAl alloy was fabricated through diffusion bonding at 850 °C for 5 h under mechanical pressure in an argon atmosphere, and subsequent hot rolling at 800 °C with 20, 37 and 50% rolling reduction. The annealing treatment on hot-rolled plate was carried out in vacuum at 800 °C for 480 h. Interface observation and phase analysis were performed by Electron Probe X-ray Micro-Analyzer (EPMA). The interface of clad plate was tightly bonded, and there were no cracks and pores. After 5 h solid-state diffusion bonding, the Zr3Fe phase formed at the diffusion layer with about ∼3 μm thickness. The αZrCr2, ZrFe2 and Zr3Al intermediate phases formed at the interface in the 20% and 50% hot-rolled samples. While αZrCr2, Zr3Fe and Zr3Al phases formed at the interface in the 37% hot-rolled sample. There is no reasonable evidence temporarily to explain the formation of Zr3Fe phase at diffusion layer of 37% hot-rolled sample, and further study is necessary in near future. After annealing at 800 °C for 480 h, intermetllics formed and identified as αZrCr2, ZrFe2 and Zr3Al and Zr2Fe. The average thickness of diffusion layer in FeCrAl/ZrSnNb clad plates with 20%, 37% and 50% rolling reduction was 6 μm, 9 μm and 11 μm, respectively. The results in this study could provide possible valuable guidance for fabricating multilayer fuel cladding materials for the application in nuclear reactor.
- Published
- 2020
- Full Text
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37. Copper matte - slag reaction sequences and separation processes in matte smelting
- Author
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Niko Hellstén, Ari Jokilaakso, Pekka Taskinen, Pratama Istiadi Guntoro, Department of Chemical and Metallurgical Engineering, Aalto-yliopisto, and Aalto University
- Subjects
lcsh:TN1-997 ,Materials science ,Molten phase reactions ,chemistry.chemical_element ,02 engineering and technology ,Reakcije topljenje-topljenje ,020501 mining & metallurgy ,Matte ,Flash smelting ,Materials Chemistry ,Metallurgy and Metallic Materials ,Reakcije u otopljenoj fazi ,ta215 ,Bakrenac ,Melt-melt reactions ,molten phase reactions ,lcsh:Mining engineering. Metallurgy ,Chalcopyrite ,Metallurgy ,Metals and Alloys ,Slag ,Particle combustion ,Geotechnical Engineering and Engineering Geology ,Topljenje u fleš pećima ,Copper ,Kinetic rate ,melt-melt reactions ,0205 materials engineering ,chemistry ,Mechanics of Materials ,matte ,visual_art ,Smelting ,visual_art.visual_art_medium ,Metallurgi och metalliska material ,Argon atmosphere ,flash smelting - Abstract
While particle combustion and chalcopyrite oxidation in suspension smelting is well understood, few studies are available regarding the melt-melt reactions and the separation between copper matte and slag in matte smelting. In the present work, experimental investigations in air and argon atmosphere were conducted using a mixture of synthetic slag and chalcopyrite concentrate. The sequential reaction and separation processes occurring in matte smelting are outlined. Possible limiting factors in the overall process are also proposed. The result of the present work forms an important foundation for future work in the kinetic rate formulation of molten phase reactions between copper matte and slag in matte smelting.
- Published
- 2018
38. The Effect of Temperature and Carbon to Hematite Ratio on the Formation of Cementite During the Couple of STMA and Partial Melting Processes
- Author
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Amir Peyman Soleymani, Masoud Panjepour, and Mahmood Meratian
- Subjects
Materials science ,Cementite ,Metallurgy ,Metals and Alloys ,Partial melting ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,Hematite ,Condensed Matter Physics ,020501 mining & metallurgy ,chemistry.chemical_compound ,0205 materials engineering ,chemistry ,Mechanics of Materials ,Phase (matter) ,visual_art ,Materials Chemistry ,visual_art.visual_art_medium ,Graphite ,Carbon ,Argon atmosphere ,Stoichiometry - Abstract
In this research, the role of the couple of simultaneous thermal-mechanical activation (STMA) and partial melting (PM) processes in the carbothermic reduction of hematite and cementite formation was studied. For this purpose, the STMA process was performed for 6 hours at 1073 K (800 °C) on the mixture of hematite and graphite with stoichiometry ratio (22 wt pct C) in argon atmosphere in the first stage, and then this process was coupled to the PM process at 1453 K (1180 °C) for 25 minutes. The results obtained showed that the percentage of cementite phase in the product of the STMA process was only about 24 wt pct and after carrying out the PM process, this value reached 77 wt pct in the final product. In the second stage, the effect of the ratio of the parameters of carbon to hematite on the initial mixture (1:1, 1:25, and 1:5 times the stoichiometry ratio) and STMA process temperature [1073 K, 1123 K, and 1173 K (800 °C, 850 °C, and 900 °C)] was studied. The results were indicative of the fact that by an increase in the ratio of carbon to hematite and at STMA temperature, the percentage of cementite in the final product obtained from the PM process significantly increased. In fact, the specimens obtained from the couple of the STMA and PM processes with a carbon to hematite ratio of 1.5:1 at 1073 K (800 °C) and that of 1.25:1 at 1173 K (900 °C) showed the greatest percentage of cementite. The mechanism regarding the processes showed that by controlling the amount and manner of free carbon distribution in the STMA product based on the parameters of the ratio of carbon to hematite and temperature, it was possible to obtain pure cementite. Therefore, the couple of STMA and PM processes can also be brought up as a new method in the production of pure cementite.
- Published
- 2015
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39. Investigations of the wetting behaviors of Zn–25Sn, Zn–25Sn–XPr and Zn–25Sn–YAl high temperature lead free solders in air and Ar ambient
- Author
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Kwang-Lung Lin and Xi Niu
- Subjects
Materials science ,Mechanical Engineering ,Metallurgy ,Metals and Alloys ,Intermetallic ,chemistry.chemical_element ,Zinc ,chemistry ,Mechanics of Materials ,Soldering ,Air atmosphere ,Materials Chemistry ,Dewetting ,Wetting ,Oxidation resistance ,Argon atmosphere - Abstract
Zn–25Sn based alloys possess great potential as candidates for high temperature lead-free solders. But it exhibits poor oxidation resistance due to the high Zinc content. This study selected Pr (0.01–0.08 wt%) and Al (0.01–0.25 wt%) as alloying elements to improve the wetting performance of Zn–25Sn based solder alloy. It was found that the addition of 0.01 wt% Pr increased the wetting force. However, dewetting was observed under air atmosphere for the Zn–25Sn, Pr-containing solder, and solder containing 0.01% Al. It was also be found that the dewetting of Pr-containing solder could be avoided under argon atmosphere as well as with higher Al addition.
- Published
- 2015
- Full Text
- View/download PDF
40. Oxidation behavior of Nb–24Ti–18Si–2Al–2Hf–4Cr and Nb–24Ti–18Si–2Al–2Hf–8Cr hypereutectic alloys at 1250 °C
- Author
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Lina Jia, Zhen Hong, Hu Zhang, Junfei Weng, Li Zhen, and Linfen Su
- Subjects
Materials science ,020502 materials ,Kinetics ,Metallurgy ,Metals and Alloys ,Analytical chemistry ,Intermetallic ,Crucible ,02 engineering and technology ,Laves phase ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,Isothermal process ,0205 materials engineering ,Materials Chemistry ,Physical and Theoretical Chemistry ,0210 nano-technology ,Oxidation resistance ,Argon atmosphere - Abstract
Nb–24Ti–18Si–2Al–2Hf–4Cr and Nb–24Ti–18Si–2Al–2Hf–8Cr alloys were prepared by arc melting in a water-cooled crucible under argon atmosphere. Microstructural characteristics and oxidation resistance of the alloys at 1250 °C were investigated. The results show that, when the Cr content is 4 at%, the microstructures consist of (Nb,Ti)SS and Nb5Si3; as Cr content increases to 8 at%, C14 Laves phase Cr2Nb is formed. The isothermal oxidation tests show that the oxidation kinetics of the two alloys follow similar features. The weight gains of the two alloys after oxidation at 1250 °C for 100 h are 235.61 and 198.50 mg·cm−2, respectively. During oxidation, SiO2, TiO2, Nb2O5 and CrNbO4 are formed at first. Then, Ti2Nb10O29 is formed after oxidation for 20 min and begins to change into TiNb2O7 as the oxidation proceeds. SiO2 is formed as solid state at first but later evolves into glassy state to improve the cohesion of the scale. After oxidation for 100 h, oxidation products consist of SiO2, TiNb2O7, Nb2O5 and CrNbO4.
- Published
- 2015
- Full Text
- View/download PDF
41. Phosphine-Free Synthesis and Characterization of Cubic-Phase Cu2SnTe3 Nanocrystals with Optical and Optoelectronic Properties
- Author
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Tao Ding, Wenling Feng, Qing Yang, and Wenliang Wang
- Subjects
Materials science ,General Chemical Engineering ,General Chemistry ,Characterization (materials science) ,chemistry.chemical_compound ,chemistry ,Nanocrystal ,Oleylamine ,Phase (matter) ,Materials Chemistry ,Physical chemistry ,Phosphine ,Stoichiometry ,Argon atmosphere - Abstract
Cu2SnTe3 nanocrystals with a cubic structure are prepared by reacting stoichiometric amounts of Cu(acac)2 and Ph4Sn in presence of oleylamine (argon atmosphere, 130 °C, 30 min) followed by injection of a TeO2 solution in 1-dodecanethiol (210 °C, 90 min).
- Published
- 2015
- Full Text
- View/download PDF
42. Thermal Analysis Study on the Carbothermic Reduction of Chromite Ore with the Addition of Mill Scale
- Author
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Bo Björkman, Lena Sundqvist Ökvist, Xianfeng Hu, and Qixing Yang
- Subjects
Thermogravimetric analysis ,Mill scale ,Materials science ,Metallurgy ,Alloy ,Metals and Alloys ,Petroleum coke ,chemistry.chemical_element ,02 engineering and technology ,engineering.material ,Condensed Matter Physics ,020501 mining & metallurgy ,Chromium ,0205 materials engineering ,chemistry ,Materials Chemistry ,engineering ,Chromite ,Physical and Theoretical Chemistry ,Thermal analysis ,Argon atmosphere - Abstract
This paper presents a fundamental study on the carbothermic reduction of chromite ore with the addition of mill scale, which forms the basis for designing an alloying precursor, “chromite ore + mill scale + carbon,” for direct chromium alloying. The reduction of chromite ore by petroleum coke with or without the addition of mill scale is investigated by Thermogravimetric Analysis (TGA) under non-isothermal conditions (from room temperature to 1823 K) in the argon atmosphere; the fractional reduced samples were characterized by SEM/EDS and XRD analyses. The experimental results show that the mill scale in the alloying mixture is reduced to high active iron first and disseminated around the chromite ore particles; the reduction of chromite ore is enhanced with the addition of mill scale especially at temperatures higher than 1623 K, and the enhancing effect increased with increasing mill scale addition. The enhancing effect is attributed to the presence of molten Fe–C alloy in the vicinity of chromite ore, which can decrease the thermodynamic activity of chromium by having chromium in situ dissolve into the melt.
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- 2015
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43. Selective formation of benzo[c]cinnoline by photocatalytic reduction of 2,2′-dinitrobiphenyl using TiO2 and under UV light irradiation
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Jaspreet Kaur and Bonamali Pal
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Titanium ,Aqueous solution ,Ultraviolet Rays ,Biphenyl Compounds ,Metals and Alloys ,Light irradiation ,General Chemistry ,Irradiation time ,Phenanthrenes ,Photochemical Processes ,Photochemistry ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Ceramics and Composites ,Photocatalysis ,Benzo(c)cinnoline ,Argon atmosphere ,Cinnoline - Abstract
Photocatalytic reduction of 25 μmol 2,2'-dinitrobiphenyl in 50% aqueous iso-propanol and 50 mg P25-TiO2 under an argon atmosphere and 20 h UV light irradiation selectively produced 23.8 μmol of benzo[c]cinnoline (95%), and 2,2'-biphenyldiamine (5%) whose amount gradually increased with the irradiation time beyond 20-24 h due to further reduction of benzo[c]cinnoline.
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- 2015
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44. Structural and magnetic properties of melt-spun Y1−Gd Co2 (0 ⩽x⩽ 1) alloys
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Z. Śniadecki, A. Musiał, Roman Puzniak, A. Wisniewski, Marcin Jarek, and Bogdan Idzikowski
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Quenching ,Materials science ,Mechanical Engineering ,Gadolinium ,Metals and Alloys ,chemistry.chemical_element ,Arc melting ,Microstructure ,Crystallography ,Paramagnetism ,chemistry ,Mechanics of Materials ,Phase (matter) ,Materials Chemistry ,Curie temperature ,Argon atmosphere - Abstract
Structural and magnetic properties of a series of melt spun alloys Y 1− x Gd x Co 2 , with x = 0, 0.2, 0.4, 0.5, 0.6, 0.8 and 1, were investigated. The studied samples were prepared by arc melting in argon atmosphere and next were synthesized in the melt-spinning process in the form of flakes. During the synthesis, large number of defects such as free volumes, vacancies, and alloyed atoms were introduced into the samples. It was found that magnetic properties of the studied samples are determined by two factors: the effect of Y substitution by Gd and by the impact of microstructure defects. The substitution of gadolinium leads to a significant, linear increase in the Curie temperature, T C , at which transition to paramagnetic phase occurs, T C = 75, 195, 245, 280 K, for the samples with x = 0.2, 0.4, 0.5, 0.6, respectively, and is above 340 K for the samples with x = 0.8 and 1. At lower temperatures, of about 20–30 K, an additional peak in ac susceptibility is observed. Position of this peak depends both on frequency and on Gd content. The origin of the low temperature maximum appears to be due to magnetic ordering induced by microstructure effects.
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- 2015
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45. A simple method for preparing superconducting FeSe pellets without sealing in evacuated silica tubes
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Jean-Claude Grivel
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Superconductivity ,Materials science ,Specific heat ,Annealing (metallurgy) ,Process Chemistry and Technology ,Metallurgy ,Pellets ,FeSe ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Heat treatment ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Tetragonal crystal system ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,Processing parameters ,Tube furnace ,010306 general physics ,0210 nano-technology ,Quartz ,Argon atmosphere ,Chalcogenides - Abstract
Superconducting tetragonal FeSe pellets were made by reacting mixtures of elemental Fe and Se powders in argon atmosphere without sealing in evacuated silica tubes. A simple tube furnace has been used. Although the tube's material consisted of quartz, an alumina tube could be used as well. X-ray pure samples with onset of superconducting transition between 8.0 K and 8.5 K were obtained under specific heat treatment conditions. Residual, unreacted Fe particles could be virtually eliminated through prolonged annealing. A key factor for the synthesis of good samples consists in using processing parameters that minimize Se losses.
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- 2017
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46. Surface modification of carbon nanofibers with SiC by heating different SiO vapor sources in argon atmosphere
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Morinobu Endo, Guosheng Xu, Tomohiro Yamaguchi, Isao Kubo, Seiichi Taruta, and Tomohiko Yamakami
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Materials science ,Carbon nanofiber ,Dispersibility ,General Chemistry ,Condensed Matter Physics ,SiC coating ,Surface modification ,Carbon nanofibers ,Materials Chemistry ,Ceramics and Composites ,Composite material ,Silicon sources ,Argon atmosphere - Abstract
In order to improve interfacial bonding strength between carbon nanofibers (CNFs) and SiC matrix in CNFs/SiC composites and to disperse CNFs uniformly in the matrix, SiC coating on surface of CNFs was performed in argon atmosphere in the temperature range of 1400 to 1800°C using SiO2, SiO, and mixture of Si and SiO2 powders (Si/SiO2 powder) as silicon sources, and the modification and dispersibility of the treated CNFs were investigated. β-SiC particles were deposited on the surface of the CNFs in all the specimens at 1600–1800°C. So more SiC was formed by heating CNFs with SiO powder at 1600°C. However, the formed SiC was oxidized at higher temperature, practically, at 1800°C. This oxidation was advanced more by using SiO2 and Si/SiO2 powders as silicon sources and very fine carbon fibers were observed on the surface of CNFs. The dispersibilities of CNFs heated with Si/SiO2 and SiO powders were superior to those of as-received CNFs, CNFs treated with NaClO3 solution and CNFs heated with SiO2 powder, which resulted from the advanced oxidation of CNFs and the silanol group (–SiOH) on surface of formed SiC., Article, J. Ceram. Soc. Jpn. 122(1429):822-828 (2014)
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- 2014
47. A novel electroless plating of Ni–P–Al–ZrO2 nanocomposite coatings and their properties
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Ramesh Chandra Agarwala, Vijaya Agarwala, D.D. Mishra, and Preeti Makkar
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Materials science ,Nanocomposite ,Process Chemistry and Technology ,Metallurgy ,Indentation hardness ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Wear resistance ,Electroless plating ,Transmission electron microscopy ,Materials Chemistry ,Ceramics and Composites ,Particle size ,Composite material ,Ball mill ,Argon atmosphere - Abstract
The wear performance of electroless deposited Ni–P–Al–ZrO 2 nanocomposite coatings on mild steel was studied. Nanosized aluminium–zirconium composites were first prepared by mechanical alloying in a high energy planetary ball mill for different extents of time (5, 10, 20, 30, 40 and 50 h). The 50 h milled Al+ZrO 2 powder was then used as the second phase (4 g/L) for the development of electroless Ni–P–Al–ZrO 2 nanocomposite coatings using alkaline bath. The phases, size, morphology of 50 h milled Al+ZrO 2 nanopowder and Ni–P–Al–ZrO 2 nanocomposite coatings were determined by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) respectively. These coatings were heat treated at 400 °C for 1 h in argon atmosphere. Wear resistance of coatings was measured by the ball on disc method at different loads (1 N, 1.5 N, 2 N) and velocities (0.1, 0.2 m/s). Microhardness, wear and friction studies of all heat-treated coatings were investigated and compared with Ni–P coatings. The results show that the Al+ZrO 2 nanopowder milled for 50 h shows unevenly sphericsl shape with particle size ranges from 30 to 40 nm. The microhardness and wear resistance of the nanocomposite coatings are improved as compared to Ni–P coatings. Hardness and wear resistance of the nanocomposite coatings further enhances on heat treatment.
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- 2014
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48. Evaluation of Phase Equilibria Involving the Liquid Phase in the Hf-Si System
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Carlos Angelo Nunes, Paulo Atsushi Suzuki, João Carlos Jânio Gigolotti, and Gilberto Carvalho Coelho
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Diffraction ,Structural material ,Materials science ,Silicon ,Scanning electron microscope ,Metals and Alloys ,Analytical chemistry ,Mineralogy ,chemistry.chemical_element ,Liquid phase ,Condensed Matter Physics ,Hafnium ,chemistry ,Materials Chemistry ,Argon atmosphere ,Phase diagram - Abstract
Metal-silicon-boron (Me-Si-B) alloys have been extensively studied due to their potential to develop high temperature structural materials. In this sense, information from accurate phase diagram becomes important. This work presents results of detailed microstructural characterization of as-cast hafnium-silicon alloys to assess the liquid composition associated to the invariant reactions of this system. The alloys were prepared by arc melting from high purity hafnium and silicon under argon atmosphere. The phases present in the alloys were identified by scanning electron microscopy and x-ray diffraction. Important discrepancies were found between the data obtained in this work and those of the most recent phase diagrams, especially the composition of the liquid phase in the following reactions: L + Hf5Si3 ⇄ Hf2Si, 32.5 at.% Si instead of 21 at.% Si, L + Hf3Si2 ⇄ Hf5Si3, 37.0 at.% Si instead of 30.3 at.% Si and L + Hf5Si4 ⇄ HfSi, 52.5 at.% Si instead of 58.3 at.% Si.
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- 2014
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49. Effective preparation of graphite nanoparticles using mechanochemical solid-state reactions
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K. Fukui, Nobuhiro Ogawa, Masami Nishikawa, T. Uehara, Satoshi Motozuka, Takaomi Kobayashi, Kota Shiba, and Motohiro Tagaya
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Diffraction ,Materials science ,Nanostructure ,Chemistry(all) ,Solid-state ,Nanoparticle ,Nanotechnology ,General Chemistry ,Condensed Matter Physics ,law.invention ,symbols.namesake ,Chemical engineering ,law ,symbols ,Materials Chemistry ,Graphite ,Electron microscope ,Raman spectroscopy ,Argon atmosphere - Abstract
The mechanochemical milling was utilized to control the nanostructures of plate-like graphite (Gp) microparticles in an argon atmosphere and at room temperature. The aggregated Gp nanoparticles were prepared by the simple solid-state process without organic solvent. Electron microscope observations, X-ray diffraction patterns and Raman spectra revealed the fractured plate-like Gp microparticles as well as the Gp microparticles agglomerated to each other through the dissociative edge surfaces by the milling process to finally generate the Gp nanoparticle aggregates. In the process, the ratio of the edge plane surfaces with the dangling bondings to layered internal surfaces clearly increased with the milling. Therefore, the low environmental burden process for preparing the Gp nanoparticle aggregation was achieved.
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- 2014
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50. New compounds with Nd11Pd4In9 structure type in the systems RE–Pd–In (RE = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy)
- Author
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M. Demchyna, Bohdana Belan, Mykola Manyako, L. Sojka, and Ya.M. Kalychak
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Crystallography ,Materials science ,Lattice constant ,Mechanics of Materials ,Mechanical Engineering ,Pure metals ,Materials Chemistry ,Metals and Alloys ,General Chemistry ,Structure type ,Argon atmosphere ,Powder diffraction - Abstract
RE 11 Pd 4 In 9 compounds ( RE = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy) were synthesized by arc-melting of pure metals under an argon atmosphere with subsequent annealing at 870 K and characterized by X-ray powder diffraction. They belong to the Nd 11 Pd 4 In 9 structure type (space group Cmmm , Z = 2) with the following lattice constants: a = 15.581(5), b = 22.606(8), c = 3.767(1) A for La 11 Pd 4 In 9 ; a = 15.431(6), b = 22.516(9), c = 3.763(2) A for Ce 11 Pd 4 In 9 ; a = 14.883(3), b = 22.319(4), c = 3.736(1) A for Pr 11 Pd 4 In 9 ; a = 14.825(6), b = 22.269(8), c = 3.779(1) A for Nd 11 Pd 4 In 9 ; a = 14.706(2), b = 22.094(3), c = 3.729(1) A for Sm 11 Pd 4 In 9 ; a = 14.701(3), b = 22.046(5), c = 3.722(8) A for Gd 11 Pd 4 In 9 ; a = 14.614(5), b = 21.985(3), c = 3.679(2) A for Tb 11 Pd 4 In 9 , a = 14.606(4), b = 21.896(6), c = 3.626(9) A for Dy 11 Pd 4 In 9 . The structure is a member of the homological series RE m + n M 2 n X m based on AlB 2 ( m ) and CsCl ( n ) types.
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- 2014
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Catalog
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