70 results on '"Zhao, Jie"'
Search Results
2. Effect of Electric Field on the Microstructure and Properties of NiAl Alloy Sheet Prepared by Foil Reaction Synthesis.
- Author
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Wang, Shuai, Wang, DongJun, Zhao, Jie, Qin, ShaoHua, Wei, WenQing, Zhai, Bin, Wang, ZhiNan, and Liu, Gang
- Subjects
ELECTRIC field effects ,MOLECULAR dynamics ,MICROSTRUCTURE ,ALLOYS ,ELECTRIC fields - Abstract
NiAl alloy sheet was successfully prepared using current-assisted sintering, thus verifying the possibility of preparing a NiAl thin-wall component by current-assisted sintering and foil/foil reaction synthesis. Ni/Al laminated sheets were obtained by annealing at 550 °C at 5 MPa for 0.5 h; uniform NiAl alloy sheets were fabricated by annealing at 1150 °C at 15 MPa for 20 min. The experimental results showed that current-assisted sintering significantly reduced the reaction temperature and reaction time. Microstructural characterization revealed that the inter-diffusion ability of Al atoms is considerably weaker than that of Ni atoms. Molecular dynamics simulation confirmed these experimental results and showed that this difference becomes significant under the action of an electric field. The mechanism of synthesis of Ni/Al laminated sheets using current sintering is mainly determined by the diffusion behavior of Ni atoms. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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3. Effects of Co on Microstructure, Mechanical Properties, and Corrosion Resistance of Ti-Nb-Zr-Co Biological Alloys
- Author
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Zhao, Jie, Ma, Fengcang, Liu, Ping, Liu, Xinkuan, Li, Wei, and He, Daihua
- Published
- 2020
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4. A Novel Method for Preparing Intermetallics/Superalloy Dissimilar Materials Using Current Sintering of Metallic Powders.
- Author
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Ning, Hanwei, Wang, Dongjun, Qin, Shaohua, Zhao, Jie, Wei, Wenqing, Liu, Ze, and Liu, Gang
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HEAT resistant alloys ,CONSTRUCTION materials ,SINTERING ,POWDERS ,MICROSTRUCTURE - Abstract
Herein, a novel method is proposed to prepare the multimaterial composite component for aerospace applications using the current sintering. Two representative high‐temperature structural materials, the new potential intermetallic NiAl and the widely used Ni‐based superalloy K4202, have been employed to achieve the target. As shown by the results, a clean interface with almost no defects is successfully obtained in NiAl/K4202 alloy. Nevertheless, the existence of a continuous Cr(Mo) phase along the region leads to an insufficient bonding ability. To optimize the interfacial microstructure, a Ni foil is employed as the interlayer. The results indicate that the interlayer can hinder the intense diffusion of elements and prevent the abnormal growth of Cr(Mo) phases, which result in a considerable improvement of interfacial properties. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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5. Microstructure and Tribological Performance of Laser Cladding Ti2AlC Particle Reinforced Coatings on Ti6Al4V.
- Author
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Hua, Shi-Wei, Pang, Ming, Chen, Jie, Zhao, Jie, and Ji, Feng-Qin
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FRETTING corrosion ,COMPOSITE coating ,ADHESIVE wear ,WEAR resistance ,MICROSTRUCTURE - Abstract
By applying the TC4-Ti
2 AlC composite coatings to the Ti6Al4V substrate by laser, the wear resistance of the Ti6Al4V alloy was improved. Analysis was done on the composite coatings' microstructure, phase composition, microhardness, and tribological characteristics. According to the findings, coatings without defects can be created when Ti2 AlC content ranges between 5 and 15 wt.%. Furthermore, the coating without Ti2 AlC consisted of a α-Ti solid solution while coatings with Ti2 AlC included a α-Ti solid solution, hard phases of TiC and Ti3 Al, as well as a Ti2 AlC ceramic phase. During laser cladding, Ti2 AlC partially dissolved and turned into TiC and Ti3 Al, resulting in an average hardness of 371.61 ± 3.95 HV0.5 , 382.92 ± 3.61 HV0.5 , 388.91 ± 3.29 HV0.5 for the coatings with Ti2 AlC weight fractions of 5, 10, and 15%, respectively. These numbers were about 1.16 ~ 1.22 times the hardness of the titanium alloy matrix (320 ± 3.12 HV0.5 ). Besides, the Ti2 AlC lubricant and hard phases act synergistically to bring composite coatings better performances in wear resistance and friction reduction compared to the pure TC4 coating. The lowest coefficient of friction (0.382) (COF) and the greatest wear resistance (8.87 × 10−5 mm3 /N m) were obtained at the composition of TC4-10wt.%Ti2 AlC; more particularly, the wear resistance at TC4-10wt.%Ti2 AlC was 1.2–2.1 times that of pure TC4 coating. The principal causes of wear in a pure TC4 coating are adhesive wear and oxidation, however, these wear processes shift to minor abrasive wear and oxidation when assisted by oxide coatings, Ti2 AlC lubricant, and TiC, Ti3 Al hard phases. [ABSTRACT FROM AUTHOR]- Published
- 2023
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6. Effect of Solution Treatment on the Microstructure and Mechanical Properties of High-Borated Steel Composites.
- Author
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Li, Yong-Wang, Wang, Zhao-Jie, Liu, Hai-Tao, and Li, Gang
- Subjects
COMPOSITE plates ,MICROSTRUCTURE ,STAINLESS steel ,CONSTRUCTION materials ,HOT rolling - Abstract
High-borated stainless steels prepared via ingot casting and hot rolling have a relatively low ductility, which limits their use as structural and functional materials in fuel reprocessing systems. In this study, 2.1 wt.% B stainless steel composites were prepared by a novel method of hot-roll bonding and solution treatment using an ingot casting slab and two layers of boron-free stainless steel. The aim of this study was to determine the effect of solution treatment on the interfacial microstructure and mechanical properties of high-borated stainless steel composites. As expected, a high-borated stainless steel slab containing many brittle ceramic (Cr, Fe)
2 B-type particles was successfully hot-rolled and bonded with boron-free stainless steel slabs. Furthermore, metallurgical bonding was realized via the formation of ~ 50 μm wide transition regions by solution treatment, for which the mechanism was found to consist of recrystallization and diffusion-controlled reactions. The formation of transition regions enhanced the geometrical restriction effect. Neither delamination nor cracking was observed along the interfaces during a bending test of the composite plates. [ABSTRACT FROM AUTHOR]- Published
- 2023
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7. Microstructure damage of directionally solidified alloy turbine blade after service.
- Author
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WANG Qiankun, WANG Wei, CHI Qingxin, CAO Tieshan, CHENG Congqian, and ZHAO Jie
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TURBINE blades ,DIRECTIONAL solidification ,HARDNESS testing ,MICROSTRUCTURE ,ALLOYS ,GAS turbine blades ,AIRPLANE motors - Abstract
Turbine blades are the most demanding components in aircraft engines, and their performance is related to the safety of the whole engine. Due to the complex service environment and harsh service conditions of blades, various types of damage cannot be prevented in service. Therefore, it is of great engineering and economic significance to study the service damage of blades. In this paper, the directional solidification alloy turbine blade after actual service was selected as the research object. The cross section position of 80% upper height of the blade was intercepted, and the qualitative and quantitative microstructure analysis was carried out by SEM and EDS analysis. The results show that there are two different types of γ' phases in this leaf. One kind of γ' phase has small size and regular shape, the other has large size and irregular shape. The degree of microscopic damage among different parts of the blade is characterized with the help of dimensional distribution characterization of the γ' phase of each part, combined with the analysis of hardness testing of each part of the cross-section.The results show that the service conditions of different parts are different, and the degree of microstructure damage is different. In addition, matrix crack and coating crack in some parts of blade are summarized and analyzed. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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8. A Non-Flat Terrain Biped Gait Planner Based on DIRCON.
- Author
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Chen, Boyang, Zang, Xizhe, Zhang, Yue, Gao, Liang, Zhu, Yanhe, and Zhao, Jie
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BIPEDALISM ,ROBOTS ,GAIT in humans ,ROBOTICS ,MICROSTRUCTURE - Abstract
Various constraints exist in bipedal movement. Due to the natural ability of effectively handling constraints, trajectory optimization has become one of the mainstream methods in biped gait planning, especially when constraints become much more complex on non-flat terrain. In this paper, we propose a multi-modal biped gait planner based on DIRCON, which can generate different gaits for multiple, non-flat terrains. Firstly, a virtual knot is designed to model the state transitions when the swing foot contacts terrain and is inserted as the first knot of the target trajectory of the current support phase. Thus, a complete gait or multi-modal gaits sequence can be generated at one time. Then, slacked complementary constraints, which can avoid undesired trajectories, are elaborated to describe the coupling relationships between terrain information and bipedal motion for trajectory optimization based gait planning. The concrete form of the gait planner is also delivered. Finally, we verify the performance of the planner, as well as the structural design of our newly designed biped robot in CoppeliaSim through flat terrain walking, stairs terrain walking and quincuncial piles walking. The three experiments show that the gaits planned by the proposed planner can enable the robot to walk stably over non-flat terrains, even through simple PD control. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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9. Microstructure evolution and mechanical properties of the cladding layer of Ti-6Al-4V alloy depending on ultrasonic-assisted forging
- Author
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Guo-Fu Gao, Zi-Long Guo, Ting-Ting Su, Wang Yi, Zhang-Dong Li, and Zhao-Jie Yuan
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Cladding (metalworking) ,0209 industrial biotechnology ,021103 operations research ,Materials science ,Alloy ,0211 other engineering and technologies ,Titanium alloy ,02 engineering and technology ,engineering.material ,Microstructure ,Industrial and Manufacturing Engineering ,Forging ,020901 industrial engineering & automation ,Control and Systems Engineering ,Ultrasonic vibration ,engineering ,Ultrasonic assisted ,Ti 6al 4v ,Composite material - Abstract
The cladding layer of Ti-6Al-4V alloy was treated by traditional forging and ultrasonic-assisted forging with the self-made forging device. The forged titanium alloy cladding layer was characterize...
- Published
- 2020
10. Microstructure, mechanical properties and wear resistance of Ti particles reinforced AZ31 magnesium matrix composites.
- Author
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Ye, Junliu, Chen, Xianhua, Luo, Huan, Zhao, Jie, Li, Jianbo, Tan, Jun, Yang, Hong, Feng, Bo, Zheng, Kaihong, and Pan, Fusheng
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WEAR resistance ,MECHANICAL wear ,TENSILE strength ,INTERFACIAL bonding ,MAGNESIUM ,TITANIUM composites ,ALUMINUM composites - Abstract
The compromise between strength and plasticity has greatly limited the potential application of particles reinforced magnesium matrix composites (MMCs). In this work, the Ti particles reinforced AZ31 magnesium (Mg) matrix composites achieved simultaneous improvement in strength, elongation and wear resistance. The Ti particles reinforced AZ31 composites were fabricated by ultrasonic-assisted stir casting with hot extrusion. The results showed that a strong interfacial bonding was obtained at Ti/Mg interface because of the formation of semi-coherent orientation relationship of TiAl/Mg, TiAl/Al 2 Ti and Al 2 Ti/Mg interfaces. The as-extruded 6 wt.%Ti/AZ31 composite presented the best compressive mechanical properties and wear resistance with ultimate tensile strength, elongation and wear rate of 327 MPa, 20.4% and 9.026 × 10
−3 mm3 /m, obviously higher than those of AZ31 alloys. The enhanced mechanical properties were attributed to the grain refinement and strong interfacial bonding. The improved wear resistance was closely related to the increased hardness of composites and the formation of protective oxidation films. • Ti particles refine the grain size of Ti/AZ31 composites. • A strong interfacial bonding forms at Ti/Mg interface. • Ti/AZ31 composites get an increase in strength, elongation and wear resistance. [ABSTRACT FROM AUTHOR]- Published
- 2022
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11. Multistimuli-Responsive Microstructured Superamphiphobic Surfaces with Large-Range, Reversible Switchable Wettability for Oil
- Author
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Hujun Wang, Yunhong Liang, Zhihui Zhang, Zhao Jie, Xiujuan Li, Luquan Ren, Zuankai Wang, and Cui Zhenquan
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Materials science ,Nanotechnology ,02 engineering and technology ,Adhesion ,Large range ,Hexadecane ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,0104 chemical sciences ,Contact angle ,chemistry.chemical_compound ,chemistry ,Oil droplet ,General Materials Science ,Wetting ,0210 nano-technology - Abstract
The switchable wettability is essential for widespread applications in droplet manipulation, rewritable liquid patterning, fluid carrying, and so forth. However, it remains difficult to achieve the multistimuli-responsive, large-range, and reversible wetting switching especially for liquids with low surface tensions through surface topographical management. Here, we apply a simple and effective template-free self-assembly strategy to fabricate microstructured superamphiphobic surfaces that can reversibly switch the wetting performance for oil by transforming the surface morphology in response to multiple stimuli of magnetic fields and mechanical strains. Notably, the noticeably different wetting switching of oil triggered by different stimuli is demonstrated. The contact angles of hexadecane droplets on the as-prepared surfaces can be reversibly switched between 150 ± 1° and 38 ± 2° in response to mechanical strains. Furthermore, the underlying mechanism of wetting switching has been further elucidated using mathematical models. Interestingly, these switchable surfaces dramatically demonstrate the ability to transport oil droplets, without requiring lubricating liquid films. This work not only achieves the large-range and reversible wetting switching for oil but also opens new avenues for fabricating tunable superamphiphobic surfaces with transformable mushroom-like microstructures that can be easily extended to microstructure-dependent friction or adhesion control and used in other fields.
- Published
- 2019
12. Ultra-fine microstructure and excellent mechanical properties of high borated stainless steel sheet produced by twin-roll strip casting
- Author
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Zhao-Jie Wang, Hai-Tao Liu, Guodong Wang, Huang Xiaoming, and Yong-Wang Li
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Austenite ,Materials science ,Mechanical Engineering ,0211 other engineering and technologies ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,Brittleness ,Mechanics of Materials ,Ultimate tensile strength ,engineering ,General Materials Science ,Ingot ,Composite material ,Austenitic stainless steel ,Deformation (engineering) ,0210 nano-technology ,021102 mining & metallurgy ,Eutectic system - Abstract
High borated stainless steel sheets have been widely applied in the nuclear power industry because of good thermal neutron absorption property. However, the large and network-like borides existing around the austenite grains in the conventional ingot casting steel seriously deteriorate the hot workability and the mechanical properties at ambient temperature. In this work, we tried to acquire ultra-fine microstructure by sub-rapid solidification using a novel twin-roll strip casting technology so as to enhance the mechanical properties of 2.1%B austenitic stainless steel. Surprisingly, dispersive and very fine borides mostly smaller than 5 µm were produced in the as-cast microstructure without network-like distribution. The morphologies and crystal structure of borides as well as the stacking faults in borides were investigated in detail. After subsequent hot-rolling and solution treatment, ultra-fine borides were observed with more than 50% of which in a size range of 0.3–1.5 µm, significantly smaller than those of the conventional ingot casted and hot rolled steel. Benefiting from the ultra-fine borides, excellent mechanical properties which had not been reported were obtained. In particular, a total elongation of 14.1% was exhibited, which was twice as high as that of the conventional ingot casted and hot rolled steel. Thus a new structure-function combining high borated stainless steel sheet was achieved. The strengthening and plasticity increasing mechanism was discussed based on Hall-Petch relationship, Orowan mechanism and strain-hardening rate analysis. The fracture behavior in tensile deformation was studied in detail. A characteristic fracture process accompanied with the initiation and coalescence of cavities in austenite matrix was found. This work not only developed a new processing way to produce high borated stainless steel with excellent mechanical properties, but also provided a potential solution for some other hard-worked metallic materials with brittle eutectic phase.
- Published
- 2019
13. A Novel Method for Observing Tumor Margin in Hepatoblastoma Based on Microstructure 3D Reconstruction.
- Author
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Liu, Jie, Wu, XiongWei, Xu, Chongzhi, Ma, Mingdi, Zhao, Jie, Li, Min, Yu, QiYue, Hao, XiWei, Wang, GuoDong, Wei, Bin, Xia, Nan, and Dong, Qian
- Subjects
GLYPICANS ,HEPATOBLASTOMA ,IMAGE registration ,MICROSTRUCTURE ,DIGITAL images - Abstract
Objective: We investigated three-dimensional (3 D) reconstruction for the assessment of the tumor margin microstructure of hepatoblastoma (HB). Methods: Eleven surgical resections of childhood hepatoblastomas obtained between September 2018 and December 2019 were formalin-fixed, paraffin-embedded, serially sectioned at 4 μm, stained with hematoxylin and eosin (every 19th and 20th section stained with alpha-fetoprotein and glypican 3), and the digital images of all sections were acquired at 100× followed by image registration using the B-spline based method with modified residual complexity. Reconstruction was performed using 3 D Slicer software. Results: The reconstructed orthogonal 3 D images clearly presented the internal microstructure of the tumor margin. The rendered 3 D image could be rotated at any angle. Conclusions: Microstructure 3 D reconstruction is feasible for observing the pathological structure of the HB tumor margin. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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14. Fracture Behavior of Cold Sprayed 304 Stainless Steel Coating During Cold Rolling
- Author
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Meng, Xian-ming, Zhang, Jun-bao, Han, Wei, and Zhao, Jie
- Published
- 2012
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15. Synthesis, in vitro biocompatibility and antibacterial property of novel silk fibroin@Ag spheres.
- Author
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Zhang, Jianan, Zhao, Jie, Chen, Song, Jiao, Xiong, Li, Xiaona, and Chen, Weiyi
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SILK fibroin , *SILK , *GRAM-negative bacteria , *STAPHYLOCOCCUS aureus , *ESCHERICHIA coli , *BIOCOMPATIBILITY - Abstract
• Silk fibroin@Ag spheres were prepared by in situ deposition of Ag nanoparticles on silk fibroin spheres. • Silk fibroin@Ag spheres were not cytotoxic and biocompatible. • Silk fibroin@Ag spheres showed antibacterial activity against the growth of bacteria. In this study, novel silk fibroin@Ag spheres were synthesized by in situ growth of Ag nanoparticles (NPs) on silk fibroin (SF) spheres and their microstructure, in vitro biocompatibility, and antibacterial property were evaluated. SEM observation showed that SF@Ag spheres had a spherical morphology with a diameter of 1–10 µm. TEM observation revealed that each SF@Ag sphere had a dense structure and its surface was deposited with Ag NPs with a diameter of 10–50 nm. In vitro biocompatibility evaluation indicated that SF@Ag spheres were not cytotoxic when incubated with osteoblast MC3T3-E1 cells. Moreover, when exposed to two representative types of gram-negative Escherichia coli and gram-positive Staphylococcus aureus , SF@Ag spheres showed a good antibacterial property against the growth of both types of bacteria. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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16. Microstructural evolution and mechanical properties of titanium-alloying high borated steel sheets fabricated by twin-roll strip casting
- Author
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Zhao-Jie Wang, Hai-Tao Liu, Yong-Wang Li, Guodong Wang, and Weina Zhang
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Materials science ,020502 materials ,Mechanical Engineering ,Metallurgy ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,Slip (ceramics) ,Brittleness ,0205 materials engineering ,chemistry ,Mechanics of Materials ,visual_art ,Volume fraction ,visual_art.visual_art_medium ,General Materials Science ,0210 nano-technology ,Ductility ,Boron ,Titanium ,Eutectic system - Abstract
High borated steels have been applied in the nuclear power industry as excellent neutron-shielding materials, but their ductility was relatively low due to the large and brittle borides, restricting their wider utilization. In this work, the high-performance borated steels containing 2.40 wt% B were fabricated through a designing combination of titanium-alloying along with twin-roll strip casting technology. It was found that titanium addition facilitated the increasing boron content of eutectic point for steels. The TiB2 particles solidifying firstly from molten steel depleted massive boron atoms in advance, leading to an as-cast microstructure consisting of more γ-Fe and less M2B-type borides comparing with titanium-free steels. Besides, TiB2 particles were 200–240 nm, and they could act as heterogeneous nucleation cores for M2B borides. Thus dispersive and fine M2B borides smaller than 5 μm were produced in as-cast microstructure. After subsequent hot-rolling and solution-treating, ultra-fine borides were obtained with more than 80% of which in a size range of 0.1–2 μm. In this case, the steels exhibited an excellent total elongation of 16.2% that was twice as high as that of titanium-free steels. Additionally, the relations between microstructure and mechanical properties of hot-rolled and solution-treated steels were clarified. The ductility of steels was determined by the volume fraction of γ-Fe matrix that could accommodate large deformation, but the strength of steels was dominated by the volume fraction of borides that provided the strengthening effects including grain refinement, load transfer term and hindering the dislocation slip. This work provided a new promising method to enhance the ductility of such high borated steels.
- Published
- 2021
17. Effects of hot rolled microstructure after twin-roll casting on microstructure, texture and magnetic properties of low silicon non-oriented electrical steel
- Author
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Zhao-Jie Wang, Jun-Mou Chen, An Lingzi, Dao-Yuan Hou, Guodong Wang, Yin-Ping Wang, and Hai-Tao Liu
- Subjects
010302 applied physics ,Fabrication ,Materials science ,Silicon ,Annealing (metallurgy) ,chemistry.chemical_element ,Recrystallization (metallurgy) ,02 engineering and technology ,engineering.material ,Atmospheric temperature range ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,01 natural sciences ,Grain size ,Electronic, Optical and Magnetic Materials ,chemistry ,0103 physical sciences ,engineering ,Composite material ,0210 nano-technology ,Electrical steel - Abstract
In this work, a 0.71 wt%Si+0.44 wt%Al as-cast strip was produced by novel twin-roll casting. Some as-cast samples were respectively reheated and hot rolled at different temperatures in order to obtain different microstructure prior to cold rolling and annealing. The effects of the hot rolled microstructure on microstructure, texture evolution and magnetic properties were investigated in detail. A coarse deformed microstructure with λ-fiber texture was formed after hot rolling at 850–1050 °C, finally leading to an inhomogeneous recrystallization microstructure with strong λ-fiber, Goss and extremely weak γ-fiber texture. By contrast, a fine transformed microstructure was formed after hot rolling at 1150–1250 °C, finally leading to a fine and homogeneous recrystallization microstructure with stronger α-fiber, γ-fiber and much weaker λ-fiber texture. It should be noted that both the magnetic induction and core loss non-monotonically decreased or increased according to the hot rolling temperature. The unfavorable α-fiber and γ-fiber textures in the annealed sheets were much weaker than those of the conventional products regardless of the hot rolling temperature, thus contributing to a much higher magnetic induction. However, the average grain size in the annealed sheets was much lower than those of the conventional products regardless of the hot rolling temperature, thus leading to a higher core loss except the case of 1050 °C. Hence, it is underscored that better integrated magnetic properties than those of the conventional products can be obtained by optimizing the hot rolled microstructure to produce final desirable recrystallization microstructure and texture.
- Published
- 2016
18. Effects of boron content on the microstructure and mechanical properties of twin-roll strip casting borated steel sheets
- Author
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Guodong Wang, Hai-Tao Liu, Zhao-Jie Wang, and Yong-Wang Li
- Subjects
010302 applied physics ,Microstructural evolution ,Materials science ,Morphology (linguistics) ,Mechanical Engineering ,Metallurgy ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,01 natural sciences ,Strip casting ,chemistry ,Mechanics of Materials ,0103 physical sciences ,General Materials Science ,0210 nano-technology ,Boron ,Eutectic system - Abstract
High borated steel sheets containing 0.25 wt% to 4.0 wt% boron including hypoeutectic (0.28 wt% B and 2.11 wt% B), eutectic (2.43 wt% B) and hypereutectic (4.01 wt% B) compositions were tried to be fabricated by a novel strip casting technology, and the effects of boron content on sub-rapid solidification behavior and subsequent microstructural evolution together with mechanical properties was studied. It was found that the morphology of borides depended greatly on the boron content. When increasing boron, the morphological change of borides was network-like → grainy → cluster-like → plate-like. Various orientation relationships between different morphological borides and γ-Fe in as-cast steels were also identified. After subsequent hot-rolling and solution-treating, ultra-fine (
- Published
- 2020
19. Microstructure, mechanical properties and springback behaviour of Ti‑6Al‑4V alloy connection rod for spinal fixation device
- Author
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Weiqiang Wang, Qiaochu Li, Bai Shuyu, Zhong Gongcheng, Zhao Jie, Bai Pengfei, Tao Xiaojie, and Min Xiaohua
- Subjects
Equiaxed crystals ,Materials science ,Annealing (metallurgy) ,Alloy ,Bioengineering ,02 engineering and technology ,engineering.material ,010402 general chemistry ,01 natural sciences ,Biomaterials ,Flexural strength ,Hardness ,Tensile Strength ,Ultimate tensile strength ,Materials Testing ,Alloys ,Composite material ,Titanium ,Titanium alloy ,021001 nanoscience & nanotechnology ,Microstructure ,Spine ,0104 chemical sciences ,Orthopedic Fixation Devices ,Mechanics of Materials ,Vickers hardness test ,engineering ,0210 nano-technology - Abstract
The effect of annealing condition on microstructure, mechanical properties and springback behaviour was examined in the connection rod of Ti-6Al-4V alloy for spinal fixation devices. Compared with the deformed microstructure in the sample before annealing, relatively few equiaxed grains were present after annealing at 1003 K after 1.8 ks, and a considerable amount appeared at 7.2 ks. When annealing time was extended to 36 ks, the recrystallised grains further grew. Vickers hardness, tensile strength and bending strength decreased with increasing annealing time, whereas the elastic and bending moduli showed no significant change with annealing time of up to 7.2 ks and then slightly decreased at 36 ks. The springback ratio was closely associated with strength and modulus and applied bending deflection. The springback ratio reached the highest and lowest values in the sample before and after annealing for 7.2 ks, respectively. A good combination of strength, modulus and springback ratio was obtained in the sample after annealing for 7.2 ks.
- Published
- 2017
20. Microstructure and Tensile Elongation Enhancement of 1.6 wt% B stainless Steel Plates Fabricated by Composite Rolling
- Author
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Liu Guangjun, Zhao-Jie Wang, Hai-Tao Liu, Xiaoming Zhang, Yong-Wang Li, and Bao-Guang Zhang
- Subjects
Materials science ,Composite number ,Materials Chemistry ,Metals and Alloys ,Steel plates ,Physical and Theoretical Chemistry ,Composite material ,Condensed Matter Physics ,Microstructure ,Tensile testing - Published
- 2019
21. Microstructure evolution and mechanical properties of the cladding layer of Ti-6Al-4V alloy depending on ultrasonic-assisted forging.
- Author
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Gao, Guo-Fu, Su, Ting-Ting, Li, Zhang-Dong, Wang, Yi, Guo, Zi-Long, and Yuan, Zhao-Jie
- Subjects
TITANIUM alloys ,FORGING ,MICROSTRUCTURE ,ALLOYS ,SCANNING electron microscopy ,MATERIAL plasticity - Abstract
The cladding layer of Ti-6Al-4V alloy was treated by traditional forging and ultrasonic-assisted forging with the self-made forging device. The forged titanium alloy cladding layer was characterized by scanning electron microscopy, and the hardness distribution of the counterparts was examined by Rockwell hardness tester. The reasons for the difference of microstructure under two different forging methods were analyzed, and the influences of ultrasonic amplitude and forging force on the microstructure were discussed. The results showed that the ultrasonic vibration-assisted forging process was more advantageous to the plastic deformation of titanium alloy cladding layer than the traditional forging process and was beneficial to the evolution of the original Widmanstatten structure to the duplex microstructure. Meanwhile, the hardness of titanium alloy cladding layer was improved by about 10%. Furthermore, with the increase of ultrasonic amplitude and forging force, the microstructure of titanium alloy cladding layer gradually changed to equiaxed microstructure with better properties. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
22. Microstructure and corrosion performance of X100 steel in the oilfield produced water.
- Author
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Zhao, Jie, Wang, Shengnan, Gu, Yanhong, Xiong, Dan, and Tian, Bin
- Subjects
- *
OIL field brines , *STEEL , *WATER temperature , *MICROSTRUCTURE , *OIL field flooding - Abstract
The corrosion performances of X100 steels in the oilfield produced water with different temperature (30°C, 40°C, 60°C) under the simulated working conditions were studied by potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) test. Energy dispersive spectroscopy (EDS) was used to measure the element composition of the sample after corrosion. The phase and chemical compositions of the specimens were analyzed by X-ray diffraction (XRD) and Raman spectrometry. The electrochemical results showed that the corrosion resistance of the specimen exposed for 24 hours increased with the increase of the testing temperature, indicating the better protective effect due to the corrosion product film formed under high temperature despite the impact of turbulence. The corrosion products consist of Fe3O4, Fe2O3, α-FeOOH, and γ-FeOOH. The corrosion mechanism model of X100 steel was established and the corrosion behavior was analyzed under simulated working conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
23. Shale Gas Slippage Dynamic Characteristics in Nano-Scale Pores
- Author
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Zhi Ping Li, Yang Wang, Xiang Dong Yang, Gang Liu, Zhao Jie Song, and Zhi Feng Li
- Subjects
Permeability (earth sciences) ,Molecular diffusion ,chemistry.chemical_compound ,Petroleum engineering ,Chemistry ,Capillary action ,Desorption ,General Engineering ,Slippage ,Composite material ,Microstructure ,Oil shale ,Methane - Abstract
There are two important features on microstructure of shale.Firstly, Shale rocks are composed of rather fine grained particles, and their pores are very small, at the scale of nanometers.Gas slippage is complicate because its pore diameter is typically less than 10 nm. Secondly, a large amount of shale gas are absorbed in shale the same as coal-bed methane. Adsorbed gas desorption changes the structure. Permeability of shale is dynamic because of Nano-pore structure and desorption of absorbed gas during production. Shale gas slippage dynamic characteristics is researched in Nano-scale pores,based on capillary bundle medle and solid deformation theory. Mathematical model results show that pore diameter and pressure have important effect on permeability. Permeability increases firstly then reduces because of pressure drawdown when pore diameter is less than 10 nm. The lager pore diameter is, the lower pressure point of permeability Inflection and the faster permeability decline rate is. Gas molecular diffusion has less influence on flow when pore diameter is lager than 20 nm and when pressure is lager than 10 MPa. This model can be used for shale gas evaluation and production optimization.
- Published
- 2012
24. Recrystallization behavior during hot tensile deformation of TA15 titanium alloy sheet with substantial prior deformed substructures.
- Author
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Zhao, Jie, Wang, Kehuan, Huang, Ke, and Liu, Gang
- Subjects
- *
CRYSTAL grain boundaries , *TITANIUM alloys , *BEHAVIOR , *ANNEALING of metals , *MICROSTRUCTURE - Abstract
Dynamic recrystallization to a large extent determines the microstructure of near-α titanium alloys during the thermo-mechanical processing in α + β two phases zone. And the initial microstructure has a dramatic effect on the recrystallization behavior. Therefore, this paper deals with the recrystallization behavior of a near-α TA15 titanium alloy sheet with substantial prior deformed substructures during the annealing and hot tension at 800 °C. Undeformed and deformed regions of tensile samples, viz., static recrystallization and dynamic recrystallization, were studied respectively through EBSD observation. It was found that, the unusual intragranular nucleation of discontinuous recrystallization was observed in the relatively coarse grains, which was formed by the enclosed low angle grain boundaries rearranged by the thermally activated recovery. And most of the recrystallized grains manifested as three types of special grain boundaries, namely [0001]30°, 11 2 ¯ 0 75 ° and 13 8 ¯ 5 ¯ 3 90 ° , which showed the cusps in grain boundary energy and can stabilize the recrystallized grain embryo. The substantial prior deformed substructures of the employed TA15 sheet, viz., low angle grain boundaries and dislocations, can facilitate the formation of subgrains and nucleation, which brought about a mixture of continuous and discontinuous recrystallization, regardless of dynamic or static. During the hot tension, the activation of dislocations would accelerate the annihilation and rearrangement of dislocations, thus, recrystallization can take place more frequently, which finally leads to an equiaxed microstructure. • Quasi-in-situ annealing treatment of the initial TA15 sheet was carried out. • A mixture of continuous and discontinuous recrystallization was observed during annealing and hot tension. • Effect of substantial prior deformed substructure on the recrystallization behavior was investigated. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
25. Effect of hot-dip siliconizing time on phase composition and microstructure of Mo–MoSi2 high temperature structural materials.
- Author
-
Zhang, Yingyi, Zhao, Jie, Li, Jinghui, Lei, Jie, and Cheng, Xiangkui
- Subjects
- *
SILICONIZING (Metallurgy) , *MOLYBDENUM compounds , *EFFECT of temperature on metals , *CRYSTAL structure , *METAL microstructure - Abstract
Abstract Mo–MoSi 2 high temperature structural materials were obtained by hot-dip siliconizing method. The results show that the silicon melt and molybdenum substrate have good wettability, molten silicon reacts with molybdenum substrate to form a molybdenum silicide phase with a columnar structure, and a strong MoSi 2 crystallographic preferred orientation (CPO) on the (110) crystal face is characterized. While, the Mo–MoSi 2 high temperature structural materials consist mainly of silicon rich layer, MoSi 2 layer, interface layer and molybdenum substrate. The coating surfaces contain a high silicon concentration (55–65 wt%) than the MoSi 2 layer (30–35 wt%). Moreover, the thicknesses and the average grain sizes of siliconized coatings increase sharply with increasing siliconizing time. The coatings thicknesses are 20, 25, 30, and 50 µm, respectively. And the average grain sizes are 6.9, 9.3, 11.7, and 11.8 µm, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
26. Functionally graded metal/ceramic composites by tape casting, lamination and infiltration
- Author
-
Hani Henein, Prasad S. Apte, X. Zhao-jie, and Stephen F. Corbin
- Subjects
Tape casting ,Fabrication ,Materials science ,Triple point ,Mechanical Engineering ,Oxide ,chemistry.chemical_element ,Condensed Matter Physics ,Microstructure ,Infiltration (hydrology) ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,Aluminium ,General Materials Science ,Composite material ,Porosity - Abstract
Alloying aluminum with magnesium and a the use of a N2 atmosphere led to the spontaneous infiltration of ZrO2 preforms with a graded porous structure and the successful fabrication of functionally graded Al–Mg/ZrO2 components. The infiltration process was controlled by an incubation phenomenon resulting from the time needed to destabilize an oxide film present on the molten aluminum droplet. Oxide destabilization depended critically on the presence of Mg, a N2 gas atmosphere and preform microstructure. It is proposed that the destabilization process occurs by a complex reaction localized at the triple point formed between the liquid, solid and gas. The driving force for oxide removal depends on the amount of triple point area present at the infiltration front. A simple model is developed which indicates that this triple point area increases with a decrease in the scale of porosity present in the preform. The model is used to explain the dependence of the incubation time on preform microstructure.
- Published
- 1999
27. Microstructural Evolution of Oxidation Film on a Single Crystal Nickel-Based Superalloy at 980 °C.
- Author
-
Hu, Yebing, Cheng, Congqian, Zhang, Li, Cao, Tieshan, Guo, Guangping, Meng, Xianming, and Zhao, Jie
- Subjects
MICROSTRUCTURE ,HEAT resistant alloys ,SINGLE crystals ,NICKEL ,OXIDATION - Abstract
The isothermal oxidation behavior of a single crystal nickel-based superalloy was investigated at 980 °C through XRD, SEM/EDX and EPMA. The mass gain process exhibited two periods: an initial stage followed by a steady-state stage. Based on the experimental results, the rapid formation of alumina and NiO was responsible for the initial stage of mass gain, and the formation of complex spinels phases may dramatically effect on the steady stage. The microstructure of oxidation film, from the top surface down to the base material, was clarified as Ni-rich oxides, Ni-Cr oxides, Cr-Ta-Co oxides, Ni-Al oxides and finally a continuous Al
2 O3 . In addition, AlN formed in the γ′-free zone. The effect of oxidation film evolution on the oxidation kinetics and mechanism were discussed. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
28. Effect of Bi on the microstructure evolution of Sn-3Ag-0.5Cu/Cu solder joint
- Author
-
Qi Lin, Han Shuang-qi, Zhao Jie, and Wang Lai
- Subjects
Materials science ,Metallurgy ,Alloy ,Electronic packaging ,chemistry.chemical_element ,engineering.material ,Microstructure ,Copper ,chemistry ,Soldering ,engineering ,Wetting ,Joint (geology) ,Eutectic system - Abstract
The reliability of the solder joints is very important for lead-free solders to be applied extensively. The properties of joints have a close relationship with microstructure of the joints (W. Yang et al., J. Electr. Mater. vol. 24, no. 10, 1995). Therefore, this paper studied the microstructure evolution of Sn-3Ag-0.5Cu-XBi/Cu (where X=0-3%) solder joints after aging at varying temperatures. Sn-Ag-Cu-Bi solders have been selected for research because experiments revealed the eutectic Sn-Ag-Cu alloy to be a very promising solder in avionics and automotive applications where the solder joints are subject to numerous thermal cycles and mechanical vibrations. It has good wetting properties and forms good quality joints with copper, and also has good thermo-mechanical properties and soldering technology (C.M. Miller et al, ibid., vol. 23, no. 7, 1994), but compared with SnPb eutectic, it has higher melting temperature and high cost. It is well known that Bi has beneficial effect on mechanical properties of bulk solder when the addition of Bi is within 3%; however, there are only initial reports on the effect of Bi in solder joints, and a full understanding of Bi effects in solder applications is crucial.
- Published
- 2003
29. Ultrathin, flexible, conductive silver nanowires@polyvinyl alcohol composite film fabricated via the combination of air plasma treatment and thermal sintering for electromagnetic interference shielding.
- Author
-
Li, Gang, Zhao, Jie, Wang, Zhuang, Yu, Xuecheng, Zhao, Tao, Liang, Xianwen, Sun, Rong, Cao, Liqiang, and Zhu, Pengli
- Subjects
- *
ELECTROMAGNETIC shielding , *ELECTROMAGNETIC interference , *THERMAL plasmas , *SINTERING , *SILVER - Abstract
• AgNWs@PVA composite films were fabricated via a unique combination method. • The AgNWs@PVA film shows high EMI SE of 55 dB at 11 μm ultra-low thickness. • The AgNWs@PVA film retains excellent stability after 2000 bending cycles. It remains still a challenge to prepare thin, flexible, conductive films for electromagnetic interference shielding, which are highly desired in next-generation electronic applications such as aerospace, medical and wearable devices, etc. Herein, silver nanowires@polyvinyl alcohol (AgNWs@PVA) composite films were fabricated via a unique combination of air plasma treatment followed by thermal sintering of AgNWs network. The prepared composite ultra-thin film (11 µm) with 24.2 wt% of AgNWs displays relatively low density of 1.58 g cm−3. Remarkably, the sheet resistance and electromagnetic interference shielding effectiveness are separately achieved to 0.29 Ω/sq and 55 dB at the measured frequency range of 8.2 GHz to 12.5 GHz. These traits underscore a significant promising prospect of AgNWs@PVA film in the modern flexible electronic devices. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
30. Analysing the Interaction between Microscopic Deformation, Microstructure and Void Evolution of Near-α Titanium Alloys during Non-Superplastic Hot Deformation by an Integrated Crystal Plasticity Finite Element Model.
- Author
-
Zhao, Jie, Wang, Kehuan, Lv, Liangxing, Wang, Liliang, Politis, Denis J., and Liu, Gang
- Subjects
- *
TITANIUM alloys , *FINITE element method , *MICROSTRUCTURE , *DEFORMATIONS (Mechanics) , *CRYSTAL grain boundaries , *CRYSTALS - Abstract
High-efficiency and low-cost hot forming technologies for titanium alloys have been developed for producing complex-shaped, thin-walled tubular components under non-superplastic forming conditions. Under these forming conditions, there exist complex and highly integrated material evolution processes including microscopic heterogeneous deformation, microstructure evolution and damage behaviour. This paper presents an integrated crystal plasticity finite element model of near-α titanium alloys during non-superplastic hot deformation conditions considering grain boundary sliding (GBS), dynamic recrystallisation (DRX), as well as void evolution. The polycrystalline model of a near-α TA15 titanium alloy was established, containing α phase, β phase and grain boundary (GB) regions, in which the GB region was a visualised representation of GBS. The quantitative strength ratio between the GB regions and α phase was calculated according to the Zener–Holloman parameter Z and grain size, which determined the microscopic deformation behaviour. There were found to be two high microscopic strain regions in the α phase: intragranular deformation bands through the most favourable slipping and near the GBs through multiple slipping, which promoted continuous and discontinuous DRX, respectively. With the decrease in parameter Z or grain size, the activated dislocations accommodating GBS were found to no longer pile up inside the grain, but instead travel across the grain interior. Finally, methods to improve the macroscopic plastic formability were proposed for the difficult-to-form titanium alloys experiencing non-superplastic hot deformation. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
31. Microstructure Evolution and Nitridation in an As-Cast 25Cr-35Ni-1Mo Radiant Tube After Long-Term Service.
- Author
-
Zhu, Zhichao, Cheng, Congqian, Liu, Chunhui, and Zhao, Jie
- Subjects
MICROSTRUCTURE ,NITRIDATION ,COMBUSTION ,CARBON ,X-ray diffraction ,CARBIDES - Abstract
The microstructure evolution of 25Cr-35Ni-1Mo radiant tubes was investigated after approximately two years of service in a continuous annealing furnace. The inner and outer tube walls were exposed to N-containing combustion environment and protective atmosphere, respectively. The decarburization feature analysis indicated that carbon content decreased toward the tube surface. However, precipitates at the inner and outer walls were coarser, their content increased and the microhardness value also increased compared to that in the central area. X-ray diffraction illustrated that M(C,N) and M(C,N) were the dominant carbide at the inner and outer walls, and precipitates in the central area were mainly MCand M(C,N) phases. The results were assumed to be associated with the nitridation phenomenon that occurred in the N-containing environment at elevated temperatures. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
32. Effects of a ZnTe buffer layer on structural quality and morphology of CdTe epilayer grown on (001)GaAs by molecular beam epitaxy
- Author
-
Zhao, Jie, Zeng, Yiping, Liu, Chao, and Cui, Lijie
- Subjects
- *
ZINC alloys , *CADMIUM , *DIMENSIONAL analysis , *ROOT-mean-squares , *MICROSTRUCTURE , *MOLECULAR beam epitaxy , *GALLIUM arsenide - Abstract
Abstract: The structural properties, crystalline quality and surface morphology of CdTe thin films without and with a ZnTe buffer layer grown on (001)GaAs by molecular beam epitaxy (MBE) have been studied. CdTe thin film directly prepared on GaAs substrate displays (111) orientation with an island growth mode, whereas the CdTe epilayers with a ZnTe buffer are (001)-oriented single-crystalline film with a two-dimensional (2D) growth mode. The morphology and surface root-mean-square (RMS) roughness of CdTe epilayers are also dramatically improved by using a ZnTe buffer. Furthermore, it is suggested that the high-temperature (HT) ZnTe buffer grown at 360 °C is more efficient for enhancing CdTe structural quality than the low-temperature (LT) one at 320 °C. The CdTe epilayer on the HT-ZnTe buffer shows a narrower full-width at half-maximum (FWHM) of double-crystal X-ray rocking curve (DCXRC) for (004) reflection and a smaller RMS roughness. [Copyright &y& Elsevier]
- Published
- 2012
- Full Text
- View/download PDF
33. Role of Zinc on Shear Property Evolution between Sn-0.7Cu Solder and Joints.
- Author
-
Gao, Yanjun, Hui, Jinkai, Sun, Xinge, Zhao, Fuquan, Zhao, Jie, Cheng, Congqian, Luo, Zhongbing, and Wang, Lai
- Abstract
Abstract: Effect of zinc addition on the shear property evolution between Sn-0.7Cu solder alloy and their joints reflowed at 250°C was investigated. The shear strength of Sn-0.7Cu/Cu joint was found to be higher than of Sn-0.7Cu solder alloy. Although a small addition of zinc element strengthened Sn-0.7Cu solder alloy, it decreased the shear strength of Sn- 0.7Cu solder joints. Based on the fractography analysis and interfacial microstructure observation, it is proposed that the deposition of Cu-Zn intermetallic toward the interface during reflowing is largely responsible for the shear property evolution between the Sn-0.7Cu solder alloy and their joints. [Copyright &y& Elsevier]
- Published
- 2011
- Full Text
- View/download PDF
34. Microstructure and Mechanical Properties of Biomedical Ti-27Nb-8Zr Alloy with Low Elastic Modulus.
- Author
-
Zhao, Jie, Duan, Hongtao, and Li, Haitao
- Abstract
Abstract: Microstructure evolutions of Ti-27Nb-8Zr (mass fraction, %) biomedical alloy subjected to different aging treatments after solution treatment were studied by optical microscopy, scanning electron microscopy and X-ray diffraction, and the influence of various microstructures on the elastic modulus and tensile strength was discussed. The results indicate that the Ti-27Nb-8Zr alloy after solution treatment consists of β+α” phases and has relatively lower elastic modulus and tensile strength, while for the alloy after aging treatment, it contains β, α and ω phases and exhibits significantly higher elastic modulus and tensile strength. With increasing of the aging temperature, the microstructure became coarser and the elastic modulus and tensile strength became lower. It is recommended that a Ti-27Nb-8Zr alloy with comparatively lower elastic modulus (85.5 GPa) and optimal comprehensive properties can be obtained by adopting following process: solution treatment at 800 °C for 1 h and then quenched, aged at 500 °C for 12 h then air-cooled. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
35. The relationship between mechanical properties and crossed-lamellar structure of mollusk shells
- Author
-
Liang, Yan, Zhao, Jie, Wang, Lai, and Li, Feng-min
- Subjects
- *
MOLLUSKS , *STRUCTURAL shells , *MICROMECHANICS , *MICROSTRUCTURE - Abstract
Abstract: Composites produced in nature, such as mollusk shells, bones, etc., are renowned for their unique structures and excellent properties. In this paper the microstructure and mechanical properties of the shell of Conus betulina Linnaeus are investigated. The results indicate that the mechanical properties of the shell are anisotropic. After removal of the organic protein in the shell, the three-point bending strength significantly decreases, to about 1/20th or 1/30th of the original value. The organic matrix plays an important role in the hierarchical structure of the conch shells, as it promotes load transfer between adjacent aragonite layers. [Copyright &y& Elsevier]
- Published
- 2008
- Full Text
- View/download PDF
36. Remaining life assessment of a CrMoV steel using the Z-parameter method
- Author
-
Zhao, Jie, Han, Shuang-qi, Gao, Hong-bo, and Wang, Lai
- Subjects
- *
STEEL , *STRAINS & stresses (Mechanics) , *CURVES , *MICROSTRUCTURE - Abstract
A
Z- parameter method based on the Larson–Miller relationship is proposed to assess the remaining life of a CrMoV steel. It is found that the non-linear master curve of stressσ vs Larson–Miller parameterP of the steel can be expressed as:P=26.68-2.49 log σ-0.01σ. A family of curves parallel to the master curve can be expressed as:P=Z-2.49 log σ-0.01σ, where the value ofZ represents the deviation from the master curve which corresponds with the deterioration in rupture properties. The deterioration in rupture properties is connected with the degradation of microstructure, namely the spheroidization of carbides in the pearlitic steel. A relationship between the value of theZ -parameter and the level of spheroidizationE can be expressed as:Z=27.32-0.54E. A normal distribution is supported for the value of theZ -parameter by both normal probability plotting paper and Shapiro–Wilk normality tests. [Copyright &y& Elsevier]- Published
- 2004
- Full Text
- View/download PDF
37. Influence of Bi on microstructures evolution and mechanical properties in Sn–Ag–Cu lead-free solder
- Author
-
Zhao, Jie, Qi, Lin, Wang, Xiu-min, and Wang, Lai
- Subjects
- *
MICROSTRUCTURE , *METALLIC composites , *INTERMETALLIC compounds , *BISMUTH - Abstract
Sn–Ag–Cu–Bi solders, which have high quality and performance that can meet the requirement of electronic packaging, have been investigated in this paper. The research was focused on the influence of aging on the microstructural evolution and mechanical properties in Sn–3Ag–0.5Cu–xBi (
x=0 –3 wt.%) solders. The effect of Bi was discussed based on the experimental results. The experimental results indicated that the addition of Bi enhanced the tensile strength of the solders but decreased their elongation. After aging treatment, Sn–3Ag–0.5Cu solder showed significant change in strength and elongation which resulted from the obvious coarsening of Ag3Sn and Cu6Sn5 intermetallics. As for Bi-bearing solders, Bi precipitation in Sn matrix was only observed in Sn–3Ag–0.5Cu–3Bi solder after being aged at 120 °C for 100 h, while all the Bi-bearing solders exhibited relatively stable mechanical properties with aging time which can be attributed to the strengthening effect of Bi from solid solution strengthening to precipitating strengthening. [Copyright &y& Elsevier]- Published
- 2004
- Full Text
- View/download PDF
38. Effect of aging treatment on fatigue crack growth in eutectic Sn–Pb alloy
- Author
-
Zhao, Jie
- Subjects
- *
FATIGUE testing machines , *MICROSTRUCTURE - Abstract
The current work investigated the influence of aging treatment on fatigue crack growth behavior of eutectic Sn–Pb alloy. After aging treatment, the eutectic grain structure changed to particle structure. This seriously influenced the time-dependent fatigue crack growth behavior, as well as the cyclic dependent behavior resistance in near-threshold regime at high frequency, while having slight influence on the crack propagation in Paris regime. [Copyright &y& Elsevier]
- Published
- 2003
- Full Text
- View/download PDF
39. Influence of Gas Temperature on Microstructure and Properties of Cold Spray 304SS Coating.
- Author
-
Meng, Xianming, Zhang, Junbao, Zhao, Jie, Liang, Yongli, and Zhang, Yujun
- Subjects
MICROSTRUCTURE ,SURFACE coatings ,TEMPERATURE effect ,STAINLESS steel ,METAL spraying ,SUBSTRATES (Materials science) ,COLD gases ,DEFORMATIONS (Mechanics) - Abstract
In the present study, 304 stainless steel coatings were deposited on interstitial-free steel substrates by cold gas dynamic spray technology. The effect of gas temperature on microstructure, micro-hardness, cohesive strength, and electrochemical property of the coatings were investigated and compared. The results showed that increasing gas temperature had a great contribution to enhancing the bonding strength between the deposited particles and making the microstructure more density. Therefore, the porosity of the coatings decreased from 6%±0.5% to 2%±0.3%, and the tensile strength of the coatings increased from 56±4 MPa up to 73±3 MPa. In addition, the corrosion resistance of the coatings was also deeply influenced by process gas temperature. The corrosion kinetics of the coatings were affected by both of the plastic deformation of deposited particles and the porosity in the coatings. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
40. A microstructural investigation of 52100 steel by N+ implantation and recoil implantation
- Author
-
Ye Weiyi, Zhao Jie, Li Wang, Liu Fu-run, Su Yawen, Li Huijun, Lu Kemin, Zhan Zhenzong, and Lu Guangyuan
- Subjects
Nuclear and High Energy Physics ,Materials science ,Metallurgy ,Intermetallic ,chemistry.chemical_element ,Nitride ,Microstructure ,Indentation hardness ,Amorphous solid ,Recoil ,chemistry ,Surface modification ,Tin ,Instrumentation - Abstract
The microstructure of N-implanted and recoil-implanted 52100 steel (coated with Ti or Cr and then bombarded by N+) was investigated with TEM and AES analyses. The results of the analyses show that the improvement of microhardness and the wear resistance are due to the formation of nitrides (Fe2N, CrN, Cr2N, TiN, Ti2N) and intermetallic compounds (Fe2Ti) on the surface of steel specimens. Especially those nitrides presented in amorphous form are beneficial to surface modification.
- Published
- 1989
41. The improvement in the wear properties of GCr15QBe2 wear pairs by ion implantation
- Author
-
Su Yawen, Li Wang, Zhao Jie, Ye Weiyi, Liu Fu Run, and Lu Guangyuan
- Subjects
Chromium ,Auger electron spectroscopy ,Ion implantation ,Materials science ,chemistry ,Metallurgy ,General Engineering ,chemistry.chemical_element ,Beryllium ,Nitride ,Microstructure ,Electron spectroscopy ,Fluence - Abstract
We have studied the influence of overlapping nitrogen ion implantation and recoil implantation on the wear resistance of GCr15 bearing steel and QBe2 beryllium bronze wear pairs. GCr15 bearing steel speciments were implanted with nitrogen ions (N + ) at 120, 70 and 30 keV in sequence at the same fluence of 1 × 10 17 ions cm −2 . For the recoil case, after the surface of the GCr15 steel specimens had been coated with 300 A of chromium, nitrogen implantation was performed at energies of 30 and 70 keV at a fluence of 2 × 10 17 ions cm −2 . A series of wear measurements were carried out on the specimens under two different loads applied with a pin-on-disk wear tester. During the wear testing, an unimplanted QBe2 beryllium bronze pin was fixed on the tester as the pin and the implanted GCr15 bearing steel specimen was used as the disk, as usual. In the recoil implantation of GCr15 steel specimens, the improvement in wear resistance is remarkable for both GCr15 and QBe2. The wear resistance of GCr15 steel specimens subjected to overlapping implantation, however, did not change significantly. In order to investigate the microstructure, Auger electron spectroscopy was used to measure the depth profile of the implanted nitrogen and electron spectroscopy for chemical analysis was also performed. On the surface of the specimens, Cr 2 O 3 and various nitrides were found. The existence of these compounds is thought to be the main reason for the improvement in wear properties.
- Published
- 1987
42. Effects of boron content on the microstructure and mechanical properties of twin-roll strip casting borated steel sheets.
- Author
-
Wang, Zhao-Jie, Li, Yong-Wang, Wang, Guo-Dong, and Liu, Hai-Tao
- Subjects
- *
BORON steel , *CAST steel , *SHEET-steel , *HYPEREUTECTIC alloys , *BORON , *MICROSTRUCTURE , *BORIDES - Abstract
High borated steel sheets containing 0.25 wt% to 4.0 wt% boron including hypoeutectic (0.28 wt% B and 2.11 wt% B), eutectic (2.43 wt% B) and hypereutectic (4.01 wt% B) compositions were tried to be fabricated by a novel strip casting technology, and the effects of boron content on sub-rapid solidification behavior and subsequent microstructural evolution together with mechanical properties was studied. It was found that the morphology of borides depended greatly on the boron content. When increasing boron, the morphological change of borides was network-like → grainy → cluster-like → plate-like. Various orientation relationships between different morphological borides and γ-Fe in as-cast steels were also identified. After subsequent hot-rolling and solution-treating, ultra-fine (<10 μm) borides were obtained in hypoeutectic and eutectic steels. Benefiting from that, excellent mechanical properties was achieved, which was much better than that of steels prepared by traditional ingot casting. Particularly, when the boron content approached eutectic composition, of which the effect on the microstructure and mechanical properties was more sensitive. The steels containing 2.11 wt% and 2.43 wt% boron exhibited different morphological borides with a total elongation of 14.1% and 8.0%, respectively. Moreover, a thin hypereutectic borated steel sheet was also prepared, but the borides were very large and the total elongation was very low. The correlation between microstructure and strength was clarified based on the Hall-Petch behavior and intermetallic strengthening effect. Smaller γ-grains and higher volume fraction of borides were responsible for higher strength. The plastic behavior of steels was influenced by strain-hardening rate that was determined by the volume fraction of γ-Fe matrix. A better sustainable strain-hardening capability was beneficial to extend the stage of uniform deformation and enhance the ductility. In addition, the mechanical properties of steels were also decided by the fracture mechanism that was dominated by the size of borides. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
43. Effect of high magnetic field on the morphology of (Cu, Ni)6Sn5 at Sn0.3Ni/Cu interface
- Author
-
Cheng, Cong-qian, Zhao, Jie, and Xu, Yang
- Subjects
- *
INTERMETALLIC compounds , *MAGNETIC fields , *METAL microstructure , *INTERFACES (Physical sciences) , *METAL crystals , *PHASE diagrams , *MAGNETIC properties of metals - Abstract
Abstract: The effect of high magnetic field on the microstructure of (Cu, Ni)6Sn5 intermetallic compound layer in Sn0.3Ni/Cu couples at 250 °C was examined. The applied magnetic field changed the morphology of outer (Cu, Ni)6Sn5 crystals on the Sn side from faceted shape to stick shape. The high magnetic field affected the crystal orientations of (Cu, Ni)6Sn5 and reduced the Ni content in the outer layer. The morphology evolution of (Cu, Ni)6Sn5 is attributed to the content of Ni solute decreased by magnetic field. The effects of high magnetic field on the liquid convection and phase diagram are considered to be responsible for the Ni content. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
- View/download PDF
44. Microstructure and Tensile Elongation Enhancement of 1.6 wt% B stainless Steel Plates Fabricated by Composite Rolling.
- Author
-
Li, Yong‐Wang, Liu, Guang‐Jun, Wang, Zhao‐Jie, Zhang, Bao‐Guang, Zhang, Xiao‐Ming, and Liu, Hai‐Tao
- Subjects
MICROSTRUCTURE ,BORON steel ,TENSILE strength ,COMPOSITE plates ,MATERIAL plasticity - Abstract
A 3‐layered composite plate is innovatively fabricated via composite rolling of 1.6 wt% B stainless steel surrounded by two layers of boron‐free steels. The tensile properties of composite and non‐composite plates are comparatively tested and analyzed. Besides, the microstructure evolution of the investigated plates is characterized in detail. It is found that the composite specimens exhibit higher tensile elongation comparing with that of non‐composite specimens. Specifically, the engineering strain of the 1050 °C × 30 min solution‐treated specimens reaches to 12.5 ± 0.8% which is 2.5–3.0 times as high as that of non‐composite specimens. In addition, the as‐cast lamellar borides break into bar‐shaped structures in hot rolled plates, however, their morphology and distribution hardly change after solution treatment. Besides, the transition regions between the core and clad layers are formed and characterized by medium‐sized recrystallized grains and fine borides in the solution‐treated composite specimens. The enhancement mechanism of tensile elongation is mainly analyzed in term of the geometrical restriction of necking in the composite plate during tensile deformation. This paper provides a promising method to effectively enhance the tensile fracture elongation for these metallic materials with poor plasticity like high borated stainless steels. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
45. Towards high strengthening efficiency of equiaxed and platelet-shaped alumina reinforced zirconia ceramics with textured microstructure using DLP-based stereolithography.
- Author
-
Wang, Yang, Zhou, Qingxuan, Han, Zhuoqun, Han, Yongning, Bi, Lunan, Zhang, Xia, Lu, Xiang, Zhao, Jie, Chu, Wei, Li, Jian, Zhao, Zhicheng, Wang, Yingying, Liu, Jia, Li, Ling, and Liu, Futian
- Subjects
- *
ALUMINUM oxide , *STEREOLITHOGRAPHY , *CERAMICS , *MICROSTRUCTURE , *FRACTURE toughness - Abstract
ZrO 2 –Al 2 O 3 (ATZ) ceramics are attracting high interest in biomedical applications because of their desirable mechanical performance and biocompatibility. However, strength and toughness are mutually exclusive in structural ceramics. In this paper, based on digital light processing, novel textured ATZ ceramics with obvious crystallographic orientations were fabricated by incorporating Al 2 O 3 platelets with a high aspect ratio and equiaxed particles into the ZrO 2 matrix. The optimized fracture toughness of 16.9 ± 0.8 MPa m1/2 was achieved in the textured ATZ ceramic, which was about 67.3 % higher than non-textured ZrO 2 ceramics, without sacrificing strength. The coupling toughening effects of macrolayer structure, equiaxed and platelet-shaped Al 2 O 3 particles, and ZrO 2 particles were responsible for the enhanced mechanical performance. The macroscale toughening of 3D-printed lamellar architecture led to effective energy dissipation. Additionally, the crack deflection and crack branching induced by dual-morphology Al 2 O 3 particles, accompanied by the phase transformation of the ZrO 2 matrix, were significant microscopic toughening mechanisms. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
46. Experimental and modelling study of an approach to enhance gas bulging formability of TA15 titanium alloy tube based on dynamic recrystallization.
- Author
-
Wang, Kehuan, Liu, Gang, Zhao, Jie, Huang, Ke, and Wang, Liliang
- Subjects
- *
TITANIUM alloy welding , *LASER welding , *METAL formability , *MICROSTRUCTURE , *RECRYSTALLIZATION (Metallurgy) - Abstract
In order to further improve the hot gas bulging formability of laser-welded TA15 titanium alloy tube, studies about the effects of initial microstructures on the formability were carried out at 800 °C. Vacuum annealing procedures were performed to obtain different microstructures. The formability of these TA15 titanium alloy sheets with different microstructures was subsequently investigated by hot tensile tests and hot gas free bulging. A unified physically based material model considering dislocation density, work hardening, recrystallization, grain size and damage was built to analyze the deformation process. Results show that a good agreement was achieved between the unified material model and experiment results. The evolution of physical variables such as recrystallization fraction, and grain size can be predicted properly by the model. In the unified material model, the initial dislocation density would affect the dynamic recrystallization (DRX) rate. The DRX rate would increase with the increasing dislocation density. Therefore more DRX occurred at the early stage of deformation of initial material with higher dislocation density, while most of the DRX occurred at the middle-late stage of deformation of the annealed material with lower dislocation density. The initial material demonstrated the best formability due to the wide occurrence of DRX at the early stage of deformation, which increased the fraction of high angle grain boundaries, refined the microstructure, promoted the occurrence of grain boundary sliding and enhanced the formability of the material. However, most of the DRX occurred at middle-late stage of deformation of annealed material, which may increase the softening rate and lower the formability. Hence increasing the occurrence of DRX at the early stage of deformation by increasing the initial dislocation density in the material is an efficient approach to improve the gas bulging formability. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
47. Grain boundary migration-induced directional coarsening of the γʹ phase in advanced ultra-supercritical superalloy.
- Author
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Li, Huifang, Ye, Fei, Zhao, Jie, Cao, Tieshan, Xu, Fanghong, Xu, Qingshuang, Wang, Yan, Cheng, Congqian, and Min, Xiaohua
- Subjects
- *
HEAT resistant alloys , *CRYSTAL grain boundaries , *CREEP (Materials) , *DEFORMATIONS (Mechanics) , *PRECIPITATION (Chemistry) , *MECHANICAL stress analysis - Abstract
This study investigated the features of grain boundary regions in a Ni-based superalloy which underwent creep deformation. Large grain boundary zones were denuded in fine γʹ precipitates but contained coarsened microscale γʹ rods. The coarsening direction of these rods was along the <110> of the γ matrix and γʹ precipitates. The orientation of the grain boundary zone was the same as that of the adjacent grain behind the migrating boundary. This result indicated that the formation of these zones was accompanied by the migration of the grain boundary. Then, numerous slip features were observed through detailed local disorientation analysis. It is proposed that the driving force for the grain boundary migration was the local stress induced by the dislocation creep. The dissolution–reprecipitation of the precipitates at the boundary migration front resulted in the directional coarsening of the γʹ rods. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
48. Microstructure and high-temperature properties of NiAlV sheet prepared by magnetron-sputtering and foil-reaction.
- Author
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Wang, Bao, Wang, Dongjun, Zhao, Jie, Wang, Shuai, Ning, Hanwei, Qiu, Gaosong, and Liu, Gang
- Subjects
- *
MICROSTRUCTURE , *MAGNETRON sputtering , *MICROALLOYING , *TENSILE strength , *HIGH temperatures , *ALLOYS - Abstract
[Display omitted] • NiAlV sheet was prepared by magnetron-sputtering and foil-reaction process. • Solid-liquid reaction is applied without pressure to accelerate the process. • The tensile strength of NiAl-1.01V alloy was 128.9 % higher than pure NiAl at 1000 °C. To prepare NiAl sheets with improved high-temperature strength, the V layers with different thicknesses were deposited on the single-side of Ni foils by magnetron sputtering and then the hot-pressing of laminated Ni(V)/Al foils were carried out. A NiAlV sheet consisting of V precipitates and NiAl matrix was successfully prepared using this reaction technique of laminated foils. The NiAlV alloy prepared by microalloying method can obtain better mechanical properties (166.4 MPa) and retain considerable fracture strain (54.5 %) at high temperature. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
49. Fabrication and joining of NiAl and TiAl intermetallics by additive sintering.
- Author
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Ning, Hanwei, Wang, Dongjun, Zhao, Jie, Wang, Bao, and Liu, Gang
- Subjects
- *
SINTERING , *ADDITIVES , *HIGH temperatures , *MICROSTRUCTURE - Abstract
To manufacture hard-to-deform intermetallics and their components at high temperatures and for a short-time, a novel additive sintering method based on solid-state powder densification is proposed, which aims to achieve the fabrication and joining of intermetallics. In this study, the sintering and joining of NiAl/NiAl and NiAl/TiAl alloys were conducted using this method. The results show that good bonding was achieved between similar intermetallics of NiAl/NiAl. Nevertheless, due to the formation of brittle phases, defects were observed in the bonding interface of the NiAl/TiAl alloy. An interlayer of V was employed to optimize the microstructure of the interface, which can prevent the formation of the brittle phase and improve the property of the interface. • A additive sintering method is proposed to manufacture dissimilar-material component. • The method can achieve fabrication and joining of dissimilar material simultaneously. • V foil as interlayer eliminates brittle IMCs at the joining interface of NiAl/TiAl. • The NiAl/V/TiAl sample shows significantly improved interfacial property. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
50. Study of the microstructure evolution of alloy structural steel and inhomogeneity effect of the microscale pulsed currents during current-assisted plane strain compressions by modeling a novel cellular automata method.
- Author
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Chen, Can, Xia, Qinxiang, Zhou, Haoyang, Zhao, Jie, Qin, Yi, and Xiao, Gangfeng
- Subjects
- *
CELLULAR automata , *GRAIN refinement , *MODEL airplanes , *MICROSTRUCTURE , *CURRENT distribution , *STRUCTURAL steel - Abstract
The current-assisted forming process is considered to be a novel process that utilizes the electroplasticity effect to reduce the deformation resistance of difficult-to-deform metals and to refine the grain size while improving the mechanical properties of the part. However, the lack of understanding of the mechanisms by which pulsed current affects grain refinement still makes it difficult to experimentally develop analytical or empirical models of the relationship between grain size, pulse current parameters, and deformation amount. It will seriously hinder the further development and application of the current-assisted forming process. To reveal the mechanism of grain refinement coupling with electroplasticity, a series of Electron Back Scattering Diffraction observation tests were carried out after current-assisted plane strain compressions. The results show that the grain orientation spread value of the pulse current condition is lower than that of the non-current condition, while the refined grain area percentage is higher than that of the non-current condition. Based on the microstructure observation results, a cellular automata model for grain refinement is proposed. This consists of a dislocation density evolution, sub-grains generation, grain fragmentation, and a grain orientation rotation algorithm. To study the electroplasticity of the grain refinement process, the cellular automata model is also embedded with a finite difference numerical algorithm for solving the microscopic current density distribution of the model. The cellular automata model simulation results show that the error of grain size accuracy of this cellular automata model under non-current and pulse current conditions is 10.48% and 8.55%, respectively. It shows that the model can accurately characterize the grain refinement behavior of the current-assisted plane strain compression. The simulation results reveal the deep mechanism of pulsed current promotion on grain refinement, i.e., an inhomogeneous microstructure leads to uneven distribution of pulse current density. The inhomogeneous current distribution will further increase the grain refinement rate in the coarse-grained regions, thus increasing the proportion of the refined grain regions in the microstructure and leading to a relatively more homogeneous microstructure under pulse current conditions. The cellular automata model accurately reveals the mechanism of electroplasticity on the grain refinement. The model will serve as a crucial theoretical reference in designing current-assisted forming process routes to ensure excellent microstructure and properties in manufactured parts. It will enhance the widespread utilization of current-assisted forming process. [Display omitted] • The acceleration effect of pulse current on grain refinement was verified by the CAPSC tests. • There is a positive correlation between the intensity of the electroplastic effect and the degree of grain refinement. • An innovative cellular automaton model for grain refinement was constructed using the grain fragmentation theory. • The model introduces a pulsed current accelerated grain orientation rotation mechanism to couple the electroplasticity. • The inhomogeneous current density distribution will promote the production of a more homogeneous microstructure. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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