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Your search keyword '"Jin, Yunxue"' showing total 123 results
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123 results on '"Jin, Yunxue"'

2. Microstructure and properties of Cu-Sn-Zn-TiO2 Nano-composite coatings on mild steel

Author

Gao, Weidong, Cao, Di, Jin, Yunxue, Zhou, Xiaowei, Cheng, Guang, and Wang, Yuxin

Subjects
Physics - Applied Physics, Condensed Matter - Materials Science
Abstract

Cu-Sn-Zn coatings have been widely used in industry for their unique properties, such as good conductivity, high corrosion resistance and excellent solderability. To further improve the mechanical performance of Cu-Sn-Zn coatings, powder-enhanced method was applied in the current study and Cu-Sn-Zn-TiO2 nano-composite coatings with different TiO2 concentration were fabricated. The microstructure of Cu-Sn-Zn-TiO2 nano-composite coatings were investigated by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The mechanical properties of coatings including microhardness and wear resistance were studied. The results indicate that the incorporation of TiO2 nanoparticle can significantly influence the properties of Cu-Sn-Zn coatings. The microhardness of Cu-Sn-Zn coating was increased to 383 HV from 330 HV with 1g/L TiO2 addition. Also, the corrosion resistance of coating was enhanced. The effects of TiO2 nanoparticle concentration on the microstructure, mechanical properties and corrosion resistance of Cu-Sn-Zn-TiO2 nano-composite coatings were discussed.

Published
2017

23. Fabrication and Properties of Ni3Si-TiC Composites by In Situ Reaction Sintering.

Author

Niu, Muye, Bao, Shuai, Wu, Jianjie, Zhang, Xinghua, Chen, Hao, and Jin, Yunxue

Subjects
MECHANICAL wear, MATERIAL fatigue, SPECIFIC gravity, SINTERING, FRETTING corrosion, ALLOY fatigue, TRIBOLOGY
Abstract

Ni3Si-based composites with different TiC contents are fabricated by in situ reaction sintering method. The phase composition, microstructure, microhardness, and tribological properties of the composites are studied. The results show that the addition of TiC particles prevents the formation of γ-Ni31Si12 phase, and the composites mainly consist of β1-Ni3Si and TiC phases. The composites have high hardness and relative density, and the values are above 580 HV and 87%, respectively. The friction coefficients are as low as 0.22. The wear rates of the composites are in the order of 10–6 mm3 m−1, which are two orders of magnitude lower than that of Ni3Si alloy. The primary wear mechanism of Ni3Si alloy is oxidation wear and slight abrasive wear, and the composites with TiC addition are oxidation wear and fatigue wear. The incorporation of TiC particles improves the tribological performance of Ni3Si alloy significantly. The composite with 20 wt.% TiC has the optimal tribological property. [ABSTRACT FROM AUTHOR]

Published
2023
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26. Friction and Wear Performance of in-Situ (TiC+TiB)/Ti6Al4V Composites

Author

Jin Yunxue, Chen Yanan, Bai Xue, and Lu Xuan

Subjects
In situ, 0209 industrial biotechnology, Materials science, Scanning electron microscope, Abrasive, General Engineering, Titanium alloy, 02 engineering and technology, Wear testing, 021001 nanoscience & nanotechnology, Wear resistance, 020901 industrial engineering & automation, Small range, Profilometer, Composite material, 0210 nano-technology
Abstract

(TiC+TiB)/Ti6Al4V composites with different TiC and TiB contents were prepared by in situ synthesis. The influence of load on the dry sliding friction and wear performance of in-situ (TiC+TiB)/Ti6Al4V composites (TMC) was studied by HT-1000 friction and wear testing machine, and the wear behavior of the composites was also investigated by scanning electron microscopy (SEM) and Bruker 3D profilometer. The results show that the wear resistance of TMC is improved by the formation of TiC and TiB phases compared to the Ti6Al4V matrix. For the composites with different volume fractions of reinforcing phases, the wear rate and wear depth increase with the increase of the applied load, and the friction coefficient decreases and fluctuates within a small range. Under low loads, the worn surface is covered with grooves and a small amount of wear debris; under heavy loads, the worn surface is covered with narrow and shallow grooves and a large amount of wear debris. The wear mechanism is abrasive wear and oxidation wear. As the load increases, the size of the debris increases.

Published
2018

27. Experimental and computational analysis of the two-step demagnetization behavior of the surface grains of sintered Nd-Fe-B magnets.

Author

Chen, Fugang, Zhang, Lanting, and Jin, Yunxue

Subjects
DEMAGNETIZATION, NEODYMIUM compounds, MAGNETS, KERR electro-optical effect, MAGNETIC properties, MAGNETIC fields
Abstract

The two-step demagnetization behavior was observed before the coercive field of a sintered Nd-Fe-B magnet with a large specific surface (S/V). The squareness factor of the demagnetization curve and the energy product decreased with the increase in the S/V, while the remanence and the coercivity were relatively independent of the S/V. The magneto-optical Kerr effect was used to study the magnetic properties of the magnet surface. The surface magnetization switched freely, while the bulk magnetization remained unchanged under a low cyclic magnetic field. Micromagnetic simulations revealed that the anti-demagnetization abilities of grains at the polar surface perpendicular to the c-axis were larger than those at the lateral surface parallel to the c-axis. The different anti-demagnetization abilities of the surface grains induced the initial two-step demagnetization behavior. [ABSTRACT FROM AUTHOR]

Published
2018
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36. The effect of high-current pulsed electron beam on phase formation and surface properties of chromium/copper system

Author

Peng Lv, Conglin Zhang, Jin Yunxue, Qingfeng Guan, Lei Li, Nana Tian, Huajun Zhu, and Zirun Yang

Subjects
010302 applied physics, Materials science, Passivation, chemistry.chemical_element, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Copper, Hardness, Crystallographic defect, Surfaces, Coatings and Films, Corrosion, Chromium, chemistry, 0103 physical sciences, Composite material, Dislocation, 0210 nano-technology, Instrumentation, Solid solution
Abstract

In this paper, high-current pulsed electron beam (HCPEB) irradiation was used as surface alloying of chromium/copper (Cr/Cu) system to improve the surface hardness and corrosion resistance. After surface alloying, an alloying layer with a spot of craters and plentiful crystal defects (eg. dislocation walls and cells) was prepared on the surface of sample. The existence of crystal defects induced by HCPEB irradiation offered a mass of diffused channels for Cr atoms to facilitate the formation of Cu (Cr) solid solution. Subsequently, partial solid solutions were decomposed to generate GP zone, lobe-shaped particles and spherical particles, which had the characteristic of relationship Nishiyama-Wassermann (N–W) and Kurdjumov-Sachs (K–S) orientation relationship with the Cu matrix. These features account for that surface hardening of Cr alloyed sample was significantly higher than that of W alloyed samples. The corrosion performance of the Cr-alloyed sample exhibited much stable corrosion resistance comparing with that of W-alloyed samples. The enhancement of passivation property was mainly resulted from the formation of more stable passive film, which was associated with the existence of the crystal defects and the alloying particles.

Published
2020

42. Effect of heat treatment on structure and properties of GTAW and laser beam welded super-duplex stainless steel joints.

Author

Qi, Kai, Wang, Guangjin, Jin, Yunxue, Gu, Jiayang, Zhang, Zhongyu, and Tao, Yanwu

Subjects
LASER welding, STAINLESS steel welding, STAINLESS steel, HEAT treatment, GAS tungsten arc welding, DUPLEX stainless steel
Abstract

Duplex stainless steel, consisting of ferrite and austenite, has good corrosion resistance and is often used in harsh marine environments. In this paper, welding on SAF2507 duplex stainless steel with 5 mm thickness was finished by laser beam welding (LBW) and gas tungsten arc welding (GTAW). The post-weld solid solution treatment was also conducted at temperature of 1 0 5 0 ∘ C followed with cooling by water after 1 h. The results showed that both LBW and GTAW could produce well-produced welds. The microstructures of the welds were composed of ferrite and austenite phases. After solid solution treatment at 1 0 5 0 ∘ C, the two-phase structure of LBW joint became uniform, while σ phase was produced in GTAW joint. The impact test of welded joints at room-temperature was carried out. After solid solution treatment at 1 0 5 0 ∘ C, the impact toughness of LBW joints obviously increased, but the impact toughness of GTAW joint decreased with the fracture morphology of brittle mode. The electrochemical experiments on the welded joints showed that the pitting corrosion resistance of LBW joints improved after solid solution treatment, while the pitting corrosion resistance of GTAW joints decreased. [ABSTRACT FROM AUTHOR]

Published
2020
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