YAN Yuhe YANG Yongqiang ZHAO Changming Tianjin Institute of Textile Science and Technology
,
Tianjin
,
ChinaWU Weitao WANG Maocai Institute of Corrosion and Protection of Metals
,
Academia Sinica
,
Shenyang
,
ChinaLU Mengfu Tianjin Institute of Science and Technology
,
Tianjin
,
China Lecturer
,
Laser Processing Lab.
,
Tianjin Institute of Textile Science and Technology
,
Tianjin 300160
,
China
金属学报(英文版)
Partially amorphous Ni-Nb alloy was made by 1.91 kW cw CO_2 laser melt-quenching, and fully amorphous by 4.5 kW and 4.9 kW.The corrosion resistance of the amor- phous layer was improved by adding Cr.Potentiodynamic polarization curves show that the amorphous Ni_(50)Nb_(40)Cr_(10) is in more corrosion-resistant than the amorphous Ni_(60)Nb_(40)and 18-8 stainless steel.
关键词:
Ni-Nb allay
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null
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XIA Zhenhai Hebei Institute of Technology
,
Tianjin
,
ChinaMAO Zhiying ZHOU Yaohe Northwestern Polytechnical University
,
Xi'an
,
China Doctor
,
Faculty of Foundry
,
Department of Mechanical Engineering No.2
,
Hebei Institute of Technology
,
Tianjin 300132
,
China
金属学报(英文版)
On the basis of fluid kinetics,a model for infiltration kinetics of liquid metals into fibre pre- fabricated composite has been proposed.The infiltration processing,together with the measurements of infiltrating velocity and permeability,for the C fibre-reinforced Al matrix composites have been studied.The model proposed seems to be in good agreement with the ex- perimental results.Two different infiltration modes,uniform and non-uniform,were found and a new technique was suggested.Thus,the quality composites of C fibre-reinforced Al may be made under low pressure regardless of non-wettability of liquid metal to the fibres.
关键词:
liquid metal
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null
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DAI Zurong LI Baocheng Taiyuan Institute of Mechanical Engineering
,
Taiyuan
,
ChinaWU Houzheng CHEN Yuru LIU Wenxi Tianjin University
,
Tianjin
,
China
金属学报(英文版)
A dynamic process of the martensitic transformation in(Y,Mg)-PSZ ceramics was observed in situ using TEM.Under the effect of contact stress between tetragonal(t)-ZrO_2 precipi- tates,a group of substructural martensite variants may occur priorly and then another one was induced by the elastic strain relaxation,both form(100)_m twins further.In addition,the crystallography of the martensitic transformation was also discussed.
关键词:
ceramics
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null
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null
WAMG Chunqi YANG Jiguang Tianjin University
,
Tianjin
,
China associate professor
,
Faculty of Foundry
,
Tianjin University.Tianjin 300072
,
China
金属学报(英文版)
Melted cast iron was inoculated by FeSi,then quenched to interrupt the dissolution, the non-metallic inclusions,in which the graphite phase was already occured,formed in the dissolution region,They dissolved into the melt soon,but the inclusions coated by graphite could exist for along time.The function of inoculant is to create an undercooling solution for carbon,thereby the non-metallic inclusions in the solution may be activated as the nuclei for graphite.
关键词:
inoculation
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null
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QI Yunxin TANG Wentai XIA Jianguo Nei Mongol Institute of Metallic Materials
,
Baotou
,
ChinaLI Wang ZHAN Zhenzong Institute of Physical and Chemical Engineering Research
,
Tianjin
,
China
金属学报(英文版)
The surface segregation of substrate elements through the Au layer in the Au-Ni-Kovar sys- tem specimens heated at 250—350℃ for 0.5—1.5 h has been studied by SAM and XPS. Visual evidence of the mechanism for Ni and Co surface segregation of the complicated sys- tem has been given,i.e.Ni and Co penetrated the gold layer mainly by grain boundary diffu- sion and then covered the Au layer by surface diffusion.The strdy results of the chemical states of surface segregation elements not only indicate that oxygen adsorption and oxidation reaction are the driving force for the surface segregation of Ni and Co,but also show that the above segregation can result in water absorption on surfaces.
关键词:
Au-Ni-Kovar alloy system
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null
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null
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null
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XU Bojun GU Nanju YAN Dianran YIN Fuxing Hebei Institute of Technology
,
Tianjin
,
China GU Nanju Division of Heat Treatment
,
Hebei Institute of Technology
,
Tianjin 300132
,
China
金属学报(英文版)
Using a self-made pulse magnetic field heat treatment equipment with low or medium intensi- ty,the tempering process of high speed steel W6Mo5Cr4V2 was investigated.It was found that the secondary hardening process and the transformation of retained austenite for the steel were accelerated by the pulse magnetic field,and the tempering period could be reduced to half of the original.It was shown by the analyses of X-ray and eletron microscopy that the precipitation of carbides becomes more homogeneous and dispersive,and the tetragonality of martensite increases obviousely,which causes the improvement of hardness and red-hardness for the steel.It was confirmed that the service life of tools as centre bits,screw taps and punches for nuts could be increased by 0.4 to 1.4 times by the tempering in magnetic field.
关键词:
pulse magnetic field
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null
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