T. Imai
,
L. Geng
,
J. F. Mao and I. Tochigi 1) National Industrial Research Institute of Nagoya
,
1-1 Hirate-cho
,
Kita-ku
,
Nagoya
,
462-8510
,
Japan 2) School of Materials Science & Engineering
,
Harbin Institute of Technology
,
Harbin 15001
,
China 3) Kanagawa High-Technology Foundation
,
Kanagawa Science Park
,
3-2-1
,
Sakado
,
Takatsu-ku
,
Kawasaki
,
Kanagawa 213
,
Japan
金属学报(英文版)
β-Si3N4 whisker reinforced aluminum composites was fabricated by squeeze casting before extrusion and an effect of content of Mg on the High Strain Rate Superplastic- ity (HSRS) were investigated, The optimum temperature of the composites at which maximum total elongation is obtained decreases according to magnesium content and the β-Si_3N_4w/Al-3Mg exhibits the total elongation of about 200% at the strain rate of 10~(-1) s~(-1) and at 853-858 K, although the β-Si_3N_4w/Al-0Mg composite shows about 100% elongation at the strain rate of about 1×10~(-1) s~(-1) at 903-913 K. Optimum strain rate of the composites fabricated by squeeze casting was about 1×10~(-1) s~(-1) but TEM observation indicates that the β-Si_3N_4w/Al-Mg has a fine grain of about 2- 3μm and that the whisker might no react with Mg at the interfaces, although the β-Si_3N_4 whisker react with aluminum matrix.
关键词:
high strain rate superplasticity
,
null
,
null
J. C. Feng
,
M. Naka
,
J. C. Schuster(School of Materials Science and Engineering
,
Harbin Institute of Technology
,
Harbin
,
150001
,
China
,
Joining and Welding Research Institute
,
Osaka University
,
Mihogaoka 11 - 1
,
Ibaraki
,
Osaka 567
,
Japan
,
Institute of Physical Chemistry
,
University of Vienna
,
Austria )
金属学报(英文版)
Bonding of SiC to SiC using Ni and Ni - 25at%Cr foils was performed at high temperature.Interface structures and reaction phases were investigated by EPMA analyses and XRD diffraction method, re- spectively. At a bonding temperature of 1273K Ni reacts with SiC and forms various Ni silicides con- taining graphite baside SiC. Ni3Si without graphite was formed at Ni side.The interface structure of SiC/Ni joint was SiC/Ni2Si + C/Ni31 Si12 + G/Ni3 Si/Ni. At the interface between SiC and Ni- 25at%Cr alloy the Ni silicide was only Ni2Si at the same bonding temperature,and further(Cr, Ni)7 (Si, C)3 carbide was formed between Ni silicide + graphite zone and Ni - 25at%Cr alloy.The interface structure of SiC/Ni - 25at%Cr alloy was SiC/Ni2Si + C/(Cr, Ni)7 (Si, C)3+Ni(ss. Cr, Si)/Ni - 25at%Cr.
关键词:
interfacial structure
,
null
,
null
,
null
C.L. Chu
,
G.J. Shen
,
S.D. Wang
,
B. Li
,
S.G. Zhang and Z.D. Yin(BOX 433
,
School of Materials Science and Engineering
,
Harbin Institute of Technology
,
Harbin 150001
,
China)(Analysis and Testing Center
,
Southeast University
,
Nanjing 210018
,
China)(Research Institute of Electric Light Source Materials
,
Ministry of Light Industry
,
Nanjing 210015
,
China)
金属学报(英文版)
From the orientation relationship between "Ti11Ni14" phase and matrix phase (B2),the accurate molecular formula of "Ti11N14" phase has been derived in this paper. The results also show that the rhombohedral unit cell of the "Ti11Ni14" phase includes six Ti atoms, seven Ni atoms and one vacancy, belonging to space group R3.
关键词:
TiNi
,
null
,
null
J. T. Niu
,
H. T. Li
,
X. D. Meng and P. Karjaleinen 1) Analysis and Measurement Center
,
Harbin Institute of Technology
,
Harbin 150001
,
China 2) Department of Mechanocal Engineering
,
The University of Oulu
,
Finland
金属学报(英文版)
With the development of modern science and technology, especially computer science, the numerical simulation method has been widely used in material hot-working. Mary achievements have been made in this field by using the numerical simulation method. The numerical simulation method, especially finite element method fully described in this paper.Applications of the numerical simulation method in material hot-working are also discussed. Finally, the future of the numerical simulation method is outlined.
关键词:
numerical simulation
,
null
,
null
Yiyong WU
,
Yongqian WANG
,
Yongzhong ZHANG and Mei YAO (School of Materials Science and Technology
,
Harbin Institute of Technology
,
Harbin
,
150001
,
China)Xinguo HU(Applied Chemical Department
,
Harbin Institute of Technology
,
Harbin
,
150001
,
China)
材料科学技术(英文)
Initial process is influenced by substrate microstructure according to the study of initial stage of electroless plating on low carbon steel and pure iron. For low carbon steels, depositing on cementite is prior to that on ferrite, and for pure iron, the grain boundaries and some favourable grains are deposited more easily. The initial reactions of electroless depositing of Ni-P alloy have been tentatively proposed
关键词:
G.P. Li
,
D. Li
,
Y. Y. Liu
,
Q.J. Wang
,
S.X. Guan
,
and Q.C. Li (Institute of Metal Research
,
The Chinese Academy of Sciences
,
Shenyang 110015
,
China)(School of Materials Science and Engineering
,
Harbin Institute of Technology
,
Harbin 150001
,
China)
金属学报(英文版)
The Ti-35V-15Cr-0.05C (wt% is a new nonburning titanium alloy. The test for alloy combustibility was carried out by using CO2 laser. A 430 watt and 6mm diameter laser spot impinges directly on the sample within normal atmospheric pressure and temperature. The results show that the ignition time of the nonburning titanium alloy is the longest in the eight examined titanium alloys, and is 3.5 times that of TC4 alloy. The ignition tempeerature of the nonburning alloy is 2991° C, and is higher than that of TC4 alloy by 1976°C. On the condition of high tempeerature and rich oxygen,the surface of alloy forms a melting layer which plays roles of oxygen insulation, heat insulation and burning products insulation. This is the mechanism of combustion resistance.
关键词:
Ti-35V-15Cr-0.05C (wt%) nonburning titanium alloy
,
null
X.B. Tian
,
X.F. Wang
,
A.G. Liu
,
L.P. Wang
,
S. Y. Wang
,
B. Y. Tang and P. K. Chu 1)Advanced Welding Production & Technology National Key Laboratory
,
Harbin Institute of Technology
,
Harbin 150001
,
China 2)Department of Physics & Materials Science
,
City University of Hong Kong
,
China
金属学报(英文版)
The research on plasma immersion ion implantation has been conducted for a little over ten years. Much is needed to investigate including processing technlogy, plasma sheath dynamics, interaction of plasma and surface, etc. Of the processing methods elavated temperature technique is usually used in PIII to produce a thick modified layer by means of the thermal diffusion. Meanwhile plasma ion heating is more recently developed by Ronghua Wei et al[1]. Therefore the temeperature is a critical parameter in plasma ion processing. In this paper we present the theoretical model and analysize the effect of imlantation voltage, plasma density, ion mass,etc on the temperature rise.
关键词:
plasma immersion ion implantation
,
null
,
null