J.T. Guo
,
L.Z. Zhou
,
Z.G. Liu and W.M. Yin(Institnte of Metal Research
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China Manuscript received 26 August 1996)
金属学报(英文版)
Ternary Ni-Al-Fe alloys with different Fe-additions have been synthesized by mechan ical alloying.The results show that 5 and 10 at% Fe-additions prolong the milling time prior to the explosive formation of NiAl(Fe) compound, 15 at.% Fe-addition results in the formation of an "amorphous-like" phase,20 at.% Fe-addition turns the final products to Ni(Al, Fe)supersaturated solid solution with fcc structure,and the increase of Fe-addition can speed up the formation of the solid solution.The addition of Fe improves the plastic deformation ability of the alloys.
关键词:
:mechanical alloying
,
null
,
null
MA Zongyi YAO Zhongkai Harbin Institute of Technology
,
Harbin
,
China
金属学报(英文版)
The SiC_w/Al composite prepared by squeeze casting has a combination of superior room temperature specific strength and modulus together with excellent thermal properties.The extrusion can make an improvement on the strength and ductility of the composite from 582 MPa as squeeze casted up to 639 MPa,and on the transformation from isotropic to the anisotropic structure.This seems to be explained by the orientation of whiskers and the densification of dislocations in matrix.TEM observation indicates that the stacking fault is the usual planar defect on the SiC_w surface. composite;;SiC whisker;;Al alloy;;microstructure
关键词:
composite
,
null
,
null
,
null
ZANG Qishan LIU Kang Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
ChinaKE Wei ZHENG Yuli Institute of Corrosion and Protection of Metals
,
Academia Sinica
,
Shenyang
,
China
金属学报(英文版)
Investigation was carried out of the crack growth rate in weld metal and heat affected zone (HAZ)of offshore structural steels,homemade steel 36Z together with foreign steel A537 of similar strength grade by comparison,in artificial sea water undergone fatigue with different frequencies.The crack growth rate in weld metal and HAZ of steel 36Z fatigued at low fre- queney may be 3—5 and 4—10 times as high as that at high frequency respectivley.The crack growth rate for steel 36Z may fairly match that of A537,The crack growth model and frac- ture of weld metal in corrosive medium were also discussed.
关键词:
weld metal
,
null
,
null
,
null
,
null
刘永
,
宋耀祖
工程热物理学报
本文采用M-Z干涉测量的方法,研究了半三角形翼片纵向涡发生器强化换热方案对矩形通道内气体流动换热的影响,获得了安装纵向涡发生器前后对流换热温度场的M-Z干涉图像.通过对实验获得的干涉图像进行分析处理,表明安装纵向涡发生器后,通道内入口段流动的热边界层明显变薄,反映了纵向涡对流动换热的强化作用,验证了将M-Z干涉测量方法应用于纵向涡强化换热研究的可行性.
关键词:
纵向涡
,
强化换热
,
M-Z干涉
,
热边界层
F. Pan
,
F. Zeng
,
B. Zhao
金属学报(英文版)
Ion beam assisted deposition technique (IBAD) was utilized to systematically studyamorphization in binary metal systems of Nb-magnetic element, i.e., Nb-M (M=Fe,Co or Ni). The glass forming range terned as Nb fraction of Nb-Fe system was about34at.% to 56at.%, that of Nb-Co system was about 32at.% to 72at.% and that of Nb-Ni about 20at.% to 80at.%. Similar percolation patterns were found in amorphousalloy films. The fractal dimensions of the percolation patterns approach to 2, whichindicates 2-D layer growth for amorphous phases. It is regarded that the assistedAr+ ion beam duringthe deposition process plays important role for the 2-D layergrowth. Some metastable crystalline phases were obtained in these three systems byIBAD, e.g., bcc supersaturated solid solutions in Nb-Fe and Nb-Co systems, fcc andhcp phases in Nb-Co and Nb-Ni systems. The formation and competing between theamorphous and the metastable crystalline phases were determined by both the phases'thermodynamic states in binary metal systems and kinetics during IBAD process.
关键词:
amorphization
,
null
,
null
,
null
Corrosion
This paper introduces the design of a localized corrosion rate monitoring instrument that can monitor and evaluate the maximum and stable localized corrosion rate of a nonpassivable metal in a corrosive environment by measuring the current density in a corrosion sensor with an occluded anode.
关键词:
instrument;localized corrosion rate;monitor
XU Xiangxing SU Yi ZHOU Wei Tsinghua University
,
Beijing
,
ChinaCAI Qigong Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
China XU Xiangxing
,
Dept.of Mechanical Engineering
,
Tsinghua University
,
Beijing
,
100084
,
China
金属学报(英文版)
The cleavage fracture mechanism of granular bainitie weld metal in 15MnVN steel has been investigated.SEM observation of a special specimen for revealing simultaneously fracture sur- face and microstructure shows that the cleavage of the weld is initiated by M-A constituent. The 95th percentile equivalent diameter of M-A constituent controls the cleavage fracture stress of the weld metal.
关键词:
granular bainite
,
null
,
null
,
null
郑凯
,
王艳丽
,
李时磊
,
吕绪明
,
王西涛
,
薛飞
金属学报
doi:10.3724/SP.J.1037.2012.00560
利用TEM和HRTEM研究了400℃热老化2×104 h后Z3CN20-09M不锈钢的微观组织,用纳米力学探针研究了微区力学性能.结果表明:相比于原始状态,经400℃热老化2×104 h后,Z3CN20-09M不锈钢中的铁素体发生了调幅分解并且析出了G相,导致铁素体的硬度增加和塑性变形能力下降.利用原位疲劳试验机、SEM和电子探针研究了400℃热老化2×104 h后Z3CN20-09M不锈钢的微型平板试样拉伸行为.结果表明:热老化后,不锈钢的屈服强度和断裂强度升高,延伸率下降.热老化不锈钢中铁素体发生解理断裂,微裂纹萌生于相界并向铁素体内扩展；奥氏体主要发生微孔聚集型韧性断裂,并且在局部区域发生撕裂.调幅分解是铁素体发生硬脆化和热老化前后Z3CN20-09M不锈钢拉伸断裂行为发生改变的根本原因.
关键词:
Z3CN20-09M不锈钢
,
热老化
,
调幅分解
,
G相
,
拉伸行为
李在元
,
顾惠敏
,
翟玉春
稀有金属材料与工程
用NH4OH 把H2WO4转化成(NH4)2WO4,再以CuSO4水溶液和(NH4)2WO4水溶液为反应物,用NH4OH和H2SO4调节pH值,进行W-Cu (70 g: 30 g)共沉淀反应,考察了pH值对W-Cu共沉淀回收率的影响;理论计算了pH值对W-Cu共沉淀回收率的影响.实验结果表明:Cu的回收率随pH值增大而提高,pH值大于6.0时,Cu的回收率有下降的趋势; W的回收率随pH值增大而降低;当pH值为5.2时,W和Cu的回收率相等,且只有一个相等点,此时两者的回收率大于99%,这与理论计算结果相符合.
关键词:
H2WO4
,
CuSO4·5
,
H2O
,
共沉淀
,
pH值
,
回收率
