材料期刊网

INVESTIGATION ON THIN-WALL EFFECT OF A DIRECTIONALLY SOLIDIFIED SUPERALLOY BY USING TUBULAR SPECIMENS

R.Z.Chen and H. W. Zhang(Beijing Institute of Aeronautical Materials , Beijing 100095 , China Manuscript received 26 August 1996)

金属学报(英文版)

The thin-wall effect of DZ25G, a directionally solidified (DS) superalloy, has been studied by ustng tubular investment cast thin-wall specimens with shape and wall thickness near the air-cooled hollow blades.The results show that the stress-rupture properties of the thin-wall specimens (thickness 0.8, 1.2 and 1.6 mm) are equivalent to the standard ones (diameter 5 mm),i.e., under the experimental conditions in this study the alloy DZ25G has insignificant thin-wall effect. It is apparent that the resulte are different from previous work. In the paper the reasons resulting in the difference were discussion in terms of the specimen manufacture process and thus microstructure feature.

关键词: :DS superalloy , null , null , null

Ion sputter erosion in metallic glass-A response to "Comment on: Homogeneity of Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass" by L-Y. Chen, Y-W. Zeng, Q-P. Cao, B-J. Park, Y-M. Chen, K. Hono, U. Vainio, Z-L. Zhang, U. Kaiser, X-D. Wang, and J-Z Jiang J. Mater. Res. 24, 3116 (2009)

Journal of Materials Research

The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.

关键词: room-temperature

R & D ACTIVITIES ON AEROSPACE MATERIALS IN KOREA

H.M. Kim(Korea Institute of Machinery and Materials , Korea Manuscript received 26 August 1996)

金属学报(英文版)

This paper briefly reviews research and development programs in Korean aerospace industry,with an emphasis on aircraft materials technology. International collaborations in these areas are outlined and the R & D activities are highlighted against the　background of the national economy.It is shown that the investment from government agencies and large enterprises has led to healthy development of aerospace materials industries in Korea.

关键词: :R & D , null , null , null

MICROSTRUCTURE AND PROPERTIES OF SiC_w/6061Al COMPOSITE The Author is now with Institute of Metal Research,Academia Sinica,China

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

Institute of Materials Science at Jilin University——A Brief Overview

WANG Yuming Institute of Materials Science , Jilin University , Changchun , 130023 , China

材料科学技术（英文）

关键词:

Image analysis of periodic rain accelerated corrosion of aeronautical aluminium alloys

Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing

Periodic rain tests have been carried out for simulating atmospheric corrosion of aeronautical aluminium alloys. A digital image preprocessing and analysis method based on wavelet transformation was used to study the corrosion morphology of aluminium alloys samples, through which an image feature parameter 8 was extracted and discussed. The influences of orthogonal experiment parameters on acceleration were analyzed according to image feature parameter 6 with analysis of variance (ANOVA) method, and the optimal parameters for accelerated corrosion test were also obtained. The result was shown to be consistent with that from weight loss method. (c) 2007 Elsevier B.V. All rights reserved.

关键词: aeronautical aluminium alloys;accelerated corrosion;linage analysis;simulated environment;atmospheric corrosion;electrochemical impedance;pitting corrosion;exposure;steel;zinc

抗HIC压力容器用钢Q345R-Z35特厚板的开发

许少普 , 崔冠军 , 李治强 , 杨东 , 庞百鸣 , 张智慧

钢铁研究

采用模铸浇注、3 800 mm轧机轧制、正火热处理工艺成功地开发并批量生产了82 mm厚Q345R-Z35锅炉压力容器用钢板,钢板超声波探伤全部符合JB/T 4730--2008一级标准,钢板屈服强度平均为350 MPa,抗拉强度平均为520 MPa,伸长率平均值为28%,平均冲击功为144 J,抗层状撕裂厚度拉伸性能全部合格,抗氢致开裂性(HIC)试验检测结果表明:裂纹敏感率、裂纹长度率、裂纹宽度率均为0.

关键词: 抗氢致裂纹 , 抗层状撕裂 , 特厚压力容器板

Preparation and Arc Breakdown Behavior of Nanocrystalline W-Cu Electrical Contact Materials

Wenge CHEN

材料科学技术（英文）

Nanostructured (NS) W-Cu composite powder was prepared by mechanical alloying (MA), and nanostructured bulk of W-Cu contact material was fabricated by hot pressed sintering in an electrical vacuum furnace. The microstructure, electric conductivity, hardness, breakdown voltage and arcing time of NS W-Cu alloys were measured and compared to conventional W-Cu alloys prepared by powder metallurgy. The results show that microstructural refinement and uniformity can improve the breakdown behavior, the electric arc stability and the arc extinction ability of nanostructured W-Cu contacts materials. Also, the nanostructured W-Cu contact material shows the characteristic of spreading electric arcs, which is of benefit to electric arc erosion.

关键词: Nanostructured materials , null , null , null

快速凝固Al—Li─Cu—Mg—Zr合金中H相和Z相的TEM研究

张立春 , 何安强 , 叶恒强 , 张永昌

材料研究学报

用HRTEM、TEM及EDAX分析研究了Al─Li—Cu—Mg—Zr合金中的一种新相(暂名H相)和六角Z相的结构,确定H相具有四方点阵,点阵参数为α=2.8nm,c=2.4nm,EDAX分析表明H相和Z相均含Al、Mg、Cu发现H相与Z相的共存取向关系为[100]‖[1120]Z,[1010]H‖[0001]Z。还观察到Z相中一种特有的旋转畴结构

关键词: Al─Li─Cu─Mg─Zr合金.四方H相 , tetragonal H phase , hexagonal Z phase

合金元素对低合金高强度H型钢Z向性能的影响

李虎 , 王作成 , 薛长深 , 庄栋栋 , 王晓 , 张思勋

材料热处理学报

为了研究钢中合金元素Nb、B、Ni对低合金高强度H型钢抗层状撕裂能力(Z向性能)的影响,设计了对照试验,通过常温下拉力试验,对其力学性能尤其是断面收缩率进行了测试,使用XRD、SEM、TEM以及EDS对其组织和成分进行了分析.结果表明:微合金元素Nb、B和微量元素Ni对钢材的Z向性能产生了明显的不良影响,含有Nb、B和Ni,经过钢包精炼的Q345E钢的Z向性能显著低于不含Nb、B和Ni,未经钢包精炼且含有较多夹杂物的Q345B钢.其原因主要在于Nb、B、Ni的存在阻碍了钢材变形过程中位错在晶界和晶内的移动.

关键词: 低合金高强度钢 , Z向性能 , 合金元素 , 夹杂物 , 阻碍位错