材料期刊网

THE MECHANICAL BEHAVIOR OF LABORATORY CROSS-WELD SPECIMEN AND ITS RELATION WITH THE PRACTICAL CASES AT ELEVATED TEMPERATURE

Author S.T. TU , J.M. Gong and X. Ling Nanjing University of Chemical Technology , Nanjing 210009 , ChinaManuscript received 18 October 1998

金属学报(英文版)

In order to interpret the test results of crossweld specimens for application in practical welded components, the present paper studies the high temperature behavior of laboratory cross weld specimens in terms of the uniaxial material tests and numerical simulations. It is found that the crossweld specimen may be used for the high temperature strength assessment, but can hardly be used for life assessment of the practical welded components, which depends on the loading conditions of the components.

关键词: high temperature , null , null , null , null

University of Science and Technology Beijing

JIA Shizhen University of Science and Technology Beijing , China.

材料科学技术（英文）

关键词:

CORRELATION BETWEEN STRESS COMPONENTS AND STRESS CORROSION CRACKS IN BRASS Lecturer,Department of Materials Physics,University of Science and Technology Beijing,Beijing 100083,China

QIAO Lijie LIU Rui XIAO Jimei University of Science and Technology Beijing , Beijing , China

金属学报(英文版)

The effects of stress components on nucleation sites and propagation directions of stress cor- rosion cracks in brass were investigated with specimens under mode Ⅱ and mode Ⅲ loadings. The results indicated that under mode Ⅱ loading,stress corrosion cracks nucleated on the site with maximum normal stress component and propagated along the plane perpendieular to the maximum normal stress,under mode Ⅲ loading,the stress corrosion crack was not evident on the 45°plane due to the general corrosion in aqueous solution with high NH_4OH concentra- tion,while stress corroded in aqueous solution with low NH_4OH concentration, numerous cracks with spacings of 10—150μm were found on the 45°plane with maximum normal stress and no stress corrosion cracks was observed on the plane with maximum shear stress.

关键词: stress corrosion cracking , null , null , null

First principles study of the alloying effect on chemical bonding characteristics of helium in La-Ni-M tritides

Materials Science and Engineering B-Solid State Materials for Advanced Technology

The alloying effect on the electronic structure of La-Ni-M tritides is investigated using the first principles discrete variational X alpha(DV-X alpha) method. The calculated results show that the covalent interaction between atoms will play a much more important role in studying the alloying effect on chemical bonding characteristics in La-Ni-M tritides than ionic interaction. It is also found that in La-Ni-M tritides helium forms stronger covalent bonds with the weaker hydride forming elements than La. By analyzing the relation between the binding energy difference and bond order, our study indicates that after some alloying elements substituting for Ni locating in 3g site in tritides, the helium retention capability becomes stronger, changes as the following sequence: Al > Cr > Mn > Fe > Co > Ni, and is also very distinct for Cu although the chemical bonding between Cu atom and Ni atom is degraded drastically. (c) 2005 Published by Elsevier B.V.

关键词: tritides;electronic structure;chemical bonding;helium retention;iron grain-boundary;intermetallic compounds;electronic-structures;neutron-scattering;hydrogen storage;metal tritides;al tritides;hydrides;dynamics;behavior

M40J和T300碳纤维的微结构

孙银洁 , 胡胜泊 , 李秀涛

宇航材料工艺 doi:10.3969/j.issn.1007-2330.2010.02.027

利用SEM、TEM、XPS、XRD、Raman和元素分析仪分析了M40J和T300的表面化学、物理及微观结构特征.研究发现:M40J含碳量高于T300纤维,而含氮量低于T300纤维,且表面活性基团比T300纤维低;M40J和T300碳纤维表面具有大量沟槽,前者相对长而浅,后者相对短而深;T300纤维端面皮芯结构明显,而M40J端面结构较均匀;M40J的微晶结构及取向性优于T300碳纤维.

关键词: M40J碳纤维 , 微观结构 , 化学特征 , 物理特征

卫星构件用M40J/BA204复合材料性能

韩建平 , 秦滢杰 , 高伟 , 刘新东

宇航材料工艺 doi:10.3969/j.issn.1007-2330.2014.05.010

针对卫星构件的不同需求,开发了一种芳香胺固化的环氧树脂BA204.研究了无溶剂及溶剂法成型的M40J/BA204复合材料力学、真空放气性能和管件在模拟温度交变条件下的性能变化情况.结果表明:两种方法制备的复合材料力学性能均能满足卫星构件要求,无溶剂法制备的复合材料力学性能优于溶剂法.采用无溶剂法制备的M40J/BA204复合材料其真空质损率为0.23％,可收集挥发性凝聚物为0.009％;复合材料管件经200次热循环冲击后力学性能变化不大,表明M40J/BA204复合材料具有良好的热稳定性.

关键词: 卫星构件 , M40J/BA204复合材料 , 纤维缠绕 , 无溶剂法

M40J/CE/EP复合材料出气性能研究

惠雪梅 , 王晓洁 , 尤丽虹 , 王益 , 全小平

宇航材料工艺 doi:10.3969/j.issn.1007-2330.2006.z1.011

通过地面环境模拟实验,分析了高模碳纤维/环氧树脂改性氰酸酯复合材料(M40J/CE/EP)的表面元素,研究了高真空加热环境下复合材料的真空出气性能和出气气体成分.结果表明,M40J/CE/EP复合材料的表面主要由C、O、N元素构成;经高真空加热后,复合材料的出气气体成分以小分子挥发物和碳氢化合物电离碎片为主,有可能在空间低温条件下冷凝在航天器的敏感器件表面而造成污染;通过真空出气性能实验测得,M40J/CE/EP复合材料的总质量损失(TML)的平均值为0.27%,收集到的可凝挥发物(CVCM)为0,完全达到出气筛选合格的指标要求.

关键词: 氰酸酯树脂 , 复合材料 , 出气 , X射线光电子能谱

电子束固化M40J/EB99-1复合材料性能研究

包建文 , 徐松华 , 李晔 , 陈祥宝

材料工程 doi:10.3969/j.issn.1001-4381.2003.05.005

研究了电子束固化高模量石墨化碳纤维M40J增强EB99-1环氧树脂复合材料的常规力学性能、耐热疲劳性能和热物理性能.结果表明,电子束固化M40J/EB99-1复合材料具有比热固化M40J/5228和M40/4211复合材料优异的综合力学性能和耐热疲劳性能.

关键词: 电子束固化 , 复合材料 , 石墨纤维 , 力学性能

耐深低温、高补偿量新型磁温补偿合金1J30M的研制

宁波 , 赵宇 , 李波

钢铁研究学报

磁温补偿合金1J30经深低温处理后合金中的部分奥氏体转变为马氏体,致使合金的磁温补偿能力下降.通过调整镍含量,同时添加铬,得到了新型磁温补偿合金1J30M.这种新型磁温补偿合金既具有1J30合金的磁温补偿能力,又具有1J32合金的耐深低温能力.

关键词: 磁温补偿合金 , 深低温 , 马氏体相变

通过J/Ψ→N(N-)M衰变研究N*时的核子极点效应

沈彭年 , 梁伟红 , 邹冰松

原子核物理评论 doi:10.3969/j.issn.1007-4627.2004.02.009

研究了J/Ψ→ p(p-)π衰变过程中核子极点图的贡献,特别是由离壳效应带来的贡献.发现衰变宽度对形状因子是敏感的.在通过用J/Ψ→ p(p-)π衰变研究N*时,核子极点图作为背景道的贡献是非常重要的; 在通过J/Ψ→ p(p-)η和 p(p-)η研究N*时,核子极点图的贡献可忽略不计; 在通过J/Ψ→ p(p-)ω研究N*时,核子极点图有明显的贡献.

关键词: J/Ψ衰变 , 核子激发态