材料期刊网

IMPROVEMENT ON FATIGUE LIFE OF ALLOY LY12CZ AFTER LASER RADIATION AND ITS DAMAGE EVOLUTION

ZO U Hongcheng DAI Shujuan QIAN Zhixiong LI Guangxia Huazhong University of Science and Technology , Wuhan , China [Originally published in ACTA METALL SIN(CHINESE EDN)25(3)1989 pp A207—A212 , Associate Professor , Division of Materials , Huazhong University of Science and Technology , Wuhan , China

金属学报(英文版)

The change of microstructure of fatigue specimens before and after laser radiation was studied by transmission electron microscopy.The results show that the diameter of dislocation cell λ tends to a constant at fatigue failure.Based on the principles of continuous damage mechanics,expressions of the fatigue damage criterion and processes of fatigue damage evolu- tion for L Y12CZ have been derived.

关键词: laser radiation , null , null , null

Huazhong University of Science and Technology(H.U.S.T)

材料科学技术（英）

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University of Science and Technology Beijing

JIA Shizhen University of Science and Technology Beijing , China.

材料科学技术（英）

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Abstracts of papers from Journal of University of Science and Technology Beijing

稀有金属（英文版）

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欢迎投稿、订阅《Journal of Wuhan University of Technology-Materials Science Edition》

武汉理工大学学报-材料科学版(英文版)

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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

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）

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U720Li合金高温变形行为及变形机理研究

周舸 , 丁桦 , 韩寅奔 , 曹富荣 , 曲敬龙 , 张北江

稀有金属材料与工程

对U720Li合金的高温变形行为进行了系统的研究.通过对该合金高温变形过程中力学行为特征及组织演变规律的分析与计算,得出了不同应变速率、不同变形温度下应变速率敏感性指数m值、变形激活能Q值和晶粒指数P值的变化规律.分别绘制动态材料模型热加工图及包含位错数量的U720Li合金高温变形机理图.应用动态DMM热加工图分析了合金的适合加工区间.运用U720Li合金高温变形机理图,根据不同温度下U720Li合金柏氏矢量补偿的晶粒尺寸、模量补偿的应力值预报了该合金的高温变形机理.

关键词: U720Li合金 , 变形激活能Q , 应变速率敏感性指数m , 晶粒指数p , 加工图 , 变形机理图

定向凝固U720Li合金的高温塑性变形行为^*

高博 , 王磊 , 梁涛沙 , 刘杨 , 宋秀 , 曲敬龙

金属学报 doi:10.11900/0412.1961.2015.00374

采用热模拟实验研究了定向凝固与等轴晶U720Li合金的高温塑性变形行为, 利用OM, SEM和EBSD分析了不同变形条件下合金的组织特征及动态再结晶机制. 结果表明, 定向凝固与等轴晶合金的变形抗力均随变形温度升高而降低. 定向凝固U720Li合金沿垂直柱状晶方向变形时变形抗力较低, 枝晶间协调变形能力良好, 未出现裂纹. 与等轴晶合金相比, 相同变形条件下定向凝固合金的动态再结晶组织均匀; 高温塑性变形过程中, 定向凝固合金的动态再结晶主要以晶界弓弯和位错塞积方式形核. 定向凝固U720Li合金的变形激活能为766 kJ/mol, 比等轴晶合金降低了38.6%, 定向凝固合金呈现出更好的热加工特性.

关键词: 定向凝固 , U720Li合金 , 热加工塑性 , 动态再结晶

定向凝固U720Li合金的高温塑性变形行为

高博 , 王磊 , 梁涛沙 , 刘杨 , 宋秀 , 曲敬龙

金属学报 doi:10.11900/0412.1961.2015.00374

采用热模拟实验研究了定向凝固与等轴晶U720Li合金的高温塑性变形行为,利用OM,SEM和EBSD分析了不同变形条件下合金的组织特征及动态再结晶机制.结果表明,定向凝固与等轴晶合金的变形抗力均随变形温度升高而降低.定向凝固U720Li合金沿垂直柱状晶方向变形时变形抗力较低,枝晶间协调变形能力良好,未出现裂纹.与等轴晶合金相比,相同变形条件下定向凝固合金的动态再结晶组织均匀;高温塑性变形过程中,定向凝固合金的动态再结晶主要以晶界弓弯和位错塞积方式形核.定向凝固U720Li合金的变形激活能为766 kJ/mol,比等轴晶合金降低了38.6％,定向凝固合金呈现出更好的热加工特性.

关键词: 定向凝固 , U720Li合金 , 热加工塑性 , 动态再结晶