耐热Al-Cu-Mg-Ag合金的高温蠕变行为  

High-temperature creep behavior of heat-resistant Al-Cu-Mg-Ag alloy

作　　者：欧林南 刘志义[1] 柏松[1] 何光宇 罗磊 曹靖 刘飞[1] 郭帅 OU Lin-nan;LIU Zhi-yi;BAI Song;HE Guang-yu;LUO Lei;CAO Jing;LIU Fei;GUO Shuai(School of Materials Science and Engineering,Central South University,Changsha 410083,China)

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《轻合金加工技术》2022年第2期24-30,共7页Light Alloy Fabrication Technology

基　　金：国家重点研究与发展计划项目(2016YFB0300900)。

摘　　要：通过蠕变试验、扫描电子显微镜和透射电子显微镜分析,对比研究了170℃下,蠕变应力(200 MPa、225 MPa、250MPa、275MPa、300MPa)对峰时效态Al-Cu-Mg-Ag合金蠕变行为的影响。结果表明:合金的稳态蠕变速率8对应力状态非常敏感,它们之间的关系符合幂指数关系:ε=e^(-64.81)σ^(8.99)。合金在不同应力下的蠕变断口特征类似,均为韧窝穿晶型断裂。TEM组织表现出明显的晶内位错滑移。合金的真应力指数为3,蠕变门槛应力值为160 MPa,在170C下的蠕变机制为位错滑移机制。The effect of creep stress(200 MPa,225 MPa,250 MPa,275 MPa,300 MPa)on the creep behavior of the peak-aged Al-Cu-Mg-Ag alloy at 1709C was investigated by a creep test,the scanning electron microscopy(SEM)and the transmission electron mi-croscopy(TEM)analysis.The results show that the steady creep rates of the alloy is very sensitive to the stress state,and the relationship between them conforms to the power expo-nent law:ε=e^(-64.81)σ^(8.99).The creep fracture characteristics of the alloy under different stresses are similar,which are all dimple transgranular fractures.The TEM structure shows obvious intragranular dislocation slip.The true stress exponent of the alloy is 3,the creep threshold stress is 160 MPa,and the creep mechanism of the alloy 170 C is the disloca-tion slip mechanism.

关 键 词：AL-CU-MG-AG合金 蠕变应力 蠕变本构方程 蠕变断裂行为 蠕变机制 

分 类 号：TG146.21[一般工业技术—材料科学与工程]