高温短时人工时效对2524合金疲劳性能的影响  

Effect of artificial ageing on fatigue behaviour of 2524 aluminum alloy

作　　者：刘志义[1,2] 周杰[1,2] 刘延斌[1,2] 李云涛[1,2] 段水亮[1,2] 柏松[1,2] 邓才智[1,2] 

机构地区：[1]中南大学有色金属材料科学与工程教育部重点实验室,湖南长沙410083 [2]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2009年第1期112-116,共5页Journal of Central South University:Science and Technology

基　　金：国家"973"重点基础研究发展资助项目(2005CB623705-04)

摘　　要：研究高温短时时效对2524合金室温拉伸及疲劳性能的影响,采用3DAP分析、透射电镜等对合金组织进行观察。结果表明:经过高温短时时效试样的抗拉强度与自然时效试样的相当,但是塑性有很大的提高;高温短时时效后试样的疲劳裂纹扩展速率比自然时效试样低。经过高温短时人工时效的2524合金组织中Cu和Mg原子发生强烈偏聚形成圆盘状的GPB区,尺寸较大,这种人工时效组织既能提高应力循环下的裂纹张开扩展阻力,又不影响裂纹闭合,从而降低疲劳裂纹扩展速率。The effects of artificial ageing on the fatigue crack propagation and room mechanical properties of 2524 aluminum alloy were investigated. The results of tension test at room temperature show that the elongation of samples artificially aged at high temperature for short time is much higher than that of naturally aged samples, at the same time, both of the high temperature-short time artificial aged and naturally aged samples have the similar tensile strength. The fatigue crack growth rate tests indicates that the fatigue crack growth of high temperature-short time artificially aged samples decreases. 3DAP （three-dimensional atom probe） analysis suggests that a bigger size and a plate-shaped Cu-Mg clusters form when artificially aged at high temperature for short time. These GPB zones can improve the fatigue crack propagation resistance of 2524 aluminum alloy, however the crack closure does not change.

关 键 词：2524合金 高温短时时效 疲劳裂纹扩展 GPB区 裂纹闭合 

分 类 号：TG146[一般工业技术—材料科学与工程]