微量Sc对2099铝锂合金组织与性能的影响  

Effects of small addition of Sc on microstructure and properties of 2099 Al-Li alloy

作　　者：张海锋[1] 郑子樵[1] 林毅[1] 薛喜丽 罗先甫[1] 钟警[1] 

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：《中南大学学报（自然科学版）》2014年第5期1420-1427,共8页Journal of Central South University:Science and Technology

基　　金：国家重点基础研究发展规划("973"计划)项目(2012CB619563)

摘　　要：采用金相显微组织观察、扫描电镜观察、拉伸力学性能测试及透射电镜分析等手段研究添加微量Sc元素对2099铝锂合金的不同状态下组织、元素分布、力学性能和显微组织结构的影响。研究结果表明:微量钪元素的添加能够抑制再结晶的发生,使合金铸态、均匀化态及固溶态的晶粒粒度明显减小;拉伸断口出现明显分层现象,显著增强合金的时效强化效果,但对达到时效峰值所需的时间没有明显影响,合金时效响应速率明显减慢;微量钪元素的添加影响了合金的时效析出过程,使基体中析出了更多、更细小的δ′相和T1相,使合金具有较高的力学性能。The effects of trace Sc on the microstructure and mechanical properties of 2099 Al-Li alloy were investigated by metallographic optical microscope （OM）, scanning electron microscope （SEM）, tensile, and transmission electron microscopy （TEM）. The results show that the small addition of Sc to 2099 alloy exhibits obvious grain refining and serves to inhibit recrystallization in ascast, homogenization and solution treatmentin, respectively. The Sc-containing alloy shows obvious short transverse delamination phenomenon in the SEM fractographs and improvement of tensile properties. But it slows the ageing strengthening rate obviously and has no distinct effects on the aging time to reach the peak. The small addition of Sc causes precipitation of more and smaller 5＇ and T1 phase, which improves the strength of 2099 alloy.

关 键 词：钪 铝锂合金 力学性能 微观组织 

分 类 号：TG146.2[一般工业技术—材料科学与工程]