2A97铝锂合金时效行为研究  

The Aging Behavior of Aluminum-Lithium Alloy 2A97

作　　者：袁志山[1,2] 吴秀亮[2] 陆政[2] 谢优华[2] 戴圣龙[2] 刘常升[1] 

机构地区：[1]东北大学,辽宁沈阳110004 [2]北京航空材料研究院,北京100095

出　　处：《稀有金属材料与工程》2008年第11期1898-1902,共5页Rare Metal Materials and Engineering

基　　金：国家“973”项目(2005CB623705)

摘　　要：通过DSC、XRD、TEM、硬度测试和拉伸测试等手段,研究了2A97铝锂合金时效组织和性能变化。结果表明:2A97合金淬火后在165℃时效18h的显微组织以θ″/θ′和δ′相为主,出现了大量分布不均匀T1相。在165℃时效,随时间延长,T1数量密度增加,平均长度减小,δ′数量密度增加,θ′数量密度和长度增加。在165℃时效18h得到较高的强度和塑性。淬火变形后于135℃时效的组织以细小θ″/θ′、T1和δ′为主,T1和θ″/θ′数量明显高于未变形时效组织。淬火变形后于135℃时效36h的强度明显提高,σ0.2,σb和δ5分别为441MPa,519MPa和7.4%。The evolution of microstructures and properties of aged 2A97 alloy at 165 ℃ after quenching, and at 135 ℃ after quenching and 4% plastic deformation for various times were investigated. The results show that θ″/θ′ and δ′ phases are the main strengthening phases of aged alloy at 165 ℃ for 18 h after quenching, which shows high tensile strength and ductility resulting from increasing amount of T1 phase distributed heterogeneously in matrix. With increasing aging time at 165 ℃, the number density of θ″/θ′, T1, and δ′ increase, and the length of T1 decreases, while the length of θ″/θ′ increases. Stretch before aging fines the size of θ″/θ′ and T1, and stimulates the precipitation and uniform distribution of them, so it yields higher strength for the alloy aged at 135 ℃ for 36 h after quenching and stretch, which is 441 MPa, 519 MPa, and 7.4% for σ0.2,σb, and δ5, respectively, than the alloy aged at 165 ℃ after quenching.

关 键 词：时效 回归 2A97 铝锂合金 DSC XRD 

分 类 号：TG166.3[金属学及工艺—热处理]