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.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2008年第11期1898-1902,共5页
Rare Metal Materials and Engineering
基金
国家“973”项目(2005CB623705)
