摘要
测定了 8 090 Al-Li合金的沉淀硬化动力学曲线,以及在峰值时效(T6),欠、过时效和预延展应变时效(T8)状态下的机械性能。用透射、扫描电镜考察了对应组织特征。指出,时效温度是控制δ′和s′相复合沉淀动力学的关键参数;在δ′和s′相优化组合的 T6状态,σ_(0.2)达 420 MPa;T8状态的 σ_(0.2)为 440 MPa,略改善塑性发现一种热加工后残存的块状富Cu脆性组织对塑性有重要影响。
Age hardening behavior of 8090AI--Li alloy was systematically investigated bythe way its kinetic characteristics were determined with mechanical propertiestested under peak-value aging (T6), underaging, overaging and prestretchedsLrain aging (T8), respectively, and the microstructure was studied by meansof transmission/scanning electron microscopy. It is indicated that the agingtemperature is a crucial parameter which predominats over the composite agingKinetics of δ' and s' phases. Under T6 condition or an optimized combination ofδ' and s' phases σ_(0.2) is equal to 420 MPa, but under T8 condition it up to 440 MPathat can slightly improve the ductility. A lumpish Cu--rich brittle structureremained after hot working is found having significant influence on ductility.
