一种Weldalite　049型Al－Li合金的时效硬化行为

AGE-HARDENING BEHAVIOUR OF A WELDALITE 049 TYPE Al-Li ALLOY

研究了一种Ｗｅｌｄａｌｉｔｅ０４９型Ａｌ－Ｌｉ合金的时效硬化特性、室温拉伸性能和时效析出组织．研究结果表明，无论是在人工时效还是在自然时效条件下，所研究的合金都有很强的时效硬化能力．时效前的预变形在人工时效条件下可一定程度地促进Ｔ１相析出，但在自然时效条件下却抑制ＧＰ区的形成，减少时效硬化效果．Ａｇ的添加促进了Ｔ６时效态Ｔ１相的析出，从而减少了Ｔ６和Ｔ８状态的强度差别．

The age-hardening behaviour, tensile properties and microstructures of an Al-4. 59Cu0. 91Li-0.41Ag-0.42Mg-0.14Zr alloy were investigated. Results show that this alloy has obvious age-hardening response to both artificial aging and natural aging. The addition of silver promots the precipitation of T1 phase without pre-deformation, thus decreasing the difference of strength in T6 and T8 conditions. The pre-deformation prior to aging stimulates the precipitation of T1 phase to a certain extent in the artificial aging condition, and inhibites the formation of GP zones in the natural aging condition, so the strength in T3 condition is less than that in T4 condition.