摘要
本文研究了形变时效对Al-Li-Cu-Mg-Zr合金的显微组织、拉伸性能及断裂行为的影响。结果表明,该合金的主要强化相为δ′相(Al_2Li),其次为S′相(Al_2CuMg)。预形变可加快δ′相的粗化速率,形变产生的大量位错,可促进 S′相的形核与长大;预形变使时效峰提前,使合金的强度、硬度升高,但塑性有所降低。该合金的断裂方式为穿晶和沿晶混合型。时效或预形变使沿晶断裂倾向增大。
The effects of deformation-aging on the microstructures,tensilepro-perty and fracture behavior of an Al-Li-Cu-Mg-Zr alloy were studied.The results showed that the main strengthening phase is δ′(Al_3 Li)andthe second is S′(Al_2 CuMg)in the alloy,and the nucleation and growthof S′phase are promoted due to the large amount of dislocations prod- uced by prior deformation.The aging peak occurs early and the streng-th and/or hardness of the alloy increase,but the elongation decreasesby prior deformation.The fracture mode in the alloy is a mixed transgra-nular and intergranular fracture.The tendency of intergranular fractureis intensified by aging or prior deformation.The intergranular fractureof alloy shows the dimple type.
关键词
铝锂合金
形变时效
组织
性能
Al-Li-Cu-Mg-Zr alloy
deformation-aging
micrstructures
mechanical properties
