(西北工业大学 材料科学与工程学院， 西安 710072)
摘 要: 以1420铝锂合金为对象，研究了轧板的各向异性在时效过程中的演化，并探讨了δ′相强化的各向异性机制。研究结果表明：随着时效的进行，合金的各向异性逐渐增强，合金的拉伸断裂特征也出现各向异性；且随着时效的进行，合金的断裂方式由沿晶分层断裂向沿亚晶分层断裂转变。可以认为，δ′相是通过共面滑移来软化滑移面、减少滑移系数目，从而增强合金的各向异性。
关键字: 各向异性；时效；δ′相；断裂特征
（College of Materials Science and Engineering，
Northwestern Polytechnical University，Xi′an 710072，China）
Abstract:Variations of anisotropy during aging treatment in 1420 Al-Li alloy rolled sheet，and the mechanism by which δ′ phase strengthens the alloy an isotropically were investigated. It is found that anisotropy of properties increases as aging treatment progresses. The fracture character is also anis otropic，and it transits from intergranular one to intersubgranular one as aging treatment progresses. It is deduced that δ′ phase softens slip planes and lessens the number of slip systems by coplanarslip，thereby enhances anisotropy in this alloy.
Key words: anisotropy；aging treatment；δ′ precipitate； fracture character
