Microstructure and property of stress aged Al-Cu single crystal under various applied stresses  

不同加载条件下Al-Cu合金单晶应力时效后的组织与性能（英文）

作　　者：陈继强[1] 陈志国[1,2] 郭晓斌[1] 任杰克[1] 邓运来[1,3] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]湖南人文科技学院,娄底417000 [3]中南大学高性能复杂制造国家重点实验室,长沙410083

出　　处：《Transactions of Nonferrous Metals Society of China》2016年第11期2838-2845,共8页中国有色金属学报（英文版）

基　　金：Project(51375503)supported by the National Natural Science Foundation of China

摘　　要：The stress aging behavior of Al-Cu alloy under various applied stresses, i.e., elastic stress, yield stress and plasticdeformation stress, was investigated using single crystals. The resulting microstructures and the yield strength were examined bytransmission electron microscopy （TEM） and compression tests, respectively. The results indicate that an elastic stress of 15 MPa ishigh enough to influence the precipitation distribution of θ′ during aging at 180℃. The applied stress loading along [116]Aldirection results in increased number density of θ′ on （001）Al habit planes. This result becomes more significant with increasingapplied stress and leads to lower yield strength of Al-Cu single crystals during aging. Moreover, the generation of the preferentialorientation of θ′ was discussed by the effect of the dislocation induced by applied stress as well as the role of the misfit between theθ′-precipitate and Al matrix. The results are in agreement with the effect of the latter one.利用单晶研究了Al-Cu合金在弹性应力、屈服应力及塑性变形应力等加载条件下的应力时效行为,并分别通过透射电子显微镜(TEM)和压缩试验研究了应力时效后的显微组织与屈服强度。结果表明:15 MPa的弹性应力就足够影响Al-Cu合金单晶在180°C时效过程中θ′相的析出分布。沿着[16]_(Al)方向加载的应力会增加Al-Cu合金单晶(001)_(Al)惯析面上θ′相的析出密度。随着外加应力的增大,(001)_(Al)惯析面上θ′相的析出密度则会随之增加,进而导致Al-Cu合金单晶的屈服强度降低。通过应力产生的位错的影响及θ′相与Al基体之间的错配度作用的影响两个方面对应力时效时析出相择优分布的产生进行了讨论,结果更加符合θ′相与Al基体之间错配度作用的影响。

关 键 词：Al alloy single crystal stress aging θ′ phase microstructure PROPERTY 

分 类 号：TG146.21[一般工业技术—材料科学与工程]