变形程度对强变形Al-4%Cu合金退火组织性能的影响  

Influence of severe plastic deformation degree on subsequent annealing microstructures and properties of Al-4wt.%Cu alloys

作　　者：许晓嫦[1,2] 张孜昭[1] 胡楠[1] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]中南大学有色金属材料科学与工程教育部重点实验室,长沙410083

出　　处：《材料科学与工艺》2011年第2期57-63,共7页Materials Science and Technology

基　　金：湖南省自然科学基金资助项目(05JJ40005);湖南省科技攻关项目(2007FJ3085)

摘　　要：为了研究变形程度对强变形Al-4%Cu合金退火行为的影响,通过透射电镜观察和拉伸试验,研究了人工时效Al-4%Cu合金经过不同变形量的多向压缩变形(MAC),退火(120℃/60 min)后的显微组织和力学性能.研究表明:试样中的第二相在MAC过程中破碎溶回基体后,会在后续退火过程中再次析出,且析出相回溶的程度对退火组织性能的影响很大.含θ″相试样和含θ'相试样经MAC变形后,析出相完全回溶于基体,在退火过程中有新的第二相析出,试样强度升高;同时试样的的塑性也得到了提高,这与再析出粒子对超细晶粒长大的阻碍作用有关.析出相未完全回溶的含θ相试样,退火后强度低于退火前,析出相回溶和再析出交替进行.析出相基本回溶态强韧化效果最佳.To investigate the effect of deformation degree on the annealing behavior of severely deformed aged A1 - 4wt. % Cu alloys, their tensile properties and microstructures after different passes of multi-axial compression（MAC） and annealing were measured by tensile test and transmission electron microscopy. The results showed that the precipitated phases in aged A1 alloy samples were fragmented and dissolved into the matrix during MAC, forming supersaturated solid solution. In subsequent annealing, new precipitates appeared, and the degree of the dissolution of precipitates during MAC had a significant effect on the structures and properties of the annealed samples. The 0″ and O′ precipitates could totally dissolve in the matrix, whose tensile strength increased during annealing as a result of precipitation strengthening. At the same time, their tensile elongation also increased, this is related to the retarded growth of the ultra-fined grain by the new precipitates. In the samples containing O, in which the precipitated phases dissolved incompletely during MAC, the dissolution and precipitation procedure occurred simultaneously during the subsequent annealing, and the strength of annealing samples was lower than their deformed state. Samples, whose precipitated phases just dissolved completely, exhibited the best overall tensile properties.

关 键 词：AL-CU合金 强塑性变形 析出相回溶 退火组织 

分 类 号：TG146.2[一般工业技术—材料科学与工程]