摘要
采用Ｈｏｐｋｉｎｓｏｎ压杆装置，对４种时效处理的Ａｌ—Ｌｉ合金在冲击压缩试验时变形局部化产生的力学条件和微结构进行了研究．结果指出，４种处理的合金均产生两种类型的剪切带即形变剪切带和白色剪切带它们是在局部化过程中不同形变阶段下形成的两者无本质上的差别白色剪切带内未发生相变大应变和高应变率是产生力剪切带的必要条件，即材料在一定的高应变率下形变到一定程度时才能形成剪切带电镜研究表明。
Mechanical conditions and microstructures of the shear deformation localization producedduring high speed impact compression in Al-Li alloys are investigated by split Hopkinson bar with aboutstrain rate of 103s-1. The alloys were subjected to peak-, over-, under- and natuxal aged treatmentsthat provide wide microstructuxal parameters and mechanical properties. The results show that there aredeformed shear bands and white shear bands, which are usually indicated by a different etching response in anarrow band of material in metallographic cross-sections, and there is no evidence of phase transformationin the white shear bands. Two types of shear bands are formed at different stages of deformation duringlocalization. A nUmber of observations show that a critical strain is required for their formation undera critical strain rate, i.e., there are thresold values of strain and strain rate for occurrence of both thedeformed and white shear bands. Examinations by TEM show that the fine equiaxed and distortion-freegrans in the center of the shear bands are the result of recrystallization duxing localization.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
1999年第4期384-386,共3页
Acta Metallurgica Sinica
基金
国家自然科学基金
