Mechanism of size effects in microcylindrical compression of pure copper considering grain orientation distribution  

作　　者：Chuan-Jie Wang Chun-Ju Wang Bin Guo De-Bin Shan Yan-Yan Chang 

机构地区：[1]School of Materials Science and Engineering, Harbin Institute of Technology [2]Key Laboratory of Micro-Systems and Micro-Structures Manufacturing, Harbin Institute of Technology

出　　处：《Rare Metals》2013年第1期18-24,共7页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (Nos. 50835002 and 51105102)

摘　　要：In microscale deformation, the magnitudes of specimen and grain sizes are usually identical, and size- dependent phenomena of deformation behavior occur, namely, size effects. In this study, size effects in micro- cylindrical compression were investigated experimentally. It was found that, with the increase of grain size and decrease of specimen size, flow stress decreases and inhomogeneous material flow increases. These size effects tend to be more distinct with miniaturization. Thereafter, a modified model considering orientation distribution of surface grains and continuity between surface grains and inner grains is developed to model size effects in micro- forming. Through finite element simulation, the effects of specimen size, grain size, and orientation of surface grains on the flow stress and inhomogeneous deformation were analyzed. There is a good agreement between experimental and simulation results.In microscale deformation, the magnitudes of specimen and grain sizes are usually identical, and size- dependent phenomena of deformation behavior occur, namely, size effects. In this study, size effects in micro- cylindrical compression were investigated experimentally. It was found that, with the increase of grain size and decrease of specimen size, flow stress decreases and inhomogeneous material flow increases. These size effects tend to be more distinct with miniaturization. Thereafter, a modified model considering orientation distribution of surface grains and continuity between surface grains and inner grains is developed to model size effects in micro- forming. Through finite element simulation, the effects of specimen size, grain size, and orientation of surface grains on the flow stress and inhomogeneous deformation were analyzed. There is a good agreement between experimental and simulation results.

关 键 词：MICROFORMING Cylindrical compression Sizeeffects Grain orientation Inhomogeneous deformation 

分 类 号：TG146.11[一般工业技术—材料科学与工程]