Deformation behavior of materials in micro-forming with consideration of intragranular heterogeneities  

考虑晶内异质性的微成形材料变形行为（英文）

作　　者：Zhen-wu MA Guo-quan TONG Feng CHEN 马振武;童国权;陈峰(南京航空航天大学机电工程学院,南京210016)

机构地区：[1]College of Mechanical and Electrical Engineering,Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China

出　　处：《Transactions of Nonferrous Metals Society of China》2017年第3期616-626,共11页中国有色金属学报（英文版）

摘　　要：To describe the relationship between the whole material deformation behavior and each grain deformation behavior inmicro-forming,experimental and numerical modelling methods were employed.Tensile test results reveal that contrary to the valueof flow stress,the scatter of flow stress decreases with the increase of thickness-to-grain diameter(T/d)ratio.Microhardnessevaluation results show that each grain owns unique deformation behavior and randomly distributes in each specimen.The specimenwith less number of grains would be more likely to form an easy deformation zone and produce the concentration of plasticdeformation.Based on the experiment results,a size-dependent model considering the effects of grain size,geometry size,and thedeformation behavior of each grain was developed.And the effectiveness and practicability of the size-dependent model wereverified by experimental results.采用实验和数值建模方法探究微成形中材料变形行为和晶粒变形行为的关系。拉伸实验结果表明,流动应力的离散度随厚度晶粒尺寸比(T/d)的减小而增大,这与流动应力的变化规律相反。显微硬度测试结果表明,每个晶粒都有其独特的变形行为且随机分布于试样中。含晶粒数量越少的试样越容易形成易变形区和发生变形集中现象。最后,建立了一个同时考虑晶粒尺寸、几何尺寸和个体晶粒变形行为的尺寸依赖模型,并通过对比实验证实了该模型的有效性和实用性。

关 键 词：MICRO-FORMING deformation behavior size effect model intragranular heterogeneity 

分 类 号：TB30[一般工业技术—材料科学与工程]