平面应变模具尺寸差对金属流变及其力能的影响

Effect of die geometry on metallic rheology and pressure during plane strain compression

采用MARC/Superform有限元软件对平面应变压缩过程进行了二维有限元分析,分析了上下模具尺寸不相等时,对金属流变规律及其力能参数的影响.同时应用滑移线场理论对端部的滑移线场进行了分析,分析了金属的流动情况,进一步验证了有限元模拟结果的可靠性.研究结果显示:模具尺寸相等时,金属流动呈现对称分布;当上下两个模具尺寸不等时,金属流动呈现非对称分布,有剪切变形产生.而且随着模具尺寸差的增大,其交叉剪切变形越严重,总压力也增大,平均压力相对降低,这与异步轧制过程类似.所研究结果为异步轧制过程提供了一种新的物理模拟方法.

With the aid of FE code MARC/Superform,2-D mechanical analyses of different die size during plane strain compression were conducted and metallic rheology,force and energy parameters in the process of deformation were analyzed. The slip line field of the ends was analyzed by using theory of slip line field,the flowage of metal was analyzed,and the result of simulation was further verified. It is shown that the flow pattern of metal is symmetrical when the sizes of upper die and down die are identical,however,the flow pattern of metal is asymmetrical and cross shear deformation is arised when the sizes of upper die and down die are different. With the increment of size difference between upper die and down die,cross shear deformation becomes more serious and total pressure becomes greater,but average pressure decreases. These conclusions are identical with those of cross shear rolling. The research provide for a new physical simulation method cross shear rolling.