等通道弯角挤压变形机理模拟与工艺参数优化

Deformation mechanics analysis and processing parameter optimization of equal channel angular pressing

通过等通道弯角挤压工艺 (EqualChannelAngularPressing ECAP)能够获得块状超细晶粒材料 (包括亚微米和纳米材料 )。模具几何形状、摩擦条件等工艺参数对挤压过程具有重要影响。本文应用作者自主开发的商品化软件 ,通过大量的有限元模拟 ,研究了过程参数对挤压件变形分布、挤压载荷的影响规律 ,给出了不同模具拐角和圆心角对ECAP挤压件变形区产生的累积等效应变、等效应力和载荷 行程曲线的影响 ,为优化模具形状和获得所要求的挤压件变形分布提供了大量有效的结果和规律。

Equal channel angular pressing (ECAP) has the capability of producing bulk ultra-fine grain materials (submicrostructured or nanostructured materials). It will greatly affect the extrusion process when processing parameter changed such as die geometries and friction condition. In this thesis the author used his own commercial software research effective strain and force distributing of specimen with different process parameters by a great deal simulations with finite element analysis, and confirmed cumulate effective strain, effective stress of specimen and load-stroke curve of ECAP with different channel angle and corner angle, acquired a great deal of count results and rules for die geometries optimization and effective strain distributing of specimen.