细晶GCr15合金材料ECAE过程的数值模拟

Numerical Simulation of Equal Channel Angular Extrusion of Fine-Grained GCr15 Alloy Material

等径角挤压(ECAE)可以在不改变材料横截面的条件下使其反复产生大的塑性变形,从而使材料的晶粒得到细化,是制备块状超细晶粒材料的有效方法。通过对GCr15钢ECAE变形过程进行数值模拟,获得了挤压过程中不同的外接圆弧角Ψ和不同摩擦系数μ对挤压载荷和等效应变的影响规律。结果表明,挤压载荷随着外接圆弧角Ψ的增加而减小,随着摩擦系数μ的增加而增大;而变形均匀性则随着Ψ和μ的增加而减小。

Equal Channel Angular Extrusion （ECAE） can cause repeated severe plastic deformations of material without inducing any significant change in its cross - sectional area so that the grain of material can be refined. It has become an effective method for fabricating bulk ultra - fine grain material. The influence regularity of different curvature angle ψ of the outside corner and frictional coefficient m for ECAE of GCr15 steel is obtained through numerical simulation. The resuits indicate that the extrusion load will decrease with angleψ increasing and increase with frictional coefficient increasing. On the other hand, the deformation uniformity will decrease with the increase of both angle ψ and frictional coefficient m.