Study on the cold rolling deformation behavior of polycrystalline tungsten

Abstract

Tungsten is paid special attention due to its superior properties, especially in nuclear field. Meanwhile it is suitable for texture simulation investigation of BCC metals and alloys as it's near elastically isotropic. This study investigates the cold rolling deformation texture of polycrystalline tungsten using RS model, in which the stress and strain consistence is realized simultaneously. The texture evolution and effects of deformation parameters, including external as well as internal reaction stress, strain and activation of different slip, on texture during rolling are discussed by comparing the simulated results and reported experimental results in literatures. The results show that, the cold rolling deformation texture could be simulated statistically based on RS model. The accumulation of each reaction stress is different. The up-limit of reaction stress σ'12 is found to be medium, meaning that σ'12 exerts important effect on texture evolution. Much lower accumulation level of σ'13 as well σ'23 is displayed, each of which within certain range contributes to the increase of different γ-fiber texture components. The effect of σ'22 can't be ignored during rolling, especially in the case of obtaining {111}<110> texture. Regarding the deformation textures of tungsten rolled to true strains of −1.7 and −2.91, {001}<110> texture is strengthened with the increasing strain and becomes dominant, implying the easier activation of {112}<111> slip systems; γ-fiber texture is weakened at higher strain, and the formation of {111}<112> texture shows significant effect of surface shear stress σ13, which is due to the nonnegligible surface friction when rolling at high temperature.