Texture development in Fe–3.0 mass% Si during high-temperature deformation: Examination of the preferential dynamic grain growth mechanism

Abstract

A new mechanism of texture evolution, named “preferential dynamic grain growth mechanism”, is examined experimentally by high-temperature plane-strain compression deformation of Fe–3.0mass% Si alloy. The proposed mechanism is based on preferential growth of the orientations having low Taylor factors and stability against deformation. According to the mechanism, the growing orientation is expected to be {001}〈110〉 in the case of plane-strain compression deformation. In fact, the textures formed by deformations up to the desired strain of −1.0 have high orientation densities around {001}〈110〉 in accordance with the proposed mechanism. With decreasing strain rate, the volume fraction of {001}〈110〉 increases with the increase in the average intercept length of crystal grains along the transverse direction at both 1093K and 1173K, which implies the occurrence of dynamic grain growth during the deformation. The volume fraction of {001}〈110〉 is higher at 1173K than at 1093K for the same strain rate. Electron backscatter diffraction measurements show that the density of small-angle grain boundaries decreases with increasing temperature and decreasing strain rate. The lower density of small-angle grain boundaries implies that distribution of dislocations in grains approaching homogeneity results in the enhancement of preferential dynamic grain growth at higher temperatures and lower strain rates. This suggests that high-temperature deformation might be applied as a new method for controlling texture.