Effect of Strain Path Change on Microstructure and Texture in Nickel During Cold Rolling and Annealing

The effect of strain path (unidirectional rolling and cross rolling) on microstructure and texture of pure nickel in deformed and recrystallized state was investigated by electron backscatter diffraction (EBSD) and X-ray diffraction (XRD). The results show that the lamellar structure is dominant in both of samples with two rolling modes, but the stored energy in the unidirectionally rolled (UDR) sample is higher than that in the cross rolled (CR) sample. The deformation texture is significantly affected by the strain path. The UDR sample is characterized by the typical copper type rolling texture, while the CR counterpart is mainly composed of Brass (Bs) and ND-rotated Brass (BsND) texture components. In addition, the minor cube and rotated cube are found in both of deformed samples. When the two samples were simultaneously annealed at different temperatures for 1 h, the different recrystallization textures were obtained. The cube texture was prevailed in the UDR sample, while the weakened fiber texture was dominant for the CR sample. In addition, the abnormal grain growth was observed in the UDR sample annealed at 800℃ for 1 h, which was attributed to the formation of clustered grains with a preferred cube orientation leading to the inhomogeneous microtexture, while the cross rolling mode suppressed the occurrence of abnormal grain growth during annealing. © 2019, Science Press. All right reserved.