135° CLOCK ROLLING: AN APPROACH TO IMPROVE THE MICROSTRUCTURE AND TEXTURE OF TANTALUM USED FOR SPUTTERING TARGET

摘要

An efficient approach, 135° clock rolling, to improve the microstructure and texture of tantalum (Ta) was presented in this paper. The Ta plates were processed by unidirectional (UR) and clock rolling (CR), respectively. Compared with UR, the novel CR caused a continuous change of strain paths and consequently activated slip systems from multiple directions. After cold rolling, the microstructure and texture were investigated by the optical microscopy (OM), X-ray diffraction (XRD), electron channel contrast imaging (ECCI) and electron back-scattered diffraction (EBSD) techniques. Results showed that 135°clock rolling had positive effects on weakening the texture gradients and homogenizing the deformation microstructure, thus resulting in a favorable annealing behavior and eventually improving the sputtering performance of Ta target.