Effects of substrate temperature on the structure, residual stress and nanohardness of Ti6Al4V films prepared by magnetron sputtering

This paper studies the effects of substrate temperature on the structural and properties evolution of magnetron sputtered Ti6Al4V films. X-ray diffraction results indicate that the films show a monotonically weakening (0002) texture growth as the substrate temperature rises, and completely transform into a randomly orientated growth at 500 °C deposition. The columnar and equiaxial structures of the films are observed by scanning electron microscope and transmission electron microscope. The structure evolution as a function of homologous temperature Ts/Tm is illustrated by a schematic diagram based on the Structure Zone Model. The film residual stresses are compressive, and decrease with substrate temperature increasing. The film nanohardness decreases as substrate temperature rises, which is thought to be influenced by both the decreasing texture and relaxed residual stress. These results show that the film structure and structure-related properties can be controlled by simply modifying the homologous temperature Ts/Tm.