The Effect of Interpass Peening on Mechanical Properties in Additive Manufacturing of Ti-6Al-4V

Abstract

Ti-alloys have high specific strength and are widely used for the filed of space aeronautics plant. However, it is difficult to process Ti-Alloys due to its high yield strength and it cannot raise the machining speed because it has a possibility of catching fire while processing. In order to reduce the number of processes for the Ti-alloys, the researches related to Additive Manufacturing(AM) have been actively carried out at the moment. As for the initial stage of AM market related to Ti-alloys, it started to use the raw material of powder metal, and it is currently being developed based on welding. In this study, Interpass peening reduced the size of the primary β grain in the z-axis direction, increased the nucleation site of α-colony, and decreased the length and width of α laths as though interpass rolling. Interpass peening leads to an increase in yield/ultimate tensile strength without decrease elongation, resulting decrease in anisotropy of the material.