Selective laser melting of near-α titanium alloy Ti-6Al-2Zr-1Mo-1V: Parameter optimization, heat treatment and mechanical performance

This paper presents a comprehensive study conducted to optimize the selective laser melting (SLM) parameters and subsequent heat-treatment temperatures for near-alpha high-temperature titanium alloy Ti-6Al-2Zr-1Mo-1 V (TA15), which is widely used in the aerospace industry. Based on the surface morphology and relative density analysis, the optimized process parameters were: laser power from 230 W to 380 W, scan speed from 675 mm/s to 800 mm/s, scan spacing of 0.12 mm, and layer thickness of 0.03 mm. The effects of the laser power and the layer thickness on the phase constitutions, microstructure features, as well as room-temperature and high-temperature (500 degrees C) tensile properties, were then studied to obtain an in-depth understanding of SLM-built TAI 5. Six typical temperatures (650, 750, 850, 950, 1000 and 1100 degrees C) covering three representative temperature ranges, i.e., martensite partial decomposition temperature range, martensite complete decomposition temperature range and above p transus temperature, were subsequently selected as heat-treatment temperatures. The heat treatmentmicrostructure-mechanical property relationships of SLM-built TAI 5 were elucidated in detail. These results provide valuable information on the development of SLM-built TAI 5 alloy for industrial applications, and these findings are also beneficial to additive manufacturing of other near-alpha Ti alloys with desirable high-temperature properties. (C) 2020 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.