Effect on microstructural and mechanical properties of selective laser melted pure Ti parts using stress relief heat-treatment process

Abstract

This study investigated the correlation between the microstructure and the mechanical properties of pure Ti specimens manufactured via selective laser melting (SLM) using the stress relief heat-treatment process. Similar heat treatments were performed at a rate of 10 °C/min with a dwell time of 2 h to reach post-treatment temperatures ranging from of 490–890 °C in intervals of 100 °C. Phase change analysis using X-ray diffraction was conducted to verify the effects of the post-treatment process, while electron backscatter diffraction analysis was conducted to study the effects of microstructural changes induced by the post-treatment process on the mechanical properties of pure Ti specimens. In addition, a comprehensive analysis was performed to analyze residual stress following the stress relief heat treatment. The findings of this study establish a clear relationship between the mechanical properties and microstructural changes in SLM-manufactured pure Ti after heat treatment across a broad temperature range. Furthermore, the study confirms that heat treatment effectively relieves the residual stress in SLM Ti specimens.