Investigating the effects of post-heat treatment on residual stress in AlSi12 parts processed with Selective Laser Melting

Abstract Residual stresses are the stresses that remain on a part after the original cause of any stress has been removed. In Selective Laser Melting (SLM), an additive manufacturing process, residual stress occurs in the created part due to rapid melting and rapid solidification; these stresses are responsible for distortion, which must therefore be minimised or eliminated. Residual stresses can be reduced in SLM built parts by the application of post heat treatment, and this process is investigated in this study. X-ray diffraction was employed for the experimental analysis of the residual stresses in AlSi12 parts processed by SLM that were then subjected to heat treatments at different temperatures, ranging from 200 °C to 500 °C, in order to investigate how residual stresses and microstructure changes vary with heat treatment temperatures.