History of residual stresses during the production phases of AlSi10Mg parts processed by powder bed additive manufacturing technology

Residual stresses can be detrimental to the proper functioning and the structural integrity of built parts. During the selective laser melting (SLM) process, the scanned layers are subjected to rapid thermal cycles. Steep temperature gradients generate residual stresses. In this paper, the semi-destructive hole-drilling method has been used to measure the residual stresses on AISi10Mg parts fabricated by means of an SLM process. The evolution of the profile of the residual stresses of the samples is illustrated in function of the process phase (as-built, after the thermal treatment, after shot-peening) for samples with and without supports. The outcomes have shown the presence, on the as-built components, of high tensile stresses that the usual post-processing operations are not able to minimise. This paper provides a new knowledge on the history of residual stresses during the production phases of metal parts through powder-bed additive manufacturing technology.