Effect of hot isostatic pressing on the critical defect size distribution in AlSi7Mg0.6 alloy obtained by selective laser melting

•The HIP prior to T6 is responsible has no significant impact on the fatigue behavior.•The HIP prior to T6 does not reduce the sizes of the critical defects.•The critical defect size distributions were simulated using CT scan data. This study focuses on the influence of defect density on the sizes of the critical defects responsible for fatigue failure in AlSi7Mg0.6 alloy produced by Selective Laser Melting. Samples having similar microstructures and different defect densities were obtained combining Hot Isostatic Pressing and T6 treatments. Defect populations were analyzed using X-ray tomography, and fatigue tests were performed to determine the critical defect distributions. A method allowing for the prediction of these distributions from the CT scan data was then proposed, and discussed with regard to the actual distributions obtained from the fatigue tests.