Influence of Post-Process Heat Treatments on the Fatigue Crack Propagation Behaviour of a PBF-LB/M AlSi10Mg Alloy

The microstructure has a great influence on short fatigue crack growth in metallic materials. Laser-based Powder Bed Fusion AlSi10Mg alloys exhibit in the as-built condition a fine fibrous Si structure and a supersaturated solid solution of Si in the & alpha;-Al matrix, which is significantly modified by heat treatments starting already at tem-peratures under 260 & DEG;C. This study focuses on the influence of post-process heat treatments on the micro-structural evolution and the resulting fatigue crack growth resistance. As compared to the as-built condition, two heat treatments at 265 & DEG;C/1 h and at 300 & DEG;C/2 h are found to be beneficial to the fatigue crack growth resistance of the investigated material.