Influence of Heat and Surface Treatments on the Fatigue Response of DMLS Manufactured AlSi10mg

Abstract

The aim of this study is to analyze how the fatigue behavior of DMLS built AlSi10Mg may be affected by heat and surface treatments. A three-by-three factorial plan has been arranged for this purpose. Particularly, regarding the heat treatment, three levels were considered (as built, age hardening and stress relief), whereas, for the surface treatment, three levels were investigated (micro shot-peening, micro shot-peening plus fine blasting and DMLS production, machining and lapping). Ten specimens per type were built with vertical orientation and with a cylindrical smooth geometry. 90 samples were tested on a four-point rotating bending machine, aiming at the determination of S-N curves in the finite life domain. The experimental results were statistically processed and compared. The outcome was that heat treatment significantly affects the fatigue response and stress relief may have a detrimental impact. Fractographic studies were performed as well, to individuate the crack initiation points. Finally, density measurements were carried out to quantify the porosity level.