Abstract

Fabricating metal parts with the additive manufacturing technology of laser-based powder bed fusion enables unconventional and individual geometries, such as optimized topologies. However, one drawback is that the layer-by-layer processing from the laser beam results in high thermal gradients as well as high cooling rates leading to effects like a fine microstructure, anisotropy, inhomogeneities, and residual stress. A combination of these factors with the brittleness of some materials significantly reduces a part’s lifespan. Within this study, the effect of heat treatment as well as the printing parameter set for PBF-LB AlSi10Mg on residual stress, and therefore, high cycle fatigue, is reported. Residual stress was measured using X-ray diffraction analysis. In addition to residual stress, surface roughness was determined in order to evaluate the effect of the peak in surface roughness on fatigue life due to its notch effect. Furthermore, each crack-initiating inhomogeneity was measured according to the -concept of Murakami. As a result, general sensitivity factors are reported in order to predict crack-initiating-based fatigue life affected by the stress amplitude, residual stress, and peak surface roughness.

URL

https://link.springer.com/chapter/10.1007/978-3-031-49043-9_16