Effect of building orientation, thickness, and contouring on the microstructure and mechanical properties of AlSi10Mg via laser powder bed fusion

The AlSi10Mg alloy, widely recognized for its advantages, has extensive applications in high-value-added industries, notably in the aerospace sector. Moreover, the AlSi10Mg alloy exhibits exceptional utility in producing aerospace components with complex geometries through laser powder bed fusion (LPBF), thus broadening its potential use cases. However, it is crucial to recognize that both the building orientation, the thickness, and the contouring of components can significantly impact the localized microstructure and mechanical properties of LPBF-fabricated AlSi10Mg across different regions. This introduces the risk of inaccurately predicting the overall material performance. This study, therefore, seeks to elucidate the coupling effects of building orientation and thickness through a comprehensive examination involving mechanical testing and microstructure characterization. From the results, the X-ray computed tomography tests indicated a decreasing tendency for the fraction of porous contour area due to the rescanning processes with sample thickness, leading to higher elongation and strength in the thicker sample compared to thinner ones. Regarding the effects of printing orientation on strength, the primary influencing factor is the morphology and distribution of the Al-Si eutectic networks, rather than theoretical grain size variations. The findings have important implications for optimizing the LPBF process to produce components with tailored microstructures and enhanced mechanical performance, contributing to the advancement of additive manufacturing in demanding industrial applications.