Geometrical, microstructural, and mechanical properties of curved-surface AlSi10Mg parts fabricated by powder bed fusion additive manufacturing

Abstract

Laser-based powder bed fusion (L-PBF) enables the fabrication of complex-structural AlSi10Mg parts with low material waste and high manufacturing resolution. Thus far, there have been comprehensive investigations to reveal the process-microstructure-property link of as-built AlSi10Mg planar-surface or lattice/honeycomb structural parts. However, little is known about the geometrical, microstructural, and mechanical properties of as-deposited curved-surface parts. In this paper, the effects of curvatures on the geometrical performance, defects, microstructure, and mechanical properties of as-built AlSi10Mg parts with curved surfaces were investigated. Specifically, the results of average cloud-to-cloud distances indicated that the largest curvature (the peak position) exhibited higher dimensional accuracy than the others of as-built curved-surface parts. In addition, the lowest porosity was achieved at the largest curvatures owing to the sufficient localized energy input. We also found that the grain size and the width of grain boundaries increased with an increase in the curvature. Moreover, the tensile property of as-built curved-surface specimens was assessed for the first time. The positions with the largest curvatures became the preferable failure positions due to the largest bending moment. This paper provided great insights into the curvature-microstructure-property relationship for the industrial adoption of PBF-built AlSi10Mg parts with curved surfaces.