Linking Powder Properties, Printing Parameters, Post-Processing Methods, and Fatigue Properties in Additive Manufacturing of AlSi10Mg

Abstract

Additive manufacturing (AM) of metals can be broadly accomplished via two defined technologies: powder bed fusion and directed energy deposition. During AM fabrication, the melted feedstock material experiences fast thermal cycling due to the layer-by-layer deposition process resulting in microstructures and properties that are drastically different from the traditionally manufactured parts. For AM to become a viable process for fabricating critical components made of high-performance structural alloys, such as AlSi10Mg, a comprehensive understanding is required toward developing the process-structure-property relationships prevalent in AM. AlSi10Mg, with its good castability, strength, hardness, and dynamic properties, is typically used to fabricate structural components that are required to withstand high loads. This alloy has been consolidated predominantly by the laser powder bed fusion (L-PBF) method and several critical mechanical properties, such as fatigue, have been reported to date. This article, first, summarizes the as-deposited and heat-treated microstructures of AlSi10Mg specimens fabricated by L-PBF. Then, the article discusses the linkages among the feedstock properties, printing parameters, specimen geometry, post-processing techniques, and fatigue properties. This discussion is followed by a section on the fatigue life prediction of AlSi10Mg specimens using computational modeling. Finally, the article identifies critical research gaps and pinpoints future research opportunities.

Recent developments and future trends in fatigue life assessment of additively manufactured metals with particular emphasis on machine learning modeling

“…The main process parameters considered in the literature include laser power ( P ), scanning speed ( v ), hatching space ( h ), layer thickness ( t ), beam diameter ( d ), and scanning strategy. The volumetric energy density parameter E d , which considers P , v , h , and t (Equation 2), is a measure of the energy transferred per unit volume of material, widely considered to be a key factor affecting the fatigue properties of materials 79–81 . When E d is low, the energy source is not enough to completely melt the raw material, forming defects such as LoF; when E d is optimal, the material is of great density; and when E d is too high, the raw material is over‐melted to form balling phenomena.…”

Green Approach for Electropolishing Surface Treatments of Additive Manufactured Parts: A Comprehensive Review

“…The surface quality of the AM parts is strongly influenced by both the powders or wire feedstock characteristics and the process parameters [11]. It is worth remembering the additional advantage of re-using powders for the PBF technologies, which, however, could generate final products with different characteristics from those obtained from virgin powders.…”