Journal of Materials Research and Technology (Mar 2022)
A review on the fatigue behaviour of AlSi10Mg alloy fabricated using laser powder bed fusion technique
Abstract
Laser powder bed fusion (LPBF) of AlSi10Mg alloy is widely studied for the aerospace and automotive applications. Considering safety over cost, fatigue life of the material is very critical for these applications. This article reviews the interrelationship between the LPBF process parameters-microstructure-crack initiation and crack growth mechanisms under fatigue loading conditions. It addresses current problems and potential opportunities in the fabrication of fatigue-resistant AlSi10Mg alloy for light weight structural applications. The methodology for mechanical testing techniques, specimen design guidelines, post-manufacturing treatments, and other aspects of AM parts ought to be standardised. It is possible to standardise the LPBF process thorough understanding of the interrelationships among process parameters, structural aspects such as microstructure of solidified material, and mechanical properties of the fabricated part. The deformation and fracture mechanism during the cyclic loading of influences the fatigue resistance of AlSi10Mg alloy. Influence of these microstructural features, grain morphology, texture, pore size, shape distribution, and surface roughness on the fatigue properties are vital for any applications that prioritize safety over cost. The hierarchical microstructure in the LPBF processed material showed an interesting crack growth mechanism, this mechanism of crack growth is an important novelty of this work. The influence of process of sample removal and post processing on the fatigue properties are significantly control the fatigue properties. Heating the substrate of the built sample and certain post processing conditions were observed to relieve the stress in the as-built material. Post-heat treatment observed to improve the fatigue property of the selective laser melted AlSi10Mg alloy owing to the homogeneous redistribution of Si particle from the cellular boundaries and stress relief. Hence, in this review, the inter-relationship between the LPBF process parameters-microstructure-crack initiation and crack growth mechanisms under cyclic loads were studied in detail. The major aspects reviewed in this article include influence of process parameters on fatigue life and their interaction with the formation of defects. Further, specific factors dictating the fatigue characteristics in as-built and post processed AlSi10Mg alloy are elaborately discussed, concluded by fatigue models detailing the fatigue failure mechanisms.
