Kazem Malekipour, Mohsen Badrossamay, Mohammad Mashayekhi, "Parametric investigation of micro-pores coalescence in the microstructure of LPBF manufactured AISI 316 stainless steel under high cycle fatigue loading", Engineering Failure Analysis, PP. 106942

Kazem Malekipour, Mohsen Badrossamay, Mohammad Mashayekhi, "Parametric investigation of micro-pores coalescence in the microstructure of LPBF manufactured AISI 316 stainless steel under high cycle fatigue loading", Engineering Failure Analysis, PP. 106942, 144, 2023.

Abstract:

In this study, damage growth and load-carrying capacity of specimens made by laser powder bed fusion (LPBF) at various triaxial stresses have been evaluated by the damage mechanics approach, using the Chaboche-Lemaitre stress-based damage model and Lemaitre damage model based on equivalent plastic strain under high cycle fatigue (HCF) loading. In this regard, with the development of a parametric numerical model, the effect of stress triaxiality, external HCF loading, and micro-pore geometric parameters size on the damage growth and coalescence of two-void cluster embedded in representative volume element (RVE) have been investigated. The results show that increasing the triaxial stress from 0.5 to 2.1 leads to a severe decrease in ligament load carrying capacity and eventually voids coalescence through an increase in von Mises stress around the micro-pores. The results also indicate that a two-void cluster with a relative distance of less than 10 can be considered as a crack initiating site in the microstructure of LPBF components under HCF loading.

Keywords: Mechanical engineering; Selective laser melted parts; AISI 316 stainless steel; Additive manufacturing; Finite elements analysis; Fatigue; Manufacturing defect; Laser powder bed fusion.