Prediction of residual stress and distortion in laser powder bed fusion additive manufacturing process of Inconel 718 alloy

Abstract

Rapid heating, melting, solidification and cooling cycles generates high residual stress in additively manufactured parts, causes to part distortion. Finite Element Method (FEM) is one of the common and practical ways to predict residual stress and distortion taking place during additive manufacturing. Thus, it is possible to determine appropriate parameters to eliminate such problems. In this study, laser powder bed fusion (LPBF) additive manufacturing (AM) of Inconel 718 alloy is considered for simulation. Case studies on the residual stress and distortion of arch-shaped structure parts were presented through comparing the simulation results in present study and experimental data borrowed from the literature. The influence of laser scanning parameters such as laser power, scanning speed, layer thickness, scanning strategy on residual stress and distortion of the arch-shaped structure was investigated and compared with the borrowed experimental results. Besides, the influence of heat treatment on residual stress and distortion is also simulated and predicted results are presented. This study reveals that the presented FEM based simulation is capable of capturing experimental data reasonably well.