Finite Element Method in L-PBF of Ti-6Al-4V: Influence of Laser Power and Scan Speed on Residual Stress and Part Distortion

Abstract

Laser powder bed fusion (L-PBF) is widely used in automotive, aerospace, and biomedical applications thanks to its ability to produce complex geometries. In spite of its advantages, parts produced with this technology can show distortion due to the residual stresses developed during the printing process. For this reason, numerical simulations can be used to predict thermal gradients and residual stresses that can result in part distortion. Thus, instead of performing experimental tests and using a trial and error approach, it is possible to use numerical simulation to save time and material. In this work, the effect of laser power and scan speed on residual stress and part distortion was analysed using a commercial finite element analysis (FEA) software DEFORM-3D™ with a layer-by-layer approach. Moreover, the accuracy of the numerical model with respect to process parameters and the utilised mesh was also studied. The results obtained from the numerical simulation were compared to the actual distortions to evaluate the accuracy of the FEM model. The predicted distortions using FEM analysis well fit the trend of the measured ones. The accuracy of the numerical model increases by considering a finer mesh.

Multiphysics Study of Thermal Profiles and Residual Stress in Welding

“…A range of studies have been conducted to understand the influence of welding process parameters on mechanical properties, and thus the structural reliability of welded parts [13][14][15][16][17][18][19][20]. Ferro et al [21] conducted FE simulations to examine the influence of different heat source models on thermal profiles in welding.…”

“…The influence of the heat source on residual stress was studied in several approaches [20,[25][26][27][28][29][30][31][32][33]. Huang et al [15] performed X-ray diffraction (XRD) analysis on welded structures to investigate the effects of strain hardening and annealing on the residual stress distribution of thin plates.…”