On the numerical modeling of laser powder bed fusion additive manufacturing of Ti-6Al-4V

Resumo

Laser Powder Bed Fusion (LPBF) represents an additive manufacturing methodology employed to produce intricately designed components. Residual stresses, stemming from the swift thermal transitions inherent in this process, can give rise to defects like cracks, distortions, and delamination. This research endeavors to comprehensively examine the dynamics governing the progression of residual stresses and temperatures during the LPBF of Ti-6Al-4V. A three-dimensional finite element model was developed to investigate the influence of various process parameters on the intricate variations of temperature and stresses throughout multi-layer LPBF procedure, as well as the resultant residual stress post-cooling. The outcomes reveal a substantial influence of process parameters on the temperature gradients and final stress distributions. Notably, higher input energy to the layer led to elevated induced residual stresses. The transition from 50 W to 400 W in laser power resulted in a pronounced shift in residual stress, effecting a transformation from -56 MPa (i.e., compressive) to 148 MPa (i.e.,tensile).