Preheating Effects on Multiple Material Laser Densification

A 3-dimensional thermomechanical model has been developed to study laser powder densification of multiple materials in the multi-materials laser densification (MMLD) process. Thermal and mechanical properties of the materials are porosity- and temperature-dependent. In particular, the effect of the chamber preheating on residual stresses and warping of the part fabricated has been investigated. It is found that the chamber preheating can reduce warping and residual stresses of the laser-processed part. Furthermore, the extent of the preheating effect depends on the laser-scanning pattern. Implications of the simulation result on MMLD have been discussed.