Modeling and Verification of Temperature Distribution and Residual Stress in Laser Aided Metal Deposition Process

Laser Metal Deposition is a novel, robust technique to manufacture or repair complex aerospace parts. However, as this process is very complicated and often operating at very high temperature, the resulting material behavior is hard to predict. The strain and stress induced by large thermal gradients in the fabrication process may cause parts failure such as cracking and distortion, so it is essential to make sure that the parts have sound mechanical properties after LMD. The focus of this paper is to develop a reliable model for Ti-6Al-4V laser deposition process and discuss how to reduce the residual stress. Using the commercial code ABAQUS, a 3D finite element model is developed for both thermal and mechanical analysis so temperature field generation and residual stress prediction is implemented. In addition, the impact of deposition patterns on strain and residual stress will also be studied. A set of experiments will is developed to validate the simulation results. This validated predictive model would enable the industry to control appropriate parameters during LMD process in order to fabricate or repair parts with good mechanical properties.