An investigation of laser material deposition through numerical and experimental techniques

Abstract

For Laser Material Deposition (LMD) to produce a sound end product, the optimum processing parameters need to be determined. The traditional approach undertaken to investigate the process parameters is empirical, which can be time consuming and expensive. Thus, many researchers resort to process modelling and simulation by means of which the optimum parameters can be predicted by replicating the deposition process using dedicated software. Some level of experimentation is however always required to verify the model and obtain data for verification. In this study the deposition process was simulated to obtain the thermal history in order to predict the microstructure of the deposited part. The thermal histories and cooling rates were also determined empirically for the scope of model verification and to investigate the influence process parameters have on these two physical phenomena. Macro- and micro-defects and the microstructures obtained using different process parameters were furthermore identified and reported in order to obtain the optimum operating parameters within a parameter envelope. Moreover, the thermal experimental data obtained was compared to the simulation data to evaluate the level of accuracy of the simulation model. The contribution of this study was the determination of the optimum parameters and modelling of the LMD process using the software Ansys.