The investigation of the influence factors of repairing quality during the laser directed energy deposition repair process

Purpose The purpose of this study is to analyze the molten pool dynamic behaviors during the high quality repair process and the influence factors of repairing quality in the laser directed energy deposition (LDED) repair process. This study aims to improve the service performance of metal parts. Design/methodology/approach This paper develops a dynamic model for LDED repair process by considering the interaction of laser beam and powder stream. The repaired surface morphologies under the different process parameter conditions are calculated and the corresponding repairing quality is evaluated by the quantitative evaluation method. The influence factors on the repairing quality are analyzed by the Pearson correlation coefficient. Findings The quality of the surface repaired under the condition with appropriate powder feeding amount per unit length is higher than others. The molten pool dynamic behaviors characteristics with the stable temperature distribution and molten metal flow are beneficial for stable repair process and repaired surface formation with high quality. The depth of molten pool, heat dissipation and average mass-averaged mean kinetic energy have great influences on the repairing quality. Originality/value The proposed method can provide the excellent condition for the desired molten pool dynamic behaviors characteristics in the LDED repair process. The obtained results are efficient for improving the repairing quality and service performance of metal parts.