Full cycle numerical simulation during the pulsed laser cladding process considering the interaction between laser and powder

Abstract

During the pulsed laser cladding process, complex thermal accumulation occurs between powder and beam due to the pulsed laser periodic change. The selection of process parameters affects the cladding layer quality, and the correlation between the parameters is high. It is of great significance to obtain high quality cladding layer to determine the influence of the powder-carrying gas nitrogen velocity, powder feeding port diameter, and powder feeding angle on the powder flow, as well as the optimal powder shading rate and the mechanism of powder interaction with pulsed laser beam. In this paper, a gas–solid coupling model during the pulsed laser cladding process of three-beam coaxial powder feeder was established, and the rotating Gaussian heat source function of pulsed laser was written to calculate the temperature, flow velocity, and concentration distribution considering the interaction between laser and powder. The orthogonal test method was used to optimize the process parameters in order to reduce the shading rate of powder and improve the laser energy utilization. On this basis, a full cycle three-dimensional multi-field coupling numerical model for pulsed laser cladding process was established, and the temperature, flow, stress fields, and multi-component heat and mass transfer behaviors were calculated under different powder shading rates. The flow temperature of powder was collected by infrared thermometer and compared with the numerical results, the reliability of the model was verified. This study provides a significant theoretical basis for the full-cycle optimization of process parameters and the improvement of cladding layer quality during pulsed laser cladding.