Modeling of melt pool width and melt pool temperature in laser metal deposition based on closed-loop control

Laser metal deposition technology has found broad applications in the aerospace and marine industries due to its various advantages in terms of high material utilization and unlimited forming dimension. However, due to its complex deposition variations, it is difficult to model the relationship between the process parameters. This limitation hinders research on its mechanism of action and control, leading to challenges in ensuring the quality of deposition and stability of the process. In this study, the melt pool width controller and the melt pool temperature controller were developed to investigate the relationship modeling, respectively. Laser power was selected as the only process control output. The positive correlation and strong coupling between melt pool width and temperature were experimentally verified. The Gaussian distribution of the temperature field of the deposition process was investigated as the cause of the nonlinear relationship between melt pool width and temperature. The melt pool width and melt pool temperature model obtained from this Gaussian temperature field fits the experimental data well, with an <i>R²</i> coefficient of 0.97. This study is of great significance for the mechanism of melt pool temperature on melt pool width during the deposition process. It also contributes to the integration of micro-property control and geometric accuracy control.