Modeling of laser deposition and repair process

Laser aided deposition is a material additive based manufacturing process via metallurgically bonding the deposited material to the substrate. Due to its capability to bond various materials together, it becomes an attractive technology for part repair in small scale. However, the details of the process remain an active area for research because of the complicated interactions involved. In this study, a mathematical model was established to investigate thermal and mass transportation phenomena, which include substrate melting and solidification as well as the powder heating process. Affected by the powder injection, the melt pool surface keeps fluctuating during the process and dynamic evolution of the melt pool shape is tracked by using the level set method. Melt pool shape and energy balance at liquid–vapor and solid–liquid interfaces are taken into account in the model. A typical hole repair process based on material deposition technology is presented. The detailed process together with the temperature distribution were simulated. The simulation results of the melt pool length and peak temperature are validated for the laser deposition process through the measurements on the melt pool geometry and surface peak temperature by the complementary metal–oxide–semiconductor camera and dual-wavelength temperature sensor.