Effect of laser power on molten pool evolution and convection

Abstract

The cladding layer formed by laser cladding is formed by solidification of the molten pool. The quality of the cladding layer is directly determined by the evolution of the molten pool. The numerical simulation of the evolution of the molten pool is carried out, revealing the relationship between different powers and the evolution of the molten pool. The results show that the volume of the molten pool exhibits a nonlinear expansion of “expansion-shrinkage-re-expansion” before reaching the steady state, and the volume and expansion rate of the molten pool are determined by the laser power. In addition, the degree of shrinkage of the molten pool and the speed of convection can also be controlled by the laser power. When the laser power reaches a certain level, evaporation occurs on the surface of the molten pool. The convection pattern of the molten pool can be changed by evaporation. However, due to the impact of shielding gas and Marangoni movement, the effect of evaporation on the geometry of the cladding layer is limited.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the 2016 Green Manufacturing System Integration Project of Ministry of Industry and Information Technology of China under Grant no. 201675514, Liaoning Provincial Key Laboratory of Large Equipment Intelligent Design and Manufacturing Technology under Grant no. 18006001, Research on the Theory and Method of Quality Intelligent Control in the Re-manufacturing Process of Waste Mechanical and Electrical Products under Grant no. 51305279, Program for the Top Young Innovative Talents of Lianoning Revitalization Talent Program under Grant no. XLYC1807211, and Program for the Top Young and Middle-Aged Innovative Talents of Shenyang under Grant no. RC190148.