Study on the Influence of Capillary Force and Thermal Capillary Force on Surface Bulge Morphology by Laser Micro-Melting

Metal surface laser micro-melting technology is widely used in laser cladding, laser welding and laser texture fields. In this paper, laser micro-melting model is established according to the surface morphology forming mechanism. The effects of boundary heat transfer, recoil pressure, surface tension, capillary force and thermal capillary force on micro-flow are fully considered in this model. The study found that the recoil pressure and capillary force are the main reason for the height variation of the morphology bulge. In the heating stage, the capillary force and thermal capillary force dominate the flow of molten metal, while in the cooling stage, the capillary force dominates the flow of the metal, and the capillary force gradually converges from both sides to the middle. This is also the reason why the morphology almost does not change in the radial direction but continues to change in the axial bulge height during cooling stage.

Automated summary

The study establishes a laser micro-melting model, taking into account the effects of boundary heat transfer, recoil pressure, surface tension, capillary force, and thermal capillary force on micro-flow. It reveals that the height variation of the morphology bulge is mainly caused by recoil pressure and capillary force. It shows that in the heating stage, molten metal flow is dominated by capillary force and thermal capillary force, while in the cooling stage, the capillary force is the main driving force for metal flow, gradually converging from both sides to the middle.