Melt Pool Flow Dynamics of Copper Imbued Surface Alloyed 304 Stainless Steel: Role of Laser Power and Scanning Speed Tuning

This study emphasizes the crucial role of Marangoni convection in the laser surface-alloying of 304 stainless steel (304 SS) with copper (Cu). By studying the microscopic behavior of the melt pool during CO2 laser alloying, the study reveals the association between Marangoni convection and the resulting microstructure. The findings demonstrate that the most optimum deposited track can be observed at power 80 W with a scanning speed of 0.4950 mm/s while the highest scanning speed of 0.6329 mm/s produced the finest grains. From the microhardness analysis, sample with the scanning speed of 0.6329 mm/s yielded the best microhardness due to fast cooling and solidification, highlighting the importance of controlling the process parameters to achieve the desired outcome. This data provides valuable insights into the laser-matter interaction and underscores the need to understand underlying melt pool flow dynamics mechanisms such as Marangoni convection to optimize the process for high-quality results.