A NUMERICAL MODEL OF LASER-GLAZING PROCESS APPLIED TO STAINLESS STEEL

Laser glazing of materials has grown significantly in recent decades due to its success at improving surface properties of both metals and ceramics. While applications are far ranging, and may include glazing of semiconductors in the microelectronics industry, benefits primarily stem from improved microstructure, i.e., reduction of porosity and creation of finegrained structure. Obtaining these results, however, requires understanding the relationship between input parameters such as laser intensity and scanning speed and outcome such as extent of melting.

A three-dimensional conduction model was formulated to predict the extent of melting. The model incorporates a unique variable-absorptivity function to account for absorptivity differences between solid and liquid phases, and also considers energy loss associated with phase change of melting. Predictions were compared to results from laser glazed type 304 stainless steel and to results from a constant-absorptivity model. The results were derived from experiments using a continuous-wave CO₂ laser over a range of power and scanning speed. Good agreement was found between the model and experimental results.