Optimisation of Process Parameter for Fabrication of Micro-hole in SS304 using Fiber Laser

Abstract

Micro-holes play an important role in micro-product used in aerospace, medical and nuclear application. It is a challenging task to drill micro-holes with high aspect ratio with better surface-finish and surface integrity. Fabrication of micro-holes using laser drilling process is having certain advantages over other processes. Process parameters in laser drilling process influence the quality of micro-hole like circularity, cylindricity, taper, heat affected zone and recast layer thickness. In the present investigation, the fabrication of micro-holes has been carried out in SS304 using fiber laser. The optimization of the process parameters has been carried out to achieve the quality of holes. The hole contour has been determined from the melt isotherm contour using a numerical method due to the action of multi-pulsed laser. A generalized thermal model has been developed based on the assumptions of materials removal by combination of evaporation and liquid explosion.