Abstract
High-precision mold for smaller products are required in many manufacturing fields and demands on shorter production time of the molds are ever increasing. To meet these demands, the direct processing of high-hardness mold materials by laser machining is considered to have great potential. In this paper, micro-structure has been processed to the mold materials with high hardness by using a femtosecond laser, and the processing characteristics have been studied. Effects of air-breakdown seem to be considered in the process. Removal rate is increased by its affect. Under good processing conditions, surface roughness of Ra=0.27μm has been achieved. Thickness of heat affected zone is estimated to be less than 0.5μm, with no crack on the surface. There is only a little adhesion of debris or deposition of melt observed on the processed surface.
