A new understanding of the wear processes during laser assisted milling 17-4 precipitation hardened stainless steel

Laser assisted machining is known to improve the machinability of several difficult to cut materials. For the first time, this study investigates the tool wear rates and the wear mechanisms associated with milling a precipitation hardened martensitic stainless steel with and without the assistance of laser preheating. Across both traditional low feed milling and emerging high feed milling techniques, laser assistance was found to reduce the tool wear rates by up to 50% and lower the cutting force by up to 33% in comparison to conventional room temperature machining. In all cases it is observed that tool coating breakdown by abrasive and adhesive wear processes is the dominant tool failure mechanism. Laser assisted milling is effective in prolonging tool life by delaying these processes in comparison to conventional machining.