Investigation on Operating Temperature in Laser Assisted Milling of Silicon Nitride Ceramics

This paper discusses the operating temperature in laser assisted milling (LAMill) of silicon nitride ceramics. Experimental investigation shows that the laser parameters including laser power, laser beam diameter, laser translating speed and preheat time affect the temperatures at the cutting zone. Especially, laser intensity plays an important role in the heat absorption of silicon nitride ceramics. In LAM, high laser intensity is desired. In addition, laser interaction mechanism with silicon nitride shows that high operating temperature may cause the material at the thin top layer of the workpiece to oxidize and thereby forming silica bubbles. With high operating temperature the machined surface of the workpiece has good finish and less edge chipping.