Study on the tool wear and its effect of PCD tool in micro milling of tungsten carbide

Tungsten carbide is the most promising material to produce glass molds due its unique properties. This paper conducts an tool wear experiment on PCD micro end mill in micro milling of tungsten carbide. The tool wear characteristics are observed and tool wear mechanisms are analyzed. The results show that PCD tool wear is concentrated on the tool tip, and a triangular wear belt is formed on the tool bottom surface. The involved tool wear mechanisms mainly include the adhesive wear, micro chipping and abrasive wear. After PCD tool is worn, the cutting forces is increasing, some tungsten carbide is removed with brittle fracture, then micro defects are generated on the milled surface. Tool tip shape of the worn PCD tool is copied to the milled groove and makes it a reverse cone-shape.