Investigation on Tool Performance in Ultrasonic Vibration Assisted Cutting SiCf/SiC Ceramic Matrix Composites

Ceramic matrix composites have been a promising advanced material due to its superior properties such as high strength and high temperature resistance. However, due to the high hardness and brittleness of reinforcement and matrix, the machining of this new material still needs to be solved. In this study, investigation of tool performance was conducted on SiC fiber reinforced SiC ceramic matrix composites using ultrasonic vibration assisted machining technique with taking advantages of decreasing cutting force, reducing tool wear and improving machinability. Three types of tools including PDC, brazed diamond tool and electroplated diamond tool were tested by carrying out ultrasonic vibration assisted milling-grinding experiments. The milling-grinding force, material removal volume and machined surface roughness was comparatively studied at the same machining conditions. From experimental results, it was found out that the wear mechanism of PDC and electroplated diamond tool was mainly abrasive wear and fracture of grains while pull-out of grains could be additionally found for brazed diamond tool. The PDC had a better tool performance with material removal volume being 12 times and 50.63 times as larger as that of brazed diamond tool and electroplated diamond tool respectively. It was recommended that the PDC could be used for high precision machining and brazed diamond tool could be chosen for rough machining or semi finish machining in ultrasonic vibration assisted milling-grinding SiC fiber reinforced SiC ceramic matrix composites.