Study on Diamond Cutting of Ion Implanted Tungsten Carbide With and Without Ultrasonic Vibration

Tungsten carbide (WC) is an outstanding mold material used in precision engineering. In the manufacturing of high-quality surface with nanometric roughness, ultraprecision diamond cutting is always employed. As a typical difficult-to-cut brittle material, however, WC leads to significant tool wear during the process. For the WC that contains cobalt as a binder, this classical problem has been traditionally mitigated by ultrasonic-assisted cutting. While for a binderless WC, experimental work has shown that ultrasonic vibration may aggravate tool wear and deteriorate surface integrity. Therefore, surface modification of binderless WC by ion implantation is investigated in this paper. Material lattice structure, mechanical properties and nanometric cutting process of normal and implanted WC are experimentally investigated. Molecular dynamics simulation is conducted to understand the processes from atomic-scale. Deformation mechanism, stress field and cutting forces are analyzed. The results reveal that after ion implantation, the surface layer of WC becomes amorphous and softer, which significantly improves the chip formation and the machinability at nanoscale.