Cutting of cobalt-free tungsten carbide using a monocrystalline diamond tool

—3^rd report: Effects of lubrication oil on friction and wear characteristics of diamond tool—

Abstract

Friction and cutting of cobalt-free tungsten carbide using a monocrystalline diamond tool were examined using lubrication oils, such as water-miscible cutting fluid, sulfur-based extreme-pressure additives, zemetril-silicon, oleic acid, and zinc dialkyldithiophate (ZnDTP). The tool wear was greatest under zemetril-silicon, followed by water-soluble coolant, and was smallest under ZnDTP. Chipping was greatest under water-soluble coolant, followed by sulfur-based extreme-pressure additive, and smallest under ZnDTP. Cipping contributes to tool wear more than abrasive wear. Chipping wear is minimized under ZnDTP resulting in 0.022μm Ra after 177 m cutting.