Abstract
The cutting properties of cobalt-free tungsten carbide using a monocrystalline diamond tool were investigated experimentally. Cutting-point temperature was measured using a dual-color radiation pyrometer and an optical fiber under different atmospheres, such as air, nitrogen gas, and argon gas. The cutting-point temperature was highest in argon gas, followed by nitrogen gas and air. The volume of diamond wear was also highest in argon gas, followed by nitrogen gas and air. This order agrees with that of the friction coefficient. As the maximum temperature of cutting-point was less than 250°C, the physical and chemical properties of the diamond and the tungsten carbide did not change during the cutting process. Diamond wear is caused by mechanical abrasion, rather than any chemical reaction, which will be accelerated under high temperature. Although abrasive wear of the diamond tool was reduced in air due to an adhering layer of oxygen, which acts as a lubricant, oxygen promoted the occurrence of diamond-tool chipping.
