Friction coefficient under high pressure, e.g., cold forging, was carried out by pin-on-disk test using N oil as lubricant with a viscosity of 94 sq mm/sec at 40°C and a density of 1.02 g/cc, which was applied by dropping into the concave part of the disk before testing. The coefficient of friction of a disk-type test specimen made of tool steel did not show any change with applied load, but in the case of a disk-type test specimen made of high-speed steel, the coefficient of friction decreased with applied load. The coefficient of friction was lower in the case of surface finishing with emery paper No. 800 than in that of surface finishing to a mirror-like level. The coefficient of friction decreased with a decrease of applied load, but the surface of cemented carbide finished by using emery paper No.240 to a slightly rough level did not show any reduction of the coefficient of friction even under low load conditions. The treatment of the entire surface of cemented carbide resulted in coefficient of friction larger than that observed on the untreated surface.
|Number of pages||11|
|Journal||Japanese Journal of Tribology|
|Publication status||Published - 2003|
ASJC Scopus subject areas
- Mechanical Engineering