| 摘要 |
PURPOSE:To obtain a sliding part exhibiting excellent seize resistance and low frictional coefficient over a wide temperature range by impregnating Sr- containing calcium fluoride in a porous layer formed on a sliding face by nitriding treatment. CONSTITUTION:A nitride layer 1 having three-layer structure consisting of a porous layer (nitride epsilon-layer) 1a, a dense layer 1b and a nitrogen diffusion layer 1c is formed on a sliding face of a matrix 2 by gas soft nitriding treatment, salting-in nitriding treatment, ionic nitriding treatment, etc. Calcium fluoride (CaF2) containing Sr is impregnated in the porous layer 1a. The frictional coefficient is decreased in a low-temperature range between normal temperature and 213 deg.C mainly by the effect of nitride epsilon-layer. In the medium temperature range between 213 deg.C and 620 deg.C, the friction-decreasing and antiseizing effects are attained mainly by the action of Sr contained in CaF2. CaF2 is effective in imparting antiseizing effect in a high-temperature range between 621 deg.C and 900 deg.C. |
