| 摘要 |
PROBLEM TO BE SOLVED: To obtain a lead-free material for plain bearing by incorporating tin as a principal material and further incorporating a specific amount of one metal selected from the group consisting of nickel, cobalt, and iron. SOLUTION: The content of one metal selected from the group consisting of nickel, cobalt, and iron is 1 to 5 wt.%, desirably 1.5 to 3.5 wt.%, more desirably 2 to 3 wt.%. The material is deposited by means of electroplating or physical vapor deposition such as cathode sputtering. In the deposited state, nickel is allowed to enter into solid solution in a tin matrix and this state is a metastable phase; a state where an intermetallic compound Ni3Sn4 is dispersed in a tin matrix is a stable phase. The intermetallic compound is precipitated at a temperature exceeding 100 deg.C. The extremely small size of the precipitates strengthens the resultant film and provides excellent fatigue resistance and wear resistance. In order to obtain a perfectly-lead-free bearing by combination with an overlay alloy, an aluminum-alloy-base bearing material is used. |
