| Abstract: | The frictional properties of lead‐tin thin films (thickness of 0.05–0.19 μm) with two types of copper interlayer were investigated. The thin film and the interlayer were formed on a silicon wafer surface by vacuum deposition. Friction tests were carried out using a ball‐on‐disc apparatus in a vacuum chamber. The thin copper interlayer reduced the friction coefficient and prolonged the film life. The effect of load on the friction coefficient is explained by an equation derived using the Hertzian contact area between a sphere and a plate. The thicker copper interlayer did not reduce the friction coefficient but markedly extended the life of the film. In this case, the dependence of the friction coefficient on the load is explained by an equation derived using the Hertzian contact area between a sphere with surface roughness of second order and a plate. |
