2008 年 74 巻 748 号 p. 1511-1518
In order to clarify the influence of crack density on friction and wear properties of electroplated chromium molybdenum films, the films deposited on tool steel substrate under high and normal current densities were used. The crack density of the film electroplated at high current density was higher than that electroplated at normal current density. Friction and wear properties of the films were evaluated by using a pin-on-disk type wear testing machine under un-lubricated condition. The results showed that the wear rate of both the film and pin was decreased remarkably by increasing crack density. The friction coefficient of the films indicating about 0.2 at the beginning of the wear test increased with increasing the number of rotation cycles and reached a stable value. Detailed observation of wear scar and wear products showed that flake-like delamination of film occurred by repeating sliding load, and friction and wear properties had close relationship with the flake-like delamination property.