Heterogenization of sliding surface consisting of tin（Sn）and copper (Cu) was attempted using a laser annealing to restrict junction growth on the interface．Sn was coated on a bronze disc surface with an electro chemical process then fiber laser annealing in the radial direction at intervals of 1 mm was applied．The resulting surface consisted of hard regions，forming intermetallic compound of Sn and Cu，and soft Sn on bronze substrate．Furnace heating treatment was also applied to the homogeneous Sn-Cu structure．Friction properties were evaluated with a ring on disc type testing apparatus mated with a hardened steel ring in lubricated condition．Results showed that the friction properties were influenced by the heating history．The heterogeneous structure was effective means to decrease and stabilize the friction coefficient．The effect of heterogenization of sliding surface structure on restricting junction growth to stabilize friction properties was discussed．
ONO et al. (Wed,) studied this question.