A Protective FeGa3 film on the steel surface prepared by in-situ hot-reaction with liquid metal

Ga-based liquid metal may be a novel coolant and lubricant for the steels at high temperature and extreme pressure in the nuclear reactor. It is recently reported that the formation of FeGa3 film may be responsible for the good lubricity of liquid metal, but no proof can clarify this point and its wear behavior is unclear. Therefore, an in-situ FeGa3 film was prepared through the hot-reaction between liquid Ga65In22Sn13 (65% Ga, 22% In, 13% Sn by mass) and T91 steel at 600 °C in this paper. The results indicate that FeGa3 film forms and bonds strongly to the steel surface. It has good mechanical and tribological properties at room temperature, but increases the wear at 600 °C. The finding provides the technical support for the safety service of the steels in the liquid-metal environment and is also a new strategy for protecting the steel.