Lead-bismuth liquid metal: Lubrication behaviors

Lead-bismuth eutectic liquid metal (LBE)is the primary coolant for the advanced liquid-metal nuclear reactor, and clarification of its lubrication behavior and mechanism at elevated temperature is of importance. In this paper, a self-mated high-temperature steel sliding-pair and a pin-on-disc configuration are selected to evaluate the lubrication behaviors of LBE at 250 °C and 400 °C under argon atmosphere. It is found that LBE possesses an excellent lubricity proofed by the low friction coefficient of 0.1 and the wear rate of 10⁻⁶ mm³/Nm for the steel discs. Close inspection on the friction interfaces indicates that the worn surfaces of the steel discs are covered by a smooth tribo-film consisting of Bi, Pb₇Bi₃ and the related oxides.