Effect of Graphite Filling Pore Structure Size on the Tribology Behaviors of Tin Bronze/45 Steel Pairs With Grease Under Low-Speed and Heavy Load Conditions

Copper-based solid lubrication inlay technology is widely used in industrial production, especially in low-speed and heavy load conditions, and the structure and distribution of the filling pore have a significant influence on the friction performance due to the distribution of contact stress. In this paper, based on the operating conditions of the bottom pivot of the Three Gorges gate, graphite is used as a solid filled lubricant. The effects of filling pore diameter, filling pore depth, and area distribution rate on the friction and wear properties were studied by orthogonal equivalent test on MMW-1A tester with grease. Combining the three-dimensional morphology test and ferrography analysis, the results show that: 1) the influence of three parameters on the test results are: filling pore diameter > area distribution rate > filling pore depth; 2) when the filling pore diameter is 3 mm, the area distribution rate is 12%, and the filling pore depth is 0.5 mm, which is the equivalent the optimal structure of the filling pore size under working conditions. According to this conclusion, the actual filling structure can be obtained based on the similarity theory. As Coulomb friction is material and contact stress related, the calculation of the stress distribution during dynamic operation is difficult and therefore the analysis is carried out experimentally.