New Copper-Based Composites for Heavy-Loaded Friction Units

Constraints in the use of bushings produced of the new copper-based bearing composite material alloyed with nickel and molybdenum and containing the additives of CaF2 (DN5M3KF9) solid lubricant are analyzed. The structure and tribotechnical properties are examined during reverse friction under heavy load (temperature 400–600°C and load up to 6.0 MPa in air). The study focuses on the distribution of CaF2 in a composite with Cu–Ni–Mo matrix, the role of calcium fluoride in the self-lubrication of the material, and the distribution of chemical elements of friction pair and CaF2 in the friction zone under extreme operating conditions. It is shown that the solid lubricant is evenly distributed along the contact surfaces as it envelops the entire friction zone during reverse friction under heavy load. It is established that tribofilms formed in the presence of CaF2 solid lubricant provide high wear resistance. Also, the new material possesses high thermal conductivity. These properties extend the application of new cooper-based composite bearing bushings in a chassis.