NEW COPPER-BASED COMPOSITES FOR HEAVY DUTY FRICTION UNITS

Abstract

Constraints in the use of liners produced of new copper-based bearing composite material doped with nickel and molybdenum and containing CaF₂ additions (DN5M3KF9) as solid lubricant. The structure and tribotechnical properties are examined under heavy duty reversible friction (temperature 400–600°С and pressure up to 6.0 MPa in air). The study focuses on the distribution of CaF₂ in the composite with a Cu–Ni–Mo matrix, its role in the self-lubrication of the material, 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 under heavy duty reversible friction. It is established that the tribofilms formed in the presence of the CaF₂ solid lubricant provide high wear resistance. Also, the new bushing material possesses high thermal conductivity. These properties extend the application of new cooper-based composite bearing bushings in the carriage frame.