Effect of CaF2 surface layers on the friction behavior of copper-based composite

The paper studies the effect of the process parameters for the production of new copper-based bearing composite materials doped with nickel and molybdenum, with CaF2 additions (DN5M3KF9) as a solid lubricant, on the structurization and tribotechnical properties at high-speed friction (bearings perform at a sliding speed of 6 m/sec and a pressure up to 38.5 MPa in air). The study focuses on the distribution of CaF2 in the composite with a Cu–Ni–Mo matrix, its role in self-lubrication of the material, and the behavior of CaF2 in the friction area under extreme operating conditions. It is shown that the solid lubricant is evenly distributed over the contact surfaces as it piles up over the entire friction area during high-speed friction. It is established that the tribofilms formed in the presence of the CaF2 solid lubricant provide high wear resistance of copper-based materials.