Effect of Dry Friction Parameters on the Formation of Secondary Structures in Tribosynthesis of Composite Antifriction Iron-Based Material

Abstract

The tribological characteristics of a Fe–W–CaF₂ antifriction material (CAM) in combination with 65G steel in air without lubrication at an increased sliding velocity (15 m/sec) and insignificant (0.64–1.28 MPa) pressures have been studied. It is established that with twofold increase in the pressure (from 0.64 to 1.28 MPa), the friction coefficient of the CAM decreases from 0.25 to 0.20 (by 20%), and its wear increases from 0.0158 to 0.03085 mg/km (by 49%) but remains insignificant. The factors acting in the friction process lead to the formation of secondary structural lubricating films on the material. They prevent mechanical contact between the surfaces of the friction pair and provide necessary antifriction and operating properties. It is shown that the secondary structural lubricating films in the form of thin layers of material with inclusions of solid lubricants differ from the initial material in chemical and phase composition, structure, structural state, and are characterized by increased mechanical characteristics.