PROSPECTS OF IMPROVING THE TRIBOTECHNICAL CHARACTERISTICS OF TITANIUM COMPOSITES

摘要

Titanium-based composites containing MoS_2, MoSe_2, CaF_2, and BN solid lubricants are synthesized. Their tribological characteristics are investigated without lubrication at different sliding velocities (0.5, 1, 2, 4, 6, and 15 m/sec) and low pressures (0.27, 0.54, 0.8, 1.1, 1.35, 1.47, and 2.7 MPa) in air. In view of the high friction coefficient and large wear, the composite materials cannot be proposed as antifriction ones for operation at small sliding velocities and low pressures. The titanium-based composites are promising as antifriction materials at an increased sliding velocity (15 m/sec) and low pressures when their friction coefficients range from 0.3 to 0.36 and wear ranges from 1.91 to 68.3 mg/km. In dry friction at a high sliding velocity in air, the temperature of their working surface increases resulting from the formation of titanium oxides and then a dense secondary lubricating microheterogeneous film. The composition and structure of the secondary films differ from those of the starting materials and determine their antifriction properties and friction performance.