Досліджено синтез вторинних структур на поверхні тертя самозмащувального композиційного матеріалу на основі міді Cu–Sn–P–MoS2, при роботі у вакуумі 2,10–5 мм. рт. ст. у парі зі сталлю ШХ15 при тисках 2,5 і 5,0 МПа та швидкості ковзання 1 м/с. Показано, що працездатність матеріалу СКАМ у вакуумі обумовлена особливостями його структурної побудови і функціональною адаптацією до умов експлуатації завдяки трибосинтезу на робочих поверхнях вторинних плівок ? шару матеріалу нової структури, відмінногопо хімічному і фазовому складу, структурному стані та механічним властивостям від основного вихідного матеріалу.
We have investigated the synthesis of secondary structures on the friction surface of a Cu–Sn–P–MoS2 self-lubricating composite material based on copper during operation in a vacuum of 2·10–5 Hg mm in pair with ShKh15 steel under a pressure of 2.5 and 5.0 MPa at a sliding velocity of 1 m/s. Secondary lubricating films synthesized in the process of friction, like the initial material, have a microheterogeneous structure. Their matrix is homogeneous ?-solid solution of tin in copper hardened by molybdenum phosphide, and a conglomerate of compounds (Cu2S+MoS2) plays the role of a solid lubricant. In contrast to the components of the initial material, the structural components of the secondary lubricating films are in the fine-crystalline state because the ratio H/E* for them is ~0.05. The size of structural elements is ~100 nm. Their relative strain ?es and index of normalized hardness H/E* increased twice as compared with those for the initial material. Several factors, including the chemical composition, phase composition, and structural state of the secondary films, which changed in friction under load, can be causes of the improvement of the indicated mechanical characteristics of these films. The increase in the aforementioned micromechanical characteristics and the transition of the structural components of the lubricating films into the fine-crystalline state confirm the hardening of the surface layer of the Cu–Sn–P–MoS2 self-lubricating composite material and the enhancement of its wear resistance (I < 5 ?m/km) during friction in vacuum. Thus, the serviceability of the Cu–Sn–P–MoS2 self-lubricating composite material in vacuum is due to the characteristic features of its structure formation and functional adaptation to the operating conditions owing to the fact that, on the working surfaces, the tribosynthesis of secondary films, namely, a layer of a material having a new structure and differing in chemical and phase composition, structural state, and mechanical properties from the main initial material, occurs.
