PHASE STRUCTURE AND LUBRICITY OF IN-SITU GENERATED PROTECTIVE LAYER ON WORN METAL SURFACES IN PRESENCE OF Mg_6Si_4O_(10)(OH)_8

摘要

A mechanochemical reconditioner package has been investigated in our laboratory which could be used to generate an in situ protective layer on worn metal surfaces as a result of mechanochemical reactions between worn tribosurfaces, wear debris and a special reconditioner formulation. The main constituent in the reconditioner formulation chemistry is magnesium silicate hydroxide, Mg_6(Si_4O_(10))(OH)_8. HRTEM analyses have displayed that the protective layer consists mainly of cementite nanocrystals with crystalline anisotropy. Nanoparticles of magnet iron oxide (Fe_3O_4) and iron peroxide (FeOOH) are dispersed on the habit planes of nanocrystalline cementite matrix. The protective layer obtained exhibits very smooth top surface and excellent tribological characteristics.