Comparative tribological properties of magnesium hexasilicate and serpentine powder as lubricating oil additives under High temperature

Friction and wear experiments were carried out with nanoscale serpentine (magnesium silicate mineral) and magnesium hexasilicate powder as lubricating oil additives at 400 °C. The tribological test results showed that the self-repairing protective layers could be well formed on the contact surfaces, whether nanoscale serpentine or magnesium hexasilicate powder was added into lubricating oil. The SEM and EDAX analysis demonstrate that the morphology and elements of both self-repairing layers are in accordance with each other. The research results indicate that the essence of self-repairing of serpentine power is isomorphic replacement and tribochemical reaction between magnesium silicate and metal matrix.