Enhanced ability of magnesium silicate hydroxide in transforming base oil into amorphous carbon by annealing heat treatment

Abstract

The morphology, thermal stability, phase composition, chemical groups of nanoparticles were characterized, and appropriate thermal process maintains layered structure and weakens the interlayer interaction of the MSH-AHT400. The tribological performances of MSH-AHT400 as lubricant additive are improved due to the decrease of interlaminar shear strength of nanoparticle. Usage of the as-synthesized nanoparticle leads the formation of a-C tribofilm with higher degree of graphitic structural order. Meanwhile, the degree of graphitic structural order of the a-C correlates with the tribological performances positively. The simulations of classical molecular dynamics (CMD) and Ab-initio molecular dynamics (AIMD) confirm the ability of hydroxyl (–OH) and magnesium ions (Mg2+) in transforming base oil into a-C. A tribological mechanism of MSH-AHT400 as lubricant additive is proposed based on the aspects of easier interlaminar cleavage, nano-polishing and filling and repairing of composite tribofilm containing a-C.