Pressure-dependent anti-wear mechanisms of synthetic magnesium silicate hydroxide nanoparticles

Abstract The paper describes series of four-ball tribological and dichromatic interference test results obtained under different contact pressures and performed for polyalphaolefin (PAO) suspended synthetic magnesium silicate hydroxide (MSH) nanoparticles. Results show that MSH as additives in oil exhibits excellent anti-wear performance, and even results in ‘zero wear’ under a maximum Hertzian pressure of 2.71 GPa. Their anti-wear mechanisms are various depending on the contact pressure. Under a relative mild pressure, MSH can effectively increase the oil film thickness, thus to achieve a substantial reduction in wear. As the test pressure becomes severer, a tribofilm containing Mg, Si and O would form on the worn surface to provide a secondary anti-wear guarantee.