Tribological Properties of Magnesium Ion-exchanged α-Zirconium Phosphate as a Solid Lubricant Additive in Lithium Grease

Magnesium ion-exchanged a-zirconium phosphates (Mg- α -ZrP) with particle sizes of 600 and 80 nm were prepared through the sealed ion-exchange and one-step hydrothermal synthesis methods, respectively. It was found that larger particles of Mg- α -ZrP had a higher load-carrying capacity than that of smaller particles, whereas smaller Mg- α -ZrP particles had better anti-wear properties than that of larger Mg- α - ZrP particles under mild loads. The correlation between the particle size of the sample and the surface roughness of the friction pair thus seems to be a key factor influencing the performance.