Synthesis and Tribological Performance of Different Particle-Sized Nickel-Ion-Exchanged α-Zirconium Phosphates

Nickel-ion-exchanged α -zirconium phosphate (Ni- α -ZrP) was synthesized by a mild hydrothermal synthesis method. Different raw material ratios (NaF/H 3 PO 4 /Ni(CH 3 COO) 2 ·4H 2 O) influence the particle size of the Ni- α -ZrP samples. The grain size could be controlled and distributed from 20 to 600 nm. Ni- α -ZrP was evaluated as an additive in lithium grease in a four-ball test. A 3.0 wt.% addition of Ni- α -ZrP to lithium grease yielded maximum non-seizure load values of 1235 N, and the wear scar diameter on the lower balls is 0.42 mm at 294 N. Compared with smaller particles, the addition of Ni- α -ZrP with a larger particle size to grease yields a better load-carrying capacity.