Tribological Interaction of Manganese Phosphate Coatings with Grease and Solid Lubricant Particles

Abstract

The interaction of two grease-based lubricants with and without metallic solid lubricant particles with three different surfaces was investigated in this study. Two differently prepared manganese phosphate coatings and the uncoated substrate were chosen for comparative investigation. The tribological experiments were performed employing a translatory oscillation tribometer for 125 cycles at 1000 and 2000 MPa with a steel ball counterbody (1.4034). A detailed triboanalysis showed that the grease containing solid lubricant particles forms a cohesive tribofilm on the surface, whereas with plain grease, the manganese phosphate coating formed a smooth layer at 1000 MPa. At 2000 MPa, the grease with solid lubricants showed better performance than pure grease due to decreased superficial deformation by a better stress distribution via a supporting effect.