ZnDTP (zinc dialkyl dithiophosphate) is an additive used in many lubricants, such as engine oil, and is known to protect sliding surfaces by forming a tribofilm of sulfide layers and polyphosphate films. While most ZnDTP tribofilm studies have been conducted on specimens with very smooth surfaces, this study investigates the relationship between the formation behavior of ZnDTP tribofilms and tribological properties of sliding surfaces with surface roughness close to that of actual machine parts.

Tribofilm formed on sliding surface