Influence of ZDDP tribofilm on micropitting formation and progression
Zaihao Tian, Lu Ping, Shuncai Wang, Daniel Merk, Robert E. Wood
Abstract
This paper presents insights into how Zinc Dialkyl Dithiophosphate (ZDDP) influences the formation and progression of micropitting. Experimental investigations were conducted using a twin-disc tribometer in rolling-sliding contacts under mixed or boundary lubrication conditions, focusing on the impact of ZDDP on micropitting in bearing steel samples. Results show that ZDDP reduces wear and increases surface friction by forming a tribofilm. This facilitates micropitting formation, but also retards the progression of micropitting. It highlights that understanding the chemical and mechanical interactions at the tribological interface is essential for designing effective mitigation strategies for managing micropitting and avoiding related issues in bearing applications.