Study on the wear behavior of silicon nitride under the lubrication of micro-sample lubricant

The study on the wear behavior of Si₃N₄ ball on a three Si₃N₄ discs system was carried out with a 30 min run-in at 396N under the lubrication of mineral oil only, and then followed by the second segment of the test, i.e. running with the lubrication of two microliters of mineral oil, or mineral oil containing oleic acid, stearic acid as well as zinc dialkyldithiophosphate (ZDDP) at a load of 396N until the lubrication failure (a sharp increase in friction coefficient). The wear life (failure time) was correlated to the wear scar diameter in the conventional wear test. Our results show that some high-molecular-weight product which is soluble in tetrahydrofuran (THF) is produced, and such kind of test is valuable in understanding the tribochemistry of lubricant under boundary lubrication conditions.