Microstructural aspects of lubricated mild wear with zinc dialkyldithiophosphate

Abstract The microstructure of wear particles formed under boundary lubrication with a zinc dialkyldithiophosphate (ZDDP) is investigated in the analytical scanning transmission electron microscope. This is made possible by the generation of wear particles in foil form. Physical and chemical data are reported and correlated with surface analysis data obtained on reaction films. The measurements show that the thin foil particles consist mainly of an amorphous material containing iron, phosphorus, sulphur, zinc and oxygen (carbon was not detected). These particles are the result of a reaction of the ZDDP with metals under friction.