Tribochemical behavior of Ni ion implanted pure iron lubricated with ZDDP as an additive

Abstract

An investigation of the tribochemical behavior of Ni ion implanted pure ionwas performed. Ni ion implantation increases the wear resistance of pure iron by 30–120% when liquid paraffin is used as lubricant. The wear resistance of ion implanted pure iron increases with increase in surface residual compressive stress, and decreases with increase in microhardness. When liquid paraffin containing zinc dialkyldithiophosphates (ZDDP) is used as lubricant, the wear resistance of a Ni ion implanted specimen is lower than that of an unimplanted one. This is because the wear of the specimen is controlled by the properties and amount of the antiwear reaction film, and the mechanical strengthening induced by Ni ion implantation plays a less important role in affecting the wear rate than the tribochemical effects. The existence of Ni element in the implanted pure iron retards the reactions of iron with active elements S and Zn from the additive, reduces the amount of surface antiwear film formed during the wear process, and changes the compositions of the films.