FRICTION AND WEAR BEHAVIORS OF ALUMINUM-ON-STEEL UNDER THE LUBRICATION OF GREASE CONTAINING A COMPLEX OF LANTHANUM DIALKYLDITHIOCARBAMATE AND PHENANTHROLINE

A complex of lanthanum dialkyldithiocarbamate and phenanthroline was s ynthesized, and its lubricating and antiwear behaviors as an additive in lithium grease were evaluated using a Timken tester with a SAE52100 steel ring sliding under an Al 2024 block. As a comparison, the wear behavior of a steel-on-steel system under the lubrication of the same grease was also investigated under the same test conditions. The prote ctive film formed on the rubbed surface of aluminum was investigated b y both XPS and AES. Results of friction and wear tests indicate that t his rare earth complex possess good antiwear ability for aluminum, and its antiwear and friction reduction properties for the aluminum-on-st eel system is even superior to that for the steel-on-steel system. The results of AES and XPS analyses illustrate that the prepared La compl ex as an additive in lithium grease forms a protective film containing lanthanum oxide, aluminum sulphide, and an organic compound containin g sulfur and nitrogen on the rubbed surface of aluminum.