The Study of Tribo-Induced Deposits from a Copper-Containing Antiwear Additive

Abstract

Effects of oil-soluble copper salts on oil oxidation and corrosion have been extensively studied in the literature. However, little attention has been paid to the deposits produced from the copper-containing additives by tribochemical reactions on the rubbing surface.

In this paper, the authors have successfully synthesized another copper ligand, copper(II) dioctyl dithiocarbamate, and tested its tribological behavior with a four-ball machine and a block-on-ring test rig. Furthermore, emphasis has been given to the deposits on the wear track of the block. The quantitative picture of the influence of tribological parameters of load, additive concentration and test time on the amounts of weight loss is also presented. Surface analyses by Auger electron spectroscopy and X-ray photoelectron spectroscopy reveal that the deposits are in fact composed of numerous materials in which metallic copper predominates. Finally, a deposition mechanism is postulated to elucidate the transformation of copper(II) to metallic copper.

Presented as a Society of Tribologists and Lubrication Engineers paper at the ASME/STLE Tribology Conference in San Francisco, California, October 13–17, 1996

KEY WORDS:

• Copper
• Antiwear Additives
• Corrosion
• Oxidation

Notes

Presented as a Society of Tribologists and Lubrication Engineers paper at the ASME/STLE Tribology Conference in San Francisco, California, October 13–17, 1996