Scaling relationships for the abrasion of steel by diamondlike carbon coatings

Abstract

In previous work we found that the rate of abrasion of steel by metal-containing diamondlike carbon Me-DLC coatings is not constant but decreases significantly during the course of our test. In this work we provide quantitative scaling relationships which show how the time dependence of the abrasion rate of a steel ball by a Me-DLC-coated disk varies with important parameters of dry sliding wear such as sliding velocity, distance travelled, number of cycles, and wear track radius. We also demonstrate how to predict wear volume when the wear track radius is changed in the middle of an experiment. We show that changes in the Me-DLC coatings, not in the (steel ball) counterparts, are responsible for the reduction in the measured abrasion rates. We find that the volume of steel abraded does not depend strongly on the average nominal contact stress between the coated coupon and the steel ball or on the state of wear of the ball.