A Study on the Mechanism of Generating Wear Track Grooves

Abstract

The mechanism of generating wear track grooves on metallic materials was investigated to elucidate the cause of similar wear track appearance based on pin-on-disk wear test results. As previously shown, most wear tracks on metallic materials appear similar in appearance irrespective of test conditions and materials. This phenomenon is attributed to the similar scales of prominent grooves in wear tracks, as wear tracks have common characteristic groove sizes in terms of width and depth. The ploughing by transfer particles adhering to counter surface initially generates these grooves, which become larger along with the growth of transfer particles. Pin-on-disk wear tests revealed that transfer particles adhering to the pin surface stopped growing at a certain size upon being enclosed by ridges forming along the sides of grooves on the disk and penetrating the pin surface. This final transfer particle size determines the characteristic scales of wear track grooves. We supposed that this enclosure by ridges terminated particle growth. Based on this supposition, the formation of ridges had a key effect on determining the sizes of grooves. Ridges form when the grooves grow to a certain size; thus, characteristic grooves could be expected to be a bit larger than this size. Therefore, these processes generate the characteristic scales of wear track grooves which lead to similar wear track appearance.