In-situ fast and long observation system for friction surfaces during scuffing of steel

The objective of this study is to better understand the scuffing phenomenon using a specially designed in-situ observation system. The developed in-situ observation system comprises four sets of a digital CCD camera and a xenon flashing lamp. The independent operation of the capture devices could capture four successive images over short time intervals during a long-duration experiment. Scuffing behaviour that occurs in a friction surface between a rotating sapphire disc and a stationary martensitic steel pin in dry conditions was observed by the developed in-situ observation system. The results showed the behaviour of plastic flow that occurred in the frictional contact area. Plastic flow was observed to occur immediately after the transfer layer passed through the contact area. Each instance of plastic flow was a few milliseconds long. The speed of plastic flow was much less than the sliding speed. At the end of the fast plastic flow process, the brightness of the area of the plastic flow increased, which could be attributed to the oxidation of the steel surface.