Mechanisms of Graphite Transfer on Steel as Studied by Image Analysis

The friction and transfer of graphite rubbing as a compacted material on mirror polished steel discs has been studied at (275°C) 548 K and at 170°C as a function of rubbing time and of various disc surface states induced by varying the polishing and cleaning methods. Image analysis is shown to be a useful technique for the semi quantification of transfer and for the investigation of the mechanism of particle growth. In particular the variations of the area fraction X of large particles and the evolution of the size distribution curves with rubbing time are shown to be very sensitive to any change in the surface state of the discs. A systematic study of the particle size distribution curves and SEM observations allowed the authors to develop a revised theory for the mechanism of transfer. Presented at the 35th STLE/ASME Tribology Conference In Fort Lauderdale, Florida October 16-19, 1989