THE ROLE OF OXIDE PARTICLES IN THE FRETTING WEAR OF MILD-STEEL

It is important to identify the role of oxide debris during fretting. In this work, oxide particles were artificially supplied between surfaces before fretting in order to demonstrate the role of the oxide wear debris. Experiments were carried out using a mild steel, S45C, under the following conditions: peak-to-peak slip amplitude and normal load were varied from 50 to 200-mu-m and from 0.98 to 9.8 N respectively at 20 Hz. A ring specimen was pressed on a flat specimen. The particles supplied were alpha-Fe2O3 with a mean particle size of 1-mu-m. The amount of the supply was 0.2 g. The wear volume for the case with oxide particles was compared with that without the particles. The action of the oxide to facilitate of to prevent wear depended on the experimental conditions. The map for the effect of the oxide was obtained. Compaction of the oxide particles reduced the wear, while abrasive action of the particles promoted the wear. The balance of the removal rate of particles from the interface and their compaction rate between surfaces determined the negative or positive role.