Mechanism of rubber abrasion: Part 2. General rule in abrasion pattern formation in rubber-like materials

Abstract The mechanism of rubber abrasion proposed in the previous paper was reconfirmed not only in unfilled and filled NR but in SBR and silicone rubber. It is an essential and general rule in rubber abrasion that the microvibration induced in the slip phase of stick-slip oscillation generates the initial abrasion patterns and the stick-slip motion propagates them to the final abrasion patterns. The initial pattern spacing agrees with the distance determined by the relation between the natural frequency of the material and the mean sliding velocity, meanwhile the final pattern spacing in the propagation reaches the distance given by the frequency of the stick-slip oscillation and the mean sliding velocity. Reinforcement by carbon blacks makes the frequencies of the both periodic motions in rubber larger, which of course gives the smaller initial and final pattern spacings in rubber abrasion. In addition, the microvibration attenuates more rapidly in more filled rubbers when it spreads over the rubber surface as a surface wave. Both phenomena have a great influence on the smaller abrasive wear of more filled rubbers.