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Wear mechanisms of rubber tread compounds
Abstract
Rubber tread compounds worn by grinding wheels on a Lambourn abrader exhibited fatigue and cutting wear mechanisms. Fatigue wear occurred on blunt alumina grinding wheels and cutting wear on sharp, faceted silicon carbide grinding wheels. The rubber wear rate in cutting was directly proportional to the normal load and increased with grit sharpness and rubber modulus. Fatigue wear was characterized by the formation of a pattern of ridges, and wear took place by fatigue crack growth at the base of the ridge, eventually rupturing a portion of the ridge. A fatigue wear model reduced the wear rate to the crack growth rate for a calculated tearing energy, which depended on the friction force and the morphology of the rubber-alumina grinding wheel contact. The derived crack growth rate as a function of the calculated tearing energy showed superposition of the wear data from the different alumina grinding wheels. And, the tearing energy exponent for the derived crack growth rate in wear were 14 and 19 for EXXPRO and SBR which are close to 1.6 and 2.6 obtained in tensile FCG for the two compounds, respectively. However, the derived crack growth rate in wear is an order of magnitude smaller than the tensile FCG at the same tearing energy. Analysis of the ridge pattern movement showed that the movement rate was similar to the derived crack growth rate supporting the fatigue wear model but revealed that only 18% of the calculated tearing energy was being used in crack growth, the remainder being dissipated in viscous deformation. The role of viscous deformation as a rate controlling process of wear was flaggested from an activation energy analysis of the Eyring type temperature and stress dependence of wear. The activation energies for fatigue wear were between 25-50 kJ/mol which are in general close to the activation energy for viscous deformation.
Subject Area
Mechanical engineering|Plastics
Recommended Citation
Ramakrishnan, Ramesh, "Wear mechanisms of rubber tread compounds" (1996). Doctoral Dissertations Available from Proquest. AAI9619429.
https://scholarworks.umass.edu/dissertations/AAI9619429