THE MECHANISM OF TWO AND THREE BODY ABRASIVE WEAR IN DUCTILE METALS

The mechanism of two and three body abrasive wear in ductile metals has been studied analytically and experimentally. For two body abrasive wear the statistical distribution of the size of the abrasive particles was included in the analysis. It is interesting that the predicted variation of wear with load, distance travelled and hardness of the abraded material is similar to that obtained from a simple model based on a single particle. Three body abrasive wear was observed experimentally by using a tester which was developed to simulate the abrasive wear that occurs in many practical applications.; The effect of temperature on two and three body abrasive wear was observed experimentally up to 400(DEGREES)C. In two body abrasive wear the wear rates of commercially pure aluminum and copper were insensitive to the change in temperature. In three body abrasive wear aluminum was again insensitive to temperature while copper showed an increase in wear rate as the temperature was raised. However, it was shown that if oxidation effects are allowed for then the mechanical wear of copper is also insensitive to temperature. The insensitivity of wear rate to the change in temperature is rationalized by considering two factors. One of these is the adiabatic heating that occurs during abrasive wear due to large strains and moderately high strain rates. The other is the tendency of the flow stress to become insensitive to the change in temperature at high strain rates.; An important and as yet unexplained aspect of abrasive wear, erosion and grinding processes is the "size-effect". Particle size has little influence on wear rate until it is decreased to about 100 (mu)m. For particles below this size the wear rate decreases rapidly. In the present work it is suggested that a surface energy, similar to that observed in fracture test, must be supplied during wear in addition to the energy required for plastic deformation. On this basis it is shown that the size-effect may be explained and the effect of particle size on wear rate may be predicted.