Modelling of dry sliding oxidation-modified wear in two phase materials

Models for oxidation-modified wear in two phase materials have been proposed extending the earlier models of Archard and Quinn, for predicting the oxidative wear in homogeneous materials. Three distinct possibilities have been considered—(a) case A, both the phases having the same oxidation behaviour and also, the same critical thickness for oxidative wear; (b) case B, both the phases having the same oxidation behaviour but distinctly different critical thicknesses; and (c) case C, both the phases having different oxidation behaviour and also, different critical thicknesses. In all these cases the wear rate varies linearly with the real area of contact estimated as the ratio of normal load to the rule of mixture hardness. The oxidation-modified wear in dual phase steels, as observed experimentally appear to belong to case A but it may also belong to case B with small difference in critical thickness in both the phases of ferrite and martensite. The wear behaviour calculated for case B is similar to those observed experimentally but the calculated values of wear rates are lower. It is possible that the oxidation behaviour could also be different in different phases and case C could be more appropriate.