A model for the friction of multiphase materials in abrasion

摘要

A model is presented for the sliding friction of multiphase materials in abrasion. The friction is described in terms of the load distribution between the phases. Different load distribution modes are used with Amontons' first law of friction to derive both the friction force and the coefficient of friction as functions of the area fractions of the phases, their individual coefficients of friction and their wear resistance. It is shown that the coefficient of friction of a multiphase material should depend on the load distribution mode and that the upper and lower limits for the coefficient of friction expected from composites or multiphase materials can be identified. For most pressure distribution modes, the friction depends on the wear resistance of the phases. The model is compared with results from abrasion tests on a silicon carbide reinforced aluminium alloy (AlSi7Mg) over a wide range of loads and with different fixed abrasive particles. The experimental results are described and interpreted in terms of the model.