Dry sliding frictional characteristics of ZE10 and AZ80 magnesium strips under plastic deformation

Frictional behaviour of ZE10 and AZ80 magnesium alloys was investigated using a sheet metal forming simulator (SMFS) with a steel pin as counterpart on dry sliding conditions. Friction coefficients were measured within a sliding velocity range of 5-35 mm/s and contact pressure range of 2-15 MPa. The results showed that increasing contact pressure lead to an increase in coefficient of friction for both alloys; while the effect of sliding speed was negligible. A theoretical model is also developed to predict the coefficient of friction as a function of contact pressure. The model takes into account the surface characteristics as well as mechanical properties of alloys. The results of the theoretical model were compared with the results obtained from experiments and showed very good correlation. To further investigate the effect of process parameters on SMFS outputs, a finite element (FE) model was developed in ABAQUS software and the effects of bending angle and pin diameter on the friction tests results were studied. The FE model showed that the friction coefficient increases by increasing the bending angle and pin diameter.