Dry sliding wear behavior of magnesium alloys

Dry sliding tests were performed on as-cast magnesium alloys Mg97Zn1Y2 and AZ91 using a pin-on-disc configuration. Coefficients of friction and wear rates were measured within a load range of 20–380 and 20–240 N at a sliding velocity of 0.785 m/s. X-ray differactometer, scanning electron microscopy, tensile testing machine were used to characterize the microstructures and mechanical properties of Mg97Zn1Y2 alloy and AZ91 alloy. Worn surface morphologies of Mg97Zn1Y2 and AZ91 were examined using scanning electron microscopy. Five wear mechanisms, namely abrasion, oxidation, delamination and thermal softening and melting, have been observed. Mg97Zn1Y2 exhibited good wear resistance compared with AZ91 for applied loads in excess of 80 N, which have been explained in terms of thermal stability of intermetallic phase and elevated temperature mechanical properties of the two materials tested, using surface temperature analysis.