Influence of Grain Orientation on Friction and Wear Behavior in Quasicrystalline Alloys

The influence of grain orientation on the friction and wear behavior of single-phase quasicrystalline alloys is investigated. Pin-on-disc wear tests and friction coefficient measurements have been performed on bulk samples of icosahedral phase AlPdMn and decagonal phase AlNiCo alloys. Wear behavior has been evaluated by optical microscopy, scanning electron microscopy (SEM) and electron back-scattered diffraction (EBSD). Coefficient of friction values of the decagonal AlNiCo alloy are found to be widely scattered (between 0.03 and 0.55) compared to the far more consistent values of the icosahedral alloys. This is explained by considering the significant variation in wear behavior that is observed between different – sometimes adjacent – oriented grains in the decagonal specimens.