The twin-ring tribometer—Characterizing sliding wear of metals excluding the effect of contact configurations

A twin-ring type wear test rig has been developed, in which two rings rotate side by side to slide in the opposite direction with the same sliding velocity. As a result, the outer most periphery of these rings are in symmetrical sliding contact. Rings were made out of ten kinds of metal and were rubbed against each other. All combinations were tested including the same metal pairs. In similar metal combinations, the wear depended on the oxidation activity and crystal structure, but not on the hardness. In dissimilar metal combinations, the wear mode relied on the hardness difference, mutual solubility, oxidation activities, and crystal structures. The twin-ring tribometer thus characterizes wear of metals in terms of the material properties themselves exclusively without being influenced by the contact configuration of specimens.