Hierarchy of micromechanical influences on friction and wear of submicron alumina and zirconia ceramics

Friction and wear of alumina and zirconia ceramics with grain sizes between 0.3 and 3 micrometers are investigated in different media. Experimental evidence is presented for a hierarchical order of micromechanical influences like the grain boundary toughness, subcritical crack growth resistance, residual microstresses, and the hardness. The different grain size dependencies of these parameters result in different grain size effects in wear depending on the active micromechanisms.