Sliding wear behavior of submicron-grained alumina in biological environment

Sliding wear behavior of sintered alumina with grain sizes between 0.45 and 4 microm was studied in bovine serum environment with unidirectional pin-on-disc wear testing machine. Submicron grained alumina of average grain size of G=0.45 microm exhibits lowest wear factor among the others. It was found that grain pull out or localized grain dislodgement caused by coalescence of grain boundary microcracks is the basic wear mechanism of submicron grained alumina though the extent of cracking and pull-out was substantially less than that with higher grained material. However, in few cases, some areas where substantial volume of material was removed following pull-out of cluster of grains have also been observed.