B. Kerkwijk et al., Processing of homogeneous zirconia-toughened alumina ceramics with high dry-sliding wear resistance, J AM CERAM, 82(8), 1999, pp. 2087-2093
The preparation of dense homogeneous zirconia-toughened alumina (ZTA) with
high dry-sliding wear resistance is described. These ZTA ceramics are obtai
ned by sintering green compacts, made by colloidal filtration of well-defin
ed ZrO2-Al2O3 particle suspensions, for 2 h at 1400 degrees C, The optimum
solid and stabilizer concentrations for the filtration process were determi
ned. The sintered ZTA microstructure consists of a homogeneous distribution
of zirconia grains in an alumina matrix with grain sizes of 0.2 and 0.5 mu
m, respectively. In pin-on-disk tribological measurements at relatively hi
gh initial contact pressures (1130 MPa) and sliding speeds (0.5 m/s) a very
low specific wear rate (about 5 x 10(-8) mm(3)/(N.m)) and a coefficient of
friction of 0.45-0.55 were found. It is shown that, in this case, wear is
dominated by: abrasion and polishing.