A study on the effect of ZrO2 additive on the properties of sintered body of 96wt.% Al2O3-2wt.% Cu2O-2wt.% TiO2 system

Unstabilized zirconia was added to the basic composition of 96wt.% Al2O3-2wt.% Cu2O-2wt.% TiO2 system. Here the amount and the particle size of zirconia were 5.40∼25.44wt.%(4-20% if converted to volume percent) and 20μm under, respectively. And the body of these compositions was fired at 1400 deg C. The results obtained were as follows. 1) The firing linear shrinkage and apparent density were inversely proportional to the additive amount of zirconia. 2) Apparent porosity and water absorption had the trend to increase according as the amount of zirconia increased. 3) Modulus of rupture was proportional to the particle size of zirconia in the range of 5.40∼10.61wt.% additive zirconia but in the range of 15.70∼25.44wt.% additive zirconia the value of that decreased in the order of 5∼10μm, 2.5∼5μm, under 2.5μm particle size. And the body containing 5.40wt.% zirconia of 10∼20μm had the highest value of M.O.R. 4) As for toughness of the body the compositions having the highest value of Kic (critical stress intensity factor) varied with the particle size of zirconia. The body containing the 5.40wt.% zirconia of 10∼20μm and 5∼10 μm had the value of Kic(MN/m3/2) 5.9 and 5.8, respectively. The body containing 10.61wt.% zirconia of 2.5∼5μm had the value of Kic 5.8 and the body containing 15.70wt.% zirconia of under 2.5μm had the value of Kic 5.7. 5) The body had the highest value of M.O.R. and Kic when the 5.40wt.% zirconia of 10∼20μm was added. (Author)