SINTERED ZIRCONIA HAVING HIGH LIGHT TRANSMISSION AND HIGH STRENGTH, USE OF THE SAME AND PROCESS FOR PRODUCTION THEREOF

摘要

Although sintered zirconia solid solutions containing Y₂O₃as the stabilizer were expected to be usable as structural materials of machines or dentistry materials by virtue of their having high strength and high toughness, none of the solid solutions is satisfactory in both strength and aesthetic appreciation on the basis of the feeling of translucency. The invention relates to a sintered zirconia produced by subjecting a primary sintered body which is prepared from a zirconia powder containing yttria fine particles and has a relative density of 95% or above to HIP sintering at 1200 to 1600°C under a pressure of 50MPa or above, which sintered zirconia exhibits both high strength and high light transmission, namely, a light transmission of 43% or above and a three-point bending strength of 1700MPa or above at a thickness of 0.5mm or a light transmission of 40% or above and a three-point bending strength of 500MPa or above at a thickness of 1mm.