High-strength zirconia type sintered body
First Claim
1. A hot isostatically pressed zirconia type sintered body consisting essentially of 50 to 98% by weight of ziroconia (ZrO2) containing 1.5 to 5 mole % of yttria (Y2 O3) and 50 to 2% by weight of alumina (Al2 O3), spinel (MgAl2 O4) or mullite (3Al2 O3 ·
- 2SiO2), said hot isostatically pressed sintered body having a three-point bending strength of at least 1700 MPa,the crystal phase of zirconia constituting the sintered body being substantially composed of a tetragonal crystal or a mixture of at least 50% of a tetragonal crystal and up to 50% of a cubic crystal,said sintered body having having a bulk density of at least 99.5% of the theoretical density and devoid of pores having a size of 30 μ
m or more, andthe crystal of said sintered body having an average grain size of not larger than 2 μ
m.
1 Assignment
0 Petitions
Accused Products
Abstract
A zirconia type sintered body consisting essentially of 50 to 98% by weight of zirconia (ZrO2) containing 1.5 to 5 mole % of yttria (Y2 O3) and 50 to 2% by weight of alumina (Al2 O3), spinal (MgAl2 O4) or mullite (3Al2 O3.2SiO2), and having a three-point bending strength of at least 1700 MPa is provided. This sintered body is prepared by a process wherein a powdery composition consisting essentially of 50 to 98% by weight of (a1) a powder of zirconia containing 1.5 to 5 mole % of yttria or (a2) a mixture comprising 1.5 to 5 mole % of a yttria powder and 95 to 98.5 mole % of a zirconia powder and 2 to 50% by weight of (b) a powder of an alumina type oxide selected from alumina, an alumina-magnesia type oxide, an alumina-silica type oxide, a mixture of alumina and magnesia and a mixture of alumina and silica is subjected to a hot isotactic pressing treatment under a pressure of at lesast 50 MPa at temperature of 1300° C. to 1700° C. or a monoazially compression-sintering treatment under a pressure of at least 20 MPa at a temperature of 1400° C. to 1700° C.
-
Citations
2 Claims
-
1. A hot isostatically pressed zirconia type sintered body consisting essentially of 50 to 98% by weight of ziroconia (ZrO2) containing 1.5 to 5 mole % of yttria (Y2 O3) and 50 to 2% by weight of alumina (Al2 O3), spinel (MgAl2 O4) or mullite (3Al2 O3 ·
- 2SiO2), said hot isostatically pressed sintered body having a three-point bending strength of at least 1700 MPa,
the crystal phase of zirconia constituting the sintered body being substantially composed of a tetragonal crystal or a mixture of at least 50% of a tetragonal crystal and up to 50% of a cubic crystal, said sintered body having having a bulk density of at least 99.5% of the theoretical density and devoid of pores having a size of 30 μ
m or more, andthe crystal of said sintered body having an average grain size of not larger than 2 μ
m. - View Dependent Claims (2)
- 2SiO2), said hot isostatically pressed sintered body having a three-point bending strength of at least 1700 MPa,
Specification
-
- Resources
-
Current AssigneeToyo Soda Manufacturing Co., Ltd. (Tosoh Corporation)
-
Original AssigneeToyo Soda Manufacturing Co., Ltd. (Tosoh Corporation)
-
InventorsTsukuma, Koji, Ueda, Kuniyoshi, Tsukidate, Takaaki
-
Primary Examiner(s)Dixon, Jr., William R.
-
Assistant Examiner(s)Group, Karl
-
Application NumberUS06/661,968Time in Patent Office566 DaysField of Search501/105, 501/107, 501/120, 501/153, 501/103, 501/104, 501/128US Class Current501/105CPC Class CodesC04B 35/488 CompositesC04B 35/4885 with aluminium oxideC04B 35/6455 Hot isostatic pressing
