Zirconia sintered body and use thereof

Patent metadata

Field	Value
Publication number	US-2016347666-A1
Application number	US-201415107053-A
Country	US
Kind code	A1
Filing date	Dec 25, 2014
Priority date	Dec 27, 2013
Publication date	Dec 1, 2016
Grant date	—

Abstract

To provide a zirconia sintered body which has at least two different color tones such as white and black, and which has no color bleeding or no gap between sintered bodies. A zirconia sintered body comprising a first zirconia sintered body and a second zirconia sintered body, characterized in that the first zirconia sintered body is a zirconia sintered body containing aluminum oxide; the second zirconia sintered body is a zirconia sintered body containing a spinel oxide; a bonding plane is formed between the first zirconia sintered body and the second zirconia sintered body; and it has no gap or no color bleeding at the bonding plane.

First claim

1 : A zirconia sintered body, comprising a first zirconia sintered body and a second zirconia sintered body, wherein:
the first zirconia sintered body comprises at least aluminum oxide or at least one lanthanoid selected from the group consisting of Ce, Pr, Nd, Eu, Tb, Ho, Er, Yb and Gd; the second zirconia sintered body comprises a spinel oxide; a grain boundary is formed between the first zirconia sintered body and the second zirconia sintered body; and the grain boundary has no gap or no color bleeding.

2 : The zirconia sintered body according to claim 1 , wherein either one of the first zirconia sintered body and the second zirconia sintered body forms a pattern on the same surface as the other zirconia sintered body.

3 : The zirconia sintered body according to claim 1 , wherein a relative density is at least 99.5%.

4 : The zirconia sintered body according to claim 1 , wherein the first zirconia sintered body comprises aluminum oxide.

5 : The zirconia sintered body according to claim 1 , wherein the first zirconia sintered body comprises aluminum oxide in an amount of from 0.25 wt % to 20 wt %.

6 : The zirconia sintered body according to claim 1 , wherein the first zirconia sintered body comprises at least one lanthanoid selected from the group consisting of Ce, Pr, Nd, Eu, Tb, Ho, Er, Yb and Gd.

7 : The zirconia sintered body according to claim 6 , wherein the lanthanoid is contained in an amount of from 0.1 wt % to 6 wt %.

8 : The zirconia sintered body according to claim 1 , wherein the spinel oxide contained in the second zirconia sintered body is a spinel oxide comprising iron and cobalt.

9 : The zirconia sintered body according to claim 1 , wherein the spinel oxide contained in the second zirconia sintered body has the following composition:
(Co X M 2+ 1-X )(Fe y M 3+ 1-Y ) 2 O 4 wherein M 2+ is at least either Zn or Mn, M 3+ is either Al or Cr, 0.1<X≦1, and 0.5<Y≦1.

10 : The zirconia sintered body according to claim 1 , wherein the spinel oxide contained in the second zirconia sintered body is a spinel oxide comprising cobalt and aluminum.

11 : The zirconia sintered body according to claim 10 , wherein the second zirconia sintered body further comprises a transition metal oxide.

12 : A process for producing the zirconia sintered body of claim 1 , the process comprising:
primary molding either one zirconia powder of a zirconia powder comprising a lanthanoid oxide or aluminum oxide, or a zirconia powder comprising a spinel oxide, to obtain a primary green body; secondary molding the other zirconia powder on the primary green body at a molding temperature lower than the primary molding, to obtain a secondary green body; firing the secondary green body at a temperature of at least 1,300° C. to obtain a preliminarily sintered body; and subjecting the preliminarily sintered body to hot isostatic pressing treatment at a temperature of from 1,250° C. to 1,650° C. under from 100 MPa to 250 MPa.

13 : The process according to claim 12 , wherein the molding in the secondary molding is injection molding.

14 : A member, comprising the zirconia sintered body of claim 1 .

Assignees

• Tosoh Corp

Inventors

• Nagayama Hitoshi
• Shinozaki Naoki
• Ito Takeshi
• Tsukuma Koji
• Yamauchi Shoichi

Classifications

• C04B2235/3225

  Yttrium oxide or oxide-forming salts thereof · CPC title

• C04B35/488

  Composites · CPC title

• C04B2235/3244

  Zirconium oxides, zirconates, hafnium oxides, hafnates, or oxide-forming salts thereof · CPC title

• C04B2235/3272

  Iron oxides or oxide forming salts thereof, e.g. hematite, magnetite · CPC title

• C04B2235/6022

  Injection moulding · CPC title