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CN-121986080-A - Sintered body of zirconium oxide having titanium and yttrium dissolved therein

CN121986080ACN 121986080 ACN121986080 ACN 121986080ACN-121986080-A

Abstract

The present invention provides a sintered body of zirconium oxide in which titanium and yttrium are solid-dissolved, a method for producing the same, and at least one of the uses thereof, wherein the sintered body is less likely to be broken and is transparent than a sintered body of zirconium oxide in which titanium and yttrium are solid-dissolved, which is transparent. A sintered body of zirconia in which titanium and yttrium are solid-dissolved, wherein the yttrium content is 3.5mol% or more and less than 6.0mol% and the titanium content is 6.0mol% or more and 18.5mol% or less, and comprises crystal grains of cubic crystals containing tetragonal crystal domains.

Inventors

  • AZECHI SHO
  • ITO AKIKO
  • YAMAMOTO YASUSHI
  • ITO TAKESHI
  • FUJISAKI HIROYUKI
  • NAGAYAMA HITOSHI

Assignees

  • 东曹株式会社

Dates

Publication Date
20260505
Application Date
20240826
Priority Date
20230831

Claims (14)

  1. 1. A sintered body of zirconia in which titanium and yttrium are solid-dissolved, characterized in that the sintered body has a yttrium content of 3.5mol% or more and less than 6.0mol% and a titanium content of 6.0mol% or more and 18.5mol% or less, and contains crystal grains of cubic crystals including tetragonal crystal domains.
  2. 2. The sintered body of claim 1, wherein the sintered body comprises alumina.
  3. 3. The sintered body according to claim 1 or 2, wherein a crystallite diameter obtained from a half width of a peak having a peak top at 2θ=74.0±0.3° in an XRD pattern of the sintered body is 1400nm or less.
  4. 4. The sintered body according to any one of claims 1 to 3, wherein the sintered body has an average crystal grain size of 5 μm or more and 50 μm or less.
  5. 5. The sintered body according to any one of claims 1 to 4, wherein the sintered body has a linear transmittance of 45% or more at a sample thickness of 1.+ -. 0.1mm and a measurement wavelength of 600 nm.
  6. 6. The sintered body according to any one of claims 1 to 5, wherein the sintered body has a fracture toughness value K IC of 1.5 MPa-m 0.5 or more.
  7. 7. The sintered body according to any one of claims 1 to 6, wherein the three-point bending strength of the sintered body is 280MPa or more.
  8. 8. The method for producing a sintered body according to any one of claims 1 to 7, comprising: A primary sintering step in which a molded body containing a zirconia source, an yttrium source, and a titanium source, the yttrium content being 3.5mol% or more and less than 6.0mol% and the titanium content being 6.0mol% or more and 18.5mol% or less, is sintered at a normal pressure in an oxidizing atmosphere at a temperature of 1260 ℃ or more to obtain a primary sintered body; a pressure sintering step in which the primary sintered body is pressure sintered in a reducing atmosphere at a temperature of 1500 ℃ or higher to obtain a pressure-treated body, and And a heat treatment step in which the pressure-treated body is heat-treated in an oxidizing atmosphere.
  9. 9. The method according to claim 8, wherein the molded article is a molded article obtained by a molding step of molding a raw material powder obtained by a mixing method of mixing a mixed raw material powder of a zirconia source and an yttrium source with a titanium source.
  10. 10. The production method according to claim 8 or 9, wherein the primary sintered body has an actual measurement density of 5.35g/cm 3 or more and 6.00g/cm 3 or less.
  11. 11. The manufacturing method according to any one of claims 8 to 10, wherein the press sintering is a hot isostatic pressing.
  12. 12. The production method according to any one of claims 8 to 11, wherein the reducing atmosphere is a weak reducing atmosphere.
  13. 13. The production method according to any one of claims 8 to 12, wherein a cooling rate from a holding temperature during pressure sintering to 1000 ℃ is 50 ℃ per minute or more and 300 ℃ per minute or less.
  14. 14. A member comprising the sintered body according to any one of claims 1 to 7.

Description

Sintered body of zirconium oxide having titanium and yttrium dissolved therein Technical Field The present invention relates to a sintered body of zirconia in which titanium and yttrium are solid-dissolved. Background As a sintered body having high transparency, a sintered body including zirconia in which titanium and yttrium are solid-dissolved and a crystal phase including only cubic crystals is known (patent document 1). However, such sintered bodies have low mechanical properties. Therefore, improvement of mechanical properties of such transparent sintered bodies is being studied. For example, patent document 2 discloses that a sintered body of transparent zirconium oxide in which titanium and yttrium are dissolved is obtained by controlling the grain size of a primary sintered body to be subjected to hot isostatic pressing (hereinafter also referred to as "HIP") to obtain a sintered body having a three-point bending strength of 255 MPa. Patent document 3 discloses that by controlling the reduction degree of titanium (Ti) in the HIP treatment, a transparent sintered body of zirconia in which titanium and yttrium are dissolved and which has a three-point bending strength of 300MPa or more is obtained. Prior art literature Patent literature Patent document 1 Japanese patent laid-open No. 62-091467 Patent document 2 Japanese patent application laid-open No. 2011-01970 Patent document 3 Japanese patent application laid-open No. 2011-102227 Disclosure of Invention Technical problem to be solved by the invention The sintered bodies disclosed in patent documents 2 and 3 have both of the linear light transmittance exhibiting transparency and the high three-point bending strength. Therefore, defects are less likely to occur than conventional transparent sintered bodies of zirconium oxide in which titanium and yttrium are dissolved in solid solution. On the other hand, these sintered bodies have weak resistance to the development of fracture such as cracking, and therefore, once defects are generated, the fracture proceeds rapidly. The purpose of the present invention is to provide a sintered body of zirconium oxide in which titanium and yttrium are solid-dissolved, a method for producing the same, and at least one of the uses thereof, wherein the sintered body is less likely to develop damage and exhibits transparency than conventional sintered bodies of zirconium oxide in which titanium and yttrium are solid-dissolved, which exhibit transparency. Technical scheme for solving technical problems In the present invention, a titania-yttria-zirconia sintered body having transparency was studied. As a result, it was found that by controlling the structure of crystal grains, the transparency is not lowered even in the composition where the transparency was conventionally thought to be lowered. Further, it was found that a sintered body having such a composition becomes a titania-yttria-zirconia sintered body improved in resistance to the development of fracture. That is, the present invention is described in the claims, and the gist of the present invention is as follows. [1] A sintered body of zirconia in which titanium and yttrium are solid-dissolved, wherein the sintered body has a yttrium content of 3.5mol% or more and less than 6.0mol% and a titanium content of 6.0mol% or more and 18.5mol% or less, and contains crystal grains of cubic crystals including tetragonal crystal domains. [2] The sintered body according to item [1], wherein the sintered body contains alumina. [3] The sintered body according to [1] or [2], wherein a crystallite diameter obtained from a half width of a peak having a peak top at 2θ=74.0±0.3° in an XRD pattern thereof is 1400nm or less. [4] The sintered body according to any one of the above [1] to [3], wherein the sintered body has an average crystal grain size of 5 μm or more and 50 μm or less. [5] The sintered body according to any one of the above [1] to [4], wherein the sintered body has a linear transmittance of 45% or more at a sample thickness of 1.+ -. 0.1mm and a measurement wavelength of 600 nm. [6] The sintered body according to any one of the above [1] to [5], wherein the fracture toughness value (K IC) of the sintered body is 1.5 MPa.m 0.5 or more. [7] The sintered body according to any one of the above [1] to [6], wherein the three-point bending strength of the sintered body is 280MPa or more. [8] The method for producing a sintered body according to any one of the above [1] to [7], comprising: A primary sintering step in which a molded body containing a zirconia source, an yttrium source, and a titanium source, the yttrium content being 3.5mol% or more and less than 6.0mol% and the titanium content being 6.0mol% or more and 18.5mol% or less, is sintered at a normal pressure in an oxidizing atmosphere at a temperature of 1260 ℃ or more to obtain a primary sintered body; a pressure sintering step in which the primary sintered body is pressure sintered in a reducing atmosphere a