EP0218853A1
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Method for manufacturing a sintered zirconia material
Assignee: Toray Industries Inc
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Filing: 1986-08-20
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Granted: —
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Expires: 2006-08-20
Abstract
Abstract A sintered zirconia material containing at least 50 mol% tetragonal zirconia and 1.5 - 5 mol% yttria, from which carbon is substantially absent, the porosity of which is not greater than 0.6%, the pore size of which is not greater than 0.1µm and the pores (2<sub>a</sub>, 2<sub>b</sub>) of which exist mainly at triple points of zirconia grain boundaries. The sintered zirconia material can be obtained by sintering the raw material zirconia powder, the green body or the presintered material containing tetragonal zirconia and yttria in a required amount and in an oxidizing atmosphere, by hot isostatic pressing.The sintered material thus obtained has a high strength and high toughness, and particularly excellent properties for use under conditions of higher than 600°C and can be used as a material of various industrial machines or tools.
Inventors
- 👤 Takaki Masaki
- 👤 Kiyokazu Shinjo
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 17:09
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/48; C04B35/486; A; A61; A61K; A61K6/00; A61K6/15; A61K6/17; A61K6/80; A61K6/802; A61K6/818; C01; C01G; C01G25/00; C01G25/02; C04B35/622; C04B35/64; C04B35/645; C04B35/6455; C01P; C01P2002/00; C01P2002/30; C01P2002/50; C01P2002/52; C01P2002/54; C01P2004/00; C01P2004/01; C01P2004/04; C01P2004/60; C01P2004/64; C01P2006/00; C01P2006/16; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3217; C04B2235/3224; C04B2235/3225; C04B2235/3229; C04B2235/3231; C04B2235/3232; C04B2235/3239; C04B2235/3241; C04B2235/327; C04B2235/3272; C04B2235/3275; C04B2235/3279; C04B2235/3281; C04B2235/44; C04B2235/443; C04B2235/444; C04B2235/65; C04B2235/656; C04B2235/6562; C04B2235/6565; C04B2235/658; C04B2235/6583; C04B2235/6584; C04B2235/6585; C04B2235/66; C04B2235/661; C04B2235/70; C04B2235/72; C04B2235/721; C04B2235/74; C04B2235/77; C04B2235/80; C04B2235/85; C04B2235/96; C04B2235/9646; C04B2235/9661; C04B35/626; C04B35/62605; C04B35/62645; C04B35/62675
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
77 words
A sintered zirconia material comprising: a substantially carbon free sintered material containing at least 50 mol% zirconia having a tetragonal crystal structure; and sintered material containing 1.5 - 5 mol% yttria; the porosity of the sintered material being not greater than 0.6%; the pore size of the sintered material being not greater than 0.1µm; and the pores (2 a , 2 b ) of the sintered material existing mainly at triple points of the zirconia grain boundaries.
Claim 2
Dependent Claim
77 words
A sintered zirconia material comprising: a substantially carbon free sintered material containing at least 50 mol% zirconia having a tetragonal crystal structure; and sintered material containing 1.5 - 5 mol% yttria; the porosity of the sintered material being not greater than 0.6%; the pore size of the sintered material being not greater than 0.1µm; and the pores (2 a , 2 b ) of the sintered material existing mainly at triple points of the zirconia grain boundaries.
Claim 3
Dependent Claim
22 words
The sintered material of claim 1, wherein the sintered material contains not less than 70 mol% zirconia having a tetragonal crystal structure.
Claim 4
Dependent Claim
22 words
The sintered material of claim 2, wherein the sintered material contains not less than 80 mol% zirconia having a tetragonal crystal structure.
Claim 5
Dependent Claim
27 words
The sintered material of claim 1, wherein the amount of zirconia having a monoclinic crystal structure present in the sintered material is not greater than 10 mol%.
Claim 6
Dependent Claim
18 words
The sintered material of claim 1, wherein the sintered material additionally contains zirconia having a cubic crystal structure.
Claim 7
Dependent Claim
16 words
The sintered material of claim 1, wherein the sintered material contains 1.75 - 4.5 mol% yttria.
Claim 8
Dependent Claim
18 words
The sintered material of claim 1, wherein the porosity of the sintered material is not greater than 0.4%.
Claim 9
Dependent Claim
18 words
The sintered material of claim 7, wherein the porosity of the sintered material is not greater than 0.3%.
Claim 10
Dependent Claim
15 words
The sintered material of claim 1, wherein the pore size is not greater than 0.05µm.
Claim 11
Dependent Claim
33 words
The sintered material of claim 1, wherein not less than 80% of the pores (2 a , 2 b ) of the sintered material have a pore size of not greater than 0.1µm.
Claim 12
Dependent Claim
33 words
The sintered material of claim 10, wherein not less than 90% of the pores (2 a , 2 b ) of the sintered material have a pore size of not greater than 0.1µm.
Claim 13
Dependent Claim
30 words
The sintered material of claim 1, wherein not less than 80% of the pores (2 a , 2 b ) of the sintered material exist at the intergranular triple points.
Claim 14
Dependent Claim
30 words
The sintered material of claim 12, wherein not less than 90% of the pores (2 a , 2 b ) of the sintered material exist at the intergranular triple points.
Claim 15
Dependent Claim
44 words
The sintered material of claim 1, wherein the sintered material additionally contains at least one metal oxide selected from the group consisting of aluminium, titanium, copper, nickel, iron, cobalt and chrome oxide in an amount of 0.1 - 1 wt.% as a third component.
Claim 16
Dependent Claim
20 words
The sintered material of claim 14, wherein the third component is present in an amount of 0.2 - 0.5 wt.%.
Claim 17
Dependent Claim
71 words
The sintered material of claim 1, wherein the sintered material additionally contains at least one colorant selected from the group consisting of 0.05 - 0.7 wt.%. chrome oxide, 0.05 - 0.2 wt.% copper oxide, 0.05 - 2 wt.% erbium oxide, 1 - 2 wt.% cerium oxide, 0.05 - 2 wt.% vanadium oxide, 0.5 - 2 wt.% neodymium oxide, 0.05 - 0.3 wt.% cobalt oxide and 0.05 - 0.5 wt.% iron oxide.
Claim 18
Independent Claim
100 words
A method for manufacturing a sintered zirconia material comprising the steps of: (a) preparing a zirconia powder containing 1.5 - 5 mol% yttria powder; (b) making a raw material zirconia powder formed as a solid solution with yttria by milling the powder after calcining the powder at 800 - 1,000°C; (c) forming a green body by compacting the raw material zirconia powder; (d) making a presintered material having a bulk density which is not less than 95% of a theoretical density by presintering the green body; and (e) sintering the presintered material in an oxidizing atmosphere by hot isostatic pressing.
Claim 19
Independent Claim
100 words
A method for manufacturing a sintered zirconia material comprising the steps of: (a) preparing a zirconia powder containing 1.5 - 5 mol% yttria powder; (b) making a raw material zirconia powder formed as a solid solution with yttria by milling the powder after calcining the powder at 800 - 1,000°C; (c) forming a green body by compacting the raw material zirconia powder; (d) making a presintered material having a bulk density which is not less than 95% of a theoretical density by presintering the green body; and (e) sintering the presintered material in an oxidizing atmosphere by hot isostatic pressing.
Claim 20
Independent Claim
86 words
A method for manufacturing a sintered zirconia material comprising the steps of: (a) preparing a zirconia powder containing 1.5 - 5 mol% yttria powder; (b) making a raw material zirconia powder formed as a solid solution with yttria by milling the powder after calcining the powder at 800 - 1,000°C; (c) forming a green body by compacting the raw material zirconia powder; and (d) putting the green body into a capsule, and presintering and sintering the green body in an oxidizing atmosphere by hot isostatic pressing.
Claim 21
Independent Claim
86 words
A method for manufacturing a sintered zirconia material comprising the steps of: (a) preparing a zirconia powder containing 1.5 - 5 mol% yttria powder; (b) making a raw material zirconia powder formed as a solid solution with yttria by milling the powder after calcining the powder at 800 - 1,000°C; (c) forming a green body by compacting the raw material zirconia powder; and (d) putting the green body into a capsule, and presintering and sintering the green body in an oxidizing atmosphere by hot isostatic pressing.
Claim 22
Independent Claim
82 words
A method for manufacturing a sintered zirconia material comprising the steps of: (a) preparing a zirconia powder containing 1.5 - 5 mol% yttria powder; (b) making a raw material zirconia powder formed as a solid solution with yttria by milling the powder after calcining the powder at 800 - 1,000°C; and (c) filling the raw material zirconia powder in a capsule, and presintering and sintering the raw material zirconia powder by directly consolidating it in an oxidizing atmosphere using hot isostatic pressing.
Claim 23
Independent Claim
82 words
A method for manufacturing a sintered zirconia material comprising the steps of: (a) preparing a zirconia powder containing 1.5 - 5 mol% yttria powder; (b) making a raw material zirconia powder formed as a solid solution with yttria by milling the powder after calcining the powder at 800 - 1,000°C; and (c) filling the raw material zirconia powder in a capsule, and presintering and sintering the raw material zirconia powder by directly consolidating it in an oxidizing atmosphere using hot isostatic pressing.
Claim 24
Dependent Claim
44 words
The manufacturing method of claim 17, 18 or 19, wherein the powder is prepared from an aqueous solution containing zirconium chloride having a purity of not less than 99.9% and an aqueous solution containing yttrium chloride having a purity of not less than 99.5%.
Claim 25
Dependent Claim
44 words
The manufacturing method of claim 17, 18 or 19, wherein the powder is prepared from an aqueous solution containing zirconium nitrate having a purity of not less than 99.9% and an aqueous solution containing yttrium nitrate having a purity of not less than 99.5%
Claim 26
Dependent Claim
38 words
The manufacturing method of claim 17, 18 or 19, wherein the powder is prepared from a zirconia powder having a purity of not less than 99.9% and a yttria powder having a purity of not less than 99.9%.
Claim 27
Dependent Claim
19 words
The manufacturing method of claim 17, 18 or 19, wherein the temperature of the calcination is 850 - 950°C.
Claim 28
Dependent Claim
49 words
The manufacturing method of claim 17, 18 or 19, wherein the raw material zirconia powder additionally contains at least one metal oxide selected from the group consisitng of aluminium, titanium, copper, nickel, iron, cobalt and chrome oxide to the extent of 0.1 - 1 wt.% as a third component.
Claim 29
Dependent Claim
20 words
The manufacturing method of claim 24, wherein the third component is presnet in an amount of 0.2 - 0.5 wt.%.
Claim 30
Dependent Claim
76 words
The manufacturing method of claim 17, 18 or 19, wherein the raw material zirconia powder additionally contains at least one colorant selected from the group consisting of 0.05 - 0.7 wt.% chrome oxide, 0.05 - 0.2 wt.% copper oxide, 0.05 - 2 wt.% erbium oxide, 1 - 2 wt.% cerium oxide, 0.05 - 2 wt.% vanadium oxide, 0.5 - 2 wt.% neodymium oxide, 0.05 - 0.3 wt.% cobalt oxide and 0.05 - 0.5 wt.% iron oxide.
Claim 31
Dependent Claim
22 words
The manufacturing method of claim 17, 18 or 19, wherein the oxygen concentration of the oxidizing atmosphere is 0.1 - 25 vol.%.
Claim 32
Dependent Claim
15 words
The manufacturing method of claim 27, wherein the oxygen concentration is 1 - 20 vol.%.
Claim 33
Dependent Claim
15 words
The manufacturing method of claim 28, wherein the oxygen concentration is 3 - 10 vol.%.
Claim 34
Dependent Claim
22 words
The manufacturing method of claim 17, 18 or 19, wherein the gas pressure of the oxidizing atomosphere is 1,000 - 2,200 kg/cm².
Claim 35
Dependent Claim
15 words
The manufacturing method of claim 30, wherein the gas pressure is 1,500 - 2,000 kg/cm².
Claim 36
Dependent Claim
23 words
The manufacturing method of claim 17, wherein the bulk density of the presintered material is not less than 97.5% of the theoretical density.
Claim 37
Dependent Claim
23 words
The manufacturing method of claim 32, wherein the bulk density of the presintered material is not less than 99% of the theoretical density.
Claim 38
Dependent Claim
59 words
The manufacturing method of claim 17, wherein the presintered material is made by first heating the green body to 850 - 1,000°C at a heating rate of 20 - 100°C/hour and then by heating the body to 1,150 - 1,550°C at a heating rate of 30 - 50°C/hour and maintaining the body at the temperature after the second heating.
Claim 39
Dependent Claim
18 words
The manufacturing method of claim 34, wherein the heating rate of the first heating is 30 - 70°C/hour.
Claim 40
Dependent Claim
18 words
The manufacturing method of claim 35, wherein the heating rate of the first heating is 30 - 50°C/hour.
Claim 41
Dependent Claim
19 words
The manufacturing method of claim 34, wherein the temperature of the body after the first heating is 900 -950°C.
Claim 42
Dependent Claim
20 words
The manufacturing method of claim 34, wherein the temperature of the body after the second heating is 1,200 - 1,450°C.
Claim 43
Dependent Claim
41 words
The manufacturing method of claim 17, wherein the presintered material is sintered by heating the material to 1,150 - 1,500°C, maintaining the material at this temperature and cooling the material to room temperature at a cooling rate of 200 - 600°C/hour.
Claim 44
Dependent Claim
15 words
The manufacturing method of claim 39, wherein the temperature for sintering is 1,300 - 1,400°C.
Claim 45
Dependent Claim
14 words
The manufacturing method of claim 39, wherein the cooling rate is 300 - 500°C/hour.
References Cited (Backward Citations)
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