Claims
- 1. A method for preparing a zirconia sintered body comprising the steps of:
- injection molding a zirconia composition comprising 100 parts by weight of zirconia powder and 5 to 30 parts by weight of an organic binder, said zirconia powder containing 2 to 10 mol % of yttria in solid solution form and having a specific surface area of up to 12 m.sup.2 /g as measured by the BET method and a product of an average particle size multiplied by the specific surface area of up to 3 .mu.m.multidot.m.sup.2 /g,
- removing the organic binder from the molded composition by heating, and
- firing the molded composition into a sintered body.
- 2. The method of claim 1, wherein the average particle size of said zirconia powder is 0.05 to 0.5 .mu.m.
- 3. The method of claim 1, wherein the average particle size of said zirconia powder is 0.1 to 0.4 .mu.m.
- 4. The method of claim 1, wherein the specific surface area of said zirconia powder is from 5 to 10 m.sup.2 /g.
- 5. The method of claim 1, wherein the product of average particle size multiplied by the specific surface area of said zirconia powder is 1 to 2.5 .mu.m.multidot.m.sup.2 /g.
- 6. The method of claim 1, wherein said zirconia powder contains 2 to 8 mol % of yttria in solid solution form.
- 7. The method of claim 1, wherein the organic binder is selected from the group consisting of polyacrylic binders, wax binders, polyolefin binders, polyvinyl acetate binders and mixtures thereof.
- 8. The method of claim 1, wherein the organic binder in the zirconia composition is present in an amount of 10 to 20 parts by weight.
- 9. The method of claim 1, wherein the injection molding conditions include an injection pressure of 100 to 2,600 kg/cm.sup.2, an injection speed of 0.1 to 10 cm/sec., a mold temperature of 10.degree. to 70.degree. C., a cylinder temperature of 100.degree. to 180.degree. C.
- 10. The method of claim 1, wherein the organic binder is removed by heating to about 500.degree. C. at a rate of 5.degree.-150.degree. C./hour so as to remove the organic binder through pyrolysis.
- 11. The method of claim 10, wherein the heating rate if 10.degree.-50.degree. C./hour.
- 12. The method of claim 10, wherein the heating time for removing the organic binder is 5 to 100 hours.
- 13. The method of claim 10, wherein the heating time for removing the organic binder is 10 to 40 hours.
- 14. The method of claim 1, wherein the molded composition is fired into a sintered body at a temperature of 1,300.degree. to 1,600.degree. C.
- 15. The method of claim 1, wherein the molded composition is fired into a sintered body at a temperature of 1,350.degree. to 1,500.degree. C.
- 16. The method of claim 1, wherein the molded composition is fired into a sintered body for a period of 0.2 to 10 hours.
- 17. The method of claim 1, wherein the composition is fired into a sintered body for a period of 1 to 4 hours.
Priority Claims (1)
Number |
Date |
Country |
Kind |
1-254101 |
Sep 1989 |
JPX |
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Parent Case Info
This application is a continuation of application Ser. No. 07/588,180, filed on Sep. 26, 1990, now abandoned.
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4713206 |
Matsuhisa et al. |
Dec 1987 |
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4873064 |
Kato et al. |
Oct 1989 |
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Continuations (1)
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Number |
Date |
Country |
Parent |
588180 |
Sep 1990 |
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