US4598052A
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US
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Alumina base substrate of recording head and process for the production thereof
Assignee: Nippon Tungsten Co Ltd
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Filing: 1985-04-29
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Granted: 1986-07-01
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Expires: 2005-04-29
Abstract
Abstract An alumina base substrate material for recording heads, which comprises a densely sintered body consisting essentially of: per 100 parts by weight of a base component of 30 to 40% by weight of a titanium compound having TiO2 to (TiC+TiO2) percentage of 5 to 15% by weight and the balance being Al2O3, components A, B and C, provided that the A to B ratio is within a hatched KLMN area in FIG. 1, in the following given parts by weight, and oxidic impurities in amounts of no higher than 0.2% by weight based on the total composition, said sintered body having an average crystal grain size of no higher than 1.3 microns, a porosity per area of no higher than 0.5%, a bending strength of at least 70 kg/cm2 and a hardness HRA of at least 93.0: wherein component A is at least one of spinels expressed by RO-Al2O3, where R is at least one of Mg, Mn, Ni and Co, in an amount of 2.0 to 17.5 parts by weight, component B is 0.2 to 2.0 parts by weight of ZrO2, and Component C is 0.05 to 2.0 parts by weight of Y2O3.
Inventors
- 👤 Toshiaki Wada
- 👤 Mitsuhiko Furukawa
- 👤 Mitsuyoshi Nagano
- 👤 Michito Miyahara
- 👤 Shigeki Mori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:44
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
225 words
An alumina base substrate material for recording heads, which comprises a densely sintered body consisting essentially of: per 100 parts by weight of a base component of 30 to 40% by weight of a mixture of carbide and oxide of titanium having a TiO 2 to (TiC+TiO 2 ) percentage of 5 to 15% by weight and the balance being Al 2 O 3 , components A, B and C, provided that the A to B ratio is within a hatched KLMN area in FIG. 1, in the following given parts by weight, and oxidic impurities in amounts of no higher than 0.2% by weight based on the total composition, said sintered body having an average crystal grain size of no higher than 1.3 microns, a porosity per area of no higher than 0.5%, a bending strength of at least 70 kg/cm 2 and a hardness H R A of at least 93.0: wherein component A is at least one of spinels expressed by RO-Al 2 O 3 , where R is at least one of Mg, Mn, Ni and Co, in an amount of 2.0 to 17.5 parts by weight, component B is ZrO 2 in an amount of 0.2 to 2.0 parts by weight, and component C is a Y 2 O 3 in an amount of 0.05 to 2.0 parts by weight.
Claim 2
Dependent Claim
225 words
An alumina base substrate material for recording heads, which comprises a densely sintered body consisting essentially of: per 100 parts by weight of a base component of 30 to 40% by weight of a mixture of carbide and oxide of titanium having a TiO 2 to (TiC+TiO 2 ) percentage of 5 to 15% by weight and the balance being Al 2 O 3 , components A, B and C, provided that the A to B ratio is within a hatched KLMN area in FIG. 1, in the following given parts by weight, and oxidic impurities in amounts of no higher than 0.2% by weight based on the total composition, said sintered body having an average crystal grain size of no higher than 1.3 microns, a porosity per area of no higher than 0.5%, a bending strength of at least 70 kg/cm 2 and a hardness H R A of at least 93.0: wherein component A is at least one of spinels expressed by RO-Al 2 O 3 , where R is at least one of Mg, Mn, Ni and Co, in an amount of 2.0 to 17.5 parts by weight, component B is ZrO 2 in an amount of 0.2 to 2.0 parts by weight, and component C is a Y 2 O 3 in an amount of 0.05 to 2.0 parts by weight.
Claim 3
Dependent Claim
65 words
A substrate material as defined in claim 1, in which Al 2 O 3 , TiC, TiO 2 , Y 2 O 3 , ZrO 2 and the spinels are uniformly dispersed in an average crystal grain size of 0.5 to 1.3 microns, and 90% or more of the crystal grains forming the overall sintered body is within a range of 0.5 to 1.3 microns.
Claim 4
Dependent Claim
210 words
A process for the production of alumina base substrate materials for recording heads, which comprises: providing a starting material consisting essentially of: per 100 parts by weight of a powdery base component of 30 to 40% by weight of TiC and TiO 2 each having an average particle size of no more than 1.5 microns wherein a TiO 2 /(TiC+TiO 2 ) percentage is 5 to 15% by weight, and the balance being Al 2 O 3 , a mixture of components A, B and C with the proviso that the A to B ratio is within a hatched KLMN area in FIG. 1, provided that the amount of oxidic impurities contained in said starting material is 0.2% by weight or lower: wherein component A is at least one of spinels expressed by RO-Al 2 O 3 where R is at least one of Mg, Mn, Ni and Co in amount of 2.0 to 17.5 parts by weight, component B is ZrO 2 in an amount of 0.2 to 2.0 parts by weight, and component C is Y 2 O 3 in an amount of 0.05 to 2.0 parts by weight; and press sintering said starting material at a temperature from about 1350° to 1650° C. in a non-oxidizing atmosphere.
Claim 5
Dependent Claim
210 words
A process for the production of alumina base substrate materials for recording heads, which comprises: providing a starting material consisting essentially of: per 100 parts by weight of a powdery base component of 30 to 40% by weight of TiC and TiO 2 each having an average particle size of no more than 1.5 microns wherein a TiO 2 /(TiC+TiO 2 ) percentage is 5 to 15% by weight, and the balance being Al 2 O 3 , a mixture of components A, B and C with the proviso that the A to B ratio is within a hatched KLMN area in FIG. 1, provided that the amount of oxidic impurities contained in said starting material is 0.2% by weight or lower: wherein component A is at least one of spinels expressed by RO-Al 2 O 3 where R is at least one of Mg, Mn, Ni and Co in amount of 2.0 to 17.5 parts by weight, component B is ZrO 2 in an amount of 0.2 to 2.0 parts by weight, and component C is Y 2 O 3 in an amount of 0.05 to 2.0 parts by weight; and press sintering said starting material at a temperature from about 1350° to 1650° C. in a non-oxidizing atmosphere.
Claim 6
Dependent Claim
47 words
A material as defined in claim 1, wherein the KLMN area in FIG. 1 is defined by the following coordinates (x, y) where x represents the component B and y represents the component A: K: (0.2, 10.5), L: (0.2, 2.0), M: (2.0, 7.0), and N: (2.0, 17.5).
Claim 7
Dependent Claim
47 words
A process as defined in claim 3, wherein the KLMN area in FIG. 1 is defined by the following coordinates (x, y) where x represents the component B and y represents the component A: K: (0.2, 10.5), L: (0.2, 2.0), M: (2.0, 7.0), and N: (2.0, 17.5).
Claim 8
Dependent Claim
17 words
A material as defined in claim 1, wherein the component A amounts to 2.0-10.5 parts by weight.
Claim 9
Dependent Claim
17 words
A process as defined in claim 3, wherein the component A amounts to 2.0-10.5 parts by weight.
Claim 10
Dependent Claim
15 words
A material as defined in claim 1, wherein R of the component A is Mg.
Claim 11
Dependent Claim
15 words
A material as defind in claim 1, wherein R of the component A is Mn.
Claim 12
Dependent Claim
15 words
A material as defined in claim 1, wherein R of the component A is Ni.
Claim 13
Dependent Claim
15 words
A material as defined in claim 1, wherein R of the component A is Co.
Claim 14
Dependent Claim
26 words
A process as defined in claim 3, wherein the press sintering is effected under application of a pressure of at least about 150 kg/cm 2 .
Claim 15
Dependent Claim
17 words
A process as defined in claim 3, wherein the sintering is effected at 1600° C. or less.
Claim 16
Dependent Claim
20 words
A material as defined in claim 2, wherein the crystal grains have an average size of 1.0 micron or less.
Claim 17
Dependent Claim
18 words
A material as defined in claim 2, wherein the bending strength is at least 75 kg/cm 2 .
Claim 18
Dependent Claim
17 words
A material as defined in claim 2, wherein the porosity per area is no higher than 0.4%.
Claim 19
Dependent Claim
17 words
A material as defined in claim 2, wherein the hardness H R A is at least 93.5.
Claim 20
Dependent Claim
17 words
A recording head slider comprising a substrate member formed of the material as defined in claim 1.
Claim 21
Dependent Claim
20 words
A recording head slider comprising a substrate member formed of the product of the process as defined in claim 3.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-30 | 1989-12-30 | 1990-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-30 | 1993-12-30 | 1994-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-30 | 1997-12-30 | 1998-07-01 | $7700.00 | Window Closed / Lapsed |