US4430440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic head slider material
Assignee: Nippon Tungsten Co Ltd
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Filing: 1982-05-28
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Granted: 1984-02-07
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Expires: 2002-05-28
Abstract
Abstract A material for magnetic head sliders comprises a mixed powder consisting of 40 to 80% by weight of Al 2 O 3 and 20 to 60% by weight of TiO 2 , and further contains, per 100 parts by weight of the Al 2 O 3 and TiO 2 mixture, 0.5 to 5 parts by weight of at least one of CaO, MgO and Y 2 O 3 , and 0.5 to 10 parts by weight of ZrO 2 .
Inventors
- 👤 Toshiaki Wada
- 👤 Mitsuhiko Furukawa
- 👤 Michito Miyahara
- 👤 Masaharu Shiroyama
- 👤 Kiyohito Misumi
- 👤 Takashi Kitahira
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:58
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111; C04B35/46; C04B35/462; C04B35/478; G; G11; G11B; G11B5/00; G11B5/10; G11B5/102; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/11; Y10T428/1164
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
145 words
A wear-resistant product which is useful in fabricating magnetic head sliders, said product consisting essentially of 40 to 80% by weight of Al 2 O 3 , 20 to 60% by weight of TiO 2 , 0.5 to 5 parts by weight, based on 100 parts by weight of combined Al 2 O 3 and TiO 2 , of at least one oxide selected from the group consisting of CaO, MgO and Y 2 O 3 , and 0.5 to 10 parts by weight, based on 100 parts by weight of combined Al 2 O 3 and TiO 2 , of ZrO 2 which has a purity of at least 99.0% and maximum particle diameters of 2 microns; said product having a hardness of between about 89.0 and 89.3 (HrA) and a wear resistance of between about 0.1 and about 0.3 mm 3 (pin-disk method).
Claim 2
Dependent Claim
145 words
A wear-resistant product which is useful in fabricating magnetic head sliders, said product consisting essentially of 40 to 80% by weight of Al 2 O 3 , 20 to 60% by weight of TiO 2 , 0.5 to 5 parts by weight, based on 100 parts by weight of combined Al 2 O 3 and TiO 2 , of at least one oxide selected from the group consisting of CaO, MgO and Y 2 O 3 , and 0.5 to 10 parts by weight, based on 100 parts by weight of combined Al 2 O 3 and TiO 2 , of ZrO 2 which has a purity of at least 99.0% and maximum particle diameters of 2 microns; said product having a hardness of between about 89.0 and 89.3 (HrA) and a wear resistance of between about 0.1 and about 0.3 mm 3 (pin-disk method).
Claim 3
Dependent Claim
16 words
A wear-resistant product as defined in claim 1 which has been formed by hot isostatic pressing.
Claim 4
Dependent Claim
14 words
A wear-resistant product as defined in claim 1 which has been formed by sintering.
Claim 5
Dependent Claim
52 words
A wear-resistant product as defined in claim 1 which displays a specific gravity of 3.99 to 4.0, a hardness of 89.1 to 89.3 (HrA), a breaking strength of 46 to 48 Kg/mm 2 , a thermal conductivity of about 0.0273 cal/mm sec.°C., and an electrical resistance of at least 10 6 Ωcm.
Claim 6
Dependent Claim
12 words
A magnetic head slider which includes the wear-resistant product of claim 1.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-02-06 | 1987-08-08 | 1988-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-06 | 1991-08-08 | 1992-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-06 | 1995-08-08 | 1996-02-07 | $7700.00 | Window Closed / Lapsed |