US4664973A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Porous metal abradable seal material
Assignee: RTX Corp
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Filing: 1985-09-05
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Granted: 1987-05-12
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Expires: 2005-09-05
Abstract
Abstract Porous metal structures are especially useful as abradable seals in axial flow compressors. Carefully defined oxide content and density provide a superior combination of abradability and particulate erosion resistance. The seals are comprised of 1-30 weight percent oxide and have 27-38 percent of the solid metal density. A preferred seal is made by plasma arc spraying a mixture of 80Ni-20Cr and polymethylmethacrylate powders and then heating the resultant deposit in air to about 315° C. to cause the polymer to flee. The nichrome seal will have less than 15 percent oxide and a density of about 2.7 g/cm 3 , about 32 percent of the solid metal density.
Inventors
- 👤 William F. Otfinoski
- 👤 Harry E. Eaton
- 👤 Richard C. Novak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:08
CPC Classifications
F; F01; F01D; F01D11/00; F01D11/08; F01D11/12; F01D11/122; C; C22; C22C; C22C1/00; C22C1/08; C23; C23C; C23C4/00; C23C4/04; C23C4/18; F16; F16J; F16J15/00; F16J15/44; F16J15/445; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249955; Y10T428/249956
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
29 words
An abradable metallic seal material comprised of porous nickel alloy metal having an apparent density of 27-38 percent and an oxide content of no more than 1-30 weight percent.
Claim 2
Dependent Claim
29 words
An abradable metallic seal material comprised of porous nickel alloy metal having an apparent density of 27-38 percent and an oxide content of no more than 1-30 weight percent.
Claim 3
Dependent Claim
11 words
The material of claim 1 having a density of 28-32 percent.
Claim 4
Dependent Claim
11 words
The material of claim 2 having a density of 30-32 percent.
Claim 5
Dependent Claim
45 words
The invention of claim 1 characterized by the material shaped as a curved seal and characterized in that glazing does not occur when titanium alloy blade tips rotating with a 290 m/s tip speed engage the seal at a penetration rate of about 0.05 mm/s.
Claim 6
Dependent Claim
45 words
The material of claim 4 characterized in that the volume wear of a set of six engaging titanium alloy blade tips is less than 1/250 of the volume wear of the curved seal material when the blades have penetrated about 1 mm into the material.
Claim 7
Dependent Claim
15 words
The invention of claim 1 characterized by the nickel alloy metal being a nichrome alloy.
Claim 8
Dependent Claim
20 words
The invention of claim 6 characterized by the nickel alloy metal consisting essentially by weight percent of 80Ni and 20Cr.
Claim 9
Dependent Claim
28 words
The invention of claim 1 characterized by the nickel alloy metal being a nichrome alloy having a density and oxide content falling within region A of FIG. 1.
Claim 10
Dependent Claim
17 words
The invention of claim 1 characterized by the pores of the nickel alloy metal having spherical shapes.
Claim 11
Dependent Claim
13 words
The invention of claim 1 characterized by an oxide content of 1-15 percent.
Claim 12
Dependent Claim
14 words
The material of claim 1 produced by plasma arc spraying the nickel metal alloy.
Claim 13
Dependent Claim
20 words
The material of claim 11 produced by spraying the nickel metal alloy onto a superalloy substrate so it adheres thereto.
Claim 14
Dependent Claim
35 words
A metallic material useful as an abradable seal comprised of a porous metal alloy having an oxide content of no more than 1-30 weight percent and a Rockwell 10 Z superficial hardness number of 45-85.
Claim 15
Dependent Claim
35 words
A metallic material useful as an abradable seal comprised of a porous metal alloy having an oxide content of no more than 1-30 weight percent and a Rockwell 10 Z superficial hardness number of 45-85.
Claim 16
Dependent Claim
11 words
The material of claim 13 having a hardness number of 50-75.
Claim 17
Dependent Claim
45 words
The invention of claim 13 characterized by the material shaped as a curved seal and characterized in that glazing does not occur when titanium alloy blade tips rotating with a 290 m/s tip speed engage the seal at a penetration rate of about 0.05 mm/s.
Claim 18
Dependent Claim
45 words
The material of claim 15 characterized in that the volume wear of a set of six engaging titanium alloy blade tips is less than 1/250 of the volume wear of the curved seal material when the blades have penetrated about 1 mm into the material.
Claim 19
Dependent Claim
14 words
The invention of claim 13 characterized by the metal alloy being a nichrome alloy.
Claim 20
Dependent Claim
19 words
The invention of claim 17 characterized by the metal alloy consisting essentially by weight percent of 80Ni and 20Cr.
Claim 21
Dependent Claim
27 words
The invention to claim 13 characterized by the metal alloy being a nichrome alloy having a density and oxide content falling within region A of FIG. 1.
Claim 22
Dependent Claim
16 words
The invention of claim 13 characterized by the pores of the metal alloy having spherical shapes.
Claim 23
Dependent Claim
13 words
The invention of claim 13 characterized by an oxide content of 1-15 percent.
Claim 24
Independent Claim
42 words
The method of obtaining a desired combination of erosion resistance and abradability in a metal abradable seal which comprises controlling both the relative density of the seal in the range 27-38 percent and the oxide content in the range of 1-30 percent.
Claim 25
Independent Claim
42 words
The method of obtaining a desired combination of erosion resistance and abradability in a metal abradable seal which comprises controlling both the relative density of the seal in the range 27-38 percent and the oxide content in the range of 1-30 percent.
Claim 26
Independent Claim
46 words
The method of obtaining a desired combination of erosion resistance and abradability in a metal abradable seal which comprises controlling both the relative Rockwell 10 Z superficial hardness of the seal in the range 27-38 percent and the oxide content in the range of 1-30 percent.
Claim 27
Independent Claim
46 words
The method of obtaining a desired combination of erosion resistance and abradability in a metal abradable seal which comprises controlling both the relative Rockwell 10 Z superficial hardness of the seal in the range 27-38 percent and the oxide content in the range of 1-30 percent.
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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) | 1990-05-11 | 1990-11-10 | 1991-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-11 | 1994-11-10 | 1995-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-11 | 1998-11-10 | 1999-05-12 | $7700.00 | Window Closed / Lapsed |