US4704338A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Steel bonded dense silicon nitride compositions and method for their fabrication
Assignee: United States Department of Energy
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Filing: 1986-11-20
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Granted: 1987-11-03
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Expires: 2006-11-20
Abstract
Abstract A two-stage bonding technique for bonding high density silicon nitride and other ceramic materials to stainless steel and other hard metals, and multilayered ceramic-metal composites prepared by the technique are disclosed. The technique involves initially slurry coating a surface of the ceramic material at about 1500 DEG C. in a vacuum with a refractory material and the stainless steel is then pressure bonded to the metallic coated surface by brazing it with nickel-copper-silver or nickel-copper-manganese alloys at a temperature in the range of about 850 DEG to 950 DEG C. in a vacuum. The two-stage bonding technique minimizes the temperature-expansion mismatch between the dissimilar materials.
Inventors
- 👤 Richard L. Landingham
- 👤 Thomas E. Shell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:03
CPC Classifications
C; C04; C04B; C04B37/00; C04B37/003; C04B37/006; B; B23; B23K; B23K35/00; B23K35/22; B23K35/24; B23K35/32; B23K35/327; C04B37/02; C04B37/023; C04B37/026; C04B2237/00; C04B2237/02; C04B2237/04; C04B2237/09; C04B2237/12; C04B2237/123; C04B2237/30; C04B2237/32; C04B2237/36; C04B2237/368; C04B2237/40; C04B2237/403; C04B2237/405; C04B2237/406; C04B2237/407; C04B2237/408; C04B2237/50; C04B2237/52; C04B2237/70; C04B2237/704; C04B2237/706; C04B2237/72; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12576; Y10T428/12771; Y10T428/12861; Y10T428/12937; Y10T428/12944
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
57 words
A multilayered composite comprising: a layer of high density, sintered silicon nitride; a layer of a refractory material comprising a mixture of powdered nickel and molybdenum silicide; a layer of a brazing alloy; and a layer of metal, with said layer of a brazing alloy sandwiched between said layer of metal and said layer of refractory material.
Claim 2
Dependent Claim
57 words
A multilayered composite comprising: a layer of high density, sintered silicon nitride; a layer of a refractory material comprising a mixture of powdered nickel and molybdenum silicide; a layer of a brazing alloy; and a layer of metal, with said layer of a brazing alloy sandwiched between said layer of metal and said layer of refractory material.
Claim 3
Dependent Claim
21 words
The composite of claim 1, wherein said brazing alloy is selected from the group consisting of nickel-copper-silver, nickel-copper-manganese, nickel-copper-gold, nickel-copper-palladium alloys.
Claim 4
Dependent Claim
13 words
The composite of claim 2, wherein said brazing alloy is nickel-copper-silver or nickel-copper-manganese.
Claim 5
Dependent Claim
27 words
The composite of claim 3, wherein the metal is selected from the group consisting of iron, steel, stainless steel, nickel, tungsten, copper, brass, titanium, platinum, and zirconium.
Claim 6
Dependent Claim
11 words
The composite of claim 4, wherein the metal is stainless steel.
Claim 7
Dependent Claim
12 words
The composite of claim 5, wherein said stainless steel is Greek Ascaloy.
Claim 8
Dependent Claim
101 words
A multilayered composite comprising: a layer of high density, sintered silicon nitride; a layer of a refractory material comprising a mixture of powdered molybdenum silicide and nickel, slurry coated onto a surface of said silicon nitride and bonded at about 1500° C. in a vacuum; a layer of a brazing alloy comprising nickel-copper-silver or nickel-copper-manganese alloy; and a layer of stainless steel, with said layer of said brazing alloy sandwiched between and bonded in a vacuum to said layer of stainless steel and said layer of said refractory material at a temperature in the range of about 850° to 950° C.
Claim 9
Dependent Claim
101 words
A multilayered composite comprising: a layer of high density, sintered silicon nitride; a layer of a refractory material comprising a mixture of powdered molybdenum silicide and nickel, slurry coated onto a surface of said silicon nitride and bonded at about 1500° C. in a vacuum; a layer of a brazing alloy comprising nickel-copper-silver or nickel-copper-manganese alloy; and a layer of stainless steel, with said layer of said brazing alloy sandwiched between and bonded in a vacuum to said layer of stainless steel and said layer of said refractory material at a temperature in the range of about 850° to 950° C.
Claim 10
Dependent Claim
15 words
The composite of claim 7, wherein any of said layers is a plurality of layers.
Claim 11
Dependent Claim
12 words
The composite of claim 7, wherein said stainless steel is Greek Ascaloy.
Claim 12
Dependent Claim
12 words
The composite of claim 9, wherein said brazing alloy is nickel-copper-silver alloy.
Claim 13
Dependent Claim
109 words
A silicon nitride rotor and steel shaft for a turbine or air compressor or diesel engine bonded together by the method comprising: (a) polishing a surface of a dense, sintered silicon nitride rotor to enhance wetting of said surface; (b) slurry coating and bonding to said surface of said silicon nitride rotor, a layer of a refractory material comprising a mixture of powdered nickel and molybdenum silicide; (c) grinding said layer of said refractory material to uniform thickness; (d) brazing said layer of said refractory material with a nickel-copper-silver or nickel-copper-manganese alloy at elevated temperatures; and (e) pressure bonding a steel shaft to said refractory material and said alloy.
Claim 14
Dependent Claim
109 words
A silicon nitride rotor and steel shaft for a turbine or air compressor or diesel engine bonded together by the method comprising: (a) polishing a surface of a dense, sintered silicon nitride rotor to enhance wetting of said surface; (b) slurry coating and bonding to said surface of said silicon nitride rotor, a layer of a refractory material comprising a mixture of powdered nickel and molybdenum silicide; (c) grinding said layer of said refractory material to uniform thickness; (d) brazing said layer of said refractory material with a nickel-copper-silver or nickel-copper-manganese alloy at elevated temperatures; and (e) pressure bonding a steel shaft to said refractory material and said alloy.
Claim 15
Dependent Claim
27 words
A silicon nitride rotor and steel shaft junction for a turbine or diesel or air compressor engine said junction comprising a multilayer composite according to claim 10.
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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) | 1990-11-02 | 1991-05-04 | 1991-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-02 | 1995-05-04 | 1995-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-02 | 1999-05-04 | 1999-11-03 | $7700.00 | Window Closed / Lapsed |