US4738389A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Welding using metal-ceramic composites
Assignee: Lockheed Martin Corp
•
Filing: 1986-03-28
•
Granted: 1988-04-19
•
Expires: 2006-03-28
Abstract
Abstract A method for welding metal composite materials, including metal-ceramic composites, whereby a weld or filler material is prepared by the in-situ precipitation of ceramic in a metallic matrix. The filler material may comprise boride, carbide, oxide, nitride, silicide, etc., while the matrix metal may constitute a alloy or intermetallic of two or more metals. A strong bond is achieved when welding two conventional metals, a conventional metal and a metal-ceramic composite, or two metal-ceramic composites.
Inventors
- 👤 William C. Moshier
- 👤 Dennis C. Nagle
- 👤 John M. Brupbacher
- 👤 Leontios Christodoulou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:06
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/23; B22F9/00; B22F9/02; B22F9/14; B23; B23K; B23K35/00; B23K35/22; B23K35/24; B23K35/32; B23K35/327; B23K35/40; B82; B82Y; B82Y30/00; C; C22; C22C; C22C29/00; C22C32/00; C22C32/0047; C22C32/0078; C22C47/00; C22C47/02; C22C47/06; C22C47/08; C22C49/00; C22C49/14
Claims Analysis
Total Claims: 82
Claim 1
Independent Claim
144 words
A method for welding, said method comprising providing first and second bodies, each body being of a metal containing material and having a welding surface, placing said bodies such that a welding surface of the first body is in close proximity to a welding surface of the second body, and welding the bodies together by contacting reactive ceramic forming constituents, in the presence of a solvent metal in which said ceramic forming constituents are more soluble than said ceramic material, at a temperature at which sufficient diffusion of said reactive ceramic forming constituents into said solvent metal occurs to cause a ceramic forming reaction of said constituents and thereby precipitate submicron ceramic particles in-situ in said solvent metal so as to produce a material comprising finely divided ceramic particles in a metal matrix in such a position as to join the two welding surfaces.
Claim 2
Independent Claim
144 words
A method for welding, said method comprising providing first and second bodies, each body being of a metal containing material and having a welding surface, placing said bodies such that a welding surface of the first body is in close proximity to a welding surface of the second body, and welding the bodies together by contacting reactive ceramic forming constituents, in the presence of a solvent metal in which said ceramic forming constituents are more soluble than said ceramic material, at a temperature at which sufficient diffusion of said reactive ceramic forming constituents into said solvent metal occurs to cause a ceramic forming reaction of said constituents and thereby precipitate submicron ceramic particles in-situ in said solvent metal so as to produce a material comprising finely divided ceramic particles in a metal matrix in such a position as to join the two welding surfaces.
Claim 3
Dependent Claim
24 words
A method as set forth in claim 1, wherein the reactive ceramic forming constituents are each provided as an alloy of the solvent metal.
Claim 4
Dependent Claim
22 words
A method as set forth in claim 1, wherein the first body is an alloy and the second body is an alloy.
Claim 5
Dependent Claim
31 words
A method as set forth in claim 1, wherein the first body is an alloy and the second body is a composite of finely divided ceramic particles in a metal matrix.
Claim 6
Dependent Claim
28 words
A method as set forth in claim 1, wherein the first and the second bodies are each a composite of finely divided ceramic particles in a metal matrix.
Claim 7
Dependent Claim
22 words
A method as set forth in claim 1, wherein the temperature is at least about the melting temperature of said solvent metal.
Claim 8
Dependent Claim
24 words
A method as set forth in claim 1, wherein the reactive ceramic forming constituents and the solvent metal are each provided as individual elements.
Claim 9
Dependent Claim
26 words
A method as set forth in claim 1, wherein the reactive ceramic forming constituents are powders and the solvent metal is a foil containing the powders.
Claim 10
Dependent Claim
18 words
A method as set forth in claim 1, wherein the reactive ceramic forming constituents are provided as filaments.
Claim 11
Dependent Claim
15 words
A method as set forth in claim 9, wherein the solvent metal is a filament.
Claim 12
Dependent Claim
34 words
A method as set forth in claim 1, wherein at least one ceramic forming constituent is selected from the group consisting of transition metals of the third to sixth groups of the Periodic Table.
Claim 13
Dependent Claim
42 words
A method as set forth in claim 11, wherein at least one ceramic forming constituent is selected from the group consisting of aluminum, titanium, silicon, boron, carbon, sulfur, germanium, molybdenum, tungsten, vanadium, zirconium, chromium, magnesium, hafnium, tantalum, nitrogen, and rare earth metals.
Claim 14
Dependent Claim
55 words
A method as set forth in claim 12, wherein said solvent metal is selected from the group consisting of aluminum, gallium, nickel, titanium, copper, vanadium, chromium, manganese, cobalt, iron, silicon, germanium, silver, gold, platinum, palladium, rhodium, ruthenium, magnesium, lead, zinc, tin, tantatum, molybdenum, tungsten, hafnium, niobium, rhenium, zirconium, and alloys and intermetallics of such metals.
Claim 15
Dependent Claim
36 words
A method as set forth in claim 13, wherein said solvent metal is selected from the group consisting of aluminum, zinc, magnesium, copper, lead, nickel, chromium, iron, titanium, cobalt, and alloys and intermetallics of such metals.
Claim 16
Dependent Claim
28 words
A method as set forth in claim 14, wherein said ceramic forming constituents are each selected from the group consisting of titanium, zirconium, magnesium, boron, silicon, and carbon.
Claim 17
Dependent Claim
23 words
A method as set forth in claim 15, wherein the solvent metal contains aluminum and the ceramic forming constituents are titanium and boron.
Claim 18
Dependent Claim
20 words
A method as set forth in claim 16, wherein the first and second bodies each contain aluminum and no silicon.
Claim 19
Dependent Claim
44 words
A method as set forth in claim 1, wherein the metal of the first body is selected from the group consisting of aluminum, zinc, magnesium, copper, lead, nickel, chromium, iron, titanium, cobalt, tantalum, molybdenum, tungsten, hafnium, niobium, rhenium, zirconium and alloys of such metals.
Claim 20
Dependent Claim
44 words
A method as set forth in claim 18, wherein the metal of the second body is also selected from the group consisting of aluminum, zinc, magnesium, copper, nickel, chromium, iron, titanium, cobalt, tantalum, molybdenum, tungsten, hafnium, niobium, rhenium, zirconium and alloys of such metals.
Claim 21
Independent Claim
107 words
A method for making a welding rod comprising precipitating at least one ceramic material in a metal matrix by contacting reactive ceramic forming constituents, in the presence of a solvent metal in which said ceramic forming constituents are more soluble than said ceramic material, at a temperature at which sufficient diffusion of said reactive ceramic forming constituents into said solvent metal occurs to cause a ceramic forming reaction of said constituents and thereby precipitate submicron ceramic particles in-situ in said solvent metal so as to produce a material comprising finely divided ceramic particles in a metal matrix, and forming the produced material into a welding rod shape.
Claim 22
Independent Claim
107 words
A method for making a welding rod comprising precipitating at least one ceramic material in a metal matrix by contacting reactive ceramic forming constituents, in the presence of a solvent metal in which said ceramic forming constituents are more soluble than said ceramic material, at a temperature at which sufficient diffusion of said reactive ceramic forming constituents into said solvent metal occurs to cause a ceramic forming reaction of said constituents and thereby precipitate submicron ceramic particles in-situ in said solvent metal so as to produce a material comprising finely divided ceramic particles in a metal matrix, and forming the produced material into a welding rod shape.
Claim 23
Dependent Claim
22 words
A method as set forth in claim 20, wherein the temperature is at least about the melting temperature of said solvent metal.
Claim 24
Dependent Claim
24 words
A method as set forth in claim 20, wherein the reactive ceramic forming constituents and the solvent metal are each provided as individual elements.
Claim 25
Dependent Claim
23 words
A method as set forth in claim 20, wherein the ceramic forming constituents are each provided as an alloy of said solvent metal.
Claim 26
Dependent Claim
34 words
A method as set forth in claim 20, wherein at least one ceramic forming constituent is selected from the group consisting of transition metals of the third to sixth groups of the Periodic Table.
Claim 27
Dependent Claim
42 words
A method as set forth in claim 20, wherein at least one ceramic forming constituent is selected from the group consisting of aluminum, titanium, silicon, boron, carbon, sulfur, germanium, molybdenum, tungsten, vanadium, zirconium, chromium, magnesium, hafnium, tantalum, nitrogen, and rare earth metals.
Claim 28
Dependent Claim
55 words
A method as set forth in claim 25, wherein said solvent metal is selected from the group consisting of aluminum, gallium, nickel, titanium, copper, vanadium, chromium, manganese, cobalt, iron, silicon, germanium, silver, gold, platinum, palladium, rhodium, ruthenium, magnesium, lead, zinc, tin, tantalum, molybdenum, tungsten, hafnium, niobium, rhenium, zirconium and alloys and intermetallics of such metals.
Claim 29
Dependent Claim
34 words
A method as set forth in claim 26, wherein said solvent metal is selected from the group consisting of aluminum, zinc, magnesium, copper, lead, nickel, chromium, iron, titanium, cobalt, and alloys of such metals.
Claim 30
Dependent Claim
28 words
A method as set forth in claim 25, wherein said ceramic forming constituents are each selected from the group consisting of titanium, zirconium, magnesium, boron, silicon, and carbon.
Claim 31
Dependent Claim
23 words
A method as set forth in claim 20, wherein the solvent metal contains aluminum and the ceramic forming constituents are titanium and boron.
Claim 32
Dependent Claim
23 words
A method as set forth in claim 20, wherein the produced material is formed into the welding rod shape by steps including extruding.
Claim 33
Dependent Claim
24 words
A method as set forth in claim 20, wherein the produced material is formed into the welding rod shape by steps including mechanical working.
Claim 34
Independent Claim
192 words
A method comprising precipitating at least one ceramic material in a metal matrix by contacting reactive ceramic forming constituents, in the presence of a solvent metal in which said ceramic forming constituents are more soluble than said ceramic material, at a temperature at which sufficient diffusion of said reactive ceramic forming constituents into said solvent metal occurs to cause a ceramic forming reaction of said constituents and thereby precipitate ceramic particles in-situ in said solvent metal so as to produce a composite material comprising finely divided ceramic particles in a metal matrix, diluting said composite material in an additional matrix metal so as to produce a body of material comprising said finely divided ceramic particles in a second metal matrix, placing the produced body adjacent a second metal containing body, placing filler material between said produced body and said second body in such a position as to join said bodies, welding the produced body to the second body by subjecting said filler material to a temperature sufficient to melt at least a portion of the filler material, and then solidifying the filler material, thereby joining the produced body to the second body.
Claim 35
Independent Claim
192 words
A method comprising precipitating at least one ceramic material in a metal matrix by contacting reactive ceramic forming constituents, in the presence of a solvent metal in which said ceramic forming constituents are more soluble than said ceramic material, at a temperature at which sufficient diffusion of said reactive ceramic forming constituents into said solvent metal occurs to cause a ceramic forming reaction of said constituents and thereby precipitate ceramic particles in-situ in said solvent metal so as to produce a composite material comprising finely divided ceramic particles in a metal matrix, diluting said composite material in an additional matrix metal so as to produce a body of material comprising said finely divided ceramic particles in a second metal matrix, placing the produced body adjacent a second metal containing body, placing filler material between said produced body and said second body in such a position as to join said bodies, welding the produced body to the second body by subjecting said filler material to a temperature sufficient to melt at least a portion of the filler material, and then solidifying the filler material, thereby joining the produced body to the second body.
Claim 36
Dependent Claim
16 words
A method as set forth in claim 32, wherein the filler material is a metal alloy.
Claim 37
Dependent Claim
21 words
A method as set forth in claim 32, wherein the filler material is finely divided ceramic particles in a metal matrix.
Claim 38
Dependent Claim
24 words
A method as set forth in claim 32, wherein the welding is conducted by arc welding using a metal electrode and inert gas shielding.
Claim 39
Dependent Claim
18 words
A method as set forth in claim 32, wherein the ceramic forming reaction occurs in the liquid state.
Claim 40
Dependent Claim
34 words
A method as set forth in claim 32, wherein at least one ceramic forming constituent is selected from the group consisting of transition metals of the third to sixth groups of the Periodic Table.
Claim 41
Dependent Claim
42 words
A method as set forth in claim 37, wherein at least one ceramic forming constituent is selected from the group consisting of aluminum, titanium, silicon, boron, carbon, sulfur, germanium, molybdenum, tungsten, vanadium, zirconium, chromium, magnesium, hafnium, tantalum, nitrogen, and rare earth metals.
Claim 42
Dependent Claim
53 words
A method as set forth in claim 38, wherein said solvent metal is selected from the group consisting of aluminum, gallium, nickel, titanium, copper, vanadium, chromium, manganese, cobalt, iron, silicon, germanium, silver, gold, platinum, palladium, rhodium, ruthenium, magnesium, lead, zinc, tin, tantalum, molybdenum, tungsten, hafnium, niobium, rhenium, zirconium and alloys of such metals.
Claim 43
Dependent Claim
34 words
A method as set forth in claim 39, wherein said solvent metal is selected from the group consisting of aluminum, zinc, magnesium, copper, lead, nickel, chromium, iron, titanium, cobalt, and alloys of such metals.
Claim 44
Dependent Claim
28 words
A method as set forth in claim 40, wherein said ceramic forming constituents are each selected from the group consisting of titanium, zirconium, magnesium, boron, silicon, and carbon.
Claim 45
Dependent Claim
18 words
A method as set forth in claim 41, wherein said solvent metal is aluminum or an alloy thereof.
Claim 46
Dependent Claim
21 words
A method as set forth in claim 42, wherein the ceramic material is titanium diboride and the filler material includes aluminum.
Claim 47
Dependent Claim
21 words
A method as set forth in claim 32, wherein said second body comprises finely divided ceramic particles in a metal matrix.
Claim 48
Dependent Claim
133 words
A method as set forth in claim 44, wherein said second body is produced by precipitating at least one ceramic material in a metal matrix by contacting reactive ceramic forming constituents, in the presence of a solvent metal in which said ceramic forming constituents are more soluble than said ceramic material, at a temperature at which sufficient diffusion of said reactive ceramic forming constituents into said solvent metal occurs to cause a ceramic forming reaction of said constituents and thereby precipitate ceramic particles in-situ in said solvent metal so as to produce a composite material comprising finely divided ceramic particles in a metal matrix, and diluting said composite material in an additional matrix metal so as to produce a body of material comprising said finely divided ceramic particles in a second metal matrix.
Claim 49
Dependent Claim
39 words
A method as set forth in claim 45, wherein at least one ceramic forming constituent for the second body is selected from the group consisting of aluminum, titanium, silicon, boron, carbon, sulfur, germanium, molybdenum, tungsten, vanadium, zirconium, and chromium.
Claim 50
Dependent Claim
57 words
A method as set forth in claim 46, wherein said solvent metal of the second body is selected from the group consisting of aluminum, gallium, nickel, titanium, copper, vanadium, chromium, manganese, cobalt, iron, silicon, germanium, silver, gold, platinum, palladium, rhodium, ruthenium, magnesium, lead, zinc, tin, tantalum, molybdenum, tungsten, hafnium, niobium, rhenium, zirconium and alloys of such metals.
Claim 51
Dependent Claim
26 words
A method as defined in claim 47, wherein the ceramic forming constituents in said second booy include titanium and boron and the solvent metal includes aluminum.
Claim 52
Dependent Claim
18 words
A method as set forth in claim 48, wherein the filler material is an aluminum alloy containing magnesium.
Claim 53
Independent Claim
187 words
A method for joining two metal containing bodies, said method comprising producing a composite material comprising finely divided ceramic particles in a metal matrix by precipitating at least one ceramic material in a metal matrix by contacting reactive ceramic forming constituents, in the presence of a solvent metal in which said ceramic forming constituents are more soluble than said ceramic material, at a temperature at which sufficient diffusion of said reactive ceramic forming constituents into said solvent metal occurs to cause a ceramic forming reaction of said constituents and thereby precipitate ceramic particles in-situ in said solvent metal, diluting said composite material in an additional matrix metal so as to produce a filler material comprising said finely divided ceramic particles in a second metal matrix, placing the two metal containing bodies in close proximity to each other, subjecting said filler material to a temperature sufficient to melt at least some of said filler material and deposit the molten filler material between the closely placed metal-containing bodies in order to provide a bond between said bodies, and solidfying the molten filler material so as to join the bodies.
Claim 54
Independent Claim
187 words
A method for joining two metal containing bodies, said method comprising producing a composite material comprising finely divided ceramic particles in a metal matrix by precipitating at least one ceramic material in a metal matrix by contacting reactive ceramic forming constituents, in the presence of a solvent metal in which said ceramic forming constituents are more soluble than said ceramic material, at a temperature at which sufficient diffusion of said reactive ceramic forming constituents into said solvent metal occurs to cause a ceramic forming reaction of said constituents and thereby precipitate ceramic particles in-situ in said solvent metal, diluting said composite material in an additional matrix metal so as to produce a filler material comprising said finely divided ceramic particles in a second metal matrix, placing the two metal containing bodies in close proximity to each other, subjecting said filler material to a temperature sufficient to melt at least some of said filler material and deposit the molten filler material between the closely placed metal-containing bodies in order to provide a bond between said bodies, and solidfying the molten filler material so as to join the bodies.
Claim 55
Dependent Claim
16 words
A method as set forth in claim 50, wherein the two bodies are each an alloy.
Claim 56
Dependent Claim
30 words
A method as set forth in claim 50, wherein one body is an alloy and the other body is an composite of finely divided ceramic particles in a metal matrix.
Claim 57
Dependent Claim
24 words
A method as set forth in claim 50, wherein the bodies are each a composite of finely divided ceramic particles in a metal matrix.
Claim 58
Dependent Claim
92 words
A method as set forth in claim 53, wherein said bodies are produced by contacting reactive ceramic forming constitutents, in the presence of a solvent metal in which said ceramic forming constitutents are more soluble than said ceramic material, at a temperature at which sufficient diffusion of said reactive ceramic forming constituents into said solvent metal occurs to cause a ceramic forming reaction of said constituents and thereby precipitate ceramic particles in-situ in said solvent metal so as to provide a composite material, and diluting said composite material in a matrix metal.
Claim 59
Dependent Claim
37 words
A method as set forth in claim 54, wherein said solvent metal of the bodies is selected from the group consisting of aluminum, zinc magnesium, copper lead, nickel, chromium, iron, titanium, cobalt, and alloys of such metals.
Claim 60
Dependent Claim
31 words
A method as set forth in claim 55, wherein said ceramic forming constituents of the bodies are each selected from the group consisting of titanium, zirconium, magnesium, boron, silicon, and carbon.
Claim 61
Dependent Claim
26 words
A method as set forth in claim 56, wherein the solvent metal of the bodies contains aluminum and the ceramic forming constituents are titanium and boron.
Claim 62
Dependent Claim
24 words
A method as set forth in claim 50, wherein the temperature for precipitating is at least about the melting temperature of said solvent metal.
Claim 63
Dependent Claim
42 words
A method as set forth in claim 50, wherein at least one ceramic forming constituent is selected from the group consisting of aluminum, titanium, silicon, boron, carbon, sulfur, germanium, molybdenum, tungsten, vanadium, zirconium, chromium, magnesium, hafnium, tantalum, nitrogen, and rare earth metals.
Claim 64
Dependent Claim
53 words
A method as set forth in claim 59, wherein said solvent metal is selected from the group consisting of aluminum, gallium, nickel, titanium, copper, vanadium, chromium, manganese, cobalt, iron, silicon, germanium, silver, gold, platinum, palladium, rhodium, ruthenium, magnesium, lead, zinc, tin, tantalum: molybdenum, tungsten, hafnium, niobium, rhenium, zirconium and alloys of such metals.
Claim 65
Dependent Claim
34 words
A method as set forth in claim 60, wherein said solvent metal is selected from the group consisting of aluminum, zinc, magnesium, copper, lead, nickel, chromium, iron, titanium, cobalt, and alloys of such metals.
Claim 66
Dependent Claim
28 words
A method as set forth in claim 61, wherein said ceramic forming constituents are each selected from the group consisting of titanium, zirconium, magnesium, boron, silicon, and carbon.
Claim 67
Dependent Claim
23 words
A method as set forth in claim 62, wherein the solvent metal contains aluminum and the ceramic forming constituents are titanium and boron.
Claim 68
Dependent Claim
20 words
A method as set forth in claim 63, wherein the first and second bodies each contain aluminum and no silicon.
Claim 69
Dependent Claim
37 words
A method as set forth in claim 50, wherein the metal of the first body is selected from the group consisting of aluminum, zinc, magnesium, copper, lead, nickel, chromium, iron, titanium, cobalt, and alloys of such metals.
Claim 70
Dependent Claim
38 words
A method as set forth in claim 50, wherein the metal of the second body is also selected from the group consisting of aluminum, zinc, magnesium, copper, lead, nickel, chromium, iron, titanium, cobalt, and alloys of such metals.
Claim 71
Independent Claim
163 words
A method for producing a weld on a metal containing body, said method comprising producing a composite material comprising finely divided ceramic particles in a metal matrix by precipitating at least one ceramic material in a metal matrix by contacting reactive ceramic forming constituents, in the presence of a solvent metal in which said ceramic forming constituents are more soluble than said ceramic material, at a temperature at which sufficient diffusion of said reactive ceramic forming constituents into said solvent metal occurs to cause a ceramic forming reaction of said constituents and thereby precipitate submicron ceramic particles in-situ in said solvent metal, diluting said composite material in an additional matrix matel so as to produce a filler material comprising said finely divided ceramic particles in a second metal matrix, sujecting said filler material to a temperature sufficient to melt at least some of said filler and deposit the molten filler material on the body, and solidifying the molten filler material on the body.
Claim 72
Independent Claim
163 words
A method for producing a weld on a metal containing body, said method comprising producing a composite material comprising finely divided ceramic particles in a metal matrix by precipitating at least one ceramic material in a metal matrix by contacting reactive ceramic forming constituents, in the presence of a solvent metal in which said ceramic forming constituents are more soluble than said ceramic material, at a temperature at which sufficient diffusion of said reactive ceramic forming constituents into said solvent metal occurs to cause a ceramic forming reaction of said constituents and thereby precipitate submicron ceramic particles in-situ in said solvent metal, diluting said composite material in an additional matrix matel so as to produce a filler material comprising said finely divided ceramic particles in a second metal matrix, sujecting said filler material to a temperature sufficient to melt at least some of said filler and deposit the molten filler material on the body, and solidifying the molten filler material on the body.
Claim 73
Dependent Claim
14 words
A method as set forth in claim 67, wherein the body is an alloy.
Claim 74
Dependent Claim
23 words
A method as set forth in claim 67, wherein the body is a composite of finely divided ceramic particles in a metal matrix.
Claim 75
Dependent Claim
24 words
A method as set forth in claim 67, wherein the temperature for precipitating is at least about the melting temperature of said solvent metal.
Claim 76
Dependent Claim
42 words
A method as set forth in claim 67, wherein at least one ceramic forming constituent is selected from the group consisting of aluminum, titanium, silicon, boron, carbon, sulfur, germanium, molybdenum, tungsten, vanadium, zirconium, chromium, magnesium, hafnium, tantalum, nitrogen, and rare earth metals.
Claim 77
Dependent Claim
53 words
A method as set forth in claim 71, wherein said solvent metal is selected from the group consisting of aluminum, gallium, nickel, titanium, copper, vanadium, chromium, manganese, cobalt, iron, silicon, germanium, silver, gold, platinum, palladium, rhodium, ruthenium, magnesium, lead, zinc, tin, tantalum, molybdenum, tungsten, hafnium, niobium, rhenium, zirconium and alloys of such metals.
Claim 78
Dependent Claim
34 words
A method as set forth in claim 72, wherein said solvent metal is selected from the group consisting of aluminum, zinc, magnesium, copper, lead, nickel, chromium, iron, titanium, cobalt, and alloys of such metals.
Claim 79
Dependent Claim
28 words
A method as set forth in claim 73, wherein said ceramic forming constituents are each selected from the group consisting of titanium, zirconium, magnesium, boron, silicon, and carbon.
Claim 80
Dependent Claim
23 words
A method as set forth in claim 74, wherein the solvent metal contains aluminum and the ceramic forming constituents are titanium and boron.
Claim 81
Dependent Claim
35 words
A method as set forth in claim 67, wherein the metal of the body is selected from the group consisting of aluminum, zinc, magnesium, copper, nickel, chromium, iron, titanium, cobalt, and alloys of such metals.
Claim 82
Dependent Claim
16 words
A method as set forth in claim 76, wherein the body contains aluminum and no silicon.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1991-04-19 | 1991-10-19 | 1992-04-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-19 | 1995-10-19 | 1996-04-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-19 | 1999-10-19 | 2000-04-19 | $7700.00 | Window Closed / Lapsed |