US3918623A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of joining by diffusion welding a hollow part of nonferrous metal onto the inner surface of a hollow part of ferrous metal
Assignee: Ebara Corp
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Filing: 1975-04-02
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Granted: 1975-11-11
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Expires: 1995-04-02
Abstract
Abstract In a method of joining by diffusion welding a hollow part of non-ferrous metal onto the inner surface of the bore of a hollow part of ferrous metal comprising the steps of inserting said hollow part, to be joined onto said hollow part of ferrous metal, of non-ferrous metal such as copper and copper alloys with a larger coefficient of thermal expansion than said hollow part of ferrous metal into and in close contact with the bore of said hollow part of ferrous metal, then inserting a core of a material with a higher strength and a higher melting point than said hollow part of non-ferrous metal into and in close contact with the bore of said hollow part of non-ferrous metal, and subsequently heating the composite part set as mentioned above to a diffusion welding temperature under a relatively low vacuum or in a non-oxidizing atmosphere under atmospheric pressure, a hollow part of non-ferrous metal is joined by diffusion welding onto the inner surface of a hollow part of ferrous metal as follows.
Inventors
- 👤 Juichi Ishiguro
- 👤 Matsuho Miyasaka
- 👤 Nobumitsu Kitajima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:22
CPC Classifications
B; B23; B23K; B23K1/00; B23K1/0008; B23K20/00; B23K35/00; B23K35/001; B23K35/004; B23P; B23P11/00; B23P11/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
329 words
A method of joining by diffusion welding a hollow part of non-ferrous metal onto the inner surface of the bore of a hollow part of ferrous metal comprising the steps of inserting said hollow part of non-ferrous metal with a larger coefficient of thermal expansion than said hollow part of ferrous metal, into and in close contact with the bore of said hollow part of ferrous metal, then inserting a core of a material with a higher strength and a higher melting point than said hollow part of non-ferrous metal into and in close contact with the bore of said hollow part of non-ferrous metal, and subsequently heating the composite part thus set to a diffusion welding temperature under a relatively low vacuum or in a non-oxidizing atmosphere under atmospheric pressure, characterized by: causing a low melting point metal in liquid phase having a lower melting point than said hollow part of ferrous metal, said hollow part of non-ferrous metal and said core to penetrate into a gap formed between said hollow part of ferrous metal and said hollow part of non-ferrous metal and a gap between said hollow part of non-ferrous metal and said core; then carrying out heating to a diffusion welding temperature to effect solid phase-liquid phase diffusion between said hollow part of ferrous metal and said hollow part of non-ferrous metal in solid phase and said low melting point metal in liquid phase; and, at the same time, effecting solid phase-solid phase diffusion between said hollow part of ferrous metal and said hollow part of non-ferrous metal in solid phase, by bringing said hollow part of ferrous metal and said hollow part of non-ferrous metal into contact with each other under pressure through the use of stress generated from the difference in thermal expansion between said hollow part of ferrous metal and said hollow part of non-ferrous metal while preventing said hollow part of non-ferrous metal from being deformed inward by means of said core.
Claim 2
Independent Claim
329 words
A method of joining by diffusion welding a hollow part of non-ferrous metal onto the inner surface of the bore of a hollow part of ferrous metal comprising the steps of inserting said hollow part of non-ferrous metal with a larger coefficient of thermal expansion than said hollow part of ferrous metal, into and in close contact with the bore of said hollow part of ferrous metal, then inserting a core of a material with a higher strength and a higher melting point than said hollow part of non-ferrous metal into and in close contact with the bore of said hollow part of non-ferrous metal, and subsequently heating the composite part thus set to a diffusion welding temperature under a relatively low vacuum or in a non-oxidizing atmosphere under atmospheric pressure, characterized by: causing a low melting point metal in liquid phase having a lower melting point than said hollow part of ferrous metal, said hollow part of non-ferrous metal and said core to penetrate into a gap formed between said hollow part of ferrous metal and said hollow part of non-ferrous metal and a gap between said hollow part of non-ferrous metal and said core; then carrying out heating to a diffusion welding temperature to effect solid phase-liquid phase diffusion between said hollow part of ferrous metal and said hollow part of non-ferrous metal in solid phase and said low melting point metal in liquid phase; and, at the same time, effecting solid phase-solid phase diffusion between said hollow part of ferrous metal and said hollow part of non-ferrous metal in solid phase, by bringing said hollow part of ferrous metal and said hollow part of non-ferrous metal into contact with each other under pressure through the use of stress generated from the difference in thermal expansion between said hollow part of ferrous metal and said hollow part of non-ferrous metal while preventing said hollow part of non-ferrous metal from being deformed inward by means of said core.
Claim 3
Dependent Claim
119 words
The method of claim 1, characterized by using an alloying metal together with said low melting point metal, which reacts with an excess of said low melting point metal, remaining in liquid phase within a groove prepared at the upper end of said hollow part of ferrous metal, to produce an alloyed phase having almost the same composition as one or both of said hollow part of ferrous metal and said hollow part of non-ferrous metal, whereby said low melting point metal in excess is prevented from reacting with one or both of said hollow part of ferrous metal said hollow part of non-ferrous metal to produce an alloyed phase with unfavorable mechanical properties and a low corrosion resistance.
Claim 4
Dependent Claim
44 words
The method of claim 2, characterized by using a composite metal wire composed of a core of said alloying metal wire coated with a sheath of said low melting point metal instead of using said alloying metal together with said low melting point metal.
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) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |