EP0515078A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Bonding to nickel-titanium alloy
Assignee: Cook Inc
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Filing: 1992-05-12
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Granted: —
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Expires: 2012-05-12
Abstract
Abstract A joint and a laminate including a nickel-titanium alloy such as nitinol and a method for preparing the surface of a nickel-titanium alloy member (14) for bonding solder material and, electively, another similar or dissimilar member thereto (25). The method includes applying an aluminum paste flux (22) to the titanium oxide coated surface of a nickel-titanium alloy member and heating the flux to its activation temperature. The flux (22) removes and suspends the titanium oxide (17) therein along with leaching titanium (20) from the base alloy member (14) surface to form a nickel-rich interface surface (18). The activated flux also coats the nickel-rich interface layer for protection from further oxidation. A bonding material such as a tin-silver solder (24) is flowed onto the nickel-rich interface surface (16) to displace the activated flux. Electively, another member (25) is applied to the molten solder to form a joint between the two members. The residual flux is cleaned from the joint to prevent further deterioration of the base metal. The solder joint includes the base nickel-titanium alloy metal, the nickel-rich interface surface, and the solder material. Electively, any other member may be applied to this joint in the molten state to form a metallic bond therebetween.
Inventors
- 👤 Todd A. Hall
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 16:17
CPC Classifications
B; B23; B23K; B23K35/00; B23K35/001; B23K35/004; B23K35/22; B23K35/36; B23K35/3601; B23K35/3603; A; A61; A61M; A61M25/00; A61M25/01; A61M25/09; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12458; Y10T428/12493; Y10T428/12771; Y10T428/12806
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
116 words
A method of preparing a surface of an alloy member comprising nickel and titanium, for bonding a layer of another metal thereto, characterised in that the method comprises the steps of applying to said member surface a flux having an activation temperature below a predetermined annealing temperature of said alloy member, said flux having a composition suitable for removing a contaminant from said member surface and for further removing at least portions of titanium from said member surface while leaving nickel therein; and removing with said flux said contaminant and at least portions of titanium from said member surface while leaving nickel therein to form a nickel-rich interface surface for bonding said other metal layer thereto.
Claim 2
Dependent Claim
62 words
The method of claim 1, characterised in that the step of removing said contaminant from said member surface includes heating said flux to said activation temperature and suspending said contaminant in said flux, and/or the step of removing at least portions of said titanium includes at least partially leaching titanium from said member surface with said flux heated to said activation temperature.
Claim 3
Dependent Claim
35 words
The method of claim 2, further characterised by the step of cooling the flux to solidify said flux and form a solid coating of said flux on said nickel-rich interface surface after said flux-heating step.
Claim 4
Dependent Claim
39 words
The method of claim 1, characterised in that said removing step comprises heating said flux to said activation temperature and scrubbing from said member surface said flux having therein said contaminant and titanium removed from said nickel-rich interface surface.
Claim 5
Dependent Claim
17 words
The method of claim 4, further characterised by applying additional flux to said scrubbed nickel-rich interface surface.
Claim 6
Independent Claim
77 words
The method of any one preceding claim, characterised in that said other metal is flowed in a molten state on said nickel-rich interface surface, optionally after applying said additional flux, and optionally displacing from said nickel-rich interface surface of said flux with said contaminant and said titanium removed from said nickel-rich interface surface, said flux optionally comprising an aluminum flux paste having at least one of tin chloride, zinc chloride, hydrofluoric acid, and ethanolamine as active ingredients.
Claim 7
Dependent Claim
52 words
The method of claim 1 or 6, characterised in that the flux is cleaned from said alloy member after said other metal has been applied thereto, and/or a pickling solution is applied to at least partially remove said contaminant from said member surface prior to applying said flux to said member surface.
Claim 8
Independent Claim
73 words
A method of any one preceding claim, characterised in that the other metal is solder, optionally selected from gold, nickel, indium, tin, silver, cadmium, lead, zirconium, and hafnium, and having a melting point below a predetermined annealing temperature of said alloy member, and in that a second metal member is optionally positioned in contact with said molten solder so that upon cooling said molten solder joins said alloy member to said second member.
Claim 9
Dependent Claim
67 words
The method of claim 8, characterised in that said nickel-titanium alloy member has nickel by weight in a range of 50 to 58 percent and titanium by weight in a range of 50 to 42 percent, and/or the said nickel-rich interface surface has titanium by weight in a range of approximately 49.5 to 0 percent and nickel by weight in a range of 50.5 to 100 percent.
Claim 10
Dependent Claim
43 words
The method of claim 8, characterised in that said second member is a nickel-titanium alloy wire having a surface prepared in the same manner as said nickel-rich interface surface of said alloy member, and/or is a wire coil of stainless steel or platinum.
Claim 11
Dependent Claim
65 words
A joint comprising: a nickel-titanium alloy member; an interface surface formed in a surface of said alloy member; a bonding material flowed on and adhered to said interface surface; and a second member adhered to said bonding material; characterised in that the interface surface is substantially contaminant free and has had titanium at least partially removed therefrom by a flux heated to its activation temperature.
Claim 12
Dependent Claim
29 words
The joint of claim 11, characterised in that said bonding material comprises a soft solder having a melting temperature below 425 degrees Celsius, and optionally comprises a silver solder.
Claim 13
Dependent Claim
98 words
A joint comprising: a base substrate of a metal alloy having by weight a first predetermined percentage of nickel and a second predetermined percentage of titanium, superelastic and shape memory properties, and an annealing temperature above which said superelastic and shape memory properties are impaired; an interface surface on said base substrate and having by weight a third percentage of nickel greater than said first percentage and a fourth percentage of titanium less than second percentage; and a solder material having a melting temperature less than said annealing temperature of said metal alloy adhering to said interface surface.
Claim 14
Dependent Claim
139 words
A laminate comprising: a base member of an alloy comprising nickel and titanium; an upper surface of said base member having a lower percentage of titanium than throughout the base member as a whole; a layer of solder material bonded to the upper surface; and a second member bonded to the solder layer, said base member optionally having titanium by weight in a range of 50 to 42 percent and nickel by weight in a range of 50 to 58 percent; the range of titanium to nickel in the upper surface optionally being by weight in a range of 49.5 to 0 percent to 50.5 to 100 percent; the solder material optionally being selected from gold, nickel, indium, tin, silver, cadmium, lead, zirconium, and hafnium; and the second member optionally being selected from nickel-titanium alloys, stainless steel, and platinum.
References Cited (Backward Citations)
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