Freestanding reactive multilayer foils

• US 6,736,942 B2
• Filed: 05/01/2001
• Issued: 05/18/2004
• Est. Priority Date: 05/02/2000
• Status: Expired due to Term

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Knio, Omar, Weihs, Timothy P., Reiss, Michael, Feldmesser, Howard, Hufnagel, Todd, van Heerden, David
• Primary Examiner(s): VerSteeg, Steven H.
• Application Number:
  US09/846,486
• Publication Number:
  US 20020182436A1
• Time in Patent Office: 1,113 Days
• Field of Search: 204/192.11, 204/192.12, 204/192.15, 427/248.1, 427/250, 427/255.11, 427/255.15, 427/255.7, 427/289, 427/404, 29/173, 29/174, 29/175, 29/178, 29/179
• US Class Current: 204/192.12
• CPC Class Codes: B23K 1/0006 Exothermic brazing
• CPC Class Codes: B23K 20/00 Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
• CPC Class Codes: B23K 20/06 by means of high energy impulses, e.g. magnetic energy
• CPC Class Codes: B23K 20/08 Explosive welding
• CPC Class Codes: B23K 20/165 involving an exothermic reaction of the interposed material
• CPC Class Codes: B23K 28/00 Welding or cutting not covered by any of the preceding groups, e.g. electrolytic welding
• CPC Class Codes: B23K 35/0233 Sheets, foils B23K35/0244 takes precedence
• CPC Class Codes: B23K 35/0238 layered
• CPC Class Codes: B23K 35/34 comprising compounds which yield metals when heated
• CPC Class Codes: B32B 15/01 all layers being exclusively metallic making layered metal workpieces by pressure cladding B23K20/22; making coatings with a metallic material characterised by its composition C23C30/00
• CPC Class Codes: B32B 15/017 one layer being formed of aluminium or an aluminium alloy, another layer being formed of an alloy based on a non ferrous metal other than aluminium
• CPC Class Codes: B32B 18/00 Layered products essentially comprising ceramics, e.g. refractory products
• CPC Class Codes: B32B 2311/24 Aluminium
• CPC Class Codes: C04B 2235/6562 Heating rate
• CPC Class Codes: C04B 2235/6565 Cooling rate
• CPC Class Codes: C04B 2237/121 based on aluminium
• CPC Class Codes: C04B 2237/122 based on refractory metals
• CPC Class Codes: C04B 2237/123 based on iron group metals, e.g. steel
• CPC Class Codes: C04B 2237/124 based on copper
• CPC Class Codes: C04B 2237/368 Silicon nitride
• CPC Class Codes: C04B 2237/40 : Metallic
• CPC Class Codes: C04B 2237/402 : Aluminium
• CPC Class Codes: C04B 2237/60 : Forming at the joining interface or in the joining layer specific reaction phases or zones, e.g. diffusion of reactive species from the interlayer to the substrate or from a substrate to the joining interface, carbide forming at the joining interface
• CPC Class Codes: C04B 2237/68 : Forming laminates or joining articles wherein at least one substrate contains at least two different parts of macro-size, e.g. one ceramic substrate layer containing an embedded conductor or electrode
• CPC Class Codes: C04B 2237/708 : of one or more of the interlayers
• CPC Class Codes: C04B 2237/72 : Forming laminates or joined articles comprising at least two interlayers directly next to each other
• CPC Class Codes: C04B 2237/78 : Side-way connecting, e.g. connecting two plates through their sides
• CPC Class Codes: C04B 37/006 : consisting of metals or metal salts
• CPC Class Codes: C04B 37/026 : consisting of metals or metal salts
• CPC Class Codes: C06B 21/0083 : Treatment of solid structures, e.g. for coating or impregnating with a modifier compositions therefor C06B23/00
• CPC Class Codes: C06B 45/14 : a layer or zone containing an inorganic explosive or an inorganic explosive or an inorganic thermic component
• CPC Class Codes: C21D 2211/008 : Martensite
• CPC Class Codes: C23C 14/14 : Metallic material, boron or silicon
• CPC Class Codes: F24V 30/00 : Apparatus or devices using heat produced by exothermal chemical reactions other than combustion
• CPC Class Codes: H05K 2203/0405 : Solder foil, tape or wire
• CPC Class Codes: H05K 2203/1163 : Chemical reaction, e.g. heating solder by exothermic reaction
• CPC Class Codes: H05K 3/3463 : Solder compositions in relation to features of the printed circuit board or the mounting process
• CPC Class Codes: H05K 3/3494 : Heating methods for reflowing of solder using integral heating means H05K1/0212
• CPC Class Codes: Y10S 228/902 : using flame
• CPC Class Codes: Y10S 428/924 : Composite
• CPC Class Codes: Y10S 428/926 : Thickness of individual layer specified
• CPC Class Codes: Y10S 428/94 : Pressure bonding, e.g. explosive
• CPC Class Codes: Y10S 428/941 : Solid state alloying, e.g. diffusion, to disappearance of an original layer
• CPC Class Codes: Y10S 72/70 : Deforming specified alloys or uncommon metal or bimetallic work
• CPC Class Codes: Y10T 156/1002 : with permanent bending or reshaping or surface deformation of self sustaining lamina
• CPC Class Codes: Y10T 29/302 : Clad or other composite foil or thin metal making
• CPC Class Codes: Y10T 29/308 : Using transitory material
• CPC Class Codes: Y10T 29/49925 : Inward deformation of aperture or hollow body wall
• CPC Class Codes: Y10T 29/49929 : Joined to rod
• CPC Class Codes: Y10T 428/12028 : Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, etc.]
• CPC Class Codes: Y10T 428/12063 : Nonparticulate metal component
• CPC Class Codes: Y10T 428/12069 : Plural nonparticulate metal components
• CPC Class Codes: Y10T 428/12076 : Next to each other
• CPC Class Codes: Y10T 428/1209 : Plural particulate metal components
• CPC Class Codes: Y10T 428/12229 : Intermediate article [e.g., blank, etc.]
• CPC Class Codes: Y10T 428/12361 : having aperture or cut
• CPC Class Codes: Y10T 428/12431 : Foil or filament smaller than 6 mils
• CPC Class Codes: Y10T 428/12438 : Composite
• CPC Class Codes: Y10T 428/12451 : Macroscopically anomalous interface between layers
• CPC Class Codes: Y10T 428/12493 : Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
• CPC Class Codes: Y10T 428/1259 : Oxide
• CPC Class Codes: Y10T 428/12632 : Four or more distinct components with alternate recurrence of each type component
• CPC Class Codes: Y10T 428/12736 : Al-base component
• CPC Class Codes: Y10T 428/1275 : Next to Group VIII or IB metal-base component
• CPC Class Codes: Y10T 428/12778 : Alternative base metals from diverse categories
• CPC Class Codes: Y10T 428/12819 : Group VB metal-base component
• CPC Class Codes: Y10T 428/12903 : Cu-base component
• CPC Class Codes: Y10T 428/12944 : Ni-base component
• CPC Class Codes: Y10T 428/24942 : including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/25 : Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/265 : 1 mil or less
• CPC Class Codes: Y10T 428/2993 : Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]
• CPC Class Codes: Y10T 428/31678 : Of metal

Abstract

Reactive foils and their uses are provided as localized heat sources useful, for example, in ignition, joining and propulsion. An improved reactive foil is preferably a freestanding multilayered foil structure made up of alternating layers selected from materials that will react with one another in an exothermic and self-propagating reaction. Upon reacting, this foil supplies highly localized heat energy that may be applied, for example, to joining layers, or directly to bulk materials that are to be joined. This foil heat-source allows rapid bonding to occur at room temperature in virtually any environment (e.g., air, vacuum, water, etc.). If a joining material is used, the foil reaction will supply enough heat to melt the joining materials, which upon cooling will form a strong bond, joining two or more bulk materials.

Claims

1. A method of making a freestanding reactive multilayer foil composed of a plurality of alternating layers that can react exothermically, comprising the steps of:

providing a substrate;

vapor depositing the alternating layers on the substrate to form a reactive multilayer foil having a thickness in the range of about 10 micrometers to about 1 cm, the vapor deposition conditions chosen for low stress so that the product of stress in the film and the film thickness is kept below 1000 N/m; and

separating the multilayer foil from the substrate to provide the freestanding reactive multilayer foil.

2. The method of claim 1 wherein the substrate has sufficient adherence to the deposited layers to retain the layers during deposition but insufficient adherence to prevent removal of the multilayer foil after deposition.

3. The method of claim 1 wherein the layers comprise one or more layers of aluminum, and at least one of the layers of aluminum is deposited in contact with the substrate.

4. The method of claim 3 wherein the substrate comprises silicon.

5. The method of claim 1 wherein the substrate comprises a coating of a release material or a coating of an adhesion material.

6. The method of claim 1 wherein the substrate comprises a removable sacrificial layer.

7. The method of claim 1 wherein the vapor depositing is under conditions chosen to minimize stress in the deposited layers.

8. The method of claim 1 wherein the vapor depositing comprises physical vapor deposition.

9. The method of claim 8 wherein the vapor depositing comprises magnetron sputtering or electron beam evaporation.

10. The method of claim 1 wherein the substrate is cooled during the vapor depositing.

11. The method of claim 1 wherein the layers are deposited to form a multilayer foil having a thickness in the range 50 μ

m-1 cm.

12. The method of claim 1 wherein vapor depositing the alternating layers comprises vapor depositing alternating layers selected from the group consisting of Rh/Si, Ni/Si, and Zr/Si.

13. The method of claim 1 wherein vapor depositing the alternating layers comprises vapor depositing alternating layers selected from the group consisting of Ni/Al, Ti/Al, Monel/Al, and Zr/Al.

14. The method of claim 1 wherein vapor depositing the alternating layers comprises vapor depositing alternating layers selected from the group consisting of Al/Fe₂O₃ and Al/Cu₂O.

15. The method of claim 1 wherein vapor depositing the alternating layers comprises vapor depositing a layer comprising boron or carbon.

16. The method of claim 1 wherein vapor depositing the alternating layers comprises vapor depositing a layer comprising a transition metal.

17. The method of claim 1 including the further step of forming openings in the foil.

18. The method of claim 1 including the further step of forming a periodic pattern of openings in the foil.

19. The method of claim 1 including the further steps of forming a plurality of openings in the foil, the openings having effective diameters in the range 10-10,000 micrometers.

20. The method of claim 1 further comprising the step of depositing an intermediate layer between the alternating layers.

21. A method of making a freestanding reactive multilayer foil composed of a plurality of alternating layers that can react exothermally, comprising the steps of:

providing a substrate comprising a removable sacrificial layer of copper, brass or photoresist;

vapor depositing the alternating layers on the substrate to form the reactive multilayer foil; and

separating the multilayer foil from the substrate.