Methods of controlling multilayer foil ignition

• US 20050142495A1
• Filed: 10/07/2004
• Published: 06/30/2005
• Est. Priority Date: 10/09/2003
• Status: Abandoned Application

• Current Assignee: Johns Hopkins University, Reactive NanoTechnologies, Inc.
• Original Assignee: Johns Hopkins University, Reactive NanoTechnologies, Inc.
• Inventors: Rude, Timothy Ryan, Besnoin, Etienne, Valliappan, Somasundaram, Heian, Ellen, Weihs, Timothy P., Knio, Omar M., Brown, Michael V., Van Heerden, David Peter, Deger, Dale, Spey, Stephen John Jr.
• Application Number:
  US10/959,502
• Publication Number:
  US 20050142495A1
• Time in Patent Office: Days
• US Class Current: 430/311
• CPC Class Codes: B23K 35/0233 Sheets, foils B23K35/0244 takes precedence
• 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: F24V 30/00 Apparatus or devices using heat produced by exothermal chemical reactions other than combustion
• CPC Class Codes: G16C 20/10 Analysis or design of chemical reactions, syntheses or processes

Abstract

Embodiments of the invention include a method of simulating an ignition of a reactive multilayer foil. Other embodiments include various methods of igniting a reactive multilayer foil by transferring energy from an energy source to a reactive multilayer foil.

Claims

1. A method for simulating an initiation and properties of a self-propagating reaction in a reactive multilayer foil, the method comprising the steps of:

providing an atomic concentration evolution equation;

providing an energy evolution equation including energy source terms associated with (i) a thermal diffusion of the reactive multilayer foil, (ii) a heat of mixing of the reactive multilayer foil, and (iii) a stimulus configured to initiate a chemical transformation of the reactive multilayer foil;

discretizing the atomic concentration evolution equation and the energy evolution equation to form a discretized system of equations; and

determining the behavior of an atomic concentration and energy fields of the reactive multilayer foil by integrating the discretized system of equations using parameters associated with the reactive multilayer foil.

2. The method of claim 1, wherein the atomic concentration evolution equation is

3. The method of claim 1, wherein the energy evolution equation is

4. The method of claim 1, wherein the energy evolution equation is

5. The method of claim 1, wherein the discretization of the atomic concentration evolution equation and the energy evolution equation is based on a finite-difference method, a finite-element method, a finite-volume method, a spectral-element method, or a collocation method.

6. The method of claim 1, wherein the parameters associated with the reactive multilayer foil include at least one of length, width, thickness, density, heat capacity, thermal conductivity, heat of fusion, melting temperature, heat of reaction, atomic weight, atomic diffusivity, and activation energy.

7. The method of claim 1, wherein the stimulus is associated with one or more of an electrical source, a thermal source, a source of mechanical action, a sound source, an ultrasound source, a microwave source, a chemical source, an RF source, and an electromagnetic source.

8. The method of claim 1, wherein the energy source term associated with the stimulus is a volumetric source term, a surface source term, or a combination of the volumetric and surface source terms.

9. The method of claim 1, further comprising varying parameters of the stimulus.

10. The method of claim 9, wherein the parameters associated with the stimulus include one or more of a position of the stimulus relative to the reactive multilayer foil, potential energy, kinetic energy, electrical potential, current voltage, pulse duration, contact area, power, wavelength, spot size, and pulse energy.

11. A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform method steps for simulating an initiation and properties of a self-propagating reaction in a reactive multilayer foil, the method comprising the steps of:

providing an atomic concentration evolution equation;

providing an energy evolution equation including energy source terms associated with (i) a thermal diffusion of the reactive multilayer foil, (ii) a heat of mixing of the reactive multilayer foil, and (iii) a stimulus configured to initiate a chemical transformation of the reactive multilayer foil;

discretizing the atomic concentration evolution equation and the energy evolution equation to form a discretized system of equations;

determining the behavior of an atomic concentration and energy fields of the reactive multilayer foil by integrating the discretized system of equations using parameters associated with the reactive multilayer foil.

12. The method of claim 11, wherein the atomic concentration evolution equation is

13. The method of claim 11, wherein the energy evolution equation is

14. The method of claim 11, wherein the energy evolution equation is

15. The method of claim 11, wherein the discretization of the atomic concentration evolution equation and the energy evolution equation is based on a finite-difference method, a finite-element method, a finite-volume method, a spectral-element method, or a collocation method.

16. The method of claim 11, wherein the parameters associated with the reactive multilayer foil include at least one of length, width, thickness, density, heat capacity, thermal conductivity, heat of fusion, melting temperature, heat of reaction, atomic weight, atomic diffusivity, and activation energy.

17. The method of claim 11, wherein the stimulus is associated with one or more of an electrical source, a thermal source, a source of mechanical action, a sound source, an ultrasound source, a microwave source, a chemical source, an RF source, and an electromagnetic source.

18. The method of claim 11, wherein the energy source term associated with the stimulus is a volumetric source term, a surface source term, or a combination of the volumetric and surface source terms.

19. The method of claim 11, further comprising varying parameters of the stimulus.

20. The method of claim 19, wherein parameters associated with the stimulus include one or more of a position of the stimulus relative to the reactive multilayer foil, potential energy, kinetic energy, electrical potential, current voltage, pulse duration, contact area, power, wavelength, spot size, and pulse energy.

21. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing an electrical energy source and the reactive multilayer foil; and

initiating the chemical transformation of the reactive multilayer foil by providing an arc-free discharge from the electrical energy source to the reactive multilayer foil.

22. The method of claim 21, wherein the electrical energy source includes one or more of a voltage source, a current source, a charged capacitor, a piezoelectric device, a thermoelectric device, and a ferroelectric device.

23. The method of claim 21, wherein the electrical energy source has a potential less than or equal to about 10V.

24. The method of claim 21, wherein the electrical energy source has a potential less than or equal to about 5V.

25. The method of claim 21, wherein the electrical energy source has a potential less than or equal to about 1V.

26. The method of claim 21, wherein the arc-free discharge has a duration less than or equal to about 1 ms.

27. The method of claim 21, wherein an electrical lead is operatively connected to the electrical energy source and placed in contact with the reactive multilayer material,

wherein a contact area between the electrical lead and the reactive multilayer foil has a diameter less than or equal to about 1 mm.

28. The method of claim 21, wherein the arc-free discharge is provided to the reactive multilayer material at a contact area having a diameter less than or equal to about 1 mm.

29. The method of claim 21, wherein the arc-free discharge has an energy less than or equal to about 40 mJ.

30. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing a laser source and the reactive multilayer foil; and

initiating the chemical transformation of the reactive multilayer foil by transferring energy from the laser source to the reactive multilayer material;

wherein the energy from the laser source impinges on a spot on the reactive multilayer foil having a diameter less than or equal to about 1 mm.

33. The method of claim 30, wherein the energy is transferred at a wavelength between about 300 nm and about 2 microns.

31. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing a laser source and the reactive multilayer foil; and

initiating the chemical transformation of the reactive multilayer foil by transferring energy from the laser source to the reactive multilayer material;

wherein the laser source has a power output less than or equal to about 300 W.

34. The method of claim 31, wherein the energy is transferred at a wavelength between about 300 nm and about 2 microns.

32. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing a laser source and the reactive multilayer foil; and

initiating the chemical transformation of the reactive multilayer foil by transferring energy from the laser source to the reactive multilayer material;

wherein the energy transferred is less than or equal to about 40 mJ.

35. The method of claim 32, wherein the energy is transferred at a wavelength between about 300 nm and about 2 microns.

36. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing a laser source and the reactive multilayer foil; and

initiating the chemical transformation of the reactive multilayer foil by transferring energy from the laser source to the reactive multilayer material;

wherein the reactive multilayer foil includes at least one layer of solder or braze.

37. The method of claim 36, wherein the at least one layer of solder or braze includes one or more of indium, lead, tin, silver, zinc, gold, and antimony.

38. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing a laser source and the reactive multilayer foil;

providing a component to be joined to another component by the chemical transformation of the reactive multilayer foil, the component including an optical path configured to allow the energy from the laser source to be transferred to the reactive multilayer foil via the optical path; and

initiating the chemical transformation of the reactive multilayer foil by transferring energy from the laser source to the reactive multilayer foil through the optical path.

39. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing a laser source and the reactive multilayer foil; and

initiating the chemical transformation of the reactive multilayer foil by transferring energy from the laser source to the reactive multilayer material;

wherein the energy from the laser source is redirected prior to being transferred to the reactive multilayer foil.

40. The method of claim 39, further comprising providing an optical system and redirecting the energy via the optical system.

41. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing a laser source, a fiber optic cable, and the reactive multilayer foil; and

initiating the chemical transformation of the reactive multilayer foil by transferring energy from the laser source via the fiber optic cable to the reactive multilayer material.

42. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing a laser source and the reactive multilayer foil, the reactive multilayer foil being partially coated with an energy absorbing material; and

initiating the chemical transformation of the reactive multilayer foil by transferring energy from the laser source to the energy absorbing material.

43. The method of claim 42, wherein the reactive multilayer foil is partially coated with an energy reflecting material.

44. The method of claim 43, wherein the energy reflecting material has a higher reflectivity than the reactive multilayer foil.

45. The method of claim 42, wherein the energy absorbing material includes carbon black or black ink.

46. The method of claim 42, wherein the energy absorbing material has a higher absorptivity than the reactive multilayer foil.

47. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing a microwave source and the reactive multilayer foil; and

initiating the chemical transformation of the reactive multilayer foil by transferring energy from the microwave source to the reactive multilayer foil.

48. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing the reactive multilayer foil and a projectile; and

penetrating the reactive multilayer foil with the projectile,

wherein the penetrating initiates the chemical transformation of the reactive multilayer material.

49. The method of claim 48, wherein the projectile is spring-loaded.

50. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing an ultrasound source and the reactive multilayer foil; and

initiating the chemical transformation of the reactive multilayer foil by-transferring energy from the ultrasound source to the reactive multilayer foil.

51. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing an induction heating source and the reactive multilayer foil; and

initiating the chemical transformation of the reactive multilayer foil by transferring energy from the induction heating source to the reactive multilayer foil.

52. The method of claim 51, wherein the reactive multilayer foil includes a magnetic element.

53. The method of claim 52, wherein the magnetic element is Ni.

54. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing the reactive multilayer foil; and

initiating the chemical transformation of the reactive multilayer foil by mechanically fracturing the reactive multilayer foil.

55. The method of claim 54, wherein the reactive multilayer foil includes a recessed portion,

wherein the recessed portion is configured to assist in the mechanical fracturing of the reactive multilayer foil.

56. The method of claim 55, wherein the reactive multilayer foil is configured to mechanically fracture at the recessed portion.

57. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing the reactive multilayer foil; and

initiating the chemical transformation of a reactive multilayer foil by generating friction on the reactive multilayer foil.

58. The method of claim 57, further comprising providing an object with an abrasive surface,

wherein generating friction includes placing the abrasive surface in contact with the reactive multilayer foil.

59. The method of claim 58, wherein generating friction includes rotating the object.

60. The method of claim 57, wherein generating friction includes sliding the object.

61. The method of claim 58, wherein the object includes a rotary tool bit.

62. The method of claim 58, wherein the object includes a diamond wheel.

63. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing an electrical energy source, the reactive multilayer foil, and an electrical lead; and

initiating the chemical transformation of the reactive multilayer foil by transferring energy from the electrical energy source to the reactive multilayer foil via the electrical lead.

64. The method of claim 63, further comprising providing a component to be joined to another component by the chemical transformation of the reactive multilayer foil,

wherein the component includes the electrical lead.

65. The method of claim 63, wherein the electrical energy source includes one or more of a voltage source, a current source, a charged capacitor, a piezoelectric device, a thermoelectric device, and a ferroelectric device.

66. A method of initiating a chemical transformation of a reactive multilayer material, comprising:

providing the reactive multilayer material and a component including an ignition source; and

initiating the chemical transformation of the reactive multilayer material by triggering the ignition source.

67. The method of claim 66, wherein triggering the ignition source includes remotely triggering the ignition source.

68. The method of claim 66, wherein the ignition source includes one or more of a voltage source, a current source, a charged capacitor, a piezoelectric device, a thermoelectric device, a ferroelectric device, a firing pin, a laser, a MEMS device, a hot filament, a solenoid, a gated switch, an abrasive surface, a microbubble, a fuse, a reactive multilayer tab, a chemical, an SHS powder, and a heated gas.

69. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing a chemical and the reactive multilayer foil; and

initiating a chemical transformation of a reactive multilayer foil by chemically transforming the chemical.

70. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing the reactive multilayer foil; and

heating the reactive multilayer foil to the foil'"'"'s ignition temperature.

71. The method of claim 70, further comprising providing a heating source;

placing the reactive multilayer foil in the source of heat,

wherein the heating includes heating the reactive multilayer foil in the heating source.

72. The method of claim 71, wherein the heating source is a furnace or reflow oven.

73. The method of claim 70, wherein the heating occurs at a rate greater than or equal to about 200°

C./min.

74. The method of claim 70, wherein the heating includes heating one side of the reactive multilayer foil.

75. The method of claim 70, wherein the reactive multilayer foil is disposed in an enclosure or assembly,

wherein the heating includes heating one side of the enclosure or assembly.

76. The method of claim 70, wherein the reactive multilayer foil is disposed between two or more components configured to be joined by the chemical transformation of the reactive multilayer foil,

wherein the heating includes heating one of the two or more components.

77. The method of claim 76, wherein the heating of one of the two or more components includes passing a current through the one of the two or more components.

78. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing the reactive multilayer foil and a molten material; and

initiating the chemical transformation of the reactive multilayer foil by transferring energy from the molten material to the reactive multilayer foil.

79. The method of claim 78, further comprising placing the molten material in contact with the reactive multilayer foil.

80. The method of claim 78, wherein the molten material is molten solder or molten braze.

81. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing the reactive multilayer foil and a microflame; and

initiating the chemical transformation of the reactive multilayer foil by transferring energy from the microflame to the reactive multilayer foil.

82. The method of claim 81, further comprising placing the microflame in contact with the reactive multilayer foil.

83. The method of claim 81, wherein the reactive multilayer foil is disposed between at least two components,

wherein a portion of the reactive multilayer foil extends past an edge of at least one of the at least two components,

the method further comprising directing the microflame towards the portion of the reactive multilayer foil.

84. A method of initiating a chemical transformation of a reactive multilayer foil, comprising:

providing the reactive multilayer foil, the reactive multilayer foil being surrounded by an enclosure or disposed within an assembly;

providing an energy source; and

initiating the chemical transformation of the reactive multilayer foil by transferring energy from the energy source to the reactive multilayer foil.

85. The method of claim 84, wherein the energy is transferred without penetrating the enclosure or assembly.

86. The method of claim 84, wherein the energy is transferred to the reactive multilayer foil when the energy source is disposed outside of the enclosure or assembly.

87. The method of claim 84, wherein the energy is transferred without placing the source of energy in physical contact with the reactive multilayer foil.

88. The method of claim 84, wherein the enclosure is substantially airtight.

89. The method of claim 84, wherein the energy source includes one or more of a microwave source, an ultrasound source, and a source of induction heating.