Multilayer susceptors for achieving thermal uniformity in induction processing of organic matrix composites or metals

• US 5,808,281 A
• Filed: 06/06/1995
• Issued: 09/15/1998
• Est. Priority Date: 04/05/1991
• Status: Expired due to Term

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Matsen, Marc R., Woods, Edward J., Hansen, deceased, Karl A., deJong, executor, John J.
• Primary Examiner(s): HOANG, TU BA
• Application Number:
  US08/469,029
• Time in Patent Office: 1,197 Days
• Field of Search: 219/602, 219/603, 219/607, 219/609, 219/615, 219/617, 219/633, 219/634, 219/645, 428/213, 428/329
• US Class Current: 219/634
• CPC Class Codes: B21D 26/021 Deforming sheet bodies
• CPC Class Codes: B21D 26/025 Means for controlling the clamping or opening of the moulds
• CPC Class Codes: B21D 26/053 characterised by the material of the blanks
• CPC Class Codes: B21D 26/055 Blanks having super-plastic properties
• CPC Class Codes: B22F 2003/1046 with separating means for articles to be sintered
• CPC Class Codes: B22F 2003/1053 by induction
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 3/105 by using electric current other than for infrared radiant energy, laser radiation or plasma B22F3/11 takes precedence; by ultrasonic bonding B22F3/115 takes precedence
• CPC Class Codes: B22F 3/18 by using pressure rollers
• CPC Class Codes: B23K 1/002 Soldering by means of induction heating
• CPC Class Codes: B23K 20/023 Thermo-compression bonding
• CPC Class Codes: B23K 2101/18 Sheet panels
• CPC Class Codes: B29C 2035/0811 using induction
• CPC Class Codes: B29C 2043/3233 exerting pressure on mould parts
• CPC Class Codes: B29C 2043/3655 Pressure transmitters, e.g. caul plates; pressure pads
• CPC Class Codes: B29C 33/06 using radiation , e.g. electro-magnetic waves, induction heating
• CPC Class Codes: B29C 33/08 for dielectric heating
• CPC Class Codes: B29C 33/60 Releasing, lubricating or separating agents in general C10M
• CPC Class Codes: B29C 35/08 by wave energy or particle radiation B29C64/00, B29C71/04 take precedence
• CPC Class Codes: B29C 43/3642 Bags, bleeder sheets or cauls for isostatic pressing
• CPC Class Codes: B29C 43/52 : Heating or cooling
• CPC Class Codes: B29C 65/14 : using wave energy , i.e. electromagnetic radiation, or particle radiation using mechanical waves B29C65/06; using ultrasonic waves B29C65/08; pressing means transparent to electromagnetic radiation B29C66/81267
• CPC Class Codes: B29C 65/18 : using heated tools
• CPC Class Codes: B29C 65/32 : Induction
• CPC Class Codes: B29C 65/34 : using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
• CPC Class Codes: B29C 65/3476 : being metallic
• CPC Class Codes: B29C 65/3492 : being carbon
• CPC Class Codes: B29C 65/364 : being a woven or non-woven fabric or being a mesh
• CPC Class Codes: B29C 65/3644 : being a ribbon, band or strip
• CPC Class Codes: B29C 65/3668 : characterised by the means for supplying heat to said heated elements which remain in the join, e.g. special induction coils
• CPC Class Codes: B29C 65/3676 : being metallic
• CPC Class Codes: B29C 65/368 : with a polymer coating
• CPC Class Codes: B29C 65/4815 : Hot melt adhesives, e.g. thermoplastic adhesives
• CPC Class Codes: B29C 65/4875 : being spherical, e.g. particles or powders
• CPC Class Codes: B29C 65/489 : being metals
• CPC Class Codes: B29C 66/54 : Joining several hollow-preforms, e.g. half-shells, to form hollow articles, e.g. for making balls, containers; Joining several hollow-preforms, e.g. half-cylinders, to form tubular articles
• CPC Class Codes: B29C 66/634 : using an inflatable core
• CPC Class Codes: B29C 66/71 : characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/721 : Fibre-reinforced materials B29C66/729 takes precedence
• CPC Class Codes: B29C 66/7392 : characterised by the material of at least one of the parts being a thermoplastic
• CPC Class Codes: B29C 66/7394 : characterised by the material of at least one of the parts being a thermoset
• CPC Class Codes: B29C 66/8122 : characterised by the composition of the material constituting the pressing elements, e.g. constituting the welding jaws or clamps
• CPC Class Codes: B29C 66/81241 : being porous or sintered
• CPC Class Codes: B29C 66/81261 : Thermal properties, e.g. thermal conductivity, thermal expansion coefficient
• CPC Class Codes: B29C 66/81811 : of the welding jaws
• CPC Class Codes: B29C 66/81821 : of the welding jaws
• CPC Class Codes: B29C 66/8223 : Worm or spindle mechanisms
• CPC Class Codes: B29C 66/8322 : Joining or pressing tools reciprocating along one axis
• CPC Class Codes: B29C 66/91221 : of the parts to be joined
• CPC Class Codes: B29C 66/91411 : of the parts to be joined, e.g. the joining process taking the temperature of the parts to be joined into account
• CPC Class Codes: B29C 66/91443 : following a temperature-time profile B29C65/38 takes precedence
• CPC Class Codes: B29C 66/91641 : the heat or the thermal flux being non-constant over time
• CPC Class Codes: B29C 66/91651 : by controlling or regulating the heat generated by Joule heating or induction heating
• CPC Class Codes: B29C 66/91655 : by controlling or regulating the current intensity
• CPC Class Codes: B29C 70/44 : using isostatic pressure, e.g. pressure difference-moulding, vacuum bag-moulding, autoclave-moulding or expanding rubber-moulding
• CPC Class Codes: B29C 70/506 : and impregnating by melting a solid material, e.g. sheet, powder, fibres B29C70/508 takes precedence
• CPC Class Codes: B29C 70/542 : Placing or positioning the reinforcement in a covering or packaging element before or during moulding, e.g. drawing in a sleeve
• CPC Class Codes: B29K 2061/00 : Use of condensation polymers of aldehydes or ketones or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2063/00 : Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2071/00 : Use of polyethers , e.g. PEEK, i.e. polyether-etherketone or PEK, i.e. polyetherketone or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2079/08 : PI, i.e. polyimides or derivatives thereof
• CPC Class Codes: B29K 2079/085 : Thermoplastic polyimides, e.g. polyesterimides, PEI, i.e. polyetherimides, or polyamideimides; Derivatives thereof
• CPC Class Codes: B29K 2081/06 : PSU, i.e. polysulfones; PES, i.e. polyethersulfones or derivatives thereof
• CPC Class Codes: B29K 2105/0854 : in the form of a non-woven mat
• CPC Class Codes: B29K 2909/02 : Ceramics
• CPC Class Codes: B32B 2305/024 : Honeycomb
• CPC Class Codes: B32B 2309/62 : Inert
• CPC Class Codes: B32B 2310/0812 : using induction
• CPC Class Codes: B32B 37/06 : characterised by the heating method
• CPC Class Codes: B64C 3/18 : Spars; Ribs; Stringers
• CPC Class Codes: B64C 3/185 : Spars
• CPC Class Codes: C09K 2205/12 : Hydrocarbons
• CPC Class Codes: C22C 47/00 : Making alloys containing metallic or non-metallic fibres or filaments
• CPC Class Codes: C22C 47/068 : Aligning wires
• CPC Class Codes: C22C 47/20 : by subjecting to pressure and heat an assembly comprising at least one metal layer or sheet and one layer of fibres or filaments
• CPC Class Codes: H05B 6/365 : using supplementary conductive or ferromagnetic pieces
• CPC Class Codes: Y02P 10/25 : Process efficiency
• CPC Class Codes: Y02T 50/40 : Weight reduction
• CPC Class Codes: Y10T 428/2495 : Thickness [relative or absolute]

Abstract

Sesceptor sheets are selected so that their magnetic permeability decreases to unity at approximately the desired operating temperature thereby limiting heating to this "Curie temperature" and providing substantial uniformity of temperature in the panel Preferably, the susceptor includes multiple layers, such as a first metal having a relatively lower Curie temperature, a thin foil of copper in contact with the surface of the first sheet, and a second metal having a relatively higher Curie temperature. Such a susceptor allows thermal control at two spaced set points defined by the Curie temperatures.

Claims

1. A method for processing a workpiece at two different temperatures, comprising the steps of:

(a) sealing the workpiece in a multilayer retort, wherein a second, inner metal sheet has a higher Curie temperature than a lower Curie temperature of a first, outer metal sheet, the second sheet being in contact with the workpiece;

(b) inductively heating the workpiece to about the first Curie temperature by inducing currents in the first sheet; and

(c) inductively heating the workpiece to about the second Curie temperature when the first sheet becomes nonmagnetic by inducing currents in the second sheet.

2. The method of claim 1 wherein the outer metal sheet is an alloy having at least one of Ni, Fe, and Co.

3. The method of claim 1 wherein the inner metal sheet is an alloy having at least one of Ni, Fe, and Co.

4. The method of claim 1 wherein the inner metal sheet is copper.

5. A multilayer susceptor for temperature control of a workpiece in induction heating operations, comprising:

(a) a first metal sheet being a first material susceptible to heating by induction and having a Curie temperature;

(b) a copper metal sheet about 0.010 inch thick abutting the first sheet substantially in surface contact the copper sheet being susceptible to heating by induction; and

(c) a third metal sheet abutting the copper sheet to form a three sheet sandwich with the first and third sheets being outer sheets and the copper sheet being an inner sheet, the third sheet being a material susceptible to heating by induction and having a Curie temperature higher than that of the first sheet.

7. The multilayer susceptor of claim 5 wherein the first material is an alloy of at least one of Ni, Fe, and Co.

8. The multilayer susceptor of claim 5 wherein both the first material and the third sheet are alloys of at least one of Ni, Fe, and Co.

9. The multilayer susceptor of claim 5 further comprising a copper cladding on an outer surface of the third sheet.

6. A retort comprising at least two multilayer susceptors of claim sealable around a workpiece.

10. A multilayer susceptor for temperature control of a workpiece in induction heating operations, comprising:

(a) a first metal sheet susceptible to heating by induction, having a Curie temperature, and being a first material selected from the group consisting of steel;

ductile cobalt alloy having about 5% Fe and 95% Co;

an alloy having about 42% Ni and 58% Fe;

an alloy having about 49% Co, 49% Fe, and 2% V; and

an alloy having about 79% Ni, 17% Fe, and 4% Mo;

(b) a second metal sheet of a second material different from the first material, the second material having a first surface abutting the first sheet substantially in surface contact with the first sheet and an opposed outer surface, the second material being susceptible to heating by induction.

11. The multilayer susceptor of claim 10 wherein the second material is an alloy of at least one of Ni, Fe, and Co.

12. The multilayer susceptor of claim 10 wherein the second material is copper.

13. The multilayer susceptor of claim 12 further comprising a third metal sheet abutting the outer surface of the copper, the copper being about 0.010 inch thick, the third metal sheet being a third material susceptible to heating by induction.

14. The multilayer susceptor of claim 13 wherein the third material is an alloy of at least one of Ni, Fe, and Co.

15. The multilayer susceptor of claim 12 wherein the first material is an alloy having about 79% Ni, 17% Fe, and 4% Mo and the third material is an alloy having about 49% Co, 49% Fe, and 2% V.

16. The multilayer susceptor of claim 14 further comprising a second cladding of copper on an outer surface of the third material.

17. The multilayer susceptor of claim 10 wherein the first material is an alloy having about 79% Ni, 17% Fe, and 4% Mo and the second material is an alloy having about 49% Co, 49% Fe, and 2% V.