For forming or consolidating organic matrix composites, for example, an organic matrix composite panel (106) is sealed between sheets of a susceptor material (100, 102) that is susceptible to induction heating. The susceptor sheets (100, 102) are heated inductively. The sheets in turn conduct heat to the organic matrix composite panel (106). When heated to the desired temperature, the composite panel (106) is consolidated and/or formed. In the present invention, the susceptor 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. Of course, the concept applies to other induction heating operations for metals including SPF, brazing, annealing, heat treating, bonding, hot pressing, and the like.

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

Apparatus and method for superplastic forming. The workpiece is held between a pair of dies that are electrically and thermally nonconductive, and is heated inductively by a coil embedded within the dies.

Superplastic forming using induction heating

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.

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

A superplastically formed, diffusion bonded sandwich structure (30) having integral metal hardpoints (40), made by joining two superplastic metal core sheets (36) together into a core pack (38) by welding or diffusion bonding along a pattern of lines which form junction lines between the core sheets (36) when the pack (38) and metal inserts (40) are interposed between the face sheets (32, 34) and the core (38) All of the sheets in the pack (30) are sealed together around an outside peripheral edge to create a gas tight envelope The pack (30) is heated to superplastic temperatures in a cavity of a die, and the top and bottom face sheets (32, 34) are diffusion bonded to top and bottom surfaces of the metal inserts (40) by application of heat and pressure from top and bottom inner surfaces of the die cavity While at superplastic temperatures, the pack (30) is inflated by gas pressure against inside surfaces of a die to form an expanded metal sandwich structure (30) having integral webs (36) and having integral hardpoints (40) formed by the metal inserts (40) After forming, the gas pressure is reduced to near atmospheric, the die is opened and the part (30) is removed from the die

Metal sandwich structure with integral hardpoint

The structure and process for making a hollow article in which the core structure is formed from two cell sheets diffusion bonded to a rib pattern sheet having a preselected pattern of ribs having passageways. The cell sheets are diffusion bonded to the rib pattern sheet using tooling pattern sheets having a geometry matching that of the rib pattern sheet thereby creating contiguous cells, interconnected by the passageways, between the cell sheets at each rib and the periphery of the structure. Inert gas is then applied to the cells during a superplastic forming process to create expanded envelopes of each cell of the core. Face sheets of the sandwich structure may then be formed from the cell sheets themselves by further expanding the cell sheets out against a mold surface. Alternatively, the envelopes of the core may be expanded and simultaneously or subsequently diffusion bonded to separate face sheets. The contour of the core may be performed, formed concurrently with separate face sheets in a single operation, or subsequently formed as a sandwich structure.

Hollow metallic structure and method of manufacture

Two face-to-face metal sheets, one or each of which is superplastically deformable, are subjected to a bonding and pressure deformation process in which the sheets are bonded together at a series of spaced positions thereon and the areas of the or each superplastically deformable sheet between these positions move away from the other sheet so that there is formed a series of cavities between the sheets, the sides of neighboring cavities being substantially adjacent to one another over substantial parts of their areas. These sides of the cavities, which are preferably substantially rectangular may come directly into contact with one another and be diffusion bonded together either directly or via reinforcing members.

Method of making a stiffened panel

A method of forming metal articles comprises placing a pair of sheet members 1, 2 or superplastically deformable material in opposed, spaced apart relationship, (conveniently by means of a reinforced member 3), heating them to the temperature range within which superplastic deformation can take place, and urging portions of the sheets toward each other until they lie one against the other thereby to effect bonding. The bonding is preferably by means of diffusion bonding.

Forming metal articles

Verfahren zur herstellung von metallgegenstaenden

LA PRESENTE INVENTION CONCERNE UN PROCEDE DE FACONNAGE D'ARTICLES METALLIQUES QUI COMPREND: LE PLACEMENT D'UNE PAIRE D'ORGANES EN FEUILLE 1, 2 EN MATERIAU DEFORMABLE SUPERPLASTIQUEMENT POUR LES METTRE EN REGARD A UNE CERTAINE DISTANCE L'UN DE L'AUTRE (COMMODEMENT AU MOYEN D'UN ORGANE DE RENFORCEMENT 3), LEUR CHAUFFAGE JUSQU'A UNE TEMPERATURE COMPRISE DANS UNE PLAGE DE TEMPERATURE DANS LAQUELLE LA DEFORMATION SUPERPLASTIQUE PEUT SE PRODUIRE, ET LA SOLLICITATION DE PORTIONS DES FEUILLES LES UNES VERS LES AUTRES JUSQU'A CE QU'ELLES SE TROUVENT LES UNES CONTRE LES AUTRES, A LA SUITE DE QUOI IL Y A LIAISON ENTRE ELLES. LA LIAISON EST DE PREFERENCE DU TYPE LIAISON PAR DIFFUSION.

Sidney John Swadling

Papers

Method of making a stiffened panel

Forming metal articles

Verfahren zur herstellung von metallgegenstaenden

Procede de faconnage d'articles comportant des premiere et seconde feuilles en metal deformable superplastiquement et pouvant se lier