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

An apparatus for forming a frame member for an automobile from a tube blank applies internal hydraulic pressure to the blank, tangent bends and preforms the internally pressurized blank into a preformed tube having a desired horizontal profile configuration, then forms the preformed tube into a finally formed frame member having a desired vertical profile configuration and a desired, varying cross-sectional configuration by placing the preformed tube in a stuffing ledge apparatus having a lower die with an upwardly facing ledge and vertically extending, punch engaging surfaces and a punch having a downwardly facing ledge and vertically extending, die engaging surfaces, internally pressurizing the tube, and then ramming the punch downwardly to form the tube into the finally formed frame member, the ledges and vertically extending surfaces substantially completely enclosing a portion of the tube before and while the punch and die come together to form the tube into the finally formed frame member. The forming components in each apparatus are submerged in an aqueous bath, allowing the blank and tube to automatically fill themselves, thereby facilitating sealing and pressurizing of the tube.

Apparatus and method for forming a tubular frame member

A method and apparatus for forming and consolidating organic matrix composites. An organic matrix composite panel comprising laid-up prepregs is placed between sheets of a susceptor material that is susceptible to inductive heating to form a workpiece. The resulting workpiece is placed within upper and lower dies formed of a material that is not susceptible to inductive heating. An induction coil embedded within the dies is energized and inductively heats the susceptor sheets surrounding the panel. The sheets in turn conductively heat the organic matrix composite panel. A pressure zone between the workpiece and one of the dies is pressurized to form the workpiece to the contour of a forming surface on one of the dies. The pressure in the pressure zone is maintained on the workpiece until the organic matrix composite panel is fully consolidated and formed.

Method and apparatus for consolidating organic matrix composites using induction heating

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

The present invention provides a method and apparatus for forming a ductile sheet or work piece into a part or component. The method includes using a forming apparatus wherein the workpiece is placed between and upper die and a blank holder and then lowered onto a punch such that continued lowering of the upper die draws the workpiece around the punch. Once the draw process is complete, gas pressure acts on one side of the workpiece to press the workpiece against a forming surface of the punch to complete the forming process.

Method and apparatus for superplastic forming

A method and apparatus for the superplastic forming of a workpiece are disclosed. The invention comprises securing the workpiece within a die assembly located within an autoclave. The die assembly is of a type suitable for use in the superplastic fabrication of workpieces. The die assembly includes a lid, a die and first and second sealing mechanisms. The first sealing mechanism seals a first volume formed between the lid and the workpiece from a main volume of the autoclave. The second sealing mechanism is for sealing a second volume formed between the workpiece and the die from the main volume of the autoclave. The second volume has a backpressure, Pb. The first volume has a pressure Pf +Pb where Pf is the forming pressure for achieving superplastic forming of the workpiece. The main volume of the autoclave has a pressure, Pm. The back pressure, Pb is established so as to minimize grain boundary cavitation. A minimal pressure differential ΔP=Pm -Pb, is established which allows retention of the required sealing, while concomitantly providing Pf for the desired superplastic forming of the workpiece and eliminating the need to seal against Pb.

Apparatus and method for superplastic forming

1,263,176. Making armatures; welding by pressure; brazing. NORTH AMERICAN ROCKWELL CORP. 4 July, 1969, No. 33942/69. Headings B3A and B3R. [Also in Divisions C7 and H2] A method of making an armature comprises joining separate magnetically permeable components 10, 12 to opposite sides of a plate 14 of non-magnetically permeable material to form a unitary mass and shaping the mass to form a body of revolution. The components 10, 12 are of steel and they are placed with the plate 14, which is of a nickel or cobalt based alloy, in a retort 16. An interleaf of Monel 400 (Trade Mark) is also provided at interface planes 20, 22. The retort is evacuated and heated to 2000‹ F. for five hours with a pressure of 3000 p.s.i. applied normal to the interface planes 20, 22. Alternatively interface layers of a gold-palladium-nickel alloy may be provided and the assembly heated as previously, but without pressure applied. The assembly is cooled slowly in the furnace and then normalized. An elongated, truncated billet 24 is formed by removal of opposed corners 26, 28, the resulting billet being square in cross-section along the line 3-3. The billet is then turned to a substantially barrel form and the resulting armature is suitable for high rotational speeds, e.g. 20,000 r.p.m.

Roy H. Lorenz

Papers

Apparatus and method for superplastic forming

Rotatable magneto-electric armature and method of fabricating same