Abstract: A method is disclosed for stretching magnesium-containing aluminum alloy sheet stock into intricate shapes such as are required in automotive body panels. The sheet stock, at a temperature in the range of about 400° C. to about 510° C., is stretched under the pressure of a working gas into conformance with the surface of a forming tool. The sheet forming pressure is increased continually in a controlled manner from ambient pressure to a final forming level in the range of about 250 psi to about 500 psi or higher. A portion of the sheet can experience strain rates substantially higher than 10−3 sec−1 and the forming of the sheet can be completed within 12 minutes.

Abstract: Unitary vehicle body compartment structures of the type comprising wall members and/or interconnected frame members that define the surface of a cylinder are made by providing a tube that is initially smaller than the cylinder and expanding at least portions of the tube to the shape of the body compartment structure. Functional openings such as windows are trimmed from the deformed tube to further define the compartment. A complete body may be assembled by attaching two or more such compartments such as, e.g., a passenger compartment, an engine compartment and a luggage compartment. Tube or tube segments may also be employed to make segments of the body compartment or smaller body parts such as doors and hoods.

Abstract: Unitary vehicle body compartment structures of the type comprising wall members and/or interconnected frame members that define the surface of a cylinder are made by providing a tube that is initially smaller than the cylinder and expanding at least portions of the tube to the shape of the body compartment structure. Functional openings such as windows are trimmed from the deformed tube to further define the compartment. A complete body may be assembled by attaching two or more such compartments such as, e.g., a passenger compartment, an engine compartment and a luggage compartment. Tube or tube segments may also be employed to make segments of the body compartment or smaller body parts such as doors and hoods.