Patent Number: 6,253,588

Title: Quick plastic forming of aluminum alloy sheet metal

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.degree. C. to about 510.degree. 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.sup.-3 sec.sup.-1 and the forming of the sheet can be completed within 12 minutes.

Inventors: Rashid; Moinuddin Sirdar (Bloomfield Hills, MI), Kim; Chongmin (Springfield Township, MI), Ryntz; Edward Frank (Warren, MI), Saunders; Frederick Irvin (Sterling Heights, MI), Verma; Ravi (Shelby Township, MI), Kim; Sooho (Troy, MI)

Assignee: General Motors Corporation

International Classification: B21D 26/02 (20060101); B21D 26/00 (20060101); B21D 026/02 ()

Expiration Date: 07/03/2018