Chimata Gandhi

US Patent:

47708484, Sep 13, 1988

Filed:

Aug 17, 1987

Appl. No.:

7/085690

Inventors:

Amit K. Ghosh - Thousand Oaks CA
Chimata Gandhi - Thousand Oaks CA

Assignee:

Rockwell International Corporation - El Segundo CA

International Classification:

B22F 314

US Classification:

419 28

Abstract:

A rapidly-solidified aluminum alloy powder having a nominal composition of 7% Zn, 2. 5% Mg, 2% Cu, 0. 3% Zr, and 0. 3% Cr is used to make a high forming-rate, superplastic, high-strength aluminum alloy. The powder is outgassed, consolidated, and extruded, thereby developing a wide range of particle size distribution of dispersoids in the process, containing respectively zirconium and chromium dispersoids, as well as age hardening precipitates. The consolidated powder is then rolled to 85% reduction to provide a sheet material which is superplastically formed at a temperature in the range of 450. degree. C. to 490. degree. C. and at a rate between 5. times. 10. sup. -3 to 5. times. 10. sup. -2 per second.