Northrop Corporation

Other

Reynolds Metals Company

Suphal P Agrawal

Bennie R Ward, Jr

Richard F Ashton

Gregory V Scarich

Improved superplastic aluminum alloys are formulated to contain less than 0.05 weight percent each of iron and silicon based on the total weight of the superplastic aluminum alloy. Advantageously these two elements are present at levels of 0.03 weight percent or below, preferably 0.01 weight percent or below. Advantageous superplastic forming properties are achieved with these low iron, low silicon alloys. Further advantageous superplastic forming properties are achieved by subjecting aluminum alloys to a thermomechanical treatment followed by a rapid recrystallization-anneal treatment as, for instance, a recrystallization-anneal treatment utilizing a molten salt bath. When these formulations and processes are practiced alone, in combination with each other or together with cavitation supression improvements in superplastic forming of component parts are achieved.

Superplastic aluminum alloys, alloy processes and component part

A method for improving mechanical properties of superplastically formed alloy by healing the cavities formed as result of a superplastic forming process is disclosed. The alloy, such as an aluminum alloy, is superplastically formed and is then placed in an autoclave and hot isostatically pressed at a pressure ranging from about 10,000 psi to 30,000 psi for a time and temperature sufficient to heal cavities.

Method of improving properties of superplastically formed alloys by

Disclosed is a method of forming metallic materials exhibiting the phenomenon of superplasticity, particularly high strength aluminum alloys, by the technique of superplastic forming by focing an alloy blank into a die cavity using opposing fluid pressures, the pressure on the die side of the blank initially balancing the pressure on the opposite blank side, the die side pressure being reduced as the other pressure is maintained constant or increased to deform the blank at a combined high pressure whereby precision molding occurs as the blank engages the die intimately and cavitation in the blank is reduced or alleviated.

Methods of enhancing superplastic formability of aluminum alloys by

The use of a sequentially applied warm working/cold working procedure in the conventional steps of preparing heat treatable superplastic alloys yields material which demonstrates substantially equiaxed fine grain structure and improved superplastic forming characteristics.

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Rancho Palos Verdes, CA, United States of America

Suphal P Agrawal