DEVELOPMENT OF SUPERPLASTIC 8090 AND 8091 SHEET

Abstract
The paper considers the superplastic forming of the alloys Lital 8090 and Lital 8091 after processing by a route designed to confer superplastic properties. Examples of the components that can be fabricated by superplastic forming are shown and the properties that can be achieved in such components after different heat treatment procedures are given. Lital 8091 possesses somewhat better forming characteristics and is capable of achieving appreciably higher strengths in the formed product. However, the alloy is relatively quench sensitive and reasonably rapid cooling is necessary to achieve the maximum properties. Lital 8090 has somewhat reduced forming capabilities and can only achieve lower strength. However, it is less quench sensitive and near to full strength properties can be achieved by air cooling from the solution treatment temperature.