PROCESSING STUDY OF TI-7AL-2NB-1TA.
Abstract
The objective of the study was to evaluate various processing techniques for increasing the yield strength of Ti-7Al-2Nb-1Ta (721) plate while maintaining satisfactory ductility and fracture toughness. Three methods were found for improving the strength of 721 plate. The first method was to refine the grain size through low temperature processing. Compared to plate processed at higher temperatures, this resulted in improved strength and a minor decrease in impact energy. It is doubtful that sufficient work could be applied to thick plate at the necessary temperatures to consistently achieve this desirable grain size. The second method involved water quenching after rolling or annealing at temperatures near the beta transus. Compared to 1-in. plate fabricated by the normal mill process, an increase of 7 to 10 ksi in yield strength was obtained without an appreciable change in the ductility and impact energy. The third method involved aging at 1100 F after the quenching treatment. The aging further increased the yield strength of quenched plate 5 to 8 ksi. However, this was accompanied by a moderate decrease in impact energy. The second and third processes offer the greatest potential for scale-up to large plate processing. The acceptable level of fracture toughness would determine which processing procedure should be further evaluated. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1965
- Accession Number
- AD0466007
Entities
People
- L. R. Deblasio
- O. Bertea
- S. R. Seagle