MECHANISM OF SUPERPLASTICITY IN A1-78%ZN ALLOYS.
Abstract
Superplasticity has been studied in the Al-78%Zn alloy with the purpose of identifying the basic mechanisms that control this unusual process. The experimental investigation has systematically covered the mechanical and microstructural relationships over a range of temperatures and strain rates, for different heat-treatments. Replication, electron microscopy, and selected area diffraction have been combined to relate the prior history of the alloy, its microstructure, and the nature of its defects. Moreover, through cinematography, such mechanisms as grain boundary sliding, grain rotation, and profuse dislocation generation are shown to occur during the actual process of superplasticity. The important experimental observations are discussed, and it is concluded that superplastic deformation in the Al-78%Zn alloy consists of grain boundary sliding, diffusional creep along grain boundaries, and dynamical interactions of dislocation. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 30, 1968
- Accession Number
- AD0670800
Entities
People
- E. U. Lee
- Ervin E. Underwood
- F. D. Fike
- H. H. Kronzlein
- H. J. Rock
Organizations
- Lockheed Martin