Synthesis and Structural Properties of New Metallic Phases Exhibiting Non-Crystallographic Symmertries.
Abstract
In carrying out research on aluminum-glasses (Al-glasses), several unusual results are found: sub millimeter dutile glassy ribbons are obtained. Significant enhancement in the tensile strength is measured in Al-glass ribbons with Al nanocrystallites embedded in them. Deformation induced crystallization within the shear bands is observed for the first time. Strong Al-transition metal interaction is inferred from x-ray and neutron diffraction measurements. These results have added to our understanding of formation and microstructure-mechanical effect relationships of metal-glasses, and also to the technological values of these materials. We have begun to apply our findings to the synthesis and studies of bulk metallic-glass and nanocrystalline alloys. Thus far, we have succeeded in making subcentimeter glasses based on rare-earths and magnesium-tin, nanocrystalline alloys based on refractory metals via conventional casting, and as well as, centimeter Al-glass button via consolidation of amorphous powders obtained by ball-milling. In collaboration with Professor T. Egami at U. Penn., a method for obtaining two-dimensional atomic pair distribution is developed to unravel the structure of decagonal crystals. The new method will be applied to study layered materials.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 15, 1994
- Accession Number
- ADA288391
Entities
People
- G. J. Shiflet
- S. J. Poon
Organizations
- University of Virginia