Accession Number:
ADA272426
Title:
The Use of Backscattered Electron Imaging Mode to Assess the Effect of Fine Dispersions on Development of Superplastic Microstructure in Al-Mg Alloys
Descriptive Note:
Master's thesis,
Corporate Author:
NAVAL POSTGRADUATE SCHOOL MONTEREY CA
Personal Author(s):
Report Date:
1993-06-01
Pagination or Media Count:
75.0
Abstract:
Microstructural evolution during thermomechanical processing of several Al-Mg alloys was studied using backscattered orientation contrast imaging in the scanning electron microscope. The microstructural evolution in A1-8Mg-0.1Zr was characterized in three phases a in the initial stages, precipitation occurred on prior boundaries and microbands were observed in the grain interiors b during intermediate stages, higher order microbands were observed and precipitates formed throughout the microstructure on both lower- and higher-order microbands c in the final stages, equiaxed regions appeared around larger particles suggesting particle stimulated nucleation of recrystallization. A higher Mg-content alloy A1-10Mg0.1Zr was compared at two stages and seen to provide a greater volume fraction of similar sized precipitate. A finer recrystallized microstructure and greater superplastic response was observed in the Al-10Mg-0.1Zr alloy.
Descriptors:
Subject Categories:
- Properties of Metals and Alloys
- Plastics
- Optics