Processing and superplasticity in lithium-containing Al-Mg alloys. Master's thesis

Technical Report · Sat Feb 28 23:00:00 EST 1987

OSTI ID:6200020

Sanchez, B W

The refined microstructures and superplastic properties resulting from controlled thermomechanical processing of an aluminum-magnesium-lithium-zirconium alloy were evaluated. The processing involved warm rolling at 300 C separately to true strains of 1.9 and 2.6. Increasing the rolling strain enhanced the superplastic ductility of the alloy at 300 C. Elongations in excess of 500 percent without cavitation, and a corresponding strain rate sensitivity coefficient of approximately 0.5, were obtained. TEM investigations of the microstructural characteristics responsible for the mechanical behavior revealed that a more uniformly refined grain structure (2-5 micrometer) evolved by continuous recrystallization in material experiencing the larger rolling strain. It was also concluded that the increase in rolling strain enhances grain refinement both preceding and concurrent with superplastic deformation. Keywords: Superplasticity, Superplastic deformation, Thermomechanical processing, Thesis.

• Research Organization: Naval Postgraduate School, Monterey, CA (USA)
• OSTI ID: 6200020
• Report Number(s): AD-A-182524/9/XAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM ALLOYS
CAVITATION
CONTROL
CRYSTAL STRUCTURE
DEFORMATION
ELONGATION
LITHIUM ALLOYS
MAGNESIUM ALLOYS
MECHANICAL PROPERTIES
MICROSTRUCTURE
PHASE STUDIES
PROCESSING
RECRYSTALLIZATION
REFINING
SENSITIVITY
STRAIN RATE
TENSILE PROPERTIES
ZIRCONIUM ALLOYS