Effects of thermo-mechanical processing on aluminum-magnesium alloys containing high weight percentage magnesium.
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Authors
Glover, Terry Lee
Subjects
Aluminum-Magnesium Alloys
High Weight Percentage Magnesium
High Weight Percentage Magnesium
Advisors
McNelley, T. R.
Date of Issue
1977-12
Date
Publisher
Monterey, CA; Naval Postgraduate School
Language
Abstract
Cast ingots of three Al-Mg alloys, containing 7% Mg , 151 Mg, and 19% Mg, were obtained from Kaiser Aluminum and Chemical Corporation Center for Technology. Billets were machined from these castings and upset forged at .9% of either the solvus or eutectic temperature, as appropriate, to a true strain of 1.5. These alloys were then evaluated by compressive stress - strain testing at various temperatures and strain rates to determine both the ambient and elevated temperature characteristics. Due to the inability to produce very fine second phase particles by upset forging, the 15% and 19% Mg alloys were high in strength but brittle at room temperature. However, refinement of the second phase particles during compression testing led to superplastic behavior at elevated temperature, with a strain rate sensitivity coefficient of .4-3 being achieved in the 19% Mg alloy. It was further observed that the addition of Mg increased strain rate sensitivity in these Al-Mg alloys at all temperatures, especially at elevated temperatures.
Type
Thesis
Description
Series/Report No
Department
Mechanical Engineering