Processing and Superplasticity in Lithium-Containing Al-Mg Alloys.

Abstract

The refined microstructures and superplastic properties resulting from controlled thermomechanical processing of a 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.

Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1987
Accession Number
ADA182524

Entities

People

  • Benjamin W. Sanchez

Organizations

  • Naval Postgraduate School

Tags

DTIC Thesaurus Topics

  • Alloys
  • Aluminum
  • Cavitation
  • Coefficients
  • Ductility
  • Elements
  • Elongation
  • Magnesium
  • Materials
  • Mechanical Properties
  • Mechanical Working
  • Metals
  • Microstructure
  • Strain Rate
  • Superplasticity
  • Zirconium
  • Zirconium Alloys

Fields of Study

  • Materials science

Readers

  • Powder metallurgy of Titanium alloys.