Hot Rolling of Gamma Titanium Aluminide Foil (PREPRINT)

Abstract

Metal flow and microstructure evolution during the thermomechanical processing of thin-gage foil of a near-gamma titanium-aluminide alloy, Ti-45.5Al-2Cr-2Nb, with an equiaxed-gamma microstructure was investigated experimentally and theoretically. Foils of thickness of 200 - 250 micrometers were fabricated via hot rolling of sheet in a can of proprietary design. The variation in gage of the rolled foils was +/-15 micrometers except in very sporadic (local) areas with variations of approximately 60 micrometers relative to the mean. Metallography revealed that the larger thickness variations were associated with large remnant colonies lying in a hard orientation for deformation. To rationalize these observations, a self-consistent model was used to estimate the strain partitioning between the softer (equiaxed-gamma) matrix and the remnant colonies. Furthermore, the efficacy of pre- or post- rolling heat treatment in eliminating remnant colonies was demonstrated and quantified using a static-spheroidization model. The elimination of remnant colonies via spheroidization prior to foil rolling gave rise to improved gage control.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 2010
Accession Number
ADA523372

Entities

People

  • B. W. Shanahan
  • F. Meisenkothen
  • Sheldon Lee Semiatin

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Air Force
  • Air Force Research Laboratories
  • Alloys
  • Aluminides
  • Aspect Ratio
  • Chemistry
  • Equations
  • Grain Size
  • Heat Treatment
  • Manufacturing
  • Materials
  • Metals
  • Microstructure
  • Orientation (Direction)
  • Thickness
  • Titanium
  • Titanium Aluminide

Fields of Study

  • Materials science

Readers

  • Marine Propulsion Engineering and Naval Architecture
  • Materials Science (Mechanical Engineering).
  • Metallurgy