Constitutive Modeling of Low-Temperature Superplastic Flow of Unltrafine Ti-6Al-4V Sheet Material (PREPRINT)

Abstract

The low-temperature superplastic flow behavior of two lots of Ti-6Al-4V sheet with an ultrafine microstructure was modeled. One lot (Sheet A) had an equiaxed-alpha starting microstructure; the flow stress/flow hardening exhibited by this material was explained on the basis of the Bird-Mukherjee-Dorn constitutive equation. The other material (Sheet B), having a mixed equiaxed- and remnant-lamellar alpha microstructure, underwent flow softening, flow hardening, or steady-state flow depending on test temperature and strain rate. These behaviors were interpreted in the context of a dynamic spheroidization model. The apparent flow softening at the end of all of the flow curves was explained using a simple flow-localization model.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 2009
Accession Number
ADA504524

Entities

People

  • G. A. Sargent
  • Sheldon Lee Semiatin

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Air Force
  • Air Force Facilities
  • Air Force Research Laboratories
  • Alpha Particles
  • Constitutive Equations
  • Equations
  • Hardening
  • Low Temperature
  • Materials
  • Metals
  • Microstructure
  • Particles
  • Softening
  • Steady State
  • Strain Rate
  • Titanium Alloys
  • Ultrafines

Fields of Study

  • Materials science

Readers

  • Fluid Mechanics and Fluid Dynamics.
  • Powder metallurgy of Titanium alloys.