Determination of Constitutive Equations for Titanium Alloys Applicable to Sheet Metal Formability

Abstract

A program to determine constitutive equations applicable to the sheet formability of the titanium alloy Ti-6Al-4V has been initiated. Load relaxation tests have been conducted at temperatures from 25 to 500 C over a strain-rate range of .1 to ten to the minus 8th power 1/sec using a programmable digital data acquisition system. The relaxation data, presented as log stress vs. log strain-rate hardness curves, illustrate the dependence of the strain-rate sensitivity, an important sheet metal formability index, on strain rate and temperature. The shapes of the hardness curves agree qualitatively with those predicted by the mechanical equation of state suggested by Hart. In particular, the transition from low temperature to high temperature grain matrix deformation behavior is clearly observed. Anomalous curvatures, apparently due to a strain aging mechanism, were observed in some room temperature hardness curves at low strain rates.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1978
Accession Number
ADA053094

Entities

People

  • Joseph F. Thomas Jr.

Organizations

  • Wright State University

Tags

Communities of Interest

  • Human Systems

DTIC Thesaurus Topics

  • Acquisition
  • Constitutive Equations
  • Data Acquisition
  • Digital Data
  • Failure Mode And Effect Analysis
  • High Temperature
  • Low Temperature
  • Materials
  • Materials Laboratories
  • Mechanical Properties
  • Metals
  • Microstructure
  • Plastic Properties
  • Sheet Metal
  • Titanium
  • Titanium Alloys
  • Yield Strength

Fields of Study

  • Materials science

Readers

  • Mechanical Engineering/Mechanics of Materials.
  • Metallurgy