Deformation and Failure of 93W-5Ni-2Fe at High Strain Rate Shear Loading

Abstract

A tungsten heavy alloy containing 93% W (Teledyne 93W-5Ni-2Fe alloy 1 swaged to 17% was tested in torsion at strain rates of 0.0001, 0.1, and 600s-1 to failure. High rate tests were conducted using a Torsional Split Hopkinson Bar apparatus. The results from these constant strain rate tests show that the yield and failure strengths of this alloy increase with increasing strain rate and the failure strain decreases with increasing strain rate. At 600 s-1 strain rate, flow stress decreases with strain, thus indicating thermal softening of the material at high strain rate of deformation. The instability that leads to the initiation of failure at high rate is due to the formation of a localized shear band. The width of the intense shear zone of deformation decreases with increasing shear strain rate reaching a limiting width of one to two grains at high strain rates. As the shear strain rate is increased, there is a reduction in the number of cleavage and brittle grain boundary fracture zones. The results under dynamic conditions show that the 93% W alloy deforms and fails quite differently compared to that under slow rate of loading.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1992
Accession Number
ADA251345

Entities

People

  • Patricia A. Beaulieu
  • Ronald Swanson
  • Tusit Weerasooriya

Tags

Communities of Interest

  • Ground and Sea Platforms
  • Space
  • Weapons Technologies

DTIC Thesaurus Topics

  • Air Force
  • Crystal Structure
  • Engineering
  • Geometry
  • Grain Boundaries
  • Information Processing
  • Materials
  • Materials Science
  • Mechanical Properties
  • Mechanical Working
  • Mechanics
  • Military Research
  • Shear Bands
  • Shear Stresses
  • Softening
  • Strain Rate
  • Tungsten

Fields of Study

  • Materials science

Readers

  • Materials Science (Mechanical Engineering).
  • Mechanical Engineering/Mechanics of Materials.