The Influence of Porosity on the Deformation and Fracture of Alloys.

Abstract

The tensile deformation and fracture behavior of alloys containing rounded porosity and with differing levels of matrix strain hardening has been examined both experimentally and analytically. The stress-strain response in uniaxial tension and, to a limited extent, plane-strain tension has been determined at room temperature for powder-fabricated titanium, and Titanium-6 Aluminum-4 Vanadium containing porosity. The strength and the ductility of both alloys decrease substantially with increasing porosity level. A large strain elastoplastic finite element model based on a regular array of equal-sized spherical voids is used to predict bulk porosity effects; the analysis is in good agreement with the experimentally observed rates of void growth, but it underestimates the degradation of strength with increasing porosity. In an analysis unique to P/M alloys, the effects of porosity on a local scale are examined successfully by a continuum imperfection model which predicts the fracture of porous materials with differing matrix strain-hardening characteristics. The analysis is significant in that it implies that a primary effect of porosity on fracture is to introduce into the material a network of planes of high local pore content (imperfections).

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1984
Accession Number
ADA148766

Entities

People

  • Donald A. Koss
  • O. Richmond
  • R. E. Smelser
  • R. J. Bourcier

Organizations

  • Michigan Technological University

Tags

Communities of Interest

  • Air Platforms
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Electron Microscopy
  • Electrons
  • Engineering
  • Materials
  • Materials Engineering
  • Materials Science
  • Materials Testing
  • Measurement
  • Mechanical Working
  • Michigan
  • Military Research
  • Porous Materials
  • Scanning
  • Sintering
  • Strain Hardening
  • Stress Strain Relations
  • United States

Fields of Study

  • Materials science

Readers

  • Computational Modeling and Simulation
  • Mechanical Engineering/Mechanics of Materials.
  • Powder metallurgy of Titanium alloys.