Strengthening of NiAl Matirix Composites.

Abstract

A detailed mechanism has been developed which will predict the formation of vacancy-producing jogged-screw dislocations. The motion of these screw dislocations is the thermally-activated rate-controlling mechanism for both the matrix and the NiAl matrix composites. With the exception of very small subgrain or grain sizes and Al2O3 particle size (0.5 micrometer), the internal stress is independent of stress and temperature. The increase in the internal stress caused by the reinforcement is the strengthening mechanism. The apparent unusual result of an increase in dislocation density due to relaxation of the thermal residual stress as the particle size increases in Al2O3/NiAl composites has been explained by a new model. This model, which employs FEM and crystal plasticity, is based on the low symmetry of the NiAl B2 crystal structure which results in a paucity of independent slip systems. jg p.4

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Document Details

Document Type
Technical Report
Publication Date
Nov 30, 1995
Accession Number
ADA302545

Entities

People

  • R. J. Arsenault

Organizations

  • University of Maryland

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Ceramic Matrix Composites
  • Composite Material Fabrication
  • Composite Materials
  • Creep
  • Crystal Structure
  • Diffraction
  • Grain Size
  • Materials
  • Materials Engineering
  • Materials Laboratories
  • Materials Science
  • Materials Testing
  • Mechanical Properties
  • Mechanical Working
  • Mechanics
  • Modulus Of Elasticity
  • Particle Size

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.
  • Mechanical Engineering/Mechanics of Materials.
  • Powder metallurgy of Titanium alloys.