Phase Field Theory and Analysis of Pressure-Shear Induced Amorphization and Failure in Boron Carbide Ceramic

Abstract

A nonlinear continuum phase field theory is developed to describe amorphization of crystalline elastic solids under shear and/or pressure loading. An order parameter describes the local degree of crystallinity. Elastic coefficients can depend on the order parameter, inelastic volume change may accompany the transition from crystal to amorphous phase, and transitional regions parallel to bands of amorphous material are penalized by interfacial surface energy. Analytical and simple numerical solutions are obtained for an idealized isotropic version of the general theory, for an element of material subjected to compressive and/or shear loading. Solutions compare favorably with experimental evidence and atomic simulations of amorphization in boron carbide, demonstrating the tendency for structural collapse and strength loss with increasing shear deformation and superposed pressure.

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 2014
Accession Number
ADA608441

Entities

People

  • John D. Clayton

Organizations

  • United States Army Research Laboratory

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boron Carbides
  • Boundary Value Problems
  • Bulk Modulus
  • Crystal Structure
  • Crystallography
  • Crystals
  • Density Functional Theory
  • Materials
  • Materials Science
  • Mechanics
  • Phase Transformations
  • Physical Properties
  • Piezoelectric Crystals
  • Shear Modulus
  • Simulations
  • Surface Energy
  • Transitions

Fields of Study

  • Physics

Readers

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