Transmission Electron Microscopy Characterization of Knoop Indentation Inelastic Deformation Regions in Three Commercial Silicon Carbides

Abstract

Understanding the deformation mechanisms in ceramic materials that govern penetration resistance is crucial for developing better ceramic materials for lightweight body and vehicle armor systems. To determine the mechanistic response of three commercially available armor-grade silicon carbide (SiC) variants to quasi-static large contact stresses, transmission electron microscopy (TEM) was used to examine cross sections of the inelastically deformed regions beneath 1-kgf Knoop indents. Due to the potential for extensive cracking around and below the indents, a multistep sample preparation technique was developed to preserve the cross sections intact. TEM specimens were made using the focused-ion beam technique. In general, TEM characterization of the inelastically deformed regions revealed stacking faults, dislocations, transgranular and intergranular microcracking and macrocracking, which varied for each commercial SiC due to variations in their processing and resultant microstructures.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 2018
Accession Number
AD1061524

Entities

People

  • Jeffrey J. Swab
  • Jerry C LaSalvia
  • Samuel G. Hirsch
  • Scott D. Walck

Organizations

  • United States Army Research Laboratory

Tags

Communities of Interest

  • Advanced Electronics
  • Weapons Technologies

DTIC Thesaurus Topics

  • Aluminum Oxides
  • Carbides
  • Ceramic Materials
  • Chemistry
  • Compound Semiconductors
  • Electron Microscopes
  • Electron Microscopy
  • Grain Size
  • Material Degradation Processes
  • Materials
  • Materials Science
  • Metalloids
  • Microscopes
  • Microscopy
  • Silicon Carbide
  • Technical Ceramics
  • Transmission Electron Microscopy

Readers

  • Materials Science (Mechanical Engineering).
  • Structural Health Monitoring of Composite Structures.
  • Thin Film Deposition Science.

Technology Areas

  • Microelectronics