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Article
A High Strength Alumina-Silicon Carbide-Boron Carbide Triplex Ceramic
Ceramics International
  • Eric W. Neuman, Missouri University of Science and Technology
  • Greg Hilmas, Missouri University of Science and Technology
  • William Fahrenholtz, Missouri University of Science and Technology
Abstract

A ceramic particulate composite composed of oxide, and carbide ceramics was found to have high strength, hardness, and fracture toughness values. A composition consisting of Al2O3 with 15 vol% SiC and 15 vol% B4C additions was produced by hot-pressing at 1650⁰C for 30 min, with full density reached after ~5 min at temperature. Both WB and WB2 were observed, with the W source presumably an impurity from WC milling media, and Al18B4O33 was also detected following densification. Strength was~880 MPa, which is greater than values reported for comparable composites of Al2O3 containing 30 vol% SiC or B4C. Vickers hardness was ~21 GPa, and fracture toughness was ~4.5 MPa m1/2, comparable to values reported for the binary mixtures. The calculated critical flaw size of the material was similar to the size of the SiC/B4C clusters and microcracking at grain boundaries. The latter resulting from thermal expansion mismatch between the Al2O3 matrix and SiC/B4C resuborcing phases.

Department(s)
Materials Science and Engineering
Keywords and Phrases
  • Aluminum oxide,
  • Boron carbide,
  • Hot-pressing,
  • Microstructure,
  • Silicon carbide,
  • Strength,
  • Binary mixtures,
  • Fracture toughness,
  • Grain boundaries,
  • Hot pressing,
  • Thermal expansion,
  • Vickers hardness
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2017 Elsevier Ltd, All rights reserved.
Publication Date
7-1-2017
Publication Date
01 Jul 2017
Citation Information
Eric W. Neuman, Greg Hilmas and William Fahrenholtz. "A High Strength Alumina-Silicon Carbide-Boron Carbide Triplex Ceramic" Ceramics International Vol. 43 Iss. 10 (2017) p. 7958 - 7962 ISSN: 0272-8842
Available at: http://works.bepress.com/greg-hilmas/11/