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This content will become publicly available on January 24, 2019

Title: Ceramic composites: A review of toughening mechanisms and demonstration of micropillar compression for interface property extraction

We present that ceramic fiber–matrix composites (CFMCs) are exciting materials for engineering applications in extreme environments. By integrating ceramic fibers within a ceramic matrix, CFMCs allow an intrinsically brittle material to exhibit sufficient structural toughness for use in gas turbines and nuclear reactors. Chemical stability under high temperature and irradiation coupled with high specific strength make these materials unique and increasingly popular in extreme settings. This paper first offers a review of the importance and growing body of research on fiber–matrix interfaces as they relate to composite toughening mechanisms. Second, micropillar compression is explored experimentally as a high-fidelity method for extracting interface properties compared with traditional fiber push-out testing. Three significant interface properties that govern composite toughening were extracted. For a 50-nm-pyrolytic carbon interface, the following were observed: a fracture energy release rate of ~2.5 J/m 2, an internal friction coefficient of 0.25 ± 0.04, and a debond shear strength of 266 ± 24 MPa. Lastly, this research supports micromechanical evaluations as a unique bridge between theoretical physics models for microcrack propagation and empirically driven finite element models for bulk CFMCs.
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  1. Univ. of California, Berkeley, CA (United States). Department of Nuclear Engineering
  2. Univ. of Oxford (United Kingdom). Department of Materials
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division
  4. General Atomics, San Diego, CA (United States). Nuclear Technologies and Materials Division
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Journal of Materials Research
Additional Journal Information:
Journal Volume: 33; Journal Issue: 4; Journal ID: ISSN 0884-2914
Materials Research Society
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Nuclear Energy (NE)
Country of Publication:
United States
36 MATERIALS SCIENCE; 22 GENERAL STUDIES OF NUCLEAR REACTORS; Ceramic Composite; Internal Friction; Neutron irradiation; Chemical Vapor; Deposition; Coating; Toughness; Fracture; Nuclear Materials; Nano-indentation
OSTI Identifier: