Effect of a Weak Fiber Interface Coating in ZrB₂ Reinforced with Long SiC Fibers

Abstract

This study reports the microstructural analysis and mechanical properties of a ZrB2 ceramic containing long BN-coated Hi-Nicalon SiC fibers. A composite was produced and thoroughly characterized by transmission electron microscopy to study the interfaces at the nanoscale level. Full densification was accomplished by hot pressing at 1450⁰C. The fiber in the sintered material retained its pristine aspect, confirming that the coating was effective in preventing degradation due to interactions with the matrix. Pull-out was observed on fractured surfaces, but toughness values were about 4.5MPam, which was comparable to those of ZrB2 materials with SiC additions in the form of particles or short fibers. However, the composites exhibited a controlled fracture behavior, as confirmed by a notably higher work of fracture, 140J/m2, compared with 20-30J/m2 of unresuborced ZrB2 or ZrB2 containing chopped fibers.

Department(s)

Materials Science and Engineering

Keywords and Phrases

Ceramic-matrix composites (CMCs); Fibers; Fracture toughness; Transmission electron microscopy; ZrB2; Ceramic materials; Coatings; Electron microscopy; Fracture mechanics; High resolution transmission electron microscopy; Hot pressing; Resuborced plastics; Silicon carbide; Sintering

International Standard Serial Number (ISSN)

0264-1275

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2015 Elsevier Ltd, All rights reserved.

Publication Date

01 Dec 2015

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