Escape from the Strength-to-Toughness Paradox: Bulk Ceramics through Dual Composite Architectures


This paper describes an approach to escape from the classic strength-toughness trade-off in bulk ceramics using the dual composite architectural concept. The key questions addressed by the research were: can dual composite architectures be fabricated? -how do dual composite architectures affect the physical properties of ceramics? -do dual composite architectures affect the mechanical behavior of composites? -do dual composite architectures have increased damage tolerance at elevated temperatures? These questions were answered positively. Reinforcing granules dispersed in loose powder mixtures were hot-pressed to obtain fully dense dual composite architectures with target overall composition. Defined sub-composites (labeled granule and matrix) of similar compositions, but differing engineered microstructures, were successfully retained. The brittle-to-ductile transition of MoSi2 above 1400 K enabled the simultaneous increase in both strength and toughness, and values of up to 440 MPa and 11.5 MPa√m, respectively, were experimentally determined at 1773 K.


Materials Science and Engineering


Funding for this joint project entitled "Dual Composite Ceramics for Improved Properties" was provided by the National Research Council of Italy and by United States National Science Foundation as part of the Materials World Network (grant DMR-1209262).

Keywords and Phrases

Dual Composite Architectures; Fracture Toughness; Hot-Pressing; Microstructure-Final; Strength; ZrB2

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Article - Journal

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© 2018 Elsevier Ltd, All rights reserved.

Publication Date

01 Jul 2018