Influence of Fibre Content on the Strength of Carbon Fibre Reinforced HfC/SiC Composites Up to 2100 °C


The influence of carbon fibre content on the mechanical behaviour of HfC/SiC composites was investigated up to 2100 °C for specimens containing 40 or 55 vol% fibres. Silicon carbide was added as a sintering aid during hot pressing. Increasing the fibre content made infiltration more difficult, which resulted in higher porosity in the specimen with 55 vol% fibres. The room temperature flexural strength ranged from 340 to 380 MPa, and it increased to more than 400 MPa at 1800 °C due to stress relaxation. Increasing temperature was accompanied by a decrease in the slope of the load-displacement curve, indicating a decrease in elastic modulus, but plastic deformation was not observed below 2100 °C. At 2100 °C, the specimen containing a higher fibre content underwent significant deformation due to low interfacial strength between the fibre plies, retaining a strength at the proportional limit of 290 MPa and an ultimate strength of 520 MPa.


Materials Science and Engineering


This work has received funding from the JECS Trust program and from the European Unions Horizon 2020 "Research and innovation programme" under grant agreement N° 685594 (C 3 HARME).

Keywords and Phrases

Ceramic-matrix composites (CMCs); Fibre-matrix interface; Hafnium carbide; High temperature mechanical properties; Ultra-high-temperature-ceramics (UHTCs)

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Article - Journal

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© 2019 Elsevier Ltd, All rights reserved.

Publication Date

01 Oct 2019