Evolution of the structure and mechanical behaviour of a carbon foam at very high temperatures

Mechanical behaviour of a low density carbon/carbon composite at very high temperature is studied in relation with its microstructure. This composite is a syntactic foam made of carbon microbeads with a binder and voids. The resulting geometrical density is 0.3 g cm(-3). Compressive tests from room temperature up to 3100 degreesC with a very high heating rate (180 degreesC s(-1)) have been conducted. Intermediate temperature tests have also been performed and show an obvious modification of mechanical behaviour from around 2000 degreesC. This result is related to a sudden modification of structure and texture of the carbonaceous matter during the high temperature mechanical test. A strong plastic deformation occurs when the mechanical experiment is performed at 3100 degreesC whereas the material elastically deforms at room temperature. (C) 2002 Published by Elsevier Science Ltd.