Exposure of composite test sample to high intensity heat flux

Research was performed on the thermal behaviour of high temperature composites (carbon/BMI and carbon/cyanate ester) and a carbon/epoxy composite with and without phenolic thermal protection layer. Test samples were made by vacuum infusion and thermocouples were integrated in the composite laminate. Heat propagation through the thickness of the composite was measured during short exposures of high-intensity heat flux. Degradation of the material after exposure was determined by performing interlaminar shear and flexural tests. The results show that there is not much difference between the resins when looking at the temperature at which pyrolysis starts. But in the first stage of pyrolysis, the phenolic resin has the smallest mass reduction and the standard epoxy the largest. Degradation in mechanical properties was not measured after multiple short exposures to the heating lamps. However, after longer exposures the standard epoxy shows the largest degradation and the BMI the smallest. Furthermore, theoretical calculations on heat propagation show a good correlation with the experimental results.

If you like to read further about this development, please download the hightempcomposites.pdf paper that we presented in April 2004 at the SAMPE Europe Conference & Exhibition in Paris (340 kB)!