Brittle destruction of carbon-based materials in transient heat load tests

To investigate the phenomenon of brittle destruction (BD), isotropic fine-grain graphites and carbon fiber composites (CFCs) with and without silicon doping have been exposed to intense transient thermal loads in the electron beam test facility JUDITH. For different pulse durations (1 to 5, 100, 5000 ms) the deposited energy density has been increased stepwise to determine the threshold for the BD process. Particle emission was diagnosed using time-resolved measurements of the absorbed current and by digital photography. A clear correlation of the absorbed current and the onset of the particle emission processes has been established.