Flexural creep of zirconium diboride-silicon carbide up to 2200 °C in minutes with non-contact electromagnetic testing

Flexural creep of ZrB2-30 vol% SiC ultra high temperature ceramic composite was studied at 1700-2200 degrees C and 20-50 MPa using the novel method of electromagnetic Lorentz force loading of electrically heated specimens. Experiments were conducted in air and in non-oxidizing atmospheres. The apparent activation energy for creep was 344 +/- 35 kJ/mol for non-oxidizing conditions. The stress exponent was 1.4 +/- 0.4. The creep rate was slightly higher in air due to a decrease in the size of the load bearing substrate because of oxidation. There was no evidence of electric field effects. Creep experiments could be performed up to 2200 degrees C very quickly, with experiments conducted in a few minutes. (C) 2013 Elsevier Ltd. All rights reserved.