COMPARISON OF THE MECHANICAL-BEHAVIOR OF SICF SIC COMPOSITES FOLLOWING NEUTRON-IRRADIATION AND HELIUM IMPLANTATION/

Thermomechanical behaviour of 2D-SiCf/SiC composites following neutron irradiation and helium implantation was studied. Three-point bending tests were carried out at room temperature (RT) and 1073 K, after neut ron irradiation (1.29, 2.69 and 5.23 dpa) at the High Flux Reactor-Pet ten. Results of RT mechanical tests on helium implanted bars are also referred and discussed. The samples with an accumulated damage dose of 1.29 dpa show a strength decrease and improved bend toughness. For th e higher neutron fluences the composite exhibits a brittle behaviour. For helium implanted materials, a strength decrease comparable to that observed for those neutron irradiated at lower fluence is present, bu t its toughness is reduced. (C) 1998 Elsevier Science B.V. All rights reserved.