An Experimental Survey on Mechanical Property Characterisations of Ion-irradiated Silicon Carbides

摘要

SiC and SiC/SiC composites have a great potential for the structural material of advanced nuclear reactors. The irradiation behaviours of SiC are important and an ion irradiation is a useful tool to simulate the expected core conditions of fusion and GEN-IV nuclear reactors. Generally, however, the radiation-induced range by ion irradiation is limited to a few micrometers. Therefore, in the case of ion-irradiated SiC, a measurement of its mechanical properties is not straightforward and thus, advanced evaluation methods are continuously being requested to establish a data base for mechanical property changes of radiation-induced materials. In this work, indentation tests are proposed for evaluating the mechanical properties of ion-irradiated SiCs. The low-temperature irradiation produced various defects in the SiC such as point defect clusters, dislocation loops and amorphous phases. These various irradiation defects were observed by TEM, which existed as a function of the penetrated ion depth. The amorphous phases and the other defects seem to provide contrary results for the hardness. The changes of the mechanical properties were exhibited with increasing indentation loads. The experimental evaluation by using the indentation techniques was discussed with relation between microstructures and the mechanical properties.