Comparative study of the mechanical properties after proton irradiation of Al2O3 and Si-SiC ceramics for fusion breeding blanket applications

Abstract

In this work, a study on the compression and indentation behavior of ceramic samples previously proton irradiated was studied. Prismatic bars were processed from commercial Al2O3 99.7%, and Si-SiC tubes manufactured by slip casting and extrusion, respectively. At least ten probes from each batch were submitted to high energy H+ ion beams (approximately 4.5 MeV) up to a fluence of 1.0 × 1016 ions/cm2 at both sample sides. A beam degrader was located inside the irradiation chamber to distribute the ions homogeneously in the target volume. The mechanical responses of these materials were examined for application as breeding blankets in nuclear fusion reactors, and their behavior after implantation was compared with similar bars in the as-received condition. Compressive and micro-indentation tests were carried out, obtaining the samples compressive strength, elastic modulus, hardness, and fracture toughness values. In addition, their relationship with the microstructure was studied by scanning electron microscopy. After ion irradiation, both ceramics show a reduction in compressive behavior. However, if the ceramics are compared with each other, the compressive properties after ion-irradiation are superior in the Al2O3 ceramic. From micro-indentation tests, no change in the material properties (hardness and fracture toughness) due to ion implantation at different depths was evidenced.