The microstructural in-sight to the mechanical behavior of alumina after high energy proton irradiation

Abstract

The mechanical behaviour of prismatic bars extracted from a high purity alumina tube was studied comparatively in the as-received condition and after being irradiated with high-energy protons. For this study, ten samples were irradiated with 8 MeV H+ ion beams up to a fluence of 1.63 × 1016 ions/cm2. Values of compressive strength, elastic modulus, hardness, and fracture toughness were determined from compression and micro-indentation tests. After the mechanical tests, the relationship of the mechanical behaviour shown with the microstructure was considered by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). A clear trend was observed, compressive strength and elastic modulus were considerably reduced, while hardness and fracture toughness increased. This change is attributed to radiation-induced cavities and dislocation loops after high-energy ion-irradiation.

Keywords

• Alpha alumina
• Compression tests
• Micro-indentation
• High-energy proton irradiation
• Fusion breeding blanket
• Flow channel inserts