3-11 Transmission Electron Microscopy Investigations of Bubble Formation along GBs in He-implanted Polycrystalline SiC

摘要

Because of the low cross-section for neutron capture and its excellent structural, chemical and mechanicalstability, silicon carbide (SiC) is an important material with application in the development of nuclear energyand waste technologies. The (n,) nuclear reaction inevitably introduces numerous He in SiC. Because of the lowsolubility of He atoms in SiC, a certain concentration of He atoms that are trapped in the matrix in the formof helium-vacancy clusters would form bubbles upon annealing. He bubbles would perhaps lead to degradation ofmaterial properties. Especially, He bubbles along Grain boundaries (GBs) can cause embrittlement by intergranularfracture, as usually observed in metals. Therefore, it is important to investigate the nucleation and growth of Hebubbles along GBs in He-implanted SiC.