Dose dependence of helium bubble formation in nano-engineered SiC at 700 °C

JOURNAL OF NUCLEAR MATERIALS

卷:472

Article

Chen, C. -H.¹  Zhang, Y.^1,2  Wang, Y.³  Crespillo, M. L.¹  Fontana, C. L.²  Graham, J. T.^1,4  Duscher, G.¹  Shannon, S. C.⁵  Weber, W. J.¹ 

[1] Univ Tennessee, Dept Mat Sci & Engn, 210 Tandec Bldg,White Ave, Knoxville, TN 37996 USA

[2] Oak Ridge Natl Lab, Div Mat Sci & Technol, Oak Ridge, TN 37831 USA

[3] Los Alamos Natl Lab, Ctr Integrated Nanotechnol, Mat Phys & Applicat Div, POB 1663, Los Alamos, NM 87545 USA

[4] Missouri Univ Sci & Technol, Dept Min & Nucl Engn, Rolla, MO 65409 USA

[5] N Carolina State Univ, Dept Nucl Engn, Raleigh, NC 27695 USA

关键词: SiC;    Helium;    High temperature;    Irradiation effects;    TEM;    ERDA;   

DOI  :  10.1016/j.jnucmat.2016.01.029

来源: Elsevier

【 摘 要 】

Knowledge of radiation-induced helium bubble nucleation and growth in SiC is essential for applications in fusion and fission environments. Here we report the evolution of microstructure in nano-engineered (NE) 3C SiC, pre-implanted with helium, under heavy ion irradiation at 700 degrees C up to doses of 30 displacements per atom (dpa). Elastic recoil detection analysis confirms that the as-implanted helium depth profile does not change under irradiation to 30 dpa at 700 degrees C. While the helium bubble size distribution becomes narrower with increasing dose, the average size of bubbles remains unchanged and the density of bubbles increases somewhat with dose. These results are consistent with a long helium bubble incubation process under continued irradiation at 700 degrees C up to 30 dpa, similar to that reported under dual and triple beam irradiation at much higher temperatures. The formation of bubbles at this low temperature is enhanced by the nano-layered stacking fault structure in the NE SiC, which enhances point defect mobility parallel to the stacking faults. This stacking fault structure is stable at 700 degrees C up to 30 dpa and suppresses the formation of dislocation loops normally observed under these irradiation conditions. Published by Elsevier B.V.

【 授权许可】

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