纳米晶碳化硅（SiC）相比单晶/微米晶SiC可能具有更强的抗辐照能力，有可能作为新的和重要的结构材料被应用在未来的核能系统中，因此近年来关于纳米晶SiC辐照效应的研究开始逐渐引起人们的关注。本项目将在前期Au离子辐照纳米晶SiC研究工作的基础上，继续使用H、C和Kr等质量较轻的离子在室温和高温（900 K）下辐照平均晶粒尺寸为2-6 nm的纳米晶SiC，分别研究：ⅰ）室温离子辐照下纳米晶SiC的非晶化过程；ⅱ）高温离子辐照下纳米晶SiC的晶粒生长行为；ⅲ）离子辐照导致纳米晶SiC模量和硬度等力学参数的变化。通过系统地分析以上材料的结构及力学性质随辐照离子种类和样品原生晶粒尺寸的变化关系，澄清晶粒边界对SiC晶粒非晶化过程的影响，建立高温离子辐照下SiC晶粒的生长模型，并探讨材料的力学性质随离子辐照变化的机理。研究结果将为纳米晶SiC材料在反应堆中的应用提供重要的实验和理论依据。

Nanocrystalline SiC may be more resistant to irradiation as compared to monocrystalline or microcrystalline SiC, and could be used as new and important structural components of advanced nuclear energy systems. As a result, the study of irradiation effects on nanocrystalline SiC is attracting growing attention in recent years. Based on our previous investigations on the nanocrystalline SiC irradiated with Au ions, we propose to further investigate the nanocrystalline SiC irradiated with H, C and Kr ions, the average grain size of which is in the range of 2-6 nm. We will concentrate on: ⅰ) the amorphization processes in nanocrystalline SiC under ion irradiation at room temperature; ⅱ) the growth behaviors of nanocrystalline SiC under ion bombardments at a high temperature (900 K); ⅲ) the changes in mechanical properties of the irradiated nanocrystalline SiC, such as elastic modulus and hardness. By investigating the changes in structures and mechical properties of the irradiated nanocrystalline SiC as functions of ion mass and average grain size of the as-grown samples, we will clarify the effects of grain boundary on the amorphization processes in SiC grains, propose a model to describe grain growth of nanocrystalline SiC under ion irradiation at high temperatures, and also explain the mechanisms of the changes in mechanical properties of the irradiated nanocrystalline SiC. The results of the investigations will have significance for nanocrystalline SiC considered for the use of structural components of advanced nuclear reactors.