单晶SiC经氦离子辐照及退火的微观组织结构研究
Microstructural Investigation of Single Crystal SiC after Helium Ion Irradiation and Post-irradiation Annealing
Abstract
SiC具有高的熔点、耐腐蚀性和热导率，以及低的热膨胀系数和热中子吸收截面等优点，是核电领域重要的候选材料。嬗变反应和氘氚反应产生的氦原子在SiC中的溶解度低，容易团聚形成大尺寸气泡，从而造成其机械性能退化，影响其服役寿命。本论文采用氦离子辐照模拟中子辐照对单晶6H-SiC进行了400keV的氦离子辐照并退火，采用TEM和SEM研究了微观结构的演变行为与规律。 在400℃下辐照1×1016He+/cm2剂量的氦离子并退火后，辐照态和900℃退火30min的试样中没有观察到明显尺寸的气泡，而在900℃退火15h后形成了稀疏分布的气泡簇和缺陷。1200℃退火30min后试样中形成了大量的气泡簇，其... SiC has the advantages of high melting point, corrosion resistance and thermal conductivity, as well as low coefficient of thermal expansion and thermal neutron absorption cross section, which is an important candidate material in nuclear power field. Because of the low solibility of helium ions produced by transmutation reaction and deuterium-tritium reaction, aggregation occurred and then large ...