Microstructure of neutron irradiation-induced defects in sintered and siliconized SiC
Microstructure of neutron irradiation-induced defects in sintered and siliconized SiC
复制标题
烧结硅化碳化硅中中子辐照诱导缺陷的微观结构
DOI：
10.1016/0022-3115(84)90708-6
复制
发表时间：
1984
影响因子：
3.1
通讯作者：
J. Corelli
中科院分区：
文献类型：
--
作者：
S. D. Harrison;J. Corelli
为了研究10B(n，α)7Li反应生成的氦气的影响，用高压电子显微镜(HVEM)和X射线衍射仪(X-射线衍射仪)研究了掺天然硼和富硼10B和11B的反应烧结碳化硅和反应结合硅化碳化硅的微观结构。X射线研究表明，两种类型的碳化硅在晶胞中都表现出1%的膨胀，而宏观膨胀为3%。对衍射峰的分析得到了强有力的证据，证实了反应结合材料中的贝塔相移到阿尔法相移。对辐照后的10B烧结体进行了Warren-AVerbach峰形分析，其晶体尺寸为150 nm，应变约为0.43%。反应结合碳化硅的特点是在所有的辐照水平下，无论掺杂剂是什么，都以大环(10-200 nm)形式的平面缺陷和位错纠缠为特征。硼烧结的碳化硅中存在许多氦伴生的缺陷，表现为40~90 nm的对称应变场结构。在1773°K下热处理后，反应烧结碳化硅的显微组织没有明显变化，而硼烧结碳化硅的应变场消失。
High voltage electron microscopy (HVEM) and X-ray diffractometry were used to examine the microstructure of boron sintered SiC and reaction bonded siliconized SiC doped with natural boron and with boron enriched in10B and11B to study the effect of helium gas from the10B(n,α)7Li reaction. X-ray studies show that both types of SiC exhibit a 1% swelling in the unit cell as contrasted with 3% macroscopic swelling. Analysis of the diffraction peaks produced strong evidence confirming the beta to alpha phase shift in the reaction bonded material. A Warren-Averbach analysis of the peak profiles of the irradiated10B sintered material shows a crystallite size of 150 nm and a strain in the crystal of ~0.43%. Reaction bonded SiC is characterized by planar defects in the form of large loops (10–200 nm) and dislocation tangles for all irradiation levels regardless of dopant. Boron sintered SiC has many helium associated defects which appear as symmetric strain field structures of 40 to 90 nm dimensions. After annealing at 1773°K, the microstructure of reaction bonded SiC does not change significantly while the strain fields in the boron sintered SiC disappear.