Abstract In the present work, neutron irradiation effects on swelling were investigated for hexagonal boron nitride (hBN) and hexagonal boron nitride-titanium diboride (hBN-TiB2) composites. hBN and hBN-TiB2 composites were irradiated by reactor neutrons which include thermal, epithermal and fast neutrons at the central thimble of the reactor. The fast neutron (En > 0.1 MeV) and thermal neutron (En∼ 0.025 eV) fluxes were 1.44 × 1016 m−2 s−1 and 6.48 × 1016 m−2 s−1, respectively. The samples were induced by reactor neutrons up to total dose of 5.7 × 1020 m-2. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses were carried out before and after irradiation of the samples. The lattice parameters and unit cell volumes were determined. The swelling percentages were calculated for hBN and hBN-TiB2 samples. For reactor neutrons irradiation, maximum swelling percentages were 4.29% for hBN and about 4.22% for hBN-TiB2 at the maximum exposed neutron dose. Furthermore, phase transition was observed from TiB2 to TiN phase in hBN-TiB2 composites with neutron irradiation. An experimental study was performed on hBN and hBN-TiB2 for nuclear applications (neutron detectors, control rods etc.).

中文翻译：

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中子诱导六方氮化硼和六方氮化硼-二硼化钛复合材料的溶胀

摘要 在目前的工作中，研究了中子辐照对六方氮化硼 (hBN) 和六方氮化硼-二硼化钛 (hBN-TiB2) 复合材料膨胀的影响。hBN 和 hBN-TiB2 复合材料受到反应堆中子的辐照，中子包括反应堆中心套管处的热中子、超热中子和快中子。快中子 (En > 0.1 MeV) 和热中子 (En∼ 0.025 eV) 通量分别为 1.44 × 1016 m-2 s-1 和 6.48 × 1016 m-2 s-1。样品由反应堆中子诱导，总剂量高达 5.7 × 1020 m-2。在辐照样品之前和之后进行扫描电子显微镜（SEM）和X射线衍射（XRD）分析。确定晶格参数和晶胞体积。计算 hBN 和 hBN-TiB2 样品的溶胀百分比。对于反应堆中子辐照，在最大暴露中子剂量下，hBN 的最大溶胀百分比为 4.29%，hBN-TiB2 的溶胀百分比约为 4.22%。此外，在中子辐照下，hBN-TiB2 复合材料中观察到从 TiB2 到 TiN 相的相变。对用于核应用（中子探测器、控制棒等）的 hBN 和 hBN-TiB2 进行了实验研究。