【摘要】 中子吸收球是应用于四代核能高温气冷堆中吸收中子的关键材料,由于该材料涉及核安全,因此对其组分、结构和性能要求非常严格。利用扫描电镜(SEM)结合能谱分析(EDS)对C-B4C中子吸收球的微观结构特点进行了分析评价。结果显示,作为中子慢化剂的石墨以片状结构存在,并且在吸收球压碎断裂过程中裂纹在大颗粒石墨片层之间扩展。而作为中子吸收剂的B4C颗粒较小,分散在石墨颗粒中。烧结后的吸收球表面存在较多的气孔,通过化学气相沉积(CVD)的碳涂层能够很好地包覆在吸收球表面,并且沉积碳能够渗透到空隙中,封闭表面气孔,形成一种致密的表面结构。更多还原

【Abstract】 Neutron absorption ball is a key material for high temperature gas cooled reactor,a kind of generation IV reactor.Because it is related to the safety of the nuclear power station,the constitution,the microstructure and the properties(both thermal and mechanical) are strictly controlled.The microstructure of the neutron absorption ball has been analyzed and characterized in this paper using scanning electron microscope(SEM) and Energy Dispersive Spectrometer(EDS).It is indicated that the graphite when used as a neutron moderator exists as a layered structure.The cracks propagate and deflect in the layers of the lager graphite particles when the ball is crushed.When used as the neutron absorber,the B4C particles are dispersed among the graphite particles.In the neutron absorption ball,small pores are distributed on the surface after sintering.These pores can be sealed by the carbon coating using chemical vapor deposition(CVD).The deposited carbon can infiltrate into the pores and seal the pores to obtain a surface with a high density.更多还原