碳纳米管-铜复合薄膜材料的抗辐照损伤性能研究

Irradiation Tolerance of Cu Nanograins on a Carbon Nanotube Scaffold

利用磁控溅射沉积技术获得的碳纳米管-金属复合材料是一种新型的纳米多孔材料,涂覆碳纳米管-金属复合材料的结构组件在新型核反应堆中具有广阔的应用前景。但是目前的报道中对碳纳米管-金属复合材料抗辐照损伤性能的研究还很少。因此,本工作通过磁控溅射沉积技术,制备了两种不同厚度的碳纳米管-铜复合薄膜,结合室温下的He离子辐照对石蜡基矿物油有机蒸汽的脱氢效应在复合薄膜表面包覆碳层,研究了碳层包覆前后碳纳米管-铜复合薄膜的抗辐照损伤性能。结果表明,随着辐照剂量和辐照温度升高,样品内逐渐产生孔洞等缺陷,且孔洞尺寸较小,这与碳纳米管-铜复合薄膜较高的晶界体积分数和比表面积以及降低的缺陷迁移速率有关。与平面基底上沉积的铜薄膜相比,复合薄膜在室温和高温辐照后,晶粒尺寸明显减小,这与一维碳纳米管基底可显著限制碳纳米管轴向垂直方向上的晶界迁移有关。碳层包覆后的碳纳米管-铜复合薄膜的高温结构稳定性和抗辐照损伤性能明显增强,这得益于碳包覆碳纳米管-铜复合薄膜较高的晶界体积分数和比表面积以及稳定的纳米晶粒。

Carbon nanotube(CNT)-copper(Cu)hybrid deposited by magnetron sputtering technique is a novel nano-porous material,and the CNT-Cu hybrid could be attractive for use in future nuclear reactors by sticking on the structural components.In this work,CNT-Cu hybrids differed in thickness were prepared by means of magnetron sputtering.Combined with the dehydrogenation effect of He ions irradiation on organic vapor of paraffin-based mineral oil at room temperature,carbon layer was coated on the CNT-Cu hybrid.The irradiation tolerance of the hybrid with and without carbon layers are carefully investigated.We found that with irradiation dose and irradiation temperature increasing,voids gradually appear,and the size and density of voids is small,which is related to the high grain boundary volume fraction,specific surface area and low diffusion rate of irradiation-induced defects.The growth in grain size of the CNT-Cu hybrid is much lower than that of the Cu films deposited on the Si/SiO 2 substrate,which is derived from the inhibition of grain boundary migration along the perpendicular to the CNT axial direction.The CNT-Cu hybrid after carbon coating exhibits significantly enhanced thermal structural stability and irradiation tolerance,owing to the high grain boundary volume fraction,specific surface area and stable nano-grains.