【摘要】 研究了PAN基碳纤维浸渍不同硼化物溶液进行高温热处理后(2500℃)对力学性能的影响。采用扫描隧道显微镜观察了渗硼处理对碳纤维表面微观形态结构的影响,同时还采用X-ray衍射技术分析了渗硼处理对纤维结构参数的影响。结果表明渗硼处理可提高CF的力学性能,采用硼化物A浸渍热处理后CF的模量和强度分别提高了10.3%和15.3%。通过STM观察可以很清楚看到渗硼处理可提高CF的择优取向和晶体尺寸,减少表面缺陷。X-ray衍射分析结果与STM一致,渗硼热处理提高了CF的晶体尺寸。更多还原

【Abstract】 A PAN-based precursor carbon fiber (carbonized at 1300℃) was impregnated with different borides and heat-treated at 2500℃ under nitrogen atmosphere. The mechanical properties of the resulting graphite fibers have been measured and their microstructure investigated by X-ray diffraction (XRD) and scanning tunneling microscope (STM). It is shown that boron-doping improves the tensile modulus and strength of the fibers. This can be explained by the STM observations, which show smoother surface with fewer defects and improved crystallite orientation along the fiber axes for the boron-treated samples. The result of XRD shows that the boron-doping treatment increased the crystallite size.更多还原