【作者】 石岳；

【导师】 迟伟东；

【作者基本信息】 北京化工大学 ， 材料科学与工程， 2010， 硕士

【摘要】 为解决难熔金属氧化物、碳化物在C／C复合材料中的分布的问题,本文以不同原料和工艺制备出3种锆掺杂C／C复合材料。对锆在C／C复合材料中的存在形式、微观形貌、结晶状态、分布情况以及复合材料的抗氧化性能等进行了研究,主要工作如下：1、以氧氯化锆为原料合成了含锆液相先驱体,并以其为浸渍剂对不同初始密度的纯C／C复合材料进行锆掺杂处理,研究了其密度和ZrO2含量的变化规律,锆在复合材料中的存在形式及分布状态和抗氧化性能。结果表明：先驱体于1000℃和1600℃处理后完全转化为纳米ZrO2晶体和纳米ZrC晶体且均匀分布于材料的表面、基体中与碳纤维表面。ZrC是在高温处理过程中是以液相反应机制生成的。所制备的C／C-纳米ZrO2和C／C-纳米ZrC复合材料的抗氧化性能得到明显提升。2、以醋酸锆溶液和石油沥青为原料,制备出ZrO2含量高达70%的C／C-纳米ZrO2复合材料和C/ZrC复合材料,对其致密化规律、材料中锆的存在形式和分布状态、高温下的抗氧化性能进行了研究。结果表明：锆经1000℃和1600℃处理后完全转化为单斜纳米ZrO2晶体和立方纳米ZrC晶体且均匀分布于材料的基体中与碳纤维表面。ZrC是以液相反应机制生成的。纳米ZrO2不仅会与C／C复合材料中的基体碳相互作用,同时能和增强体碳纤维相互作用,使纤维表面产生缺陷和孔洞,降低部分纤维的增强作用。3、合成出苯甲酸氧锆,并以其为锆源制备出不同锆含量的改性沥青,研究了锆含量对改性沥青性能的影响。以锆含量为3%的改性沥青制备出锆掺杂C／C复合材料,研究了锆在C／C复合材料中的存在形式和分布状态以及抗氧化性能。结果表明：改沥青软化点和粘度随锆含量增加而增加。经1000℃和1600℃处理后完全转化为单斜纳米ZrO2晶体和立方纳米ZrC晶体且均匀分布于材料的基体中与碳纤维表面,抗氧化性能较纯C／C复合材料有所提升。更多还原

【Abstract】 In order to solve the problems of refractory metal oxide and carbide inhomogeneous distribute in C/C composites. In this paper, three kinds of zirconium doped C/C composites were prepared by different materials and processes. The existing form、micro-morphology、crystalline state and distribution of zirconium in C/C composites were researched. The anti-oxidation behaviors of zirconium doped C/C composites were also studied.1、Taking zirconium oxchloride as the raw material, the liquid precursor solution containing zirconium was synthesized. The pure C/C composites with different densities were added with zirconium by vacuum impregnation method. The densities and contents of ZrO2 in the C/C composites were researched. The existence form and distribution of zirconium in the material were studied. The anti-oxidation performance of zirconium doped C/C composites was studied. The results showed that the liquid precursor containing zirconium was entirely converted into nano-ZrO2 and nano-ZrC, after treated at 1000℃and 1600℃. They distributed in surface of material, the inner matrix and the carbon fiber surface evenly. The ZrC was generated by liquid-phase reaction mechanism at high temperature.Compared with pure C/C composites, the anti-oxidation performance of C/C-nanoZrO2 and C/C-nanoZrC composites has improved significantly.2、Taking zirconium acetate solution and petroleum pitch as raw materials, the ZrO2 content up to 70% of the C/C-nanoZrO2 composites and C/ZrC composites was prepared by impregnation method. The densification law and anti-oxidation performance of the material was researched. The existence form and distribution of zirconium in the material were studied. The results showed that the doped zirconium was entirely converted into monoclinic crystal nano-ZrO2 and cubic crystal nano-ZrC after treated at 1000℃and 1600℃. They distributed in the inner matrix and the carbon fibers surface evenly. Compared with pure C/C composites, the anti-oxidation performance of zirconium doped C/C composites has improved significantly. The ZrC was generated by liquid-phase reaction mechanism at high temperature processing. In the process of generated ZrC, the nano-ZrO2 reacts with both the carbon fibers and matrix carbon, made the carbon fibers generate micro-holes and defects and lower the enhanced function of the carbon fibers.3、Zirconium oxybenzoate was synthesized. Taking it as raw materials, different content of zirconium modified pitch were preparation. The influences of zirconium content to the performance of modified pitch were studied. The zirconium doped C/C composites was prepared with zirconium content of 3% modified pitch. The existence form and distribution of zirconium in the material were studied. The anti-oxidation performance of zirconium doped C/C composites was studied.The results showed that the softening point and viscosity of zirconium-contenting pitch were added with the content of zirconium increases. The Zirconium oxybenzoate was entirely converted into nano-ZrO2 and nano-ZrC, after treated at 1000℃and 1600℃. They distributed in the inner matrix and the carbon fiber surface evenly. Compared with pure C/C composites, the anti-oxidation performance of zirconium doped C/C composites has improved.更多还原