【作者】 李兰；

【导师】 刘福田；

【作者基本信息】 济南大学 ， 材料工程（专业学位）， 2018， 硕士

【摘要】 锆溶胶是均匀分散在水中含带电锆微细粒子的胶体溶液,可用于制备ZrO₂薄膜、ZrO₂纤维、ZrO₂气凝胶及ZrO₂陶瓷基复合材料等。这些陶瓷材料在高温隔热、结构增强以及耐化学腐蚀等领域具有广阔的应用前景。本论文采用三种方法制备锆溶胶,通过浓缩优选出高固含量、低流动性的锆溶胶;利用优选出的锆溶胶浸渍莫来石纤维毡,目的是验证所制备锆溶胶的浸渍性能和烧结致密化的效果。本论文采用三种方法制备锆溶胶,研究了不同工艺参数对制备锆溶胶的影响。一、以氧氯化锆为原料,氨水为沉淀剂,氯化铵为底液,硝酸为胶溶剂制备锆溶胶。研究结果表明,以0.3 mol/L NH₃·H₂O为沉淀剂,0.05 mol/L NH₄Cl为底液制备锆溶胶,当胶溶温度为80℃,胶溶时间为8h时,可以制备出澄清、稳定性较好的溶胶。加入表面活性剂0.1 wt%十六烷基三甲基溴化铵（CTAB）有降低溶胶黏度的作用,同时可以增加溶胶的稳定性。二、以氧氯化锆原料,乙酰丙酮为络合剂,乙二胺为沉淀剂制备锆溶胶。研究结果表明,当锆酮比为1:1.3,锆酸比为1:1,反应温度为60℃,反应时间为6h时,可以制备出澄清、稳定性较好的溶胶。加入表面活性剂0.1 wt%CTAB有降低溶胶黏度的作用,同时可以增加溶胶的稳定性。三、以碱式碳酸锆为原料,醋酸为络合剂制备锆溶胶。研究结果表明,当锆酸比为1:1.6,反应温度为60℃,反应时间为6h时,可以制备出澄清、稳定性较好的溶胶。加入表面活性剂CTAB和聚乙烯醇（PVA）均可增加溶胶的黏度和稳定性。通过对浓缩后三种锆溶胶性能的比较,优选出固含量及产率较高的溶胶;并对浓缩后溶胶稳定性及微观结构进行了研究;利用优选出的锆溶胶进行浸渍实验,对氧化锆/莫来石纤维复合材料的致密化过程及微观结构进行了分析。研究结果表明,在溶胶稳定性较好的前提下,以乙酰丙酮锆为前驱体利用溶胶-凝胶法制备锆溶胶的固含量及产率均优于其他两种溶胶。当浓缩时间为10min时,溶胶流动性较大,溶胶黏度达到10mPa·s,固含量达到40%,陶瓷产率达到20.4%。当浓缩时间为12min时,溶胶稳定性下降,易凝胶。加入0.1 wt%CTAB对溶胶颗粒有一定的细化作用,使溶胶颗粒分布更加均匀。利用优选出的溶胶浸渍制备复合材料有利于复合材料内部的致密均匀化。更多还原

【Abstract】 Zirconium sol is a colloidal solution containing charged zirconium-containing fine particles uniformly dispersed in water.It can be used to prepare ZrO₂ films,ZrO₂ fibers,ZrO₂aerogels and ZrO₂ ceramic matrix composites.These ceramic materials have a wide range of applications in high temperature heat insulation,structural reinforcement,and chemical resistance.This article used three methods to prepare zirconium sol.The impregnation experiment was carried out by concentrating zirconium sol which preferably had a high solid content and low flowability.The mullite fiber mat was impregnated with the preferred zirconium sol in order to verify the impregnation performance of the zirconium sol and the effect of sintering densification.In this paper,zirconium sol was prepared by three methods.The effects of different process parameters and preparation conditions on the preparation of zirconium sol were studied.Zirconium oxychloride was used as a raw material,ammonia as a precipitant,ammonium chloride as a base liquid,and nitric acid as a peptizer to prepare zirconium sol.The results showed that zirconium sol was prepared with 0.3 mol/L NH₃·H₂O as precipitant and 0.05 mol/L NH₄Cl as the bottom liquid.When the peptizing temperature was 80°C and the peptizing time was 8 h,the sol was clear and stable.Adding 0.1wt%CTAB surfactant can reduce the viscosity and increase the stability of the sol.Zirconium sol was prepared from zirconium oxychloride as raw material,acetylacetone as complexing agent and ethylenediamine as precipitant.The results showed that when the ratio of zirconic ketone was1:1.3,the ratio of zirconium acid was 1:1,the reaction temperature was 60°C,and the reaction time was 6 hours,it was beneficial to prepare clear and stable sol.Adding 0.1wt%CTAB surfactant can reduce the viscosity and increase the stability of the sol.Zirconium sol was prepared from basic zirconium carbonate as a raw material and acetic acid as a complexing agent.The results showed that when the ratio of zirconium acid was 1:1.6,the reaction temperature was 60°C,and the reaction time was 6 h,it was beneficial to prepare clear and stable sol.Adding surfactants CTAB and PVA can increase the viscosity and stability of the sol.Through the comparison of the performances of the concentrated zirconium sol,the sol with higher solid content and higher yield were selected,and the properties of the concentrated sol were studied.The impregnation experiments with the preferred zirconium sol were performed to study the densification of the composites.The process and microstructure were analyzed.The results showed that the zirconium sol synthesized by sol-gel method with zirconium acetylacetonate as precursor had better solid content and yield than the others.When the concentration time was 10min,the sol viscosity was 10mPa·s,the solid content reached 40%,and the ceramic yield reached 20.4%.When the concentration time was 12 min,the sol was cross-linked,the stability was decreased,and the gel was easy to gel.The addition of 0.1wt%CTAB had a certain refining effect on the sol particles,which makes the sol particles more evenly distributed.The use of a preferred sol dip for the preparation of the composite material facilitates the homogenization of the interior of the composite material.更多还原