氧化铝基纤维复合泡沫陶瓷制备工艺的研究

发布时间：2018-06-05 22:28

本文选题：氧化铝泡沫陶瓷 + 凝胶注模　；参考：《山东理工大学》2015年硕士论文

【摘要】：氧化铝泡沫陶瓷具有耐高温、耐腐蚀等优异性能,有希望作为较理想的耐高温隔热材料,用于冶金、化工及航空航天工程中一些易被高温气流烧蚀的关键部位。本文分别研究了有机单体凝胶-发泡以及无机胶粘剂(磷酸二氢铝)发泡注凝工艺制备氧化铝泡沫陶瓷。主要实验工作和结论如下：有机单体凝胶-发泡工艺制备氧化铝泡沫陶瓷(1)在pH=9附近时,当分散剂外加量小于0.4 wt%时,陶瓷浆料的粘度减小,大于0.4 wt%时,粘度变大,流动性变差；当固含量小于68 wt%时,陶瓷浆料的粘度变化较小,流动性好,大于68 wt%时,浆料粘度急剧升高,流动性变差。因此,分散剂外加量为0.4 wt%,固含量为68 wt%时浆料的流动性能满足凝胶注模的要求。(2)坯体强度随着单体／交联剂比例的增大而不断增大。烧结后泡沫陶瓷的气孔率先减小后增大,抗压强度和体积密度(Db)先增大后减小。(3)随着固含量的增加,氧化铝泡沫陶瓷的气孔率不断减小,抗压强度以及体积密度(Db)不断增大。无机胶粘剂(磷酸二氢铝)发泡凝胶工艺制备氧化铝泡沫陶瓷(1)由XRD谱图分析可知,烧结后试样是由α-Al2O3、C-AlPO4以及T-AlPO4三种物相组成。(2)纤维外加量的增加,浆料的粘度不断增大,抗压强度和体积密度(Db)减小,气孔率增大。当氧化铝纤维外加量超过20 wt%时,抗压强度和体积密度(Db)增大,气孔率减小。随着烧结温度和保温时间的增加,纤维断面凹凸不平,表面粗糙程度增大(3)随着Al(OH)3外加量的不断增加,坯体的抗压强度不断增大；试样的气孔率不断减小,体积密度(Db)不断增大,导热系数、抗压强度不断曾大,超过15 wt%后导热系数、抗压强度减小。(4)抗压强度和体积密度(Db)随着烧结温度的升高而增大,气孔率不断降低。(5)当保温时间为4h时,体积密度(Db)、抗压强度最大,气孔率最小。随着保温时间的延长,材料的抗压强度不断降低,体积密度(Db)也随之降低,气孔率升高。
[Abstract]:Alumina foam ceramics have excellent properties such as high temperature resistance, corrosion resistance and so on. It is expected to be used as an ideal high temperature insulation material for metallurgical, chemical and aerospace engineering, which can easily be ablated by high temperature airflow. The preparation of alumina foam ceramics by organic monomer gel-foaming and inorganic adhesive (aluminum dihydrogen phosphate) foaming was studied in this paper. The main experimental work and conclusions are as follows: when the organic monomer gel-foaming process is used to prepare alumina foam ceramics, when the amount of dispersant is less than 0.4 wt%, the viscosity of ceramic paste decreases when the amount of dispersant is less than 0.4 wt%, and the viscosity becomes larger when the amount of dispersant is less than 0.4 wt%. When the solid content is less than 68 wt%, the viscosity of ceramic paste is small, and the fluidity is good. When the content of solid is less than 68 wt%, the viscosity of the slurry increases sharply and the fluidity becomes worse. Therefore, when the amount of dispersant is 0.4 wtlong and the solid content is 68 wt%, the fluidity of the slurry can meet the requirement of gel-casting.) the strength of the billet increases with the increase of monomer / crosslinking agent ratio. After sintering, the porosity of alumina foam ceramics first decreases and then increases, and the compressive strength and bulk density increase first and then decrease. 3) with the increase of solid content, the porosity of alumina foam ceramics decreases, and the compressive strength and bulk density of alumina foam ceramics increase. Inorganic adhesive (aluminum dihydrogen phosphate) foaming gel process to prepare alumina foam ceramic (1) from the XRD spectrum analysis, the sintered sample is composed of 伪 -Al _ 2O _ 3, C-AlPO _ 4 and T-AlPO4, the added amount of fiber is increased, and the viscosity of the paste is increasing. The compressive strength and bulk density decreased and the porosity increased. The compressive strength and bulk density of alumina fiber increase and the porosity decreases when the added amount of alumina fiber exceeds 20 wt%. With the increase of sintering temperature and holding time, the fiber section is uneven and the surface roughness increases. With the increase of Al(OH)3 addition, the compressive strength of the billet increases, and the porosity of the sample decreases. The volume density (Db) is increasing, and the thermal conductivity and compressive strength are increasing. After 15 wt%, the thermal conductivity and compressive strength decrease. 4) the compressive strength and bulk density increase with the increase of sintering temperature. When the holding time is 4 h, the volume density and the porosity are the largest and the lowest. With the prolongation of the holding time, the compressive strength of the material decreases, the bulk density decreases, and the porosity increases.
【学位授予单位】：山东理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ174.6

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