al2o3zro2多孔陶瓷的冷冻干燥法制备 结构及性能分析word格式论文.docxVIP

摘要多孔陶瓷由于其丰富的孔结构、较高的比表面积以及独特的物理表面特性， 对液体和气体介质的选择透过性好，耐高温，耐腐蚀等，被广泛应用于催化剂载 体、净化分离、吸声减震等方面。当前，资源短缺，环境污染日益严重，学者们 也在积极的寻找一种绿色环保的多孔陶瓷的制备方法。本文采用冷冻干燥法成功制备出了具有不同结构的 Al2O3-ZrO2 多孔陶瓷，研 究了水玻璃添加量、浆料浓度、Al2O3/ZrO2 比以及工艺过程中的球磨时间、冷冻温 度、烧结温度、保温时间等因素对多孔陶瓷气孔率、抗压强度以及微观结构的影 响。实验结果表明：在多孔陶瓷的制备过程中，向陶瓷浆料中加入水玻璃粘结剂，能够有效的改 善坯体的强度。研究表明当水玻璃含量为总固相含量 20%左右时，效果最好，AZ2 配方经 1400℃烧结后的气孔率为 65%，抗压强度为 34.8MPa。在其它工艺条件不 变时，随着烧结温度的增大，制品的气孔率逐渐降低，AZ3 配方经 1400℃烧结后 的抗压强度最大，为 38.2MPa；随烧结温度的进一步升高，制品的抗压强度又降低。 AZ4 配方经 1200℃烧结后，样品的气孔率最高为 75%。过长的保温时间会使得抗 压强度增大、气孔率减小。球磨时间为 12h 时，所制得的多孔陶瓷的性能最佳， 抗压强度为 30.2MPa，气孔率为 63.1%，过长的球磨时间对制品性能的影响不大。 浆料浓度对于多孔陶瓷的性能也有显著影响，浆料浓度越高，多孔陶瓷的抗压强 度越高，气孔率越低。通过对比 Al2O3、Al2O3-ZrO2、ZrO2 三种多孔陶瓷，研究发 现随着 ZrO2 含量的增加，气孔率降低，抗压强度升高，但是纯 ZrO2 陶瓷的气孔率 和抗压强度远小于其他几种配方。多孔陶瓷制品的微观形貌主要以片层状结构为主，连接大孔之间的孔壁上分 布很多小孔。多孔陶瓷在纵向上的微观结构基本可以划分为三个区域：致密区、 蜂窝状孔隙区和片层状结构。通过调节各种工艺参数，我们可以有效的控制孔的 结构。关键词：冷冻干燥法；多孔陶瓷；Al2O3；ZrO2AbstractPorous ceramics have excellent mechanical properties and functional characteristics, such as uniform holes, three-dimensional network skeleton structure, high specific surface area, unique surface characteristics, and well temperature and corrosion resistance. Moreover, have good permselectivity and energy absorption effect for liquid and gas. So, they can widely use in the fields of catalyst carrier, purification and separation, shock and sound absorption. With the increasingly severe environmental pollution, the scholars are seeking to find environmentally friendly methods to produce porous ceramics. Among the fabrication techniques for porous ceramic, freeze casting has recently attracted much attention as being a versatile, low cost and environmental friendly process.In this paper, Al2O3-ZrO2 porous ceramics with different structure were prepared by freeze casting process. The influences of sodium silicate content, slurry concentration, Al2O3/ZrO2 ratio, ball-milling time, freezing temperature, sintering temperature and holding time on the porosity, compressive strength and microstructure of the porous ce