氧化锆增韧氧化铝（ZTA）纳米复合材料的制备与研究
发布时间：2019-01-25 19:56
【摘要】：本文采用液相共沉淀法从粉体的制备-反应机理研究-粉体表征-烧结-陶瓷表征这一流程系统的研究了氧化锆增韧氧化铝(ZTA)纳米复合材料。首先探索了传统反应器和超重力反应器中制备Al2O2-ZrO2纳米复合粉体的工艺条件,用SEM、TEM、EDS、XRD以及粒度分布测试仪对粉体的形貌、颗粒大小、粒度分布、团聚程度、元素分布均匀性等性能进行了测试和。同时,本文利用现有条件研究了Al2O3-ZrO2纳米复合粉体的成型和烧结工艺条件,以自制粉体作为原料制备了ZTA纳米复合陶瓷材料,并用SEM对陶瓷表面的形貌进行了测试以及用阿基米德原理对陶瓷的密度和开气孔率进行计算分析。根据对粉体以及陶瓷的各项测试,本文最终得到如下结果：(1)在传统反应器中当以ZrOCl2、Y(NO3)3、AlNH4(SO4)2作为反应物,以NH4HCO3作为沉淀剂,PEG 2000作为分散剂(用量为沉淀剂的2wt%),采用反共沉淀法作为制备方法,反应温度选取45℃并不断以700r·min-1速率搅拌进行搅拌,溶液的滴定速率设定为2mL·min-1并且在反应过程中不滴加NH3H2O调节pH,而且经过冷冻干燥后在900℃下进行煅烧。在此条件下得到的粉体结晶度较高,Zr02以四方相存在；Al2O3-ZrO2纳米粉体的形貌为球形,粉体颗粒粒径较小,大约在50nm左右,粒度分布较窄,大约在30-70nm之间,而且粉体中Al元素和Zr分布均匀,没有出现明显的富集现象。(2)超重力旋转床反应器(RPB)的引入解决了传统反应器存在的组分分布不均匀以及团聚问题,提供了一种产物均匀性好,制备周期短,收率高,工艺过程简单的反应器；同时该反应器还克服了由于锆离子和铝离子沉淀所需pH相差过大所引起的组分沉淀不同步以及传统反应器反应对滴定速率限制的弊端。本文系统的研究了超重力反应器中进料速率、转速以及循环次数三个变量对于Al2O3-ZrO2纳米复合粉体性能的影响,得出当进料速率在1000mL·min-1,旋转填充床的转速为1400r·min-1,循环次数为0次时得到的粉体性能最为优异。对比传统反应器中的数据可以发现,超重力旋转床反应器最终得到的粉体具有颗粒形貌更接近球形,颗粒粒径更小(40nm),粒度分布更窄(30-50nm), Al元素和Zr元素分布更加均匀。除此之外,超重力反应器在制备Al2O3-ZrO2纳米复合粉体过程中进料速率更快(500倍),反应时间更短(1/500),能耗更低(1/70),因此,超重力反应器的引入对于大规模制备Al2O3-ZrO2纳米复合粉体具有重大意义。(3)探索了成型压力、粘结剂、烧结温度等工艺条件以及干燥方法、反应器等影响粉体性能的条件对于陶瓷性能的影响,并最终得出结论成型压力为200MPa时有利于陶瓷的烧结,粘结剂的最佳添加浓度为1.5wt%,最佳烧结温度为1600℃。而且性能优异的粉体烧结性能也同样优异,尤其是超重力反应器制备的粉体,在1500℃时即可达到较高的密度和较低的开孔率。
[Abstract]:In this paper, zirconia toughened alumina (ZTA) nanocomposites were studied by liquid phase coprecipitation method from preparation of powders, study of reaction mechanism, characterization of powders, sintering and characterization of ceramics. Firstly, the preparation conditions of Al2O2-ZrO2 nano-composite powder in traditional reactor and hypergravity reactor were studied. The morphology, particle size, particle size distribution and agglomeration degree of the powder were measured by SEM,TEM,EDS,XRD and particle size distribution tester. The uniform distribution of elements and other properties were tested. At the same time, the forming and sintering conditions of Al2O3-ZrO2 nano-composite powder were studied by using the existing conditions. The ZTA nano-composite ceramic material was prepared by using self-made powder as raw material. The morphology of ceramic surface was measured by SEM and the density and porosity of ceramics were calculated and analyzed by Archimedes principle. According to the tests of powders and ceramics, the results are as follows: (1) ZrOCl2,Y (NO3) _ 3AlNH _ 4 (SO4) _ 2 is used as reactant and NH4HCO3 as precipitant in traditional reactor. PEG 2000 was used as dispersant (2 wt% of precipitator), anticoprecipitation method was used as preparation method, reaction temperature was 45 鈩，
本文编号：2415138
[Abstract]:In this paper, zirconia toughened alumina (ZTA) nanocomposites were studied by liquid phase coprecipitation method from preparation of powders, study of reaction mechanism, characterization of powders, sintering and characterization of ceramics. Firstly, the preparation conditions of Al2O2-ZrO2 nano-composite powder in traditional reactor and hypergravity reactor were studied. The morphology, particle size, particle size distribution and agglomeration degree of the powder were measured by SEM,TEM,EDS,XRD and particle size distribution tester. The uniform distribution of elements and other properties were tested. At the same time, the forming and sintering conditions of Al2O3-ZrO2 nano-composite powder were studied by using the existing conditions. The ZTA nano-composite ceramic material was prepared by using self-made powder as raw material. The morphology of ceramic surface was measured by SEM and the density and porosity of ceramics were calculated and analyzed by Archimedes principle. According to the tests of powders and ceramics, the results are as follows: (1) ZrOCl2,Y (NO3) _ 3AlNH _ 4 (SO4) _ 2 is used as reactant and NH4HCO3 as precipitant in traditional reactor. PEG 2000 was used as dispersant (2 wt% of precipitator), anticoprecipitation method was used as preparation method, reaction temperature was 45 鈩，
本文编号：2415138
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