复合稳定剂对ZrO_2质定径水口相组成与性能的影响

Effects of Composite Stabilizers on Phase Composition and Properties of ZrO_2 Metering Nozzle

以Mg O、Ti O_2、Y_2O_3和Ce O_2为稳定剂,与单斜氧化锆细粉混合后烧结制备Zr O_2定径水口,利用正交实验研究复合稳定剂对Zr O2质定径水口性能的影响。借助于X射线衍射和扫描电子显微镜,研究了Zr O2质材料的相组成和显微结构的差异,并采用极差分析法,分析各稳定剂对样品稳定程度、耐压强度和抗热震稳定性的影响。结果表明:各样品经1 710℃烧成后,立方相氧化锆含量增加,单斜相含量明显减少,原料中稳定剂的种类和加入量对烧成后样品立方相和单斜相的含量有明显影响。当样品中立方相的含量在30%(体积分数)左右时,氧化锆颗粒呈柱状结构并交错分布,样品耐压强度、抗热震次数分别可达立方相含量过大或者过小的2倍和42倍。复合稳定时,对样品稳定程度和耐压强度影响最大的因素是Ce O2含量,对其热震稳定性影响最大的因素是Mg O含量。最佳复合稳定方案为:Ce O2、Mg O、Y_2O_3和Ti O_2的含量分别为3.0%(质量分数)、3.0%、0和5.0%。

The ZrO2 metering nozzles were fabricated using MgO, TiO2, Y2O3 and CeO2 as stabilizers and ZrO2 fine powders as mainraw materials, and the effects of composite stabilization on the properties of ZrO2 metering nozzle were researched using orthogonalexperiment. Also, the effects of stabilizers on the phase composition and microstructure of ZrO2 materials were studied by X-raydiffraction and scanning electron microscope, and the influences of each stabilizer on the degree of stability, compressive strength andthermal shock resistance of ZrO2 metering nozzle were researched by the method of extremum difference analysis. The resultsshowed that for all samples the content of cubic phase increased after sintering at 1 710 ℃, and the content of the monoclinic phasedecreased obviously, and the type and amount of stabilizers in raw materials played important roles in the contents of cubic andmonoclinic phase. For the samples with 30% cubic phase, the columnar ZrO2 grains interleaves. The values of compressive strengthand times of thermal shock resistance were 1 times and 41 times respectively higher than those of the samples with too much or toolittle cubic phase. The most important factors affecting the degree of stabilization/compressive and thermal shock resistance are thecontents of CeO2 and MgO, respectively. The optimum feed ratio of stabilizer should be 3.0%（in mass fraction） CeO2, 3.0% MgO, 0Y2O3, 5.0% TiO2.