温度梯度对BaAl2O4结合氧化锆不烧制品性能的影响

Effect of temperature gradient on properties of BaAl2O4 bonded zirconia unfired products

以BaAl2O4胶黏剂为结合剂,以不同粒度的Y2O3稳定电熔氧化锆为主要原料制备了BaAl2O4结合氧化锆不烧制品,借助于X射线衍射仪、扫描电子显微镜和能谱仪等,研究了在超高温烘烤过程中温度梯度对BaAl2O4结合氧化锆不烧制品的性能、相组成和显微结构的影响。结果显示:1)高温烘烤过程中,温度梯度显著影响着BaAl2O4结合氧化锆不烧制品各部位的常温物理性能;随温度梯度从热端向冷端过渡,制品体积密度逐渐增大,显气孔率逐渐减小。2)温度梯度影响着制品各部位的相组成,当烘烤温度达到一定温度时,制品中的全稳定ZrO2发生脱溶现象;同时温度梯度影响着制品不同部位BaAl2O4的挥发迁移量,温度越高,BaAl2O4挥发迁移越彻底。3)温度梯度改变了制品各部位的显微结构,随温度梯度从热端向冷端过渡,制品结构由疏松逐渐变得致密。

BaAl2O4 bonded zirconia unfired products were prepared using Y2O3 stabilized fused zirconia of different particle sizes as the main raw material.Effects of the temperature gradient on the properties,the phase composition and the microstructure of the products were studied by means of XRD,SEM and EDS.The results show that:(1)in the process of high temperature baking,the temperature gradient significantly affects the cold physical properties of each part of the products;from the hot end to the cold end,the bulk density of the products increases gradually,and the apparent porosity decreases gradually;(2)the temperature gradient affects the phase composition of all parts of the products;when the baking temperature reaches a certain temperature,the desolution of the completely stabilized Zr2O3 occurs;at the same time,the temperature gradient affects the volatilization and migration of BaAl2O4 in different parts of the products;the higher the temperature,the more the volatilization and migration of BaAl2O4;(3)the temperature gradient changes the microstructure of all parts of the products,from the hot end to the cold end,the products becomes denser.