矾土基β-SiAlON-刚玉料致密度的研究

Density technical study of bauxite-based β-SiAlON-corundum

以矾土粉、Al粉、Si粉、刚玉颗粒为主要原料,固定β-SiAlON的设计z值=2,SiAlON和刚玉颗粒的设计含量(质量分数)各50%,经混练、成型、干燥后,于1 500℃氮化烧结5 h制成β-SiAlON-刚玉试样,研究了生坯的成型压力、助烧剂Y2O3的加入量以及刚玉颗粒的粒度级配对试样显气孔率和体积密度的影响。结果表明,优化刚玉颗粒的粒度级配,增大成型压力,增加Y2O3的加入量,均可降低合成料的显气孔率,提高其体积密度。用逐次回归分析方法建立了合成料的显气孔率、体积密度与成型压力、Y2O3加入量之间的非线性函数模型,两模型均具有高的可信度,可用于预测矾土基β-SiAlON-刚玉料的显气孔率和体积密度。

Using bauxite, AI, Si powder and corundum grains as main raw materials, designing the z value of β-SiAlON is 2 and both content of SiAlQN and corundum are 50wt% ,the β-SiAlON -corundum specimens by reaction sintering method at 1 500 ℃ 5 h were prepared. The effects of the forming pressure,Y2O3 addition and grading of corundum aggregate for the apparent porosity, bulk density of the specimens were studied. The results show that the apparent porosity decreases and bulk density increases with optimum grading of corundum aggregate,and increase of forming pressure and Y2O3 addition. Stepwise regression method was used to establish nonlinear model relating forming pressure,Y2O3 addition to the apparent porosity and bulk density,and the models are found to be reliable for forecasting the apparent porosity and bulk density of bauxite-based β-SiAION/corundum.