Al_2O_3添加量对锆英石合成ZrN-Sialon的影响

Effect of Alumina Contents on the Synthesis of ZrN-Sialon from Zircon

借助XRD和SEM手段,研究了以锆英石和工业氧化铝为原料,在不同温度下采用碳热还原氮化工艺合成ZrN-Sialon复相材料时,氧化铝添加量对复相材料中Sialon相z值的影响。结果表明:在1 500和1 550℃下,产物形貌以颗粒状的ZrN和长柱状的β-Sialon为主;当Al2O3用量为理论量和过量5%时,Sialon相主要为Si3Al3O3N5(β-Sialon,z=3);当Al2O3用量为过量10%和20%时,Sialon相出现Si2Al4O4N4(β-Sialon,z=4)。在1 600℃下,产物均为ZrN和Sialon相,其中Sialon相转化为具有片状形貌特征的SiAl4O2N4(15R型AlN多型体);增加Al2O3添加量会促进Sialon相的转化。合成ZrN-Sialon复相材料的适宜氧化铝用量为理论量或过量5%,适宜温度为1 550℃。

The effect of alumina contents on the z value in Sialon phase at the synthesis of ZrN-Sialon composites by carbothermal reduction-nitriding of zircon and industrial alumina under various temperatures was investigated by XRD and SEM.The results showed that the products at both 1 500 and 1 550 ℃ are mainly granular ZrN and prismatic β-Sialon.When the alumina content is stoichiometric or exceeding 5%,Sialon phase exists in the type of Si3Al3O3N5（β-Sialon,z=3）,and when exceeding 10% or 20%,it is in the type of Si2Al4O4N4（β-Sialon,z=4）.The products at 1 600 ℃ are ZrN and Sialon,and Sialon phase transforms to 15R-SiAl4O2N4 which has plate-like morphology.Increasing alumina content can promote the transformation of Sialon phase.The proper alumina content is stoichiometric or exceeding 5% and the optimizing synthesizing temperature is 1 550 ℃.