Mg-α-SiAlON/MgO复合材料中Mg-α-SiAlON的原位合成  

In-situ synthesis of Mg-α-SiAlON in Mg-α-SiAlON/MgO composites

作　　者：刘新 曲殿利 郭玉香 LIU Xin;QU Dianli;GUO Yuxiang(School of High Temperature Material and Magnesite Resources Engineering,University of Science and Technology Liaoning,Anshan 114051 , China)

机构地区：[1]辽宁科技大学高温材料与镁资源工程学院,鞍山114051

出　　处：《复合材料学报》2019年第3期677-684,共8页Acta Materiae Compositae Sinica

基　　金：国家科技支撑计划项目(2014BAB02B01;2014BAB02B03)

摘　　要：为改善低品位Mg基材料高温性能,采用烧结Mg砂、金属Al粉、单质Si粉和Al_2O_3粉为主要原料,制备了Mg-α-SiAlON/MgO复合材料。通过XRD、SEM及EDS等检测手段,研究了不同原料质量分数及氮化温度条件下Mg-α-SiAlON/MgO复合材料中Mg-α-SiAlON的原位合成,结合热力学分析确定了合成Mg-α-SiAlON的气氛条件并分析了合成Mg-α-SiAlON的反应机制。结果表明:1 550℃时的氮、氧分压满足合成Mg-α-SiAlON的热力学条件。当烧结Mg砂粉、Al粉、Si粉和Al_2O_3粉的质量分数之和为40wt%时,1 550℃保温3h氮化后的Mg-α-SiAlON/MgO复合材料中板片状Mg-α-SiAlON相生成量最高可达32.1%,且相互交错构成骨架,将低熔点物相包裹其中。利用烧结Mg砂原位氮化制备Mg-α-SiAlON/MgO复合材料,有利于提高Mg基材料的抗热震性能。In order to improve the high temperature properties of low grade magnesium-based material,Mg-α-SiAlON/MgO composites were prepared using sintered magnesia,Al metal powder,Si powder and Al2O3 powder as the raw material,the Mg-α-SiAlON phase in-situ forming in the Mg-α-SiAlON/MgO composites sintered at different temperature and mass fraction were determined by XRD,SEM and EDS.The synthesis atmosphere conditions of Mg-α-SiAlON were determined by thermodynamic analysis and the reaction mechanism of Mg-α-SiAlON phase were explained.The experiment results show that the partial pressure of nitrogen and oxygen at 1 550℃ satisfies the thermodynamic requirement for the synthesis of Mg-α-SiAlON.When the total mass fraction of sintered magnesia powder,Al metal powder,Si powder and Al2O3 powder is 40 wt%,the content of Mg-α-SiAlON phase with plate-like shape is as high as 32.1%in Mg-α-SiAlON/MgO composites nitrided at 1 550℃for 3 h.Mg-α-SiAlON phase interlace to form a skeleton and envelope the low melting phase inside of it.The in-situ synthesis of Mg-α-SiAlON/MgO composites from sintered magnesia by nitridation is beneficial for improving the thermal shock resistance of magnesium-based material.

关 键 词：Mg-α-SiAlON MGO 复合材料 微观形貌 反应机制 

分 类 号：TB332[一般工业技术—材料科学与工程]