埋炭烧成MgO-Al复合材料中MgAlON的形成  

Formation of MgAlON in MgO-Al composites obtained by carbon embedded firing

作　　者：孙洋[1] 陈树江[1] 田琳[1] 李国华[1] 

机构地区：[1]辽宁科技大学高温材料与镁资源工程学院,辽宁鞍山114051

出　　处：《耐火材料》2016年第6期428-431,共4页Refractories

基　　金："十二.五"科技支撑计划资助项目(2013BAE03B00)

摘　　要：为了研究MgO-Al复合材料中MgAlON相的形成机制,以质量分数分别为70%的镁砂细粉和30%的金属Al粉为原料,在埋炭条件下分别于1150、1350和1550℃保温2h烧成,然后利用XRD和场发射扫描电镜对不同温度烧后试样进行分析和观察。结果表明:(1)在埋炭条件下烧成时,烧成初期金属Al先发生氧化反应;当气相中的氧分压低至一定程度时,金属Al的氮化反应开始进行;AlN生成后,在镁砂颗粒表面与Al_2O_3、MgO和镁铝尖晶石固溶形成MgAlON相。(2)1150℃烧后试样中,在镁砂颗粒表面生成的MgAlON粒径<100nm;随着烧成温度升高,晶粒逐渐长大;1550℃烧后试样中MgAlON的粒径达到1μm左右。To investigate the formation mechanism of MgAlON in MgO-AI composites 70% （by mass）, magnesite fines and 30% metal AI powder were used as the starting materials and carbon embedded fired at different temperatures （1150,1 350,and 1550℃） for 2 h. Then the specimens fired at different temperatures were analyzed and observed by XRD and FESEM. The results show that when firing with carbon em- bedded ,AI oxidizes at the beginning stage of the sintering ;when the partial pressure of oxygen is reduced to certain degree,nitridation of AI begins;the formed AIN reacts with Al2O3, MgO, and magnesium alumi- hate spinel forming solid solution MgAION ;in the specimen fired at 1150℃,the MgAlON grains formed on the surface of the magnesite particles have size 〈 100 nm;as the temperature keeps increasing,the grains grow;in the specimen fired at 1550℃ the grain size of MgAION reaches 1μm.

关 键 词：埋炭烧成 MgO-Al复合材料 MGALON 烧成温度 

分 类 号：TQ175.1[化学工程—硅酸盐工业]