Y_2O_3对烧结镁砂致密性的影响  

Effect of yttria on densification of sintered magnesia

作　　者：马鹏程[1] 刘涛[1] 袁磊[1] 张令[1] 于景坤[1] 

机构地区：[1]东北大学材料与冶金学院,沈阳110819

出　　处：《材料与冶金学报》2013年第3期173-176,202,共5页Journal of Materials and Metallurgy

基　　金：国家自然科学基金资助项目(50904016;51274059);中央高校基本科研业务费专项资金资助项目(N110402011)

摘　　要：以辽南产菱镁石为原料,先将菱镁石在煅烧炉中900℃煅烧2 h,冷却后得到轻烧氧化镁,然后将轻烧氧化镁按细磨—成型—烧结的工艺流程制备出烧结镁砂.采用差热分析、红外光谱分析、阿基米德排水法、X射线衍射仪和扫描电镜对合成试样的性能和微观结构进行了分析.考察了不同氧化钇添加量对试样性能和显微结构的影响,分析了氧化钇对氧化镁致密性的影响机理.结果表明:氧化钇添加剂使烧结镁砂的体积密度得到了显著的提高,氧化钇添加量为0.5%时,烧结镁砂的体积密度达到了最大值3.41 g/cm3,由于氧化钇的加入,致使氧化镁的烧结过程存在液相烧结,从而促进了MgO的烧结,提高烧结镁砂的体积密度.Y2O3与原料中的杂质相SiO2进行了反应,并生成了少量的Y2Si2O7相,新相的形成,提高了烧结镁砂的m(CaO)/m(SiO2)比以及烧结镁砂的高温使用性能.The light-burned calcined magnesia was prepared at 900 ℃ for 2 h in a calcining furnace by using magnesite from Liaonan as a raw material.After grounding,moulding and sintering,the sintered magnesia was obtained.The specimens were examined with DTA,infrared spectroscope,Archimedes principle,X-ray diffraction and scanning electronic microscope.The influences of different yttria content on the microstructure and property of the specimens were investigated.The influence mechanism of densification of sintered magnesia was analyzed.The results showed that yttria could make a significant improvement to the bulk density of the sintered magnesia.When Y2O3 addition amount was 0.5 %,the bulk density of sintered magnesia reached to a maximum of about 3.41 g /cm3.Due to the addition of yttria,a liquid-phase sintering occurred during the process of magnesia sintering,which accelerated the sintering of magnesia,and improved the densification of magnesia.Through reaction of Y2O3 with SiO2,Y2 Si2O7 was formed.The new phase improved m(CaO) /m(SiO2) ratio and high temperature performance of sintered magnesia.

关 键 词：菱镁石 烧结镁砂 氧化钇 致密性 体积密度 

分 类 号：TQ174.1[化学工程—陶瓷工业]