氮化硅加入量对镁质浇注料力学性能的影响  

EFFECTS OF Si_3N_4 ADDITION ON MECHANICAL PROPERTIES OF MgO-BASED CASTABLES

作　　者：涂军波[1] 魏军从[1] 尹建昌 牛森森[1] 

机构地区：[1]河北理工大学材料学院河北省无机非金属材料重点实验室,河北唐山063009

出　　处：《硅酸盐学报》2009年第12期2012-2017,共6页Journal of The Chinese Ceramic Society

基　　金：河北省自然科学基金(E2009000784);河北省教育厅(2008453)资助项目

摘　　要：以镁砂为主要原料,以硅灰为结合剂,研究了不同氮化硅加入量对镁质浇注料的常温物理性能和高温力学性能的影响,用X射线衍射仪、扫描电镜等对浇注料的物相和显微结构等进行了分析。结果表明:经110℃,24h烘干的浇注料的常温抗压和抗折强度随着氮化硅加入量的增加而降低;经1200℃,3h烧结后的浇注料的常温抗压和抗折强度随着氮化硅加入量的增加先升高后降低,并在氮化硅加入量为3%(质量分数,下同)时达到极值点;经高温(1500℃,3h)烧结后的浇注料的常温抗压和抗折强度随着氮化硅加入量的增加而降低;;烘干后的浇注料的高温(1400℃)抗折强度在氮化硅加入量为3%时达到最大。在加热过程中氮化硅的作用包括两方面:一方面能部分氧化成二氧化硅,进而形成纤维状的镁橄榄石,增大浇注料的强度;另一方面氮化硅保留下来妨碍烧结,导致浇注料的强度降低。The effect of Si3N4 addition on the physical properties at room temperature and hot mechanical properties of MgO-based castable refractory was investigated using magnisia as a main raw material and silica ash as a binder. The phases and the microstructure were analyzed by using X-ray diffractometer and scanning electron microscopy. The results show that the cold compressive strength and rupture strength of the castables dried at 110 ℃ for 24 h decreases with the increase of Si3N4 addition. The cold compressive strength and rupture strength of the castables sintered at 1 200 ℃ for 3 h increases first then decreases with the increase of Si3N4 addition. The cold compressive strength and rupture strength of the castables sintered at 1 500 ℃ for 3 h decreases with the increase of Si3N4 addition , and the high temperature strength （at 1 400 ℃） reaches the maximum when the addition of Si3N4 is 3%. The addition of Si3N4 has two effects, namely, the partially oxidization of SiO2 and the transformation of fibrous forsterite increased the strength and the residual Si3N4 hampered the sintering process, which can reduce the strength.

关 键 词：氮化硅 镁砂 浇注料 强度 显微结构 

分 类 号：TU175[建筑科学—建筑理论]