SiC 对铬铝锆浇注料烧结性能的影响

摘要

为了解决铬铝锆材料在氧化气氛下难以烧结，在还原气氛下烧结工艺复杂且难以控制的问题，研究了SiC 细粉加入量（质量分数分别为0、0．5％、1％和2％）和热处理温度（分别为1450和1550℃）对铬铝锆浇注料烧结性能的影响。结果表明：SiC 在试样热处理过程中氧化形成 SiO（g）和 CO（g），在试样内部营造了还原性气氛，促进了试样的烧结。但是 SiC 颗粒较大，氧化后在材料内部形成了较大的气孔，因此试样的平均孔径随着SiC 细粉加入量的增加而逐渐增大。添加1％（w）SiC 的试样具有最小的显气孔率，最大的体积密度和耐压强度。当 SiC 添加量达到2％（w）时，材料内部产生较大的体积膨胀，性能下降。添加 SiC 的试样在1450℃热处理后具有更高的烧结强度。%Chrome-alumina-zirconia materials are difficult to be sintered in oxidizing atmosphere.Besides, the sintering process in reducing atmosphere is hard to control.I n order to solve these problems,the sinte-ring property of chrome-alumina-zirconia castables containing different amounts of SiC fines (0,0.5%,1%and 2%,by mass)fired at different temperatures (1 450 and 1 550 ℃)was investigated.The results show that SiC is oxidized into SiO(g)and CO(g)during the firing process,which makes reducing atmosphere in the materials,promoting the sintering.But the oxidation of SiC brings big pores in the specimen matrix, so more SiC produces larger median pore diameter.Specimens containing 1% SiC have the lowest appar-ent porosity,highest bulk density and cold crushing strength.With the addition of SiC increasing to 2%,the physical properties decrease due to volume expansion.With the addition of SiC,specimens have higher sintering strength when fired at 1 450 ℃.