埋炭热处理温度对低碳MgO-C材料相组成、显微结构与力学性能的影响  

Influence of heat treatment temperature on phase composition,microstructure and mechanical properties of low carbon MgO-C materials in carbon embedded condition

作　　者：伊竟广 朱伯铨[1] 李享成[1] 

机构地区：[1]武汉科技大学耐火材料与高温陶瓷国家重点实验室培育基地,湖北武汉430081

出　　处：《耐火材料》2014年第3期170-173,共4页Refractories

基　　金：国家自然科学基金项目(51174152)

摘　　要：按电熔镁砂、天然鳞片石墨、沥青、Al粉、Si粉的质量分数分别为85.5%、8%、0.5%、4%、2%,外加质量分数4%热固性酚醛树脂为结合剂进行配料,经搅拌均匀后成型,分别在1 000、1 200和1 400℃保温3 h埋焦炭还原气氛下热处理,研究了热处理温度对试样物相组成、显微结构及强度的影响。结果表明:热处理温度为1 000℃时,试样中有长条状Al4C3和呈八面体状的MgAl2O4生成;1 200℃热处理后试样中有纤维状Al4C3、呈八面体状的MgAl2O4及呈片层板状的SiC生成;1 400℃热处理后试样中有针状AlN、纤维状Al4C3、呈八面体状的MgAl2O4及大量的SiC晶须生成,形成了良好的非氧化物结合,使试样具有更高的抗折强度和优异的抗热震性能。MgO-C refractory specimens were prepared using 85.5% （in mass,the same hereinafter） fused magnesia,8% natural flake graphite,0.5% pitch,4% metallic AI powder,2% Si powder,extra adding 4% phenolic resin as binder, batching, stirring, shaping, and carbon embedded firing at 1 000℃, 1 200 ℃, 1 400 ℃ for 3 h, respectively. The influence of heat treatment temperature on phase compositions, microstructure and mechanical strength of the MgO-C specimens were studied. The results show that： after heat treatment at 1 000 ℃,strip-like Al4C3 and octahedral MgAl2O4 form ;after heat treatment at 1 200 ℃,fibrous Al4C3,octahedral MgAl2O4,and plate-like SiC form;after heat treatment at 1 400 ℃, needle-like AIN,fibrous Al4C3,octahedral MgAl2O4 and a large amount of SiC whiskers form,forming good non-oxides bonding, thus endowing the specimens with high MOR and good thermal shock resistance.

关 键 词：镁碳砖 热处理温度 显微结构 抗折强度 抗热震性 还原气氛 

分 类 号：TQ175[化学工程—硅酸盐工业]