自蔓延高温合成TiC-SiC包覆鳞片石墨对含碳浇注料性能的影响  

Effects of TiC-SiC coated flaky graphite by SHS on properties of carbon containing castables

作　　者：高凯强 肖国庆[1] 陈兴 丁冬海 任耘[1] GAO Kaiqiang;XIAO Guoqing;CHEN Xing;DING Donghai;REN Yun(College of Material Science and Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,Shaanxi,China)

机构地区：[1]西安建筑科技大学材料科学与工程学院,陕西西安710055

出　　处：《钢铁研究学报》2022年第11期1286-1297,共12页Journal of Iron and Steel Research

基　　金：国家自然科学基金资助项目(52272027);陕西省重点研发资助项目(2022GY-421);陕西省教育厅协同创新中心项目(20JY039)。

摘　　要：采用钛粉、硅粉及天然鳞片石墨(GF)为原料,通过自蔓延高温合成法在GF表面制备TiC-SiC复合包覆层(包覆石墨)。通过Zeta电位与润湿角测试,研究了石墨表面涂覆对其分散性与水润湿性的影响。发现当石墨质量分数为38.6%时包覆石墨Zeta电位最低,达到-35.2;与GF和机械混合试样相比,包覆石墨的水润湿角最低,为27°,水分散性与润湿性最优。以石墨质量分数为38.6%的包覆石墨替代Al_(2)O_(3)-SiC-C浇注料中的球型沥青,研究了包覆石墨对Al_(2)O_(3)-SiC-C浇注料性能的影响。研究发现:随包覆石墨代替球型沥青加入量的提高,其热震后抗折强度呈现先增大后减小的趋势,当加入量(质量分数)为1%时,其热震前后的常温抗折强度最高,分别为17.5、8.5 MPa,其残余强度保持率为48.6%。浇注料的高温抗折强度随包覆石墨加入量增加而提高,当包覆石墨的添加量大于1.5%时,其高温抗折强度高于添加质量分数为2%球型沥青的试样,包覆石墨加入量为2%时,高温抗折强度达到2.45 MPa。TiC-SiC composite coating was prepared on GF(flaky graphite) by self-propagating high temperature synthesis(SHS) with titanium powders, silicon powders and natural GF as raw materials. The dispersion and water wettability of the TiC-SiC coated GF were studied by Zeta potential and wetting angle. It was found that when the graphite content was 38.6 wt.%, the zeta potential of the coated graphite was lowest(-35.2);compared to natural GF and mechanical mixed samples, the coated graphite exhibited lowest water wetting angle(27°), and best water dispersion and wettability. The effect of the coated graphite on the properties of Al_(2)O_(3)-SiC-C castables was studied by replacing the spherical asphalt with coated graphite containing 38.6 wt.% graphite. It was found that with the increase of the amount of coated graphite, the flexural strength after thermal shock increased first and then decreased. When the amount of the coated graphite was 1 wt.%, the flexural strength at room temperature before and after thermal shock was highest, which was 17.5 MPa and 8.5 MPa, respectively, and the retention rate of residual strength was 48.6%. The increase of the amount of coated graphite also improved the high-temperature flexural strength of the castables. When the content of the coated graphite exceeded 1.5 wt.%, the high-temperature flexural strength was higher than that of the sample with 2 wt.% spherical asphalt. When the amount of the coated graphite was 2 wt.%, the high-temperature flexural strength reached 2.45 MPa.

关 键 词：自蔓延高温合成 碳化钛-碳化硅包覆层 含碳浇注料 抗氧化性 

分 类 号：TQ175.1[化学工程—硅酸盐工业]