自蔓延高温合成TiC-SiC包覆鳞片石墨及其对Al_(2)O_(3)-C耐火材料性能的影响

Self-propagating High-temperature Synthesis of TiC-SiC Coated Graphite Flakes and Its Effect on Properties of Al_(2)O_(3)-C Refractories

以Ti、Si和天然鳞片石墨(GF)为原料,通过自蔓延高温合成法(SHS)在GF表面制备TiC/SiC复合包覆层并用作低碳Al_(2)O_(3)-C耐火材料的新型碳源;利用X射线衍射、扫描电子显微镜和能谱仪对产物物相组成和显微结构进行表征.结果表明:在燃烧波自维持下,GF的最大添加量为38.6%(质量分数),GF表面形成了连续、完整且厚度均匀(约为360 nm)的TiC-SiC包覆层.当用3%(质量分数)的包覆石墨代替GF时,Al_(2)O_(3)-C耐火材料显气孔率最低(12.9%),抗折强度最高(20.7 MPa),氧化脱碳层厚度和熔渣侵蚀深度分别降低41.8%和57.1%,综合性能最佳.

TiC/SiC coated natural flake graphite was used as a new carbon source of low carbon Al_(2)O_(3)-C refractories which was prepared by self-propagating high-temperature synthesis(SHS)using Ti,Si and GF as raw materials.The phase composition of the products was characterized by X-ray diffraction and the microstructure as well as the element distribution were studied via a scanning electron microscopy coupled with an energy dispersive spectroscopy.The effects of the amount of graphite on the reaction were studied.The results show that the maximum amount of GF added is 38.6%(mass fraction)under a self-sustained combustion wave,and a continuous,complete TiC-SiC coating layer with a uniform thickness(about 360 nm)is synthesized on the GF surface.The effects of the amount of the coated graphite on the properties of low carbon AI2O3-C refractories were invetigated.The results revel that the Al_(2)O_(3)-C refractory shows the optimal properties when 3%(mass fraction)coated graphite is used:the lowest apparent porosity(12.9%),the highest cold modulus of rupture(20.7 MPa),and the thickness of oxide decarburization layer and the erosion depth of slag are reduced by 41.8%and 57.1%,respectively.