TiO_2对SHS重力分离法合成陶瓷涂层质量的影响

Effects of TiO_2 Content on Quality of the Ceramic Coating Prepared by SHS Synthesis

研究了在SHS重力分离法制备陶瓷涂层的过程中,TiO_2的添加量对涂层质量的影响。结果表明,陶瓷层中除Al_2O_3、FeAl_2O_4、Al_6Si_2O_(13)等杂相外,还存在FeTiO_3、Ti_3O_5等相;要获得完整且厚度均匀的涂层,反应体系中的TiO_2的添加量需控制在10%以下;随着反应体系中TiO_2添加量的增加,反应速度变慢,冷却后获得的陶瓷涂层的厚度增加,显气孔率下降,致密度提高;随着TiO_2添加量的增加,涂层与基体的结合强度逐渐提高,在8%时达到最大值,而后明显降低。

Effects of TiO_2 content on coating quality were investigated in process of preparing ceramic coating by SHS gravity separation. The results show that the ceramic layer is composed of Al_6Si_20_13, FeAl_20_4, FeTiO_3 and Ti_3O_5, A1_2O_3. To obtain a comolete and uniform thickness of coating, tho a-mount of TiO_2 in the reaction system should be controlled less than 10%. With the increase of TiO_2 content in the reaction system, the reaction rate becomes slow, and the thickness of the ceramic coating is increased, meanwhile, the apparent porosity is decreased, and the volume density is increased. With the increase of the amount of TiO_2, the bonding strength of the coating with the substrate is increased grad- ually, reaching a maximum value at 8%, and then decreased obviously.