Yeh Chun-Liang, Lai Kuan-Ling
Department of Aerospace and Systems Engineering, Feng Chia University, Taichung 40724, Taiwan.
Materials (Basel). 2023 Sep 9;16(18):6142. doi: 10.3390/ma16186142.
The fabrication of TiSiC from TiC-containing reactant compacts was investigated by combustion synthesis in the mode of self-propagating high-temperature synthesis (SHS). The initial sample composition was formulated based on (3 - x)Ti + ySi + (2 - x)C + xTiC + zAl, with stoichiometric parameters of x from 0 to 0.7, y = 1.0 and 1.2, and z = 0 and 0.1. For all samples studied, combustion was sufficiently exothermic to sustain the reaction in the SHS manner. Due to the dilution effect of TiC, combustion wave velocity and reaction temperature substantially decreased with TiC content. When compared with the TiC-free sample, the TiC-containing sample facilitated the formation of TiSiC and the TiC content of x = 0.5 produced the highest yield. Excess Si (y = 1.2) to compensate for the evaporation loss of Si during combustion and the addition of Al (z = 0.1) to promote the phase conversion were effective in improving the evolution of TiSiC. All final products were composed of TiSiC, TiC, and TiSi. For the TiC-containing samples of x = 0.5, the weight fraction of TiSiC increased from 67 wt.% in the sample without extra Si and Al to 72 wt.% in the Si-rich sample of y = 1.2 and further up to 85 wt.% in the Si-rich/Al-added sample of y = 1.2 and z = 0.1. As-synthesized TiSiC grains were in a thin plate-like shape with a thickness of 0.5-1.0 μm and length of about 10 μm. TiSiC platelets were closely stacked into a layered structure.
通过自蔓延高温合成（SHS）模式下的燃烧合成法，对由含TiC的反应物坯体制备TiSiC进行了研究。初始样品组成基于(3 - x)Ti + ySi + (2 - x)C + xTiC + zAl进行配制，其中化学计量参数x为0至0.7，y = 1.0和1.2，z = 0和0.1。对于所有研究的样品，燃烧放热足够维持SHS方式的反应。由于TiC的稀释作用，燃烧波速度和反应温度随TiC含量大幅降低。与不含TiC的样品相比，含TiC的样品促进了TiSiC的形成，且x = 0.5的TiC含量产生的产率最高。过量的Si（y = 1.2）以补偿燃烧过程中Si的蒸发损失以及添加Al（z = 0.1）以促进相转化，对改善TiSiC的析出有效。所有最终产物均由TiSiC、TiC和TiSi组成。对于x = 0.5的含TiC样品，TiSiC的重量分数从不含额外Si和Al的样品中的67 wt.%增加到y = 1.2的富Si样品中的72 wt.%，在y = 1.2和z = 0.1的富Si/添加Al的样品中进一步增至85 wt.%。合成的TiSiC晶粒呈薄板状，厚度为0.5 - 1.0μm，长度约为10μm。TiSiC薄片紧密堆叠成层状结构。
