燃燒合成反應機構系列探討：鈦-碳-錫反應機構之再探討

• Main Author: 王權毅
• Other Authors: 莊和達
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/17375148018024479942

碩士 === 國立成功大學 === 化學工程研究所 === 85 === 　　In this research, the reaction mechanism of the Ti-C-Sn system was experimentally investigated by combustion synthesis. We try to understand more about the reaction mechanism according to the ignition temperature, ignition phenomena, the XRD spectrums and SEM photographs of the products. 　　When the addition of tin was less than 40wt%, the ignition temperature was not significantly decreased compared to the Ti-C system. This was due to the formation of Sn5Ti6 and SnTi2C before the ignition of reaction. As a result, the ignition of the combustion reaction was controlled by the surface reaction rate. which, in turn, was determined by contact surface area between particles. When the addition of tin was more than 40wt%, the ignition temperature was significantly decreased by the addition of tin. This was explained by the fact that the tin provides an easier route for reactant mass transfer, thus significantly increasing the reaction rate of the reaction between titanium and carbon. Thus, the ignition of the combustion reaction was controlled by the rate of solid-liquid interfacial reaction, which, in turn, was controlled by the area of solid-liquid interface and the concentration of Ti in Sn. 　　The addition of tin not only affected the ignition temperature but also changed the morphology of the product. When more tin was added, more SnTi2C was formed in the product. Fracture surfaces of the product showed that unreacted graphite particles were surrounded by a TiC layer, and SnTi2C was formed far apart the graphite. Besides, when the addition of tin was more than 40wt%, the product inside the pellet was SnTi2C and the product at the edge of the pellet was TiC. 　　As discussed above, a possible reaction mechanism was proposed that describes the ignition process and explains the formation of each type of product.