自蔓延高温合成Al_2O_3-TiC/Fe-Al复合材料的研究

Research on Al_2O_3-TiC/Fe-Al Composite by SHS

以天然钛铁矿为主要原料,采用SHS技术,通过铝热、碳热还原法合成了Al2O3-TiC/Fe-Al金属间化合物/陶瓷基复合材料。研究了SHS合成过程中制坯压力、预热时间、稀释剂和碳源对SHS合成过程的影响。研究结果表明:制坯压力在40MPa时,燃烧温度与燃烧波速率出现最大值;随着预热时间的延长,燃烧温度和燃烧波速率都增加,产物中TiC和Al2O3晶体的晶格间距增大,合成更为完全,产物中只包含有TiC相、Al2O3相、Fe-Al相和α-Fe固溶相;稀释剂会降低燃烧温度和燃烧波速率,同时使产物的密度降低,且不利于合成产物的形成;与炭黑相比用石墨做碳源时,燃烧温度、燃烧波速率以及产物的密度都高,反映了碳源结构差异对燃烧合成的影响。

Al2O3-TiC/Fe-Al composited/CMC) was synthesized by in-situ carbothermic and alumino-thermic reduction using natural ilmenite as raw material. The effect of the material-pressure, preheating-time, dilution and carbon sources on the SHS process of the product was studied. It is shown that the temperature and velocity of the combustion wave come to the max value when the material-pressure is about 40MPa; with the prolong of the preheating-time, only TiC phase, Al2O3 phase, Fe-Al phase and α-Fe binder existed in the product; the dilution can decrease the temperature and velocity of the combustion wave, meanwhile, the density of the materials can be also lowered, which is detrimental to form the ultimate product; when graphite is used as the carbon source, the temperature and velocity of the combustion wave as well as the density are higher, which can reflects the effect of the carbon source structure to the combustion synthesis.