【摘要】 研究了W /(Ti+W ) =0 .4 0 ,0 .5 4两种配比的Ti-W -C体系在不同反应条件下的燃烧合成产物相组成及燃烧块断面组织 ;结合燃烧前沿激冷淬熄法 ,分析了其燃烧前沿高温动态反应过程。研究表明 ,体系燃烧过程中存在两种反应模式。熔化 -溶解 -析出机制 :燃烧高温使燃烧前沿Ti粉熔化 ,W、C溶解于熔融Ti中 ,而后 (Ti,W)C从Ti-W -C熔体中析出。扩散 -固溶机制 :当燃烧温度不足以使燃烧前沿Ti粉熔化时 ,C沿燃烧过程中形成的Ti颗粒裂纹快速扩散 ,与固态Ti核反应形成TiC ;同时通过C的扩散 ,W与C反应先形成W2 C ,然后转变成WC ;而后WC固溶至TiC中 ,形成 (Ti,W)C。更多还原

【Abstract】 The phase composition and microstructures of the combustion-synthesized products with ratios of W/(Ti+W) of 0.4 and 0.54 in Ti-W-C system were studied.The kinetic high-temperature reaction process in the combustion front was analyzed through quenching of combustion front.The study results showed that there existed two reaction models.The first is defined as melt-solution-precipitation mechanism;Ti powder in the combustion front is molten at high combustion temperature,W and C are dissolved into liquid Ti,Ti-W-C melt is formed and (Ti,W)C is precipitated from the Ti-W-C melt.The second is described as diffusion-solution-in-solid state;when the combustion temperature is not high enough to melt Ti powder in the combustion front,C diffuses rapidly along cracks formed during combustion process and reacts with Ti to form TiC,meanwhile W 2C is formed and transformed to WC through C diffusion,then WC is dissolved into TiC to form(Ti,W)C.更多还原