燃烧合成生成的氮化钛的形貌演化

Morphology Evolution of Titanium Nitride Formed by Combustion Synthesis

采用Al-Fe-Ti-BN体系,通过燃烧合成反应生成了不同形状的氮化钛(TiNx)颗粒,讨论了TiNx颗粒的形貌演化规律和机制。结果表明,当化学计量比x较低时,{111}晶面较为稳定,此时TiNx为八面体形状。随着化学计量比x的增加,{111}晶面能稳定性下降,{100}晶面开始出现,TiNx的生长形貌由八面体转变为切角八面体。同时,TiNx的{100}晶面在高温下逐渐转变为曲面,并且随着化学计量比x的继续增加,{100}晶面曲面面积增加,TiNx的形貌由切角八面体转变为近球形和球形。

Titanium nitride(TiNx)particles with different shapes were formed by combustion synthesis reaction of Al-Fe-Ti-BN system.The morphology evolution and mechanism of TiNx particles were discussed.The results show that,when the stoichiometric ratio x is low,the{111}crystal plane is stable,and the TiNx is octahedral.With the increase of stoichiometric ratio x,the{111}plane energy increases and the stability decreases.The{100}crystal plane begins to appear and the growth morphology of TiNx changes from octahedron to tangential octahedron.At the same time,the{100}crystal plane of TiNx is gradually transformed into a curved surface at high temperature.And with the increase of stoichiometric ratio,the area of{100}surface increases.Themorphology of TiNx changes from tangential octahedron to near spherical and spherical.