科研之友
微信
新浪微博
Facebook
分享链接
摘要
In this study, titanium carbonitride composite powders containing iron were prepared via carbothermal reduction of ilmenite. Reduction was investigated in temperature-programmed and isothermal reduction experiments in a tube reactor with continuously flowing nitrogen. The phase transformation, chemical composition, microstructure and morphology of reduced samples were investigated by using X-ray diffraction, chemical nonmetal analysis, energy disperse spectroscopy, and scanning electron microscopy CO and CO2 contents in the off-gas were measured online using infrared sensors. The results confirm that reduction of ilmenite to metallic iron completed in the solid-solid reaction stage. Iron melted lower than its theoretical temperature due to carburization and further penetrated into titanium carbonitride interstice. There was no reaction occurred between iron and titanium phases in the whole process. Titanium nitride formed at 1000 degrees C. Formation of cubic phase is beneficial to grain refinement especially can be observed at 1200 degrees C when no intermediate titanium oxides existed. Reaction rate in the solid-gas step was faster, which was attributed to involvement of CO in the reduction reactions. Titanium carbonitride powders with fine grain size agglomerated and shrank in the final diffusion stage.
- 出版日期2012
- 单位重庆大学
