球磨法制备纳米TiC及其生成机理

Preparation of Nano-TiC by Ball-milling Technique and Its Formation Mechanism

采用高能球磨法制备纳米TiC颗粒,通过对不同球磨时间试样进行X射线衍射分析、扫描电镜及透射电镜进行形貌观察,得出球磨过程中TiC的生成机理。结果表明,球磨过程中,首先石墨和钛粉细化,石墨形成片状而钛粉形成细小颗粒;随着球磨时间的延长,片状石墨包裹钛粉;当磨球碰撞时达到Ti和C反应温度,Ti和C发生反应产生TiC,反应放出的热量维持反应的进行。制备的TiC粒度为10～100nm。

Nano-TiC powder was prepared by a high-energy ball-milling method.The morphologies of the samples milled with different time were analyzed by X-ray diffraction（XRD）,scanning electron microscope（SEM） as well as transmission electron microscopy（TEM）,and the formation mechanism of TiC was presented.The results show that graphite and titanium powder are refined firstly in the milling process,then graphite becomes flake,while titanium powder becomes small particles.And then almost all the titanium powder is wrapped by the flake graphite.When the temperature generated by the collision of ball reaches the reaction temperature of Ti and C,TiC is generated,and the reaction can keep advance with the help of the release heat of the reaction.The size of TiC particles is about 10 ~ 100 nm.