机械合金化法制备超细碳化铌颗粒的研究

发布时间：2018-03-31 21:08

本文选题：机械合金化　切入点：碳化铌　出处：《河北科技大学》2011年硕士论文

【摘要】：本文研究了以铌粉和石墨粉为原料,利用机械合金化(高能球磨)法合成制备超细碳化铌粉体材料的可行性。系统地分析了主要的球磨工艺参数对球磨过程及球磨产物的影响规律,提出了利用合金化的方法调整碳化铌粉体材料密度的技术途径,开展了通过向碳化铌粉末中加入碳化钒粉末,利用球磨法降低碳化铌粉体材料密度的试验研究。进行了向碳化铌粉末中加入金属粉末,利用球磨法探索一种包覆金属粉末的方法。研究结果表明:利用机械合金化法,以铌粉和石墨为原料,球料比30:1、球磨转速300r/min、球磨20h合成制备出超细碳化铌颗粒。在球磨过程中,工艺参数是决定机械合金化的关键。合成制备碳化铌颗粒的实验中,添加1.5%的过程控制剂石墨,使合成制备碳化铌的时间缩短了10h,同时添加过程控制剂球磨得到的粉末粒度更加均匀。当填充率为0.5时球磨的效果好。X射线衍射分析结果说明球磨过程中NbC的形成是靠C原子向Nb晶体中的扩散固溶形成的,是随着球磨时间的增加逐渐形成的。通过JADE软件分析可知,合成制备碳化铌的中间产物依次为Nb2C、Nb4C3、Nb6C5,最后得到NbC。合成制备碳化铌的机理是扩散机制和固溶机制共同作用的结果。碳化铌粉末和碳化钒粉末混合球磨得到的粉末的密度比纯碳化铌粉末的密度小,因此该方法可用来调整碳化铌的密度。随着加入VC粉末比例的增加,所获得的(Nb,V)C复合碳化物粉末的密度减小。碳化铌粉末和金属粉末球磨的方法不能使金属粉末包覆在碳化铌粉末的表面。
[Abstract]:In this paper, niobium powder and graphite powder are used as raw materials. The feasibility of preparing ultrafine niobium carbide powder by mechanical alloying (high energy ball milling) method was studied. The influence of main ball milling parameters on ball milling process and ball milling products was systematically analyzed. The technical approach of adjusting the density of niobium carbide powder by alloying method was put forward, and the vanadium carbide powder was added to the niobium carbide powder. The experimental study on the reduction of the density of niobium carbide powder by ball milling method was carried out. The addition of metal powder to niobium carbide powder was carried out and a method of coating metal powder was explored by ball milling method. The results showed that ultrafine niobium carbide particles were synthesized by mechanical alloying method with niobium powder and graphite as raw materials, ball material ratio 30: 1, ball milling speed 300 r / min, milling time 20 h. The process parameters are the key to mechanical alloying. In the experiment of preparing niobium carbide particles, 1.5% process control agent graphite is added. The time of preparation of niobium carbide was shortened by 10 hours, and the powder size was more uniform by adding process control agent. The effect of ball milling was good when filling ratio was 0.5. The results of X-ray diffraction analysis showed that the shape of NbC in ball milling process. The formation is formed by the diffusion of C atoms into NB crystals. Is gradually formed with the increase of ball milling time. Through the analysis of JADE software, The intermediate product of the synthesis of niobium carbide is NB _ 2C _ (4) C _ (3) N _ (4) C _ (3) N _ (b) C _ (5), and finally, NbC is obtained. The mechanism of synthesis and preparation of niobium carbide is the result of the joint action of diffusion mechanism and solution mechanism. The density is smaller than that of pure niobium carbide, So this method can be used to adjust the density of niobium carbide. The density of niobium carbide powder and metal powder can not be coated on the surface of niobium carbide powder by ball milling.
【学位授予单位】：河北科技大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TB383.3

【参考文献】