利用碳化稻壳原位合成SiC-B4C复合陶瓷粉的研究

为了稻壳更好地被回收利用,以硼酸、石油焦为原料,碳化稻壳为添加剂,采用碳热还原法经1800℃保温50 min原位合成SiC-B 4C复合陶瓷粉(A类试样),研究不同碳化稻壳的添加量(质量分数分别为2.42%、4.96%、7.69%、10.57%和13.61%)对烧后A类试样的相组成、表观形貌、粒度大小的影响;并与B 4C和SiC机械混合制备SiC-B 4C复合陶瓷粉(B类试样)的进行了对比。结果表明:原位合成和机械混合均制备了含B 4C和SiC的复合陶瓷粉;碳化稻壳的添加量为4.96%(w)时,B 4C与SiC物相的衍射峰强度均较高,晶粒生长状况较好,粒度相对最细,d 50=7.624μm;原位合成相比机械混合制备的试样在晶粒界面结合方面存在明显的优势。

In-situ synthesis of SiC-B 4C composite ceramic powders from carburized rice husk

In order to recycle and utilize the rice husk,SiC-B 4C composite ceramic powders(samples A)were in-situ synthesized with boric acid and petroleum coke as raw materials and carburized rice husk as the additive by means of carbothermal reduction at 1800℃for 50 min.The effects of the carburized rice husk addition(2.42%,4.96%,7.69%,10.57%and 13.61%,by mass)on the phase composition,the apparent morphology and the particle size of samples A were studied.Samples A were compared with the SiC-B 4C composite ceramic powders(samples B)prepared by mechanical mixing of B 4C and SiC under the same firing conditions.The results show that the two methods can both synthesize composite ceramic powders containing B 4C and SiC;when the carburized rice husk addition is 4.96%the diffraction peak intensity of B 4C and SiC phases is higher,the grain growth is better,and the crystal grains are the finest,d 50=7.624μm;compared with the mechanical mixing,the in-situ synthesis has obvious advantages in grain interface bonding.