微波烧结由于具有高效、快速、绿色等特点越来越受到人们的关注.本文以天然煤粉(C)和硼酸(H3BO3)为原料,在无气氛保护条件下,利用2.45 GHz的TE666单频微波烧结炉,快速碳热还原反应法制备出纳米碳化硼(B4C)粉体.结果发现:当煤粉(C)和硼酸(H3BO3)质量比为3∶1,微波烧结温度为1400~1800 ℃,保温时间为5 min,即可制备出结晶良好的碳化硼(B4C)晶体,调整相关工艺参数可以控制B4C晶体的形貌,如直径为50~150 nm的球形颗粒或碳化硼片状结构,通过改变Na2CO3添加剂含量(3wt%~9wt%),可得到不同尺寸的碳化硼纳米片(边长为200~800 nm),获得传统电阻烧结条件下无法得到的碳化硼(B4C)晶体.
Microwave sintering technique has recently attracted more and more attentions, due to its special heating such as high-efficiency, fast and energy-saving.Boron carbide (B4C) nano-powders were successfully synthesized by microwave sintering through rapid crabon-thermal reduction (RCR), with coal(C) and boric acid(H3BO3) used as raw minerals and in a 2.45 GHz microwave furnace (TE666) without any catalysts or shielding gas atmosphere.As a result, B4C crystals in different morphologies of nanosheets or particles can be obtained by microwave sintering at 1400-1800 ℃ for 5 min, when the weight ratio of coal to boric acid is 3∶1.The morphology of B4C crystals can be controlled by adjusting the relative parameters, obtaining spherical particles with diameter of 50-150 nm or boron carbide lamellar structure.Different sizes of B4C nanosheets with edge lengths form 200 to 800 nm can be obtained by changing the content of Na2CO3 additive (3wt%-9wt%), which can't be achieved by conventional resistance sintering.
参考文献
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%