纳米碳化钒/碳化铬的微波辅助合成及应用

Microwave Assisted Synthesis and Application of Nano Vanadium and Chromium Carbides Composite Powders

以微米级氧化钒(V_2O_5)、氧化铬(Cr_2O_3)和纳米碳黑为原料,采用机械合金化及微波辅助加热法制备了纳米碳化钒/碳化铬复合粉末。利用XRD、XPS、TG-DSC、SEM、TEM和BET对产物进行了分析表征。结果表明,纳米碳化钒/碳化铬复合粉末的最佳合成条件为:碳的质量分数为35%,反应温度为900℃,保温时间为1 h。在该条件下的反应产物主要由V_3Cr_2C_5、Cr_2VC_2和Cr_3C_2组成,颗粒为球形或类球形,分散性较好,无明显团聚现象,平均颗粒尺寸约为50 nm,复合粉末的比表面积为115.53 m^2/g。添加纳米碳化钒/碳化铬复合粉末可以提高陶瓷结合剂cBN磨具的力学性能和磨削效率,并且对磨具有减摩作用,降低磨具的损耗。

Nano-sized vanadium and chromium carbides composite powders were prepared by mechanical alloying assisted microwave heating method using micron size vanadium oxide, chromium oxide and carbon black nanoparticles as raw materials. The products were characterized by XRD, XPS, TG-DSC,SEM, TEM and BET techniques. The results showed that the optimum synthesis conditions of nano vanadium/chromium carbides composite powders were obtained as follows: mass fraction of carbon black35%, reaction temperature 900 ℃, and holding time 1 h. Under these conditions, the reaction products are mainly composed of V3 Cr2 C5, Cr2 VC2 and Cr3 C2. The particles are spherical or nearly spherical with good dispersion and no obvious agglomeration. The average particle size is about 50 nm and the specific surface area is 115.53 m^2/g. The addition of nano vanadium and chromium carbides composite powders can enhance the mechanical properties and grinding efficiency of vitrified bond c BN grinding tool, which reduces the wastage of the grinding tool, and has a good friction-reducing effect.