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在WO_3-Mg-C-Na_2CO_3体系中,引入NaCl做稀释剂,通过盐助燃烧合成法制备了超细碳化钨(WC)粉体。利用扫描电镜(SEM)、能谱仪(EDS)和X射线衍射(XRD)对产物进行分析,研究了碳(C)含量对制备的WC粉体的形貌、尺寸和相的影响。结果表明:在m=0.125(Na_2CO_3的摩尔数)基础上,将原料中碳的摩尔数从l=2增加到2.25和2.5,浸出前产物由少量大尺寸颗粒及大量小尺寸颗粒组成;浸出后产物是由亚微米小颗粒团聚而成,颗粒之间熔化烧结现象很弱,呈弱团聚状态;浸出产物的粒度分布基本符合正态分布,尺寸在200~350 nm的范围内;在l=2.25条件下,合成的产物主要为目标产物WC,副产物W2C含量极少。即k=2.0(Na Cl的摩尔数),m=0.125,l=2.25为制备单相WC的工艺条件。
In the WO_3-Mg-C-Na_2CO_3 system, the introduction of NaCl as a diluent, by salt combustion synthesis of ultrafine tungsten carbide (WC) powder. The products were analyzed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The effects of carbon content on the morphology, size and phase of WC powders were investigated. The results showed that the mole number of carbon in raw materials increased from 1 = 2 to 2.25 and 2.5 on the basis of m = 0.125 (the number of moles of Na_2CO_3), and the product before leaching consisted of a small amount of large size particles and a large number of small size particles. The product is formed by the agglomeration of sub-micron small particles, the melting and sintering phenomena between the particles are weak, and the particles are in a weak agglomeration state. The particle size distribution of the leached product basically meets the normal distribution with the size ranging from 200 to 350 nm; Under the conditions, the main product of the synthesis of the target product WC, W2C by-product content was minimal. That is, k = 2.0 (the number of moles of NaCl), m = 0.125, l = 2.25 for the preparation of single-phase WC process conditions.