硼酸三甲酯直接热解制备碳化硼

有机溶胶-凝胶技术是目前低温合成超细碳化硼粉体的研究热点。基于该技术直接采用硼酸三甲酯作为热解原料,相比有机溶胶-凝胶技术,省去了形成凝胶这一过程,简化了操作流程。通过X射线衍射和扫描电子显微镜分析,研究了反应温度、压片压力、反应时间以及升温、降温速率对产物纯度和形态的影响。分析结果显示:在以上研究因素中,反应温度及升/降温速率对形成均匀的亚微米尺寸碳化硼起主要作用,并在1 600℃、400℃/min快速升/降温速率下得到了粒径分布在1μm左右的均匀碳化硼产物。

Preparation of Boron Carbide by Direct Pyrolysis of Trimethyl Borate

The organic sol-gel is a research hotspot for the synthesis of ultrafine boron carbide powders at low temperature. Based on this technology, trimethyl borate is used as a raw material for pyrolysis. Compared with organic sol-gel technology, the gel formation process is omitted and the operation flow is simplified. Based on the XRD and SEM analysis of the products, the effects of reaction temperature, reaction time, tableting pressure and rising-cooling rate on the purity and morphology of the products were further investigated. The analysis results show that among all the above research factors, the reaction temperature and rising-cooling rate play a major role in the formation of uniform and submicron-sized boron carbide products. Uniform boron carbide products with a particle size distribution of about 1 μm are obtained at a high temperature of 1 600 ℃ and a rapid rising-cooling rate of 400 ℃/min.