自蔓延高温合成细晶六硼化钙陶瓷粉末(英文)

基于Mg–B2O3–CaO原料体系,采用自蔓延高温合成(self-propagating high-temperature synthesis,SHS)和后期酸处理工艺,制备出高纯度、均匀分布、小粒径的立方晶型细晶六硼化钙粉末。分析了Mg–B2O3–CaO自蔓延高温反应体系的燃烧产物成分及反应机理,测量了不同SHS反应物原始坯体成型压力的燃烧温度曲线,探讨了不同镁掺量和不同气氛对燃烧产物成分和形貌的影响。研究了原始坯体成型压力与最终CaB6产物粒径的关系。结果表明:采用氩气保护能抑制镁挥发;合适的原始坯体压力有利于合成分布均匀的细晶CaB6粉末。

SYNTHESIS OF FINE POWDER OF CALCIUM HEXABORIDE BY SELF-PROPAGATING HIGH-TEMPERATURE METHOD

High-purity and homogeneous powders of calcium hexaboride (CAB6) with small particle size were prepared by self-propagating high-temperature synthesis (SHS) and subsequent acid-cleaning. The phase of the SHS product and the reaction mechanism in Mg-B203-CaO system were analyzed. The combustion temperature curves under different molding pressures of the original SHS reaction body were measured. The effects of Mg content and atmosphere on the phase and morphology of the SHS product were discussed. The effect of molding pressure of the original SHS reaction body on the grain size of the final product was also investigated. The results show that the argon gas atmosphere restricts the Mg volatilization, and a proper molding pressure favors the synthesis of the homogeneous fine powder.