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以Al-B_2O_3粉末为原料,在氩气的保护下进行球磨,制备了Al_2O_3-Al B_(12)复合陶瓷粉体。对球磨不同时间的粉末进行X射线衍射(XRD)、差示扫描量热仪(DSC)和扫描电镜(SEM)检测,分析了混合粉末的物相变化、燃烧反应的临界温度变化以及混合粉末的结构变化,通过热力学计算,分析了球磨过程中化学反应发生的规律以及球磨对化学反应的影响及作用。研究结果表明:物相在球磨8 h内物相没有变化,球磨10 h时出现Al_2O_3和Al B12物相;球磨不同时间的粉末,其燃烧反应的临界温度随球磨时间的延长而下降;球磨8 h内粉末经历了塑性变形-冷焊-加工硬化-微断-破碎过程,球磨至10 h发生化学反应生成α-Al_2O_3-Al B12微米级复合粉体;由热力学计算,球磨过程中首先发生2Al+B_2O_3=Al_2O_3+2[B]的自蔓延反应,其放出的热量驱动Al+12B=Al B12的反应。球磨至4 h,反应的临界温度由1010.80℃下降到650.58℃,球磨至8 h临界温度下降到641.84℃,球磨能够促进反应进行。
Al_2O_3-Al B_ (12) composite ceramic powder was prepared by ball milling with Al-B_2O_3 powder under the protection of argon gas. X-ray powder diffraction (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were used to analyze the phase change of the mixed powder, the change of the critical temperature of the combustion reaction and the influence of the mixed powder Through the thermodynamic calculation, the regularity of the chemical reaction in the milling process and the influence and effect of the ball mill on the chemical reaction were analyzed. The results show that the phases of Al 2 O 3 and Al B 12 do not change during ball milling for 8 h, and the phases of Al 2 O 3 and Al B 12 appear during the ball milling. The critical temperature of combustion reaction decreases with the ball milling time. h, the powder underwent plastic deformation-cold welding-work hardening-micro-break-crushing process, and the ball milling to 10 h chemical reaction generated α-Al_2O_3-Al B12 micron composite powder; calculated by thermodynamics, ball milling process occurs first 2Al + B_2O_3 = Al_2O_3 + 2 [B] self-propagating reaction, the emission of heat driven Al + 12B = Al B12 reaction. Ball milling to 4 h, the critical temperature of the reaction from 1010.80 ℃ down to 650.58 ℃, ball milling to 8 h critical temperature down to 641.84 ℃, ball milling can promote the reaction.