二硼化铝在空气与水介质中的热氧化特性研究

Study on thermal properties of aluminum diboride in air and water medium

研究二硼化铝(AlB_(2))在空气、水两种环境中的热氧化特性,采用扫描电子显微镜(SEM)、氧弹量热仪和热重分析-差示扫描量热法(TG-DSC)对AlB_(2)进行形貌、燃烧热值和在空气、水两种环境气氛中的热氧化特性和动力学研究。研究结果表明,AlB_(2)微观聚集态为不规则球型,颗粒表面呈层状结构。氧弹法实测燃烧热达到了36.05kJ·g^(-1),高于无定形硼(提高119.42%)。空气氛围下AlB_(2)的氧化起始温度、反应效率、反应速率高于无定形硼,活化能相较无定形硼降低了约100kJ·mol^(-1)。水蒸气氛围下,AlB_(2)的氧化可分为铝氧化和硼氧化两个阶段,其中铝氧化阶段的反应起始温度较铝单质降低了约170℃,硼氧化阶段的反应速率高于无定形硼。

In order to study the reactivity of aluminum diboride(AlB_(2))in air and water,SEM,oxygen bomb calorimeter and TG-DSC were used to analysis the morphology,combustion calorific value,thermal oxidation characteristics and kinetic studies of AlB_(2)in air and water atmospheres.The resultsshowed that the morphology of AlB_(2)was irregular,and the particle surface was non-dense layered structure.The measured combustion heat of AlB_(2)was higher than amorphous boron(B)and spherical aluminum(Al),reached 36.05kJ·g^(-1),which was 119.42%higher than B.The oxidation onset temperature,reaction efficiency and reaction rate of AlB_(2)in air atmosphere were higher than B,and the activation energy was 100kJ·mol^(-1) lower than B.In the water vapor atmosphere,both B and AlB_(2)had a weight loss stage,which was mainly caused by the reaction of boron oxide and water vapor to generate gaseous substance.The oxidation of AlB_(2)in water vapor can be divided into Al and B oxidation stages.The initial temperature of the Al oxidation stage was 170℃lower than pure Al,and the reaction rate of B oxidation stage was higher than B.