摘要
以球形镁铝合金(Al12Mg17)颗粒为原料,在空气中直接燃烧合成氮化铝(Al N)晶体。实验样品堆积在直径为1cm的区域内,使用乙烷火焰点燃。使用高速摄像仪记录燃烧合成过程。借助XRD和SEM对原料和产物的组成及结构进行分析,并使用TG-DSC分析合金的热力学性质。结果表明:镁铝合金中的铝可以全部转化为AlN晶体。合金的点火温度约为494.4℃,一旦点燃,不需要外界热源的持续加热,样品可持续燃烧。燃烧开始后,合金颗粒中镁快速汽化,与空气中氧发生优先反应,并耗掉颗粒周围的氧气,使氮气进入液态铝表层,生成氮化铝。燃烧产物有明显分层,检测结果表明上层产物为白色氧化镁,下层产物为黑色氮化铝晶体。合成过程中,镁对氮化铝的形成起着积极的促进作用。
Aluminum nitride (AlN) was synthesized by direct combustion of spherical Mg-Al alloy powder in air. The alloy (Al12Mg17) heaped up within a heating area (1 cm in diameter) and was ignited by butane flame. Synthetic process was recorded by a high-speed camera. Morphology and phase makeup of initial powder and combustion products were analyzed by scanning electron microscope and X-ray diffraction. Thermodynamic property of the alloy was analyzed using TG-DSC. The results show that the Al in the Mg-Al alloy powder can be completely transformed to AlN. Ignition temperature of the alloy is about 494.4℃. Once the alloy powder is ignited, self-sustained combustion in the powder can be observed. When combustion begins, Mg can rapidly vaporize and react with oxygen. This oxidation reaction can consume the oxygen around the particles, leading N2 diffusing to the liquid Al layer. Combustion products of the alloy consist of two different layers.The upper white layer contains only MgO and the lower black layer contains only AlN. During synthetic process, the existence of Mg significantly promotes the nitridation of Al.
作者
谢晓
隋颖
黄晓昱
朱晨光
XIE Xiao;SUI Yin;HUANG Xiao-Yu;ZHU Chen-Guang(School of Chemical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2019年第4期439-443,共5页
Journal of Inorganic Materials
基金
国家自然科学基金(51676100)~~
