片状铝粉的制备及其活性?

采用立式球磨机,在乙酸乙酯溶剂中对平均粒径14μm的球形铝粉进行球磨,制备了具有高活性的片状铝粉。采用激光粒度仪和扫描电子显微镜(SEM)对铝粉球磨前、后的粒度及形貌进行了分析。用X射线粉末衍射(XRD)对铝粉球磨前、后晶型进行了表征,发现球磨2 h后,得到的粒径大小为1μm的片状铝粉,其晶形与原料铝粉晶形一致。通过氧化还原滴定法测试了球磨前、后铝粉中活性铝的质量分数,分别为90.41%和98.42%。采用TG-DSC法对球磨前、后的铝粉进行了热反应特性研究,发现片状铝粉在480~980℃时,氧化增重84.8%,氧化反应活性明显高于原料铝粉。因此,铝粉片状化能够提高推进剂以及火炸药体系的能量。

Preparation and Activity of Flake Aluminum Powder

In order to obtain flake aluminum powder with high activity, a vertical ball miller was employed to mill spherical aluminum powder with average particle size of 14 μm, and ethyl acetate was used as solvent. Morphology and particle size of aluminum powder before and after milling was analyzed using laser size analyzer and scanning electron microscopy ( SEM) . Crystal structure of aluminum powder before and after milling was also characterized by X-ray powder diffraction ( XRD) . It is found that 1 μm flake aluminum powder could be prepared through milling ( ethyl acetate as solvent) for 2 h, and it has the same crystal form as aluminum powder before milling. Furthermore, the mass fraction of active aluminum before and after milling was determined by oxidation-reduction titration reaction, which is 90. 41% and 98. 42% respectively. The thermal reaction characteristics of aluminum powder before and after milling were investigated by TG-DSC method. In TG-DSC test, the weight of aluminum powder after milling increases by 84. 8% between 480 ℃ and 980 ℃, indicating that oxidation reactivity of aluminum is greatly improved by ball-milling. Therefore, the superfining and laminarization of aluminum powder can enhance the energy of propellant and explosive.