高活性集中放热的Al-Mg-Zr合金燃料的制备与性能

Preparation and Performance of High Reactive Al-Mg-Zr Alloy Fuels with Intensive Heat Release

采用紧耦合气雾化法制备了Mg含量为5%~30%的新型Al-Mg-Zr三元合金燃料。用X射线衍射(XRD)、扫描电子显微镜(SEM)/能量分散谱(EDS)和热重-差热分析(TG-DTA)分别表征了合金粉的相组成、形貌和氧化放热行为,并提出了一个氧化反应机制模型,解释合金粉的集中氧化放热现象。结果表明,合金粉的相组成主要有Al、Al_3Mg_2、Al_3Zr和Al_(12)Mg_(17),且粉末具有良好的球形度。随着Mg含量的升高,Al-Mg-Zr合金发生氧化反应的温度明显降低,氧化过程由多步氧化逐渐转变为一步氧化,能量释放量先增后减。Al_(78)Mg_(20)Zr_2和Al_(73)Mg_(25)Zr_2粉末分别在945℃和938℃呈现集中氧化放热,并且Al_(78)Mg_(20)Zr_2粉末的集中氧化反应比较完全,该粉末的最高氧化放热焓为-9798.8μV·s·mg^(-1)。

Ternary Al-Mg-Zr alloy fuels with Mg content ranging from 5% to 30% were prepared by a close-coupled gas atomization. The phase composition, morphology and exothermic oxidation behavior of the alloy powders were characterized by X-ray diffraction, scanning electron microscope（SEM）/ energy dispersive spectrometer （EDS） and thermogravimetry-differential thermal analysis （TG-DTA） respectively and an oxidation reaction mechanism model was proposed to explain the intensive oxidation exothermic phenomenon. Results show that the alloy powders consist of Al, Al3Mg2, Al3Zr and Al12Mg17 mainly, and the powder has good sphericity. With the increasing of Mg content, the oxidation reaction temperature of Al-Mg-Zr alloys decreases, the multi-step oxidation process gradually transforms into single step oxidation process and the energy releasing amount increases first and then decreases. The intensive exothermic oxidations of Al78Mg20Zr2 and Al73Mg25Zr2 powders occur at 945 ℃ and 938 ℃, respectively. The intensive oxidation reaction of Al78Mg20Zr2 powder is relatively complete and the highest exothermic enthalpy of oxidation of the powder is 9798.8 μV·s·mg-1.