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采用双向球磨法,通过控制球磨时间和助磨剂的添加量,制备了具有纳米级晶粒度的Al-Mg合金,该合金很有希望应用为冲击引发含能材料中的固体燃料。结构表征表明,机械合金化处理后得到的 Al0.8Mg0.2呈粒状,且其表面存在大量尺寸约为15～30nm的纳米结构。另外,球磨后材料的晶粒度从原料Al的>100nm降低到Al0.8Mg0.2的 22.7 nm。热分析结果表明,Al0.8Mg0.2合金粒子具有很高的热反应活性。在空气中,Al0.8Mg0.2合金于熔化前就发生了明显的氧化还原反应,而这种固-气相反应在原料 Al 的 DSC 图谱中却没有出现,且Al0.8Mg0.2-O2体系的高温反应放热峰较Al-O2体系提前了33 ℃。从TG 图谱中可以看出,当加热温度达到1100 ℃后,有69.13%的 Al0.8Mg0.2被空气中的 O2氧化,而在相同的条件下原料 Al 只有 15.52%被氧化,可见原料 Al 的氧化效率远低于Al0.8Mg0.2。另外,对于Al0.8Mg0.2-Fe2O3铝热体系,其在合金熔化前也发生了显著的固-固相反应,该反应的活化能比随后的液-固相反应降低了331.664 kJ.mol-1,这表明由 Al-Mg 合金组成的铝热剂应具有优异的点火性能。
Al-Mg alloy with nano-scale grain size was prepared by controlling the ball milling time and adding amount of grinding aid by using the bidirectional ball milling method. The alloy is promising for the application of solid fuel in impact-induced energetic materials. Structural characterization shows that Al0.8Mg0.2 obtained after mechanical alloying treatment is granular, and a large number of nanostructures with sizes of about 15 ~ 30nm exist on the surface. In addition, the grain size of the material after ball milling decreased from> 100 nm of Al as raw material to 22.7 nm of Al 0.8 Mg 0.2. Thermal analysis results show that Al0.8Mg0.2 alloy particles with high thermal reactivity. In the air, Al0.8Mg0.2 alloy before melting occurred obvious redox reaction, and this solid-gas phase reaction in the DSC of the raw material did not appear in the DSC, and Al0.8Mg0.2-O2 system The exothermic peak of high temperature reaction was 33 ℃ earlier than Al-O2 system. From the TG spectrum, it can be seen that when the heating temperature reaches 1100 ℃, 69.13% Al0.8Mg0.2 is oxidized by O2 in the air, while under the same conditions, only 15.52% of the raw material Al is oxidized, and it can be seen that the Al Oxidation efficiency is much lower than Al0.8Mg0.2. In addition, for the Al0.8Mg0.2-Fe2O3 aluminum thermal system, a significant solid-solid reaction took place before the alloy was melted, the activation energy of the reaction was reduced by 331.664 kJ · mol- 1, indicating that the thermite composed of the Al-Mg alloy should have excellent ignition properties.