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为了研究不同表面包覆物对纳米铝粉热学行为的影响,采用激光-感应复合加热法制备了三种不同表面包覆的核/壳结构纳米铝粉(氧化铝钝化、碳包覆及增塑剂DOS包覆)。采用高分辨透射电镜(HRTEM)对制备的纳米粉末结构进行表征,并采用差示扫描量热及热重分析(DSC-TG)对不同物质包覆纳米铝粉的热学性能进行研究。结果表明,这些纳米粒子均呈现出明显的核壳结构,且包覆层厚度约3.5nm。这三种不同表面包覆纳米铝粉在400℃至铝熔点(660℃)之间均发生了氧化,但非氧化物包覆纳米铝粉(碳包覆与增塑剂DOS包覆)的氧化开始温度及峰温比氧化铝钝化纳米铝粉提前了约30℃左右,而且氧化放热热焓和氧化质量增重均高于氧化铝钝化纳米铝粉,表明这两种非氧化物表面包覆对纳米铝粉的热学行为有积极的影响。最后对不同物质包覆纳米铝粉的破壳氧化机制进行了探讨。
In order to study the influence of different surface coatings on the thermal behavior of nano-scale aluminum powders, three different surface-coated nano / aluminum nano-powders were prepared by laser-inductive composite heating (aluminum passivation, carbon coating, Plastic DOS coated). The structure of the prepared nano-powders was characterized by high-resolution transmission electron microscopy (HRTEM). The thermal properties of nano-powders coated with different materials were studied by differential scanning calorimetry and thermogravimetric analysis (DSC-TG). The results show that these nanoparticles showed a clear core-shell structure, and the cladding thickness of about 3.5nm. The three kinds of surface-coated aluminum nanopowders oxidized from 400 ℃ to the melting point of aluminum (660 ℃), but the oxidation of non-oxide coated aluminum nanopowders (carbon coating and plasticizer DOS coating) The initial temperature and peak temperature are about 30 ℃ ahead of the alumina passivated aluminum nanopowder, and the exothermic enthalpy of heat and mass gain of oxidative mass are both higher than that of alumina passivated aluminum nanopowder, indicating that the two non-oxide surfaces Coating has a positive effect on the thermal behavior of nano-aluminum powder. Finally, the broken shell oxidation mechanism of nano-aluminum powder coated with different materials was discussed.