氧化铝壳层对纳米铝粉的热反应特性影响研究

利用气氛保护管式炉对纳米铝粉分别进行了245℃和450℃的热处理,得到2种不同氧化铝壳层厚度和晶态结构的纳米铝粉Al-245和Al-450。XRD和XPS测试结果表明,Al-245的氧化铝壳层比Al-450薄,且壳层中的γ-Al2O3、θ-Al2O3和ε-Al2O3强度较低。相应的HRTEM表明,Al-245和Al-450都存在明显壳层,且Al-450有2个壳层。在TG-DSC中,氧化铝壳层较薄的Al-245的DSC起始反应温度和峰温分别为554.0℃和559.3℃,均低于Al-450的相应温度559.3℃和586.1℃,反应区间更窄,(Tp-Ton)仅为5.3℃,且初始氧化放热量4 652 J/g也远高于Al-450的1 681 J/g。在500～660℃间,Al-245增重21.3%,高于Al-450的10.1%,且Al-245的氧化速率0.38 mg/s也明显高于Al-450的0.033 mg/s。

Investigation of alumina shell impact on nano-aluminum thermal reaction

In the presence of general nitrogen,heat treatment for nano-aluminum was performed under 245 ℃ and 450 ℃ using tubular furnace.Then,two kinds of nano-aluminum with different alumina shell were prepared,named Al-245 and Al-450 respectively.The results of XRD and XPS reveal that Al-245 has thinner alumina shell than Al-450 whose diffraction intensity of γ-Al2O3,θ-Al2O3 and ε-Al2O3 in the alumina shell were much higher.The HRTEM images show that both the two samples had obvious shell,while Al-450 owning two shells.The results of TG-DSC show that the onset oxidation temperature and the peak temperature of Al-245 are 554.0 ℃ and 559.3 ℃,lower than the corresponding temperatures of Al-450: 559.3 ℃ and 586.1 ℃.The reaction temperature range of Al-245 is thinner,with(Tp-Ton) only 5.3 ℃.In the reaction above,Al-245 release 4 652 J/g,much higher than the heat released by Al-450.Within 500~660 ℃,the weight of Al-245 increase by 21.3%,higher than Al-450 increased weight 10.1%.Besides,the oxidation rate of Al-245 is 0.38 mg/s,much higher than Al-450 oxidation rate 0.033 mg/s.