通过置换还原法,快速、简洁、定量地制备出了纳米镍包覆的超细铝粉复合粉末.利用扫描电子显微镜(SEM)、热重分析(TGA)、差示扫描量热(DSC)和X射线衍射(XRD)等分析手段对原料Al粉和复合粉末的形貌及其氧化性能进行研究.结果表明,原料Al粉在1050℃时增重率为122%,当包覆的纳米镍粉质量分数为0.75%时,可以使铝粉在1050℃时的增重率达到135%,并且随着镍粉含量的增加,铝粉的增重率进一步提高.当镍的质量分数达到8.93%时,复合粉末在约1000℃时出现点火燃烧现象.纳米镍粉的氧传递对促进超细铝粉的氧化起到了至关重要的作用.
Nanocrystalline Ni-coated Al composite powders were prepared by a fast, simple and quantitative method, The morphology and oxidation ability of both raw Al powders and nano Ni-coated Al composite powders were investigated by scanning electron microscopy (SEM), therrnogravimetric analysis (TGA), differential scanning calorimetry (DSC), and X-ray diffraction (XRD). The results showed that the weight growth rate of raw Al powders at 1050 ℃ was 122% and could be increased to 135% when covering the raw Al powders with 0.75%(ω) nano-sized Ni particles. More covering content of Ni powders will further increase the weight growth rate of Al powders. The ignition and combustion behaviors of composite powders were observed at ca 1000 ℃ when the covering content of Ni went up to 8.93%(ω). Due to its oxygen transfer ability, the nano Ni powders play a crucial role in enhancing the oxidation of superfine Al powders.