Oxidation Ability of Nanocrystalline Ni-Coated Al Powders

Abstract

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), thermogravimetric 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%(w) 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%(w). Due to its oxygen transfer ability, the nano Ni powders play a crucial role in enhancing the oxidation of superfine Al powders.