Abstract
In-Situ direct nitriding process to produce AIN in aluminum alloy powder by utilizing the reaction between aluminum and nitrogen gas at temperatures below 823K has been developed. Topmost-surface analysis by X-ray Photoelectron Spectroscopy using Synchrotron Radiation (SR-XPS) was conducted and chemical bonding changes on aluminum powder surface during heating were investigated. Deoxidization of aluminum oxide (Al2O3) surface film by Mg contented in the powders occurred over 670K and Al2O3 film was deoxidized and reduced. After the deoxidization of Al2O3 surface film, aluminum in powder reacted with nitrogen gas and AIN layer was produced upon the powder surface. In-Situ reacted AIN had a good bonding with aluminum matrix and showed a laminar structure with a layer thickness of 20-30nm. The content of reacted AIN strongly depends on a period of heating in nitrogen gas and on surface area of raw powder.
