REDUCTION-MECHANISM OF SURFACE OXIDE IN ALUMINUM-ALLOY POWDERS CONTAINING MAGNESIUM STUDIED BY X-RAY PHOTOELECTRON-SPECTROSCOPY USING SYNCHROTRON-RADIATION

We investigated the reduction mechanism of surface oxide on aluminum a lloy powders containing magnesium, by x-ray photoelectron spectroscopy using synchrotron radiation (SR-XPS). The reduction is the initial re action in a new aluminum nitridation method developed by one of the au thors. In heating the powders to 823 K, magnesium soluted in the powde rs moves from the inner region to the surface at temperatures below 57 3 K, and finally, above 773 K, the magnesium reduces the aluminum oxid e of powder surfaces by chemical reaction, which breaks the surface ox ide films, and metallic aluminum appears on the topmost surface of the powders. These results suggest that the SR-XPS system is very useful for dynamic chemical reaction analysis of the surface via in situ meas urement. (C) 1997 American Institute of Physics.