PREPARATION OF Fe-8%Ni ALLOYED POWDER FABRICATED BY NOVEL RECYCLING PROCESS

Abstract

Fe-8%Ni alloyed powder was fabricated by oxidation and mechanical alloying technique using Fe-36%Ni scrap. Oxidation behavior of Fe-36%Ni alloy was studied in air using thermogravimetric apparatus (TGA), and oxidation rate was shown to be sharply increased after 500 degrees C. It was found that the alloyed scrap was completely oxidized at 1100 degrees C for 96 hours. Fe(2)O(3) and NiO were observed to be the major phases in oxide scale of the scrap. The scrap completely oxidized was ball-milled to make average particle size of 1.5 mu m. The oxide powder was synthesized in wet-ball milling with addition of Fe(2)O(3) powder in order to meet the desire composition. Finally, Fe-8%Ni alloyed powder was obtained after reduction in H(2) gas atmosphere at 650 degrees C for 5 hours, and the powders were examined by X-ray fluorescence (XRF), X-ray diffraction (XRD), and scanning electron microscopy (SEM).