Abstract
Argon gas atomized powder of Al-25mass%Si-3.5%Fe-3.5%Ni-1%Mg alloy was sintered by Spark Plasma Sintering (SPS) method. This powder and the bulk samples obtained by this sintering method were investigated by means of scanning electron microscopy, optical microscopy, X-ray diffraction and Rockwell hardness measurements. Results obtained were as follows;
(1) The most of powder particles have a structure consisting of Al-Si matrix and sphere like precipitates of metastable compounds enriched in Fe and Ni. The other particles have needle like shape in the precipitates of metastable compound. This metastable compound is presumed to be Alm(m=4.4) Fe structure in which a part of Fe is substituted by Ni.
(2) The Rockwell hardness of specimen sintered at 500°C by SPS method is higher than that obtained by the powder forging method. The higher hardness in the specimen procured by SPS method is attributed by the fine structure of compacts because of a completion of sintering in a short time.
