Effects of Cr Content on Properties of Fe-Cr Alloy Prepared by MA-SPS Process

Fe-xat%Cr(x=28, 38, 48, 58, 68) powders were synthesized by a mechanical alloying (MA) of elementary Fe powder and Cr powder. The MA was performed in a planetary ball mill for 360ks under 1.33kPa argon gas atomosphere. The MA powders were consolidated at 1123K for 0.3ks by a spark plasma sintering (SPS) apparatus. The shape of sample was 15mmφ× 3mmtor 5mmt. The properties of the sintered bodies, namely the coefficient of linear expansion(15mmφ×3mmt) from 303K to 773K and the polarization curve in a 0.1N H2SO4 solution were measured. As the increase of Cr content in the alloy, the coefficient of linear expansion decreased and corrosion resistance was improved. In spite of containing 32at%Fe, corrosion resistance of Fe-68at%Cr alloy was almost the same as that of pure Cr.