Exo-melt : a commercially viable process

Nickel and iron aluminides are new classes of advanced materials that exhibit excellent oxidation resistance up to 1,100 C (2,000 F). Oxidation resistance and other attributes (see sidebar) make nickel and iron aluminides attractive for many applications. However, a lack of both knowledge and willingness by vendors to prepare high-aluminum-content aluminides prevented these materials from becoming commercial until recently. Now, a major breakthrough has been made with the patented ExoMelt process, which utilizes heat released between the transition metal and aluminum. Over 100 heats of Ni{sub 3}Al and Fe{sub 3}Al-base alloy compositions have been melted at Oak Ridge National Laboratory, producing several thousand pounds of nickel and iron aluminides. The process is discussed here along with some applications.