Melting and casting of FeAl-based cast alloy

The FeAl-based intermetallic alloys are of great interest because of their low density, low raw material cost, and excellent resistance to high-temper ature oxidation, sulfidation, carburization, and molten salts. The applicat ions based on these unique properties of FeAl require methods to melt and c ast these alloys into complex-shaped castings and centrifugal cast tubes. T his paper addresses the melting-related issues and the effect of chemistry on the microstructure and hardness of castings. It is concluded that the us e of the Exo-Melt(TM) process for melting and the proper selection of the a luminum melt stock can result in porosity-free castings. The FeAl alloys ca n be melted and cast from the virgin and revert stock. A large variation in carbon content of the alloys is possible before the precipitation of graph ite flakes occurs. Titanium is a very potent addition to refine the grain s ize of castings. A range of complex sand castings and two different sizes o f centrifugal cast tubes of the alloy have already been cast. (C) 1998 Else vier Science S.A. All rights reserved.