Mechanical properties of high carbon Fe3Al-based intermetallic alloys

Fe-16 wt% Al alloys containing 0.074 to 1.1 wt% carbon were prepared by a c ombination of air induction melting and electroslag remelting (ESR). The ca st ESR ingots exhibited a two-phase structure consisting of Fe3AlC0.5 preci pitate in an Fe,Al-based matrix. The precipitate volume fraction increased with increasing carbon content of the ingot. Most of the carbon was found t o be present as the Fe,AIC,, phase. The bulk hardness of these alloys incre ases linearly with increasing volume fraction of the precipitates. However, the Young's modulus of these alloys was measured to be around 175 GPa and does not change significantly with change in volume fraction of the phases present. This is explained by arguing that both the matrix as well as preci pitate exhibit the same modulus values for the alloys studied in the presen t work. Both the bulk hardness and Young's modulus follow the rule of mixtu re for two phase alloys. However, the same may not be true for structure se nsitive properties such as yield strength, ductility and creep resistance. (C) 1998 Elsevier Science S.A. All rights reserved.