Structure of Complex Concentrated Alloys Derived from Iron Aluminide Fe3Al

Abstract

The phase structure and composition of a series of four alloys based on Fe3Al was investigated by means of scanning electron microscopy, X-ray diffraction and transmission electron microscopy. The materials were composed of Fe and Al with a fixed ratio of 3:1 alloyed with V, Cr and Ni at 8, 12, 15 and 20 at. % each (composition formula: Fe3(100-3x)/4 Al(100-3x)/4VxCrxNix). For 8% alloying, the material is single-phase D0(3). Furthermore, 12 and 15% alloying results in bcc-B2 phase separation on two length scales. Moreover, 20% alloying gives rise to the FeNiCrV & sigma; phase supplemented by B2. These findings are discussed with respect to the results obtained via Calphad modeling using the TCHEA5 database and can serve in further improvement.The phase structure and composition of a series of four alloys based on Fe3Al was investigated by means of scanning electron microscopy, X-ray diffraction and transmission electron microscopy. The materials were composed of Fe and Al with a fixed ratio of 3:1 alloyed with V, Cr and Ni at 8, 12, 15 and 20 at. % each (composition formula: Fe3(100-3x)/4 Al(100-3x)/4VxCrxNix). For 8% alloying, the material is single-phase D0(3). Furthermore, 12 and 15% alloying results in bcc-B2 phase separation on two length scales. Moreover, 20% alloying gives rise to the FeNiCrV & sigma; phase supplemented by B2. These findings are discussed with respect to the results obtained via Calphad modeling using the TCHEA5 database and can serve in further improvement.