ON THE NATURE OF THE CRYSTALLINE PHASES WHICH COEXIST WITH THE Fe_3Al INTERMETALLIC COMPOUND

摘要

The typical casting methods to produce the Fe_3Al intermetallic compounds gives rise to the coexistance of this intermetallic phase with different crystalline structures. One of the easily formed crystalline phases in melting environments with carbon availability (crucibles with carbon contents), is the Fe_3AlC phase. In this investigation alloys with Fe_3Al stoichiometric composition were obtained using a rapid solidification technique with a cooling rate of approximately 10~4 ℃/s. Different approaches to isolate the Fe_3AlC phase were obtained. These approaches are based on minor elements addition to the Al-Fe system and also with increments in the amount of iron in the composition. A microstructural characterization of the Fe_3AlC phase based on X-ray diffraction (XRD) patterns, analytical scanning electron microscopy (SEM) and analytical transmission electron microscopy (TEM) is carried out.