Induction Heat Melting The Preparation Of Nial-fe Alloy And Fe On Its Performance

Ni, Al and Fe reaction by Exo-MeltTM process, NiAl—Fe intermetallic alloy was obtained. The NiAl- Fe alloy various functions was studied with the different content of iron(wt%) condition, include room-temperature ductility, compress properties, hardness and oxidation resisance in air at 1273K, corrosion resistance at room-temperature. The organization analysis and microstructure of NiAl- Fe was carried on and the relationship between organization structure and macroscopic properties was clarified.Firstly, according to the thermodynamics laws, the adiabatic temperature of the combustion reaction was calculated to prove the possibility of the reaction. It showed that the adiabatic temperature became lower with the increment of the content of iron. The method of Exo-MeltTM can make cast NiAl—Fe.The phases are studied by XRD, room-temperature ductility, compress properties, hardness were investigated and the fracture surfaces were observed by SEM.The experiment result manifestation, The ductility phase was formed by the addition of Fe in the alloy. The cleavage and the ductility phase interact with each other mutually. The interaction improved the ductility and the tenacity of the material. It improved the ductility and the tenacity of the material. Under heat treatment condition the cast metal alloy grains were refined and the organization improved. Heat treatment was important to the mechanics properties of alloy. With the increase of the content of Fe, the O_bc of NiAl—Fe alloy increased and the anti-transform ability became better. This was because the grain boundary was surrounded by the enhancing phase, which limited the slipping of grains, and the crossing of dislocation along the boundary of grain. Thus the grain boundary was reinforced. The tiny phase in internal grains prevented the moving of dislocations and raised the strength of alloy effectively. The fracture surface and fracture energy absorbed showed that the cleavage and the ductility phase interacted with each other with the addition of Fe. This interaction makes flats split from one toanother. At the same time, the path of the expanding of cracks become twisted and rough. Fracture energy absorbed in the process aggrandized. This phenomenon with the higher content of Fe more obviously. The heat treatment could improve the mechanical properties of NiAl—Fe.With the increase of the content of Fe, the Fe occupies the position of Ni, the density of empty increases. The displacement and empty position causes the the material become hardened.The addition of Fe could effectively improve the mechanics properties of the alloy, but unfortunately it lowered the corrosion resistance, the oxidation resistance in air at 1273K. The experiment result showed Pure NiAl metal alloy with the Al₂O₃ protection film has good oxidation resistance, and good corrosion resistance. The NiAl-Fe metal alloy surface has not only Al₂O₃ but also NiO, Fe₂O₃. The protection function of the film showed a decline.The surface of the pure NiAl in the corrosion process can form the Al₂O₃ protection film, which has good corrosion resistance. The NiAl-Fe metal alloy surface has not only Al₂O₃ but also NiO, Fe₂O₃. The protection function of the film get worse and the oxides film will be dissolved by the corroding liquid, thus the corrosion process was accelerated.