A study of microstructure and ductility of directionally solidified Ni₅₀Al₂₀Fe₃₀

The microstructure and ductility of directionally solidified Ni50Al20Fe30 were studied. Calculation and experiment show that the elastic modulus of the sample with completely eutectic lamellar structure is higher than that of the sample with dendritic structure. During deformation, in the samples with dendritic structure, some load is transferred from the proeutectic area to the γ-rich eutectic area and enhances the ductility of the sample.The existence of thick interdendritic γ phase and thick lamellar γ phase in the eutectic area of the dendritic sample is very effective in suppressing the microcrack propagation and also contributes to the ductility enhancement.