Microstructure and mechanical behaviour of a Fe–Ni–Al alloy

The microstructure of a cast Fe–35% Ni–20% Al alloy has been examined and changes occurring on annealing examined in relation to the ternary equilibrium diagram for these conditions. Significant changes occur with various precipitations inside the initial dendritic cast structure. As cast material is brittle due to cleavage across the B2 regions, despite the presence of ductile fcc interdendritic phase, precipitation on annealing softens the material and allows notable room temperature ductility.