The development of significantly ductile β-NiAl(B2)-based alloys through microstructural control based on phase diagram information is presented. A marked improvement in hot-workability and room temperature tensile properties was realized in the Ni-Al-X (X: Fe, Co, Mn) systems by ensuring the presence of the disordered γ (fcc) phase in the β-phase matrix grain boundaries. Using the same principle, ductile multi-phase alloys with the β phase as the matrix and γ and γ′ (L12) as coexistent phases have also been developed using conventional processing techniques like casting, hot-rolling and heat treatment. It has been observed that the martensitic transformation from β to β′ (L10) has a significant effect on the microstructural features of the β+γ′ alloys. It is shown that possibilities for development of different microstructures through thermo-mechanical treatments as in Fe-based alloys, exist for the nickel-aluminides as well. In this respect it is emphasized that phase diagrams and their calculation using the CALPHAD (Calculation of Phase Diagrams) approach play a significant role in aiding alloy design to improve the ductility of intermetallic alloys through microstructural control.
|Number of pages||14|
|Publication status||Published - 1994|
|Event||Proceedings of the 1994 TMS Fall Symposium - Rosemont, IL, USA|
Duration: 1994 Oct 2 → 1994 Oct 6
|Conference||Proceedings of the 1994 TMS Fall Symposium|
|City||Rosemont, IL, USA|
|Period||94/10/2 → 94/10/6|