Phase relation and microstructure in Ni3Al–Ni3Ti–Ni3Nb pseudo-ternary alloy system

Phase relation and microstructure in multi-phase intermetallic alloys based on Ni3Al–Ni3Nb–Ni3V pseudo-ternary alloy system

“…The three-phase region has been reported in both the Ni 3 Al-Ni 3 Ti-Ni 3 Nb [14] and the Ni 3 Al-Ni 3 Ti-Ni 3 V [15] pseudo-ternary alloy systems although the constituent phases were different from each other. A distinct discrepancy is that three-phase region in both the Ni 3 Al-Ni 3 Ti-Ni 3 Nb [14] and the Ni 3 AlNi 3 Ti-Ni 3 V [15] pseudo-ternary alloy systems occurs in the low Ti concentration region, while that of the present Ni 3 Al-Ni 3 Nb-Ni 3 V pseudo-ternary alloy system occurs in the low Nb concentration region, and also is wider (larger) than those of the former two pseudoternary alloy systems.…”

“…A first step to develop such new class of intermetallic alloys is to know whether or not these GCP Ni 3 X phases could be directly equilibrated one another. With this motivation, the present authors have so far investigated the phase relation and microstructures of alloys based on the Ni 3 Al-Ni 3 Ti-Ni 3 Nb [14], the Ni 3 Al-Ni 3 Ti-Ni 3 V [15] and the Ni 3 Si-Ni 3 Ti-Ni 3 Nb [16] pseudo-ternary alloy systems at high temperatures. Consequently, it was found that three GCP Ni 3 X phases were directly equilibrated one another in these pseudo-ternary alloy systems Intermetallics 14 (2006) The Ni 3 Al-Ni 3 Nb-Ni 3 V pseudo-ternary alloy system is chosen: (i) to further understand the parameter governing the Ni 3 X phase stabilities, (ii) to confirm the formation of bimodal multi-phase microstructures and (iii) to obtain more preferable microstructures resulting in superior mechanical properties.…”

Mechanical properties of dual multi-phase single-crystal intermetallic alloy composed of geometrically close packed Ni3X (X: Al and V) type structures

“…Like the superalloys, the multi-phase intermetallic alloys composed of the GCP Ni 3 X intermetallic phases may have coherent interfaces and fine microstructures because of their closely related crystal structures. Actually, it was shown that the multi-phase intermetallic alloys composed of the GCP Ni 3 X intermetallic phases are thermodynamically stable in several pseudo-ternary alloy systems [4e8] and some favorable microstructures have been observed for the multi-phase intermetallic alloys composed of GCP Ni 3 X (X: Al, Ti and Nb) [4,10], (X: Si, Ti and Nb) [6,11,12], (X: Al, Ti and V) [5,9,13] and (X: Al, Nb and V) [7] intermetallic phases.…”

Further investigation on phase relation and microstructures in Ni3Si–Ni3Ti–Ni3Nb pseudo-ternary alloy system

“…In addition, the GCP Ni 3 X phases have extremely stable microstructural stabilities up to their melting points because of low atomic diffusivity owing to their close packed structures. Therefore, if multi-phase intermetallic alloys with microstructures composed of two phases or three phases among these GCP Ni 3 X phases would be obtained, a new class of intermetallic alloy may be developed, and has been actually attempted by the present authors [14][15][16][17][18][19][20][21]. To develop such a new class of intermetallic alloy is necessary to know whether or not these GCP Ni 3 X phases could be directly equilibrated one another or each other.…”