The present work reports the results of a reinvestigation of the γ liquidus and solidus temperatures of the Ni-Al system and the γ/Ni5Zr eutectic reaction temperatures in the Ni-Al-Zr system. In the Ni-Al binary system, it is found that the stability of the Ni-rich γ solid solution phase is enhanced by small additions of Al with the melting temperature of the γ phase and that the melting temperature reaches a congruent maximum at a few at.% Al. The temperature of the eutectic reaction L → γ + Ni5Zr in the Ni-Zr binary edge is confirmed to be 1196°C by differential thermal analysis (DTA), rather higher than the value reported previously. The reaction temperature increases with Al addition to reach or exceed 1206°C, forming a "saddle point," then decreasing to reach 1187°C or below by flowing into a ternary invariant reaction. These findings can be explained by γ/liquid equilibrium in the Ni-Al binary system.
ASJC Scopus subject areas
- Materials Science(all)
- Physical and Theoretical Chemistry
- Metals and Alloys