Al3Ni alloy synthesized at high pressures and its Debye temperature

The microstructures of the hypo-peritectic Al-30 wt%Ni alloy solidified at different pressures are investigated. The results show that the microstructure is composed of eutectic, Al3Ni, and Al3Ni2 phases when the alloy is solidified at ambient pressure. Bulk single phase Al3Ni alloy area (2/3) and hyper-eutectic microstructure region (1/3) co-exist after solidified at 4 GPa with a superheat degree of 800 °C. However, the eutectic and Al3Ni phases are homogeneously distributed when the alloy is solidified at the same pressure with no superheating. It provides a new method for preparing the bulk single-phase intermetallic compound. In addition, the Debye temperatures of the single-phase Al3Ni alloy fabricated at different pressures are explored using the low temperature heat capacity curve. The results reveal that the Debye temperatures of the single phase Al3Ni fabricated at ambient pressure and 4 GPa are 468.95 K and 516.7 K, respectively. Finally, the lattice parameters of Al3Ni synthesized at 4 GPa are examined using transmission electron microscopy (TEM), which shows that the lattice parameters are a = 6.6814 Å, b = 7.1910 Å and c = 4.8351 Å.