Phase equilibria in the Ni-Al-Ga system at 700 degrees C

作者：Belyavina N^*; Markiv V; Nakonechna O; Lozovyi F

来源：Journal of Alloys and Compounds, 2014, 593: 41-49.

DOI：10.1016/j.jallcom.2014.01.073

• Nickel
• Aluminum
• Gallium
• Ternary system
• Phase equilibria
• Mechanical properties

Phase relations in the ternary Ni-Al-Ga system at 700 degrees C have been established by the X-ray powder diffraction methods. In addition to already known Ni-3(Al,Ga) continuous solid solution, Ni(Al,Ga) continuous solid solution as well as Ni-2(Al,Ga)(3) and Ni-5(Al,Ga)(3) extended solid solutions were found to exist in this system. It was shown that the ternary Ni-2(Al,Ga)(3) and Ni-5(Al,Ga)(3) compounds do not belong to the continuous solid solutions because of two-phase gaps on the Ni2Al3-Ni2Ga3 (similar to 30-50 at.% Ga) and Ni5Al3-Ni5Ga3 (similar to 12-25 at.% Ga) isolines at 700 degrees C. Some crystal structure peculiarities such as atomic ordering-disordering and presence of structural vacancies have been revealed for all solid solutions existing in the Ni-Al-Ga system. It was found that the compressive strength of the Ni-3(Al,Ga) solid solution increases with small additions of gallium (about 2.5 at.%).
The isothermal section (700 degrees C) of the ternary Ni-Al-Ga system including four extended solid solutions (Ni-3(Al,Ga), Ni-5(Al,Ga)(3), Ni(Al,Ga) and Ni-2(Al,Ga)(3)) has been constructed and plotted.

• 出版日期2014-4-25