The phase equilibria of the Al–Ce–Ni system at 500 °C

The phase equilibria at 500 °C in the Al–Ce–Ni system in the composition region of 0–33.3 at.% Ce are investigated using XRD and SEM/EDX techniques applied to equilibrated alloys. The previously reported ternary phases and the variation of the lattice parameters versus the composition for different solid solution phases are investigated. It is confirmed that τ2(Al2CeNi) exists at 500 °C, while τ3(Al5Ce2Ni5) does not exist at 500 °C. A new compound τ9 with composition of about Al35Ce16.5Ni48.5 is found. The solubility of Ni in Al11Ce3 and αAl3Ce is generally about 1 at.%, while the solubility of Ni in Al2Ce is measured to be 2.7 at.%. The solubility of Ce in Al3Ni, Al3Ni2, AlNi and AlNi3 is all less than 1 at.%. The solubility of Al in CeNi5, Ce2Ni7 and CeNi3 is measured to be 30.4, 4.8 and 9.2 at.%, respectively, while there is no detectable solubility for Al in CeNi2. A revised isothermal section at 500 °C in the Al–Ce–Ni system has been presented.