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

The phase equilibria at 500 degrees 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 tau(2)(Al(2)CeNi) exists at 500 degrees C, while tau(3)(Al(5)Ce(2)Ni(5)) does not exist at 500 degrees C. A new compound tau(9) with composition of about Al(35)Ce(16.5)Ni(48.5) is found. The solubility of Ni in Al(11)Ce(3) and alpha Al(3)Ce is generally about I at.%, while the solubility of Ni in Al(2)Ce is measured to be 2.7 at.%. The solubility of Ce in Al(3)Ni, Al(3)Ni(2), AlNi and AlNi(3) is all less than 1 at.%. The solubility of Al in CeNi(5), Ce(2)Ni(7) and CeNi(3) is measured to be 30.4, 4.8 and 9.2 at.%, respectively, while there is no detectable solubility for Al in CeNi(2). A revised isothermal section at 500 degrees C in the Al-Ce-Ni system has been presented. (C) 2008 Elsevier B.V. All rights reserved.