The 400?C and 600?C isothermal sections of the Al-Co-Er system were studied
assisted with X-ray diffraction (XRD), scanning electron microscopy (SEM)
and electron probe microanalysis (EPMA) techniques. 18 three-phase fields
were identified in the 400?C isothermal section. The maximum solid
solubilities of Al in Co3Er and Co2Er were 13.93 at.% and 16.13 at.%,
respectively. Whereas the maximum solid solubilities of Co in Al2Er, Al2Er3
and AlEr2 were 6.93 at.%, 6.65 at.%, and 6.49 at.%, respectively. And the
solid solution range of ? is from 22.22 at.% Al to 44.44 at.% Al. While the
600?C isothermal section included 20 three-phase fields. The maximum solid
solubilities of Al in Co17Er2 and Co7Er2 were 10.17 at.% and 10.24 at.%,
respectively. Whereas the maximum solid solubilities of Co in Al2Er and
Al2Er3 were 3.63 at.% and 2.01 at.%, respectively.