The isothermal section at 500 °C of the Al–La–Y ternary system

Ternary Al–La–Y alloys have been studied by X-ray diffraction, optical microscopy, scanning electron microscopy and electron probe microanalysis. Phase equilibria have been established in the isothermal section at 500 °C in the 60–100 at.% Al composition range. The formation of the following solid solutions has been noticed: YxLa1-xAl2 (continuous solid solution of the cF24–Cu2Mg type), YxLa1-xAl3 (0⩽x⩽0.16 and 0.84⩽x⩽1) of the hP8-Ni3Sn type and (YxLa1-x)3Al11(0⩽x⩽0.34) of the oI28–αLa3Al11 type. No ternary compounds have been observed in the system.