Investigation of the high-Al region of Al–Cu–Ru

The Al-rich part of the Al–Cu–Ru alloy system was studied. Partial isothermal sections were determined for 600, 680, 800, 890, 1000 and 1100 °C. The Al–Ru β-phase extends along about 50 at.% Al to compositions very close to Al–Cu, the orthorhombic Al6Ru phase can dissolve up to 5 at.% Cu. The range of the liquid is close to the Al–Cu terminus at all temperatures studied. The formation region of the stable icosahedral quasicrystalline phase was determined between about Al61Cu26Ru13 and Al70.5Cu12.5Ru17. Three stable periodic phases designated ω, C and C1 were confirmed.