A study of the Al-rich part of the Al–Ru alloy system

The Al-rich part of the Al–Ru phase diagram was reinvestigated by scanning and transmission electron microscopy, powder X-ray diffraction and differential thermal analysis. The Al6Ru, Al13Ru4, Al5Ru2, Al2Ru, Al3Ru2 and AlRu phases were confirmed. The Al6Ru is formed peritectically at 734 °C, Al13Ru4 peritectically at 1420 °C and Al2Ru peritectically at 1805 °C. An orthorhombic Al5Ru2 phase (a=0.78, b=0.66 and c=0.42 nm) isostructural to Al5Fe2 was found to be formed at 1492 °C by a peritectic reaction of Al2Ru with the liquid and to decompose at 1340 °C to Al2Ru and Al13Ru4. The Al3Ru2 phase is formed by a peritectoid reaction from Al2Ru and AlRu at 1675 °C.