High-temperature mechanical behaviour of Al-10Ce alloy with Sc, Zr, Si, and Mg alloying elements

The influence of Sc, Zr, Mg, and Si addition to Al-10Ce hypereutectic alloy on the formation of intermetallics and mechanical properties have been investigated in as-cast condition and after heat treatment. The incorporation of Sc and Zr facilitated the formation of primary Al3 (Sc, Zr) intermetallics, which effectively refined the alpha-Al grains due to heterogeneous nucleation. Si addition resulted in the formation of the Al2CeSi2 phase. Aging at 300 degrees C led to the formation of nanoscale Al3(Sc, Zr) precipitates with an average diameter of 3 nm. The hardness of the alloy significantly increased and remained unaffected even after ageing for 100 h which suggests the thermal stability of the Al-Ce alloy containing these precipitates. As a result of thermal stability, Al-10Ce-(Sc, Zr) is observed to exhibit higher yield strength at 300 degrees C than a range of Al-Cu, Al-Si alloy systems.