Understanding the creep property of heat-resistant Al alloy by analyzing eutectic phase/matrix interface structures.

Interface characteristics are of great importance in mechanical performance for multi-phases heat-resistant Al alloys. Herein, Al₃Sc precipitates were created at both Al/Al₉FeNi interface and Al matrix inside Al–Fe-Ni eutectic alloy by microalloyed Sc. Critically, Al₃Sc interface precipitates were found to alleviate local lattice distortion at the Al/Al₉FeNi interface to improve interface stability. Therefore, this alloy showed superior creep properties over available reports. The underlying mechanisms were quantitatively elucidated by elevated load transfer effect from interface precipitates and enhanced threshold stress from matrix precipitates. Generally, this work provided a solid understanding to optimize the creep property of eutectic Al alloys by manipulating interface structures. This work reports that Al3Sc precipitates at Al/Al9FeNi interface can enhance load transfer effect of eutectic phase from microscopic/macroscopic factors, illustrating fundamental mechanisms for creep improvement of eutectic Al alloy. [ABSTRACT FROM AUTHOR]