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

Abstract

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.