Manipulating the powder size to achieve enhanced strength and ductility in harmonic structured Al alloy

ABSTRACT The present work reports a simple one-step powder metallurgy approach for producing bulk fine-grained Al2024 alloy with a unique harmonic structure and superior mechanical properties. The grain size of the bulk specimen could be easily manipulated by changing the initial powder size. Tensile test suggested that the yield strength of the fine-grained specimen with an average grain size of 3.78？μm (powder size ～20？μm) was about 265？MPa, which was three times higher than that of the conventional coarse-grained counterpart, maintaining a good ductility (total elongation ～15%). The reasons for the unique microstructure and the enhanced mechanical properties were discussed. GRAPHICAL ABSTRACT IMPACT STATEMENT Bulk Al alloy with a unique ‘harmonic structure' and enhanced mechanical properties was successfully fabricated by a simple one-step powder metallurgy approach using gas atomized powders