Effects of modifying the hypoeutectic AlMg5Si2Mn alloy via addition of Al10Sr and/or Al5TiB

Abstract

This work demonstrates that the combined addition of Al10Sr and Al5TiB master alloys to the AlMg5Si2Mn effectively refines the grain microstructure and partially modifies the eutectic Mg2Si phase. Thorough spectroscopic characterization reveals that the grain refinement effect is due to Al3Ti particles acting as nucleation sites for α-Al grains, and the increased nucleation temperature of α-Al is due to Al10Sr addition. It is also determined that TiB2 particles can act as nucleation substrates for the primary Mg2Si phase. The prepared alloy sample with the finest microstructure (treated with both Al10Sr and Al5TiB) exhibits the greatest corrosion resistance among all tested samples.