Effect of the heat treatment on the microstructure and hardness evolution of a AlSi10MgCu alloy designed for laser powder bed fusion

Abstract The aim of this work is to investigate the influence addition Cu on microstructure and microhardness a laser powder bed fusion (L-PBF)-fabricated AlSi10MgCu alloy. With goal, AlSi10Mg+4 wt%Cu pre-alloyed was produced by gas atomization. Following parameter optimization study, dense as-built specimens with high relative density 99.8% were fabricated. An outstanding value, exceeding 180 HV, obtained after aging at 160 °C for 16 h. This value similar that strength Al 7075 in T6 condition. aid analytical transmission electron microscopy, it concluded origin observed excellent mechanical behavior could be attributed beneficial effect reducing Al-matrix cell size, increasing decreasing size Si-based nanoprecipitates interiors. More specifically, proposed maximum hardness associated development Cu-rich GP-I zones, which act as precursors Si nanoprecipitates. Overaging leads reduction due transformation these zones into coarser ?’’ precipitates thus smaller volume fraction larger nanoparticles.