Effect of Direct Aging (DA) and Artificial Aging (AA) Heat Treatments on the Mechanical and Corrosion Properties of LPBF AlSi10Mg Alloy

AlSi10Mg alloys produced by Laser Powder Bed Fusion (LPBF) offer advantages for lightweight design and complex geometries. Still, the high residual stresses and anisotropic properties of the as-built structure can limit mechanical performance and corrosion resistance. The traditional T6 heat treatment increases ductility but reduces material hardness and corrosion resistance. This study aims to systematically compare the effects of Direct Aging (DA) and Artificial Aging (AA) heat treatments on the microstructure, mechanical properties, and corrosion behavior of AlSi10Mg alloy produced by LPBF. The specimens were produced using standard EOS parameters (370 W laser power, 1300 mm/s scanning speed) and then subjected to DA (170 ℃–240 °C) and AA (solution at 540 °C, followed by aging at 160 ℃–250 °C) treatments at different temperatures and durations. Optical Microscope, SEM, EDX, EBSD, and XRD techniques were used for microstructural characterization; mechanical performance was evaluated by hardness and wear tests, while electrochemical tests assessed corrosion behavior. The results showed that the DA process largely preserved the as-built cellular Si network, inhibiting dislocation movement and providing high hardness values. In contrast, the AA process disrupted the Si network, leading to spheroidization and grain coarsening, which reduced wear resistance. In corrosion tests, as-built specimens exhibited the best pitting potential, while the AA process significantly reduced corrosion resistance. The study reveals how Si morphology (continuous network structure vs. spherical particles) determines the balance between mechanical strength and corrosion resistance.