Abstract This study investigates the microstructural evolution, mechanical performance, and residual stress distribution of AlSi11Mg alloy wheels produced by low-pressure die casting (LPDC) under various heat treatment conditions. Unlike conventional practice, where AlSi11Mg is often used without heat treatment, this work applied T6 and alternative heat treatments to assess their influence on critical wheel regions. Microstructural observations showed that the as-cast condition contained coarse dendrites and sharp Si particles, leading to low hardness and brittle behavior. Artificial aging alone produced limited precipitation hardening, whereas T6-treated samples exhibited refined and spheroidized Si morphologies, resulting in significantly higher yield strength, ultimate tensile strength, elongation, and hardness. Among the tested scenarios, Option #3 achieved the most balanced and consistent properties across all wheel regions. Residual stress simulations confirmed stress accumulation in hub and hub–spoke areas, a potential source of cracking. While T6 treatment maximized the strength, it also increased the residual stress; in contrast, limited heat treatments reduced the stress but compromised the mechanical performance. Complementary numerical simulations were conducted using Magmasoft and its Magmastress module to model both casting and heat treatment processes. Residual stress analyses highlighted that the highest residual stresses occur after quenching in T6-treated specimens. Long artificial aging time (Option #2) gives the lowest residual stress under T6-treated specimen groups. Stress relief annealing (Option #5) significantly reduced the residual stresses by 56–68%, reducing the risk of crack initiation. Overall, the study demonstrates that T6 heat treatment optimizes the mechanical performance in AlSi11Mg wheels, while stress relief annealing effectively decreases the residual stresses. These findings provide critical insights for the design, heat treatment, and quality assurance of aluminum alloy castings in automotive applications and potentially other thin-walled, complex components. Graphical Abstract
Özaydin et al. (Wed,) studied this question.