Impact of Heat Treatment on Microstructure and Mechanical Properties of L-PBF Additively Manufactured AlSi10Mg Alloy

Abstract:

This study assesses the impact of heat treatment on the microstructure and mechanical properties of AlSi10Mg alloy produced using the L-PBF method. The research compares the mechanical properties and microstructure of samples subjected to direct aging (heat treatment at 170 °C/2 h) and stress relief annealing (at 240 °C/2 h), which is below the temperature for silicon network decomposition. These results are then compared with the as-built state (without any heat treatment) after printing, serving as a reference. Tensile and hardness tests were used to determine the mechanical properties, while electron microscopy was employed to analyze the microstructure. The findings indicate that direct aging led to an increase in yield strength, tensile strength and hardness compared to the as-built state. In contrast, samples treated with stress-relief annealing exhibited comparable yield strength to the as-built state, but significantly lower tensile strength and reduced hardness. Notably, contrary to expectations, the ductility did not increase with decreasing strength and hardness; instead, it decreased.

• Periodical: Key Engineering Materials (Volume 1032)
• Pages: 29-36
• DOI: https://doi.org/10.4028/p-CXW4rP
• Online since: November 2025
• Authors: Ludmila Džuberová*, Jana Sobotová
• Keywords: Additive Manufacturing, AlSi10Mg, Direct Aging, Eutectic Si Network, Heat Treatment, L-PBF, Mechanical Properties, Microstructure

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