Effect of Heat Treatment on Microstructure and Mechanical Properties of AlSi10Mg Alloy Fabricated by Selective Laser Melting

Abstract:

The effects of the heat treatment process parameters on the microstructure and mechanical properties of a selective laser melted (SLMed) AlSi10Mg alloy were systematically investigated. The SLMed AlSi10Mg alloy was treated with T1 (180°C× 4h + air cooling) process, which had the microstructure of fine α-Al grains, fine Si phase, and nano-sized precipitations. The microhardness significantly increased to 150 HV, which is even higher than as-SLMed one (126 HV). The microhardness of SLMed AlSi10Mg alloy treated with T4 (540°C × 2h + water cooling) heat-treatment process significantly decreased to 62 HV due to the growth of α-Al grains, Si phase and the formation of β-AlFeSi phase. However, the microhardness and ultimate tensile strength of AlSi10Mg alloy treated with T6 (540°C × 2 h water cool + 180°C × 4 h air cool) process decreased to 91 HV, although the strengthening precipitation of Mg₂Si phase formed. It indicates that the Mg₂Si phase cannot compensate for the adverse effect of grain growth. It may provide the best potential heat treatment method for fabricating the high strength SLMed AlSi10Mg alloy.

• Periodical: Materials Science Forum (Volume 1035)
• Pages: 312-317
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.1035.312
• Online since: June 2021
• Authors: Peng Qi, Bo Long Li*, Tong Bo Wang, Lian Zhou, Zuo-Ren Nie
• Keywords: AlSi10Mg Alloy, Heat Treatment, Mechanical Properties, Microstructure, Selective Laser Melting

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