Fatigue Improvement of AlSi10Mg Fabricated by Laser-Based Powder Bed Fusion through Heat Treatment

Metals

Felix Sajadi¹  Siegfried Schmauder²  Ali Cheloee Darabi²  Javad Mola³  Jan-Marc Tiemann³  Nooshin Bandari³ 

[1] Graduate School of Excellence Advanced Manufacturing Engineering, University of Stuttgart, 70569 Stuttgart, Germany;Institute for Materials Testing, Materials Science and Strength of Materials, University of Stuttgart, 70569 Stuttgart, Germany;Material Design and Structural Integrity Laboratory, Osnabrück University of Applied Sciences, 49076 Osnabrück, Germany;

关键词: additive manufacturing;    mechanical properties;    fatigue behavior;    heat treatment;    aluminum alloys;   

DOI  :  10.3390/met11050683

来源: DOAJ

【 摘 要 】

This study aimed to identify an optimal heat-treatment parameter set for an additively manufactured AlSi10Mg alloy in terms of increasing the hardness and eliminating the anisotropic microstructural characteristics of the alloy in as-built condition. Furthermore, the influence of these optimized parameters on the fatigue properties of the alloy was investigated. In this respect, microstructural characteristics of an AlSi10Mg alloy manufactured by laser-based powder bed fusion in non-heat-treated and heat-treated conditions were investigated. Their static and dynamic mechanical properties were evaluated, and fatigue behavior was explained by a detailed examination of fracture surfaces. The majority of the microstructure in the non-heat-treated condition was composed of columnar grains oriented parallel to the build direction. Further analysis revealed a high fraction of pro-eutectic α-Al. Through heat treatment, the alloy was successfully brought to its peak-hardened condition, while eliminating the anisotropic microstructural features. Yield strength and ductility increased simultaneously after heat treatment, which is due to the relief of residual stresses, preservation of refined grains, and introduction of precipitation strengthening. The fatigue strength, calculated at 10⁷ cycles, improved as well after heat treatment, and finally, detailed fractography revealed that a more ductile fracture mechanism occurred in the heat-treated condition compared to the non-heat-treated condition.

【 授权许可】

Unknown