Nammalvar Raja Rajan Aravindh, Krochmal Marcel, Wegener Thomas, Biswas Abhishek, Hartmaier Alexander, Niendorf Thomas, Moeini Ghazal
Institute of Mechanical Engineering, Westphalian University of Applied Sciences, Neidenburger Straße 43, 45897 Gelsenkirchen, Germany.
Institute of Materials Engineering-Metallic Materials, University of Kassel, Mönchebergstraße 3, 34125 Kassel, Germany.
Materials (Basel). 2022 Aug 13;15(16):5562. doi: 10.3390/ma15165562.
The unique microstructure of the alloy AlSi10Mg produced by the laser-based powder bed fusion of metals (PBF-LB/M) provides high-strength and high-strain-hardening capabilities of the material. The microstructure and mechanical properties of 3D-printed, i.e., additively manufactured, AlSi10Mg are significantly altered by post-building heat-treatment processes applied in order to tailor the final properties of the parts. Using an accurate computational model to predict and improve the mechanical performance of 3D-printed samples considering their microstructural features can accelerate their employment in envisaged applications. The present study aims to investigate the correlation between microstructural features and the mechanical behavior of as-built, direct-aged, and T6 heat-treated samples of PBF-LB/M AlSi10Mg under tensile loading using experiment and microstructure-sensitive modeling approaches. Nanoindentation tests are used to calibrate the parameters of the constitutive models for the Al and Si-rich phases. The experimental investigations revealed that heat treatment significantly changes the sub-grain morphology of the Si-rich phase, and this can have a considerable effect on the mechanical behavior of the components. The effect of the modeling of the Si-rich phase in the representative volume elements on the prediction of mechanical behavior is investigated using the J2 plasticity model. The combination of the crystal plasticity model for Al and the J2 plasticity model for the Si-rich phase is used to predict the tensile properties of the as-built and heat-treated states. The predicted results are in good agreement with the experimental results. This approach can be used to understand the microstructure-property relationship of PBF-LB/M AlSi10Mg and eventually tailor heat treatment for PBF-LB/M AlSi10Mg based on the requirement of the application.
通过金属激光粉末床熔融（PBF-LB/M）工艺生产的AlSi10Mg合金独特的微观结构赋予了该材料高强度和高应变硬化能力。为了调整零件的最终性能，对3D打印（即增材制造）的AlSi10Mg进行的后处理热处理工艺会显著改变其微观结构和力学性能。使用精确的计算模型来预测和改善考虑其微观结构特征的3D打印样品的力学性能，可以加速它们在预期应用中的使用。本研究旨在采用实验和微观结构敏感建模方法，研究PBF-LB/M AlSi10Mg的增材制造态、直接时效态和T6热处理态样品在拉伸载荷下微观结构特征与力学行为之间的相关性。纳米压痕试验用于校准Al相和富Si相本构模型的参数。实验研究表明，热处理显著改变了富Si相的亚晶粒形态，这对部件的力学行为有相当大的影响。使用J2塑性模型研究了在代表性体积单元中富Si相建模对力学行为预测的影响。结合Al的晶体塑性模型和富Si相的J2塑性模型来预测增材制造态和热处理态的拉伸性能。预测结果与实验结果吻合良好。这种方法可用于理解PBF-LB/M AlSi10Mg的微观结构-性能关系，并最终根据应用需求定制PBF-LB/M AlSi10Mg的热处理工艺。
