Experimental determination and numerical simulation of material and damage behavior in low-cycle fatigue of AlSi7Mg0.6 aluminum manufactured by the L-PBF method

Abstract The recent interest in additive manufacturing (AM) of metal alloys, particularly Al-Si alloys, is significant due to its crucial role in the design and development of complex structural components in the aerospace, defense, and automotive industries. The use of AM technology, and specifically laser powder bed fusion (L-PBF), enables the creation of lightweight structures with flexible geometries that were previously unattainable using conventional manufacturing methods. This work focuses on components manufactured from an AlSi7Mg0.6 alloy. Components manufactured using the L-PBF method are subjected to static loading and periods of fatigue loading. The microstructure and, consequently, the mechanical properties of aluminum alloys manufactured by AM are expected to differ from their conventionally manufactured counterparts due to the unique thermal history encountered during AM processes. Therefore, it is crucial to understand the microstructure and characterize the mechanical properties of aluminum alloys by AM to verify their suitability for critical fatigue applications. Additionally, it is crucial to develop appropriate material models for numerical analysis to model the behavior and damage. Therefore, it is crucial to investigate the fatigue characteristics of these components under cyclic LCF loading conditions and determine material parameters. A user material subroutine applies the complete material model for the finite element software ABAQUS 2022. To validate the material model and the parameters, a complex tensile test is performed. In order to check the finite element model, the energy transformation ratio is included in the evaluation. The numerical analyses of the mechanical stress evolution and behaviour demonstrate good agreement with the experimental test. In addition, the calculation shows the expected behaviour of the void volume fraction that rises from the initial value of 0.085 $$\%$$ to 0.129 $$\%$$ value under a complex mechanical load.