Fatigue life prediction of additively manufactured nickel-based superalloy by integrating crystal plasticity and Tanaka-Mura model

This study presents a fatigue life prediction framework for additively manufactured nickel-based superalloy GH3536 under low-cycle fatigue conditions. By integrating a crystal plasticity finite element model with the Tanaka-Mura dislocation pile-up mechanism, the framework effectively accounts for microstructural factors, including grain orientation, grain size, and defects, on crack initiation and propagation. Experimental validation demonstrates the model’s reliability, with prediction errors below 24 %. Parameterized simulation studies reveal that crystallographic orientation can induce up to 21 % dispersion in fatigue life, underscoring its critical role in fatigue performance. Furthermore, it is demonstrated that a reduction in grain size to 24 μm considerably improves fatigue life by impeding the progression of cracks, whereas the presence of defects significantly alters the trajectories of crack initiation and growth. The framework establishes a physics-based methodology for elucidating and enhancing the fatigue performance of additively manufactured components under cyclic loading conditions.