Universal Material Constants for MultiStage Fatigue (MSF) Modeling of the Process–Structure–Property (PSP) Relations of A000, 2000, 5000, and 7000 Series Aluminum Alloys

A MultiStage Fatigue (MSF) model that admits different hierarchical microstructural features and their stereological information is used to predict the fatigue behavior of 17 different processed aluminum alloys: A000 series (A319, A356, A357, and A380), 2000 series (2024, 2055, 2099, 2198, 2297), 5000 series (5052, 5456), and 7000 series (7050, 7055, 7065, 7075, 7085, 7175). A single set of MSF model constants was validated for all of the aforementioned aluminum alloys, wherein the variation in fatigue life has been captured according to distinct microstructural features (pore size, pore nearest neighbor distance, porosity, particle size, grain size, crystallographic orientation, and misorientation) that differ arising from their native material processing method (casting, rolling, or extrusion). The MSF model’s total number of cycles distinguishes two different regimes: crack incubation (Inc) and Microstructurally Small Crack (long cracks are not considered herein). The previous MSF model in the literature had been associated with the pore size, pore nearest neighbor distance, porosity, particle size, and grain size, but a new contribution in this work is the contribution of the grain orientation and misorientation angles. We show that the MSF model now has the necessary and sufficient equations to predict the Process–Structure–Property relationships for aluminum alloys, allowing for expansion of fatigue prediction even beyond the alloys studied herein.