Fatigue crack growth microstructural mechanisms and texture-sensitive predictive modeling of lightweight structural metals

• Published in: International journal of fatigue Vol. 149; p. 106278
• Main Authors: Gavras, Anastasios G., Spangenberger, Anthony G., Lados, Diana A.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.08.2021; Elsevier BV
• Subjects: Aluminum; Aluminum alloys; Crack propagation; Fatigue crack growth; Fatigue failure; Fracture mechanics; Grain orientation; Grain size; Materials fatigue; Materials selection; Metal fatigue; Microstructure; Prediction models; Safety critical; Stress ratio; Titanium alloys; Titanium base alloys; Titanium alloys; Fatigue crack growth; Aluminum alloys; Microstructure; Stress ratio
• ISSN: 0142-1123; 1879-3452
• DOI: 10.1016/j.ijfatigue.2021.106278

•Slip length controls crack growth behavior in studied lightweight structural alloys.•Critical stress intensity and grain size control intergranular failure transition.•Design maps visually interpolate crack growth mechanisms to untested stress ratios.•Grain-sensitive model predicts microstructurally small crack growth rates well. Long and small fatigue crack growth (FCG) mechanisms of various light structural aluminum and titanium alloys were studied with respect to microstructure, stress ratio, and initial flaw size and related to the effective slip length (grain and phase boundaries). Damage mechanism maps were developed to provide design tools to improve material selection for safety-critical structural components. A predictive model for grain size-controlled microstructurally small FCG was developed with consideration of crack size, grain orientation, and the stochastic effects of discrete microstructural interactions. The model allows for rapid estimation of small FCG behavior and agrees well with experimental data.