More insights into fatigue crack growth from experiments on steels and aluminium alloys—Thresholds

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 528; no. 3; pp. 1296 - 1301
• Main Authors: Steinbock, J., Gudladt, H.-J.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 25.01.2011; Elsevier
• Subjects: Aluminium; Applied sciences; Crack tip; Exact sciences and technology; Fatigue crack growth; Fractures; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Steel; Threshold; Fatigue crack growth; Aluminium; Crack tip; Steel; Threshold; Dislocation motion; Aluminium base alloys; Shear modulus; Fatigue limit; Dispersion strengthened metal; Fatigue crack; Crack propagation; Microstructure
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2010.10.005

▶ New model to describe the threshold behaviour in dependence of the R-ratio. ▶ Thresholds of steels, Al-alloys, particulate-reinforced Al-alloys can be calculated. ▶ The threshold behaviour is dependent on only two parameter. The paper deals with the influence of the R-ratio on the fatigue crack propagation threshold of different metallic materials. Based up on threshold data of steels, aluminium-alloys and two particulate-reinforced aluminium-alloys the threshold behaviour has been analyzed and a new model to describe the threshold behaviour has been deduced. With this model, which contains two quantities that can be deduced from special fatigue crack propagation tests, the threshold behaviour of different kind of materials can be explained. Finally, the existence of the threshold can be attributed to specific elastic parameters of the materials (shear modulus) and their microstructure.