Surface Integrity & Fatigue
Machining Induced Surface Integrity
The mechanical and thermal interactions which occur between the cutting tool and workpiece material during the machining processes have a critical influence on the surface and near-surface material properties of the final component. Such machining-induced alterations to the surface integrity of a component can have a critical effect on fatigue performance. By characterising residual stresses, microstructural deformation, and other machining-induced anomalies and linking these to material performance, machining processes can be optimised to ensure that components meet application demands.
Effects on Fatigue
Alterations to the micro-mechanical near-surface properties of a material significantly influence the local resistance to crack initiation and propagation behaviour. Understanding how such alterations can be induced during machining is critical to be able to ensure safe and predictable fatigue performance. Machining-induced characteristics such as compressive residual stresses can enhance a component's fatigue life, whereas, characteristics such as severe plastic deformation, tensile residual stresses, and other anomalies/defects can lead to premature fatigue failure.
Publications of Interest
The_influence_of_machining_induced_surface_integrity_and_residual_stress_on_the_fatigue_performance_of_Ti-6Al-4V.pdfSuarezetalFatigue2021.pdfA. Cox, S. Herbert, J.-P. Villain-Chastre, S. Turner, M. Jackson
International Journal of Fatigue, 2019, 124