Fabrication of artificial defects to study internal fatigue crack propagation in metals

Fabrication of artificial defects to study internal fatigue crack propagation in metals

A. Junet (1) , A. Messager (2) , X. Boulnat (1) , A. Weck (3) , E. Boller (4) , L. Helfen (5) , J.-Y. Buffiere (1)

1 MATEIS - Matériaux, ingénierie et science [Villeurbanne]
2 I2M - Institut de Mécanique et d'Ingénierie de Bordeaux
3 Department of Mechanical Engineering
4 ESRF - European Synchrotron Radiation Facility
5 KIT - Karlsruhe Institute of Technology

Fatigue specimens designed with controlled internal defects were obtained by diffusion bonding of Ti-6Al-4V sheets containing femtosecond laser drilled notches. Crack initiation from the internal defect occurred systematically. The cracks were characterised by in situ synchrotron X-ray tomography. Propagation rates are lower than those of surface cracks of comparable sizes in the same material and fall between experimental data obtained for fatigue cracks propagating in air and in vacuum. © 2019 Acta Materialia Inc.

Fatigue specimens designed with controlled internal defects were obtained by diffusion bonding of Ti-6Al-4V sheets containing femtosecond laser drilled notches. Crack initiation from the internal defect occurred systematically. The cracks were characterised by in situ synchrotron X-ray tomography. Propagation rates are lower than those of surface cracks of comparable sizes in the same material and fall between experimental data obtained for fatigue cracks propagating in air and in vacuum.

Mots clés: Titanium alloys; Ternary alloys; Synchrotrons; Synchrotron radiation; Artificial defects; Fatigue cracks; Tomography; Vanadium alloys; Aluminum alloys; Fatigue crack propagation; Fatigue of materials; Spark plasma sintering; In-situ synchrotrons; Internal defects; Propagation rate; Fatigue specimen; Three-dimensional tomography; Surface cracks

Domaines: Mécanique des matériaux [physics.class-ph]

A. Junet, A. Messager, X. Boulnat, A. Weck, E. Boller, et al.. Fabrication of artificial defects to study internal fatigue crack propagation in metals. Scripta Materialia, 2019, 171, pp.87-91. ⟨10.1016/j.scriptamat.2019.05.018⟩. ⟨hal-02405423⟩