Contributions of internal hydrogen and room-temperature creep to the abnormal fatigue cracking of Ti6246 at high Kmax

Frédéric Mignot (1) , Véronique Doquet (1) , Christine Sarrazin-Baudoux (2)

1 LMS - Laboratoire de mécanique des solides
2 LMPM - Laboratoire Mécanique et Physique des Matériaux

This study aims at explaining the absence of a threshold for crack propagation in an α/β titanium alloy during cyclic tests performed with constant Kmax and increasing Kmin, if Kmax is higher than 60–70% of KIc. Tensile, creep as well as fatigue crack growth tests are performed on specimens with various hydrogen content. SIMS analyses of hydrogen content around the tip of a crack developed in the abnormal regime are made. Solute hydrogen is shown to segregate at the crack tip and to enhance room-temperature creep, strain localisation and decohesion along α/β interfaces.

Mots clés: Titanium; Hydrogen; Creep; Cracking; Fatigue threshold

Domaines: Mécanique [physics.med-ph]

Frédéric Mignot, Véronique Doquet, Christine Sarrazin-Baudoux. Contributions of internal hydrogen and room-temperature creep to the abnormal fatigue cracking of Ti6246 at high Kmax. Materials Science and Engineering: A, 2004, 380 (1-2), pp.308-319. ⟨10.1016/j.msea.2004.04.006⟩. ⟨hal-00111412⟩