Effect of welding defects on plastic behaviour and fatigue lifetime of friction stir welded Al-Cu-Li alloy

Thomas Le Jolu (1) , Thilo F. Morgeneyer (1) , Anne Denquin (2) , Anne-Françoise Gourgues-Lorenzon (1)

1 MAT - Centre des Matériaux
2 ONERA - The French Aerospace Lab [Palaiseau]

The effects of joint line remnant (JLR), kissing bond (KB), and clearance between the sheets (Gap) on tensile and fatigue properties of 2198-T851 friction stir welds have been quantitatively evaluated with respect to a reference weld made using one single sheet. The JLR has no significant influence in the investigated conditions. KB and Gap-induced defects do not significantly influence plastic yield but may induce premature crack initiation by ductile tearing and intergranular decohesions respectively. A critical value for KB opening (280 MPa), a threshold value for fatigue crack propagation from the KB (1 MPa√m) and crack growth rates consistent with literature data have been determined.

Mots clés: Friction stir welds; Welding defects; Tensile properties; Fatigue resistance

Domaines: Sciences de l'ingénieur [physics]; Matériaux

Thomas Le Jolu, Thilo F. Morgeneyer, Anne Denquin, Anne-Françoise Gourgues-Lorenzon. Effect of welding defects on plastic behaviour and fatigue lifetime of friction stir welded Al-Cu-Li alloy. 13th international conference on fracture, Jun 2013, Beijing, China. 10 p. ⟨hal-00853558⟩