Fracture-mechanics experiments were carried out on ultrafine-grained (UFG) samples of aluminum and two Al alloys to obtain the fracture behavior under static and cyclic loading. The UFG materials investigated show crack resistance behavior under static loading, which was confirmed by ductile fracture surfaces. Under cyclic load, the crack growth rate was described well by the ESACRACK model. The crack propagation results show no influence of the type of the severe plastic deformation method in the Paris region but more effect in the threshold region.

Fracture-mechanics experiments were carried out on ultrafine-grained (UFG) samples of copper, titanium and an Al alloy to obtain the fracture behaviour under static and cyclic loading. The UFG-materials investigated show crack resistance behaviour under static loading, which was confirmed by ductile fracture surfaces. Under cyclic load the crack growth rate was described well by the ESACRACK model.

Fracture-mechanics experiments were carried out on ultrafine-grained (UFG) samples of copper, titanium and an Al alloy to obtain the fracture behaviour under static and cyclic loading. The UFG-materials investigated show crack resistance behaviour under static loading, which was confirmed by ductile fracture surfaces. Under cyclic load the crack growth rate was described well by the ESACRACK model.

KurzfassungAn ultrafeinkörnigen Werkstoffen aus Aluminium, Kupfer, Titan und Al-1,5MgScZr wurden statische und zyklische Bruchmecha- nikkennwerte ermittelt. Bei statischer Beanspruchung wiesen alle untersuchten ultrafeinkörnigen Werkstoffe Risswiderstandsverhalten auf, welches durch duktile Bruchflächenmorphologien bestätigt wurde. Bei zyklischer Beanspruchung wurden verringerte Schwellenwerte und geringere Risswachstumsgeschwindigkeiten im Bereich II der Risswachstumskurve ermittelt.