An investigation of fatigue and fracture in NiAl–Mo composites

The effects of reinforcement morphology (particulate versus fibers) and particulate volume fraction on the fatigue and fracture behavior of NiAl–Mo composites are discussed. The improved fracture toughness observed in these composites are not associated with improved tensile ductility. The improved fracture toughness levels are explained by quantifying the shielding contributions due to crack trapping mechanisms. Stable crack growth under cyclic loading was observed at room temperature in all the NiAl–Mo composites that were studied. The potential implications of the results are discussed for future composite development.