DAMAGE TOLERANT COPPER-NIOBIUM MICROCOMPOSITE

In this paper, the microstructure, tensile response, cyclic stress amplitude-controlled fatigue response, damage tolerance and fracture characteristic of a copper-niobium microcomposite based on an oxide dispersion strengthened matrix are presented and discussed. The microcomposite samples were deformed in uniaxial tension and cyclically over a range of stress amplitudes, at both ambient and elevated temperatures, and at two different stress ratios. At a given stress ratio, an increase in test temperature was observed to have a detrimental influence on the cyclic fatigue life of the microcomposite. At given temperature the fatigue resistance. The influence of reinforcement on the mechanical response, damage tolerance and fracture behavior of the material is discussed in light of the specific roles of intrinsic microstructural effects, nature of loading, stress ratio, test temperature and macroscopic aspects of fracture.