Interaction of experimental and modelling procedure to improve the fatigue behaviour of a metal matrix composite

Metal matrix composites are gaining popularity for several applications where high performance materials are needed. Titanium matrix composites continuously reinforced by silicon carbide fibres are under development for applications in aeroengines. Their use in blades, rings and shafts promises a significant weight reduction and performance improvement due to their high specific strength and stiffness. Since the aerospace industry requires high reliability of the materials used, models for predicting failure and life time are of special interest. Predicting models based on the properties of the single constituents of the composite are most suitable to reduce the number of experiments and to develop methodologies to improve specific mechanical properties. Nevertheless, both experiments on the single constituents as well as on the composite are necessary to validate the model. A previously developed rheological model is used to asses different pre-treatment procedures to improve the fatigue behaviour of a titanium matrix composite. The usage of the model and experiments on the system SCS-6/Ti-6Al-2Sn4Zr-2Mo are presented. In general the results of both are fitting very well. Where occasional disagreement between prediction and experiment occurs, its origin and measures to improve agreement will be discussed.