| Abstract: | The fatigue behaviour of titanium 829 in its oil quenched (‘basketweave’) and air cooled (‘aligned’) microstructural forms has been examined at 600°C and room temperature under fully reversed, total strain controlled conditions. Identical endurances are observed for each microstructure together with a low transition life. Similarly, almost perfect cyclic stability is exhibited irrespective of microstructure, temperature, strain range and rate. This is tentatively attributed to the ability of the aligned colonies present in both microstructures to accomodate plasticity. It is argued that a reduction in strain rate shortens life due to environmental effects. Multiple crack initiation is generally associated with facet-like features, with later growth surfaces bearing striations only after fatigue at 600°C. |
