Short fatigue crack growth behaviour in Waspaloy at room and elevated temperatures

Short fatigue crack growth tests have been carried out at room and elevated temperatures using the nickel-based superalloy known as Waspaloy. A fully automated computer controlled system has been developed and employed for controlling the testing and monitoring of the growth of freely initiated surface short cracks on smooth specimens. Surface cracks as small as 10 μm in length have been detected and recorded at temperatures up to 700 °C. Anomalous short crack propagation behaviour was observed when comparisons were made with the corresponding long crack behaviour. Some aspects of mechanical, microstructural and environmental effects on the short fatigue crack growth behaviour of the material are discussed.