In situ short crack characterization of a nickel-base superalloy at ambient and elevated temperature.

摘要

Fatigue experiments were performed using a nickel-base superalloy at various temperatures in a load frame attached to a scanning electron microscope. An elevated temperature stage was designed, constructed, and coupled to the apparatus, allowing temperatures in excess of 700Experiments on Waspaloy at 25The dominant mechanism of fatigue crack growth for the short cracks at 25Short fatigue crack growth rates at R = 0.1 were faster at 500Closure and nonclosure mechanisms were present at 25Qualitative observations made relating to the material microstructure showed a large decrease in "short crack growth behavior" as the temperature was increased from 25