The deformation behaviour of the single crystal superalloy SC16 has been studied under low cycle fatigue (LCF) load- Ing at 1223 K, 1123 K and 298 K with a strain amplitude Range of 0.4/100 to 1.0/100 and a constant strain rate of 10~-3 s~-1. Microstructural investigation by transmission electron microscopy of the deformed specimens revealed that the deformation mechanism depends on strain ampli- tude as well as on temperature of deformation. At large strain amplitudes at elevated temperatures, the γ' precipi- tates are sheared by the matrix dislocations leading to stack- ing fault (SF) formation within the precipitates, while at small strain amplitudes deformation is confined within the γ matrix.
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