TEMPERATURE-DEPENDENCE OF SUPERSTRUCTURE AND FUNDAMENTAL REFLECTIONS - STUDY OF A CREEP DEFORMED SINGLE-CRYSTAL NICKEL-BASE SUPERALLOY AM1

High-energy X-ray synchrotron radiation was used to measure internal s trains inside the bulk of creep deformed AM1 single crystal superalloy specimen. A sample creep deformed at 1050 degrees C with gamma' raft- like precipitates was studied 'in situ' in temperature. The superstruc ture reflections (100) and (001) as well as fundamental reflections (2 00) and (002) were measured up to the temperature of deformation using a high-resolution triple crystal diffractometer. The lattice paramete r distribution which is related to internal stress distribution was de termined for each phase in parallel and perpendicularly to the rafts. It was shown that these parameters depend strongly on the thermomechan ical history of the analysed material and on the temperature at which measurement is performed. (C) 1997 Elsevier Science S.A.