In Situ Measurement of the γlγ' Lattice Mismatch Evolution of a Nickel-Based Single-Crystal Superalloy During Non-isothermal Very High-Temperature Creep Experiments

摘要

The evolution of the γ/γ' lattice mismatch of the AMI single-crystal superalloy was measured during in situ non-isothermal very high-temperature creep tests under X-ray synchrotron radiation. The magnitude of the effective lattice mismatch in the 1273 K to 1323 K (1000 °C to 1050 °C) temperature range always increased after overheatings performed at temperatures lower than 1403 K (1130 °C). In contrast, a decrease of its magnitude was observed after overheatings at temperatures greater than 1453 K (1180 °C) due to massive dislocation recovery processes occurring at very high temperature.