In situ measurement of the γ/ γ′ lattice mismatch evolution of a nickel-based single-crystal superalloy during non-isothermal very high-temperature creep experiments

Abstract

The evolution of the γ/ γ′ lattice mismatch of the AM1 single-crystal superalloy was measured during in situ nonisothermal 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. © 2012 The Minerals, Metals & Materials Society and ASM International.