Microstructural Parameters Controlling High-Temperature Creep Life of the Nickel-Base Single-Crystal Superalloy MC2

Thermal–mechanical fatigue behaviour of a new single crystal superalloy: Effects of Si and Re alloying

“…The results indicate that the TMF performance of STAL-15 -which is not far from highly alloyed materials such as CMSX-4 -may be due to the absence of any such instability; none of the STAL-15 variants considered here show any precipitation of TCP phases during TMF testing up to 950°C. Where TCP phases -which are often rich in Cr, Re, W and Mo -arise, they are often considered to be detrimental to alloys aiming for high temperature applications, see for example [15,17,40]. These elements strengthen the c-phase and if the elements instead form TCP phases, creep resistance is impaired.…”

“…A recent study has shown that the twinning behaviour shows a tension/compression asymmetry where the formation of twins occurs in compression in the beginning of the TMF cycling [8]. When subjected to high temperatures and loads, precipitation of topologically close-packed (TCP) phases occurs in superalloys [15][16][17], and during TMF cycling it has been suggested that this is detrimental to the TMF properties [11]. In that study [11] in which CMSX-4 was investigated, a l-type of TCP phase -rich in W, Ta and Re -precipitated during TMF and drained the c-matrix from its main strengthening elements.…”

Creep of a nickel-based single-crystal superalloy during very high-temperature jumps followed by synchrotron X-ray diffraction

“…Three temperature/ stress creep regimes can be distinguished for single-crystal superalloys depending on the alloy chemistry [16][17][18][19]. Low temperature creep regimes ($750°C) are characterized by stable microstructures with a possible growth of the c 0 precipitates by Ostwald ripening processes and a plastic deformation due to c 0 shearing for high applied stresses, and due to dislocation bypassing for lower applied stresses [20,21].…”

Creep and Stress Relaxation Anisotropy of a Single-Crystal Superalloy

“…[34] Another study has also shown that TCP phases play a dominant role for the observed variability in creep life during high temperature creep. [35] However, this scatter is mainly associated with a highly localized failure process around the TCP phases during tertiary creep while the creep rates during primary and secondary creep are very reproducible. However, since TCP phase formation was observed for all directions in this study it seems that it does not affect the material anisotropy.…”