Creep‐fatigue behaviour of single‐crystal Ni‐base superalloy CMSX‐8

Abstract

The creep‐fatigue behaviour of a lower cost, reduced rhenium Ni‐base superalloy, CMSX‐8, a variant of CMSX‐4, cast in a single crystal was experimentally evaluated over a broad range of conditions, from room temperature to 1100°C, and for two loading orientations: <001> and <111>. The fatigue lives depend on the orientation, cycle type, and temperature. The relative importance of these parameters on influencing the life is identified and discussed. From this understanding, a simple life model is constructed to capture the influence of these broad test conditions. The results are compared with those of the higher Re superalloy, CMSX‐4.

Relationship between the microstructure and the heat treatment and creep behavior of Fe–33Ni–19Cr alloy

“…2 A large number of triple junctions in fine-grained specimens can limit crack propagation. [36][37][38][39][40][41][42] These results agreed with the critical length criterion for intergranular creep rupture 43 and are found to be applicable in Ni-based alloy 32,[44][45][46][47] and 316 stainless steel. 12,44 The percentage elongation results, which are the ductility, were slightly affected by the testing temperature.…”

Employing sequential experiments to gain insights on the interaction between creep and fatigue damage in Ni‐base superalloys

“…In experiments, the hold times may be either under stress‐ or strain‐controlled modes and typically imposed at either the maximum or minimum peaks of loading profile, or sometimes both, to approximate the extremes of the possible conditions in components. Compressive dwells tend to be more damaging than tensile dwells 18–21 . The influence of the dwell is magnified when the strain amplitude is lower 18,22 .…”

Characterization of isothermal and cyclic thermal damage of EB‐PVD TBCs with the help of the 3D‐DIC technique

“…It is widely known that nickel base single crystal superalloys for aeroengine turbine blades are significantly sensitive to temperature variation. 1 Therefore, in the last decades, the electron beam physical vapor deposition thermal barrier coatings (EB-PVD TBCs) have been widely used in aero-engines for the advanced thermo-mechanical property. The purposes of TBCs are to provide heat protection for high-temperature components, such as turbine blades, and to meet the requirements of improving the performance of advanced aeroengines.…”

“…It is widely known that nickel base single crystal superalloys for aeroengine turbine blades are significantly sensitive to temperature variation 1 . Therefore, in the last decades, the electron beam physical vapor deposition thermal barrier coatings (EB‐PVD TBCs) have been widely used in aero‐engines for the advanced thermo‐mechanical property.…”