Crystallographic Orientation Relationship with Geometrically Necessary Dislocation Accumulation During High-Temperature Deformation in RR1000 Nickel-Based Superalloy

Abstract

In the current study, it is demonstrated that soft grains along 〈100〉 fiber provided a pure shear condition for easy dislocation movement leading to a relatively low dislocation density. The hard grains along the 〈111〉 fiber, however, were not favorably oriented for slip system activation and caused high dislocation accumulation. It is concluded that the average overall dislocation density does not provide a meaningful value, as it is largely dependent on the original material crystallographic texture, the numbers of hard and soft grains in the electron backscatter diffraction (EBSD) mapped area, and the grain size factor.

Establishment of unified creep–fatigue life prediction under various temperatures and investigation of failure physical mechanism for Type 304 stainless steel

“…23,24 In particular, a geometrically necessary dislocation (GND) map evaluated from EBSD misorientation data was introduced to understand the degradation process of the material under specific loading conditions. [25][26][27] Some details of dislocation movement, [28][29][30] damage accumulation, 31,32 and crack initiation 33,34 under single fatigue or creep damage-driven loading have been disclosed by the GND map. Furthermore, such oblique representations interwoven with transmission electron microscope (TEM) can qualitatively elucidate the evolution process of dislocations.…”

Effect of Si on the Solidification Segregation Behavior of a New Ni–Co‐Based Superalloy

“…To meet the operational requirements of high‐efficiency engines, the compressor discharge and turbine entry temperature are continuously increased. At present, new and advanced turbine disk Ni‐based superalloys, such as ME3 [ 1 ] and RR1000, [ 2 ] have been developed. These alloys are fabricated by powder metallurgy processing route due to their high‐refractory element contents.…”

Archives of Metallurgy and Materials

“…to increase the hightemperature strength, the alloys are alloyed with a high chromium content. however, a high chromium content can cause the appearance of topologically close-packed phases of the μ, σ type in the casting structure during the development process, which will lead to phase-structural instability and embrittlement of parts [16][17][18][19][20][21][22][23][24].…”