Effect of Solidification Parameters on the Microstructure and Creep Property of a Single Crystal Ni-base Superalloy

Zhang, Jian; Li, Jinguo; Jin, Tao; Sun, Xiaofeng; Hu, Zhuangqi

doi:10.1016/s1005-0302(10)60142-9

Cited by 34 publications

(9 citation statements)

References 9 publications

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“…Furthermore, differences between the SDAS was observed between samples. Whilst there is a known correlation between the superalloy cooling rate and the SDAS [51,52,53], this is unlikely to be the reason for the differences observed. Again, the effect of local composition must also be the controlling factor; elements such as Cr, Co, Re and Re are known to segregate to dendrite core regions, whilst the γ forming elements have greater affinity to interdendritic regions [54,55] and the magnitude of the partitioning coefficients of these elements in particular have a strong correlation to the SDAS [56].…”

Section: Macroscopic Behaviourmentioning

confidence: 84%

Ultra high-temperature deformation in a single crystal superalloy: Meso-scale process simulation and micro-mechanisms

Tang¹,

D’Souza²,

Roebuck³

et al. 2020

Preprint

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A mesoscale study of a single crystal nickel-base superalloy subjected to an industrially relevant process simulation has revealed the complex interplay between microstructural development and the micromechanical behaviour. As sample gauge volumes were smaller than the length scale of the highly cored structure of the parent material from which they were produced, their subtle composition differences gave rise to differing work hardening rates, influenced by varying secondary dendrite arm spacings, γ phase solvus temperatures and a topologically inverted γ/γ microstructure. The γ precipitates possessed a characteristic 'X' morphology, resulting from the simultaneously active solute transport mechanisms of thermally favoured octodendritic growth and N-type rafting, indicating creep-type mechanisms were prevalent. High resolution-electron backscatter diffraction (HR-EBSD) characterisation reveals deformation patterning that follows the γ/γ microstructure, with high geometrically necessary dislocation density fields localised to the γ/γ interfaces; Orowan looping is evidently the mechanism that mediated plasticity. Examination of the residual elastic stresses indicated the 'X' γ precipitate morphology had significantly enhanced the deformation heterogeneity, resulting in stress states within the γ channels that favour slip, and that encourage further growth of γ precipitate protrusions. The combination of such localised plasticity and residual stresses are considered to be critical in the formation of the recrystallisation defect in subsequent post-casting homogenisation heat treatments.

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Section: Macroscopic Behaviourmentioning

confidence: 84%

Ultra high-temperature deformation in a single crystal superalloy: Meso-scale process simulation and micro-mechanisms

Tang¹,

D’Souza²,

Roebuck³

et al. 2020

Preprint

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show abstract

“…The same outcome is achieved when comparing 3Zr and 4Zr, which showed the same colony sizes and porosities. The porosity is assumed not to play a critical role considering that compression loading was used and that the specimens were not deformed into the tertiary creep regime, where pre-existing porosity leads to faster creep rates and smaller rupture strains [44].…”

Section: Mechanical Propertiesmentioning

confidence: 99%

The effect of zirconium addition on sintering behaviour, microstructure and creep resistance of the powder metallurgy processed alloy Ti–45Al–5Nb–0.2B–0.2C

et al. 2015

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“…This area is subjected, among others, to the largest vibration amplitudes [22]. The morphology and the size of the dendrites, as well as their primary spacing, depend on the crystallization rate [1,23,24] and, thus, the interaction of dendrites of different sizes with the mould walls may be dissimilar. Therefore, the blades obtained at different withdrawal rate are examined in the present study.…”

Section: Introductionmentioning

confidence: 99%

Primary Crystal Orientation of the Thin-Walled Area of Single-Crystalline Turbine Blade Airfoils

et al. 2019

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The thin-walled airfoil areas of as-cast single-crystalline turbine blades made of CMSX-4 superalloy were studied. The blades were produced by the industrial Bridgman technique at withdrawal rates of 2, 3 and 4 mm/min. The angle between the [001] crystallographic direction and blade axis, related to the primary orientation, was defined by the Ω-scan X-ray diffraction method at points on the camber line located near the tip of an airfoil and at points of a line located in parallel and near the trailing edge. Additionally, primary crystal orientation was determined by Laue diffraction at the selected points of an airfoil. The influence of mould wall inclination on the primary crystal orientation of the thin-walled areas is discussed. The effect of change in the [001] crystallographic direction, named as “force directing”, was considered with regard to the arrangement of primary dendrite arms in relation to the trailing edge and the camber line. It was stated that when the distance between the mould walls is less than the critical value of about 1.5 mm the “force directing” increases as the distance between the walls of the mould decreases. The effect may be controlled by selecting an appropriate secondary orientation using a seed crystal in the blade production process. The model of dendrite interaction with the mould walls, including bending and “deflection”, was proposed.

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Effect of Solidification Parameters on the Microstructure and Creep Property of a Single Crystal Ni-base Superalloy

Cited by 34 publications

References 9 publications

Ultra high-temperature deformation in a single crystal superalloy: Meso-scale process simulation and micro-mechanisms

Ultra high-temperature deformation in a single crystal superalloy: Meso-scale process simulation and micro-mechanisms

The effect of zirconium addition on sintering behaviour, microstructure and creep resistance of the powder metallurgy processed alloy Ti–45Al–5Nb–0.2B–0.2C

Primary Crystal Orientation of the Thin-Walled Area of Single-Crystalline Turbine Blade Airfoils

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