Microstructural evolution and creep mechanisms in Ni-based single crystal superalloys: A review

Xia, Wanshun; Zhao, Xinbao; Liang, Yue; Zhang, Ze

doi:10.1016/j.jallcom.2019.152954

Cited by 112 publications

(19 citation statements)

References 175 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Heat-treated microstructure. Figure 1b 1 shows the heat-treated microstructure in Alloy SMSC, being representative of conventional two-phase microstructure [12,32]. The cubic γ '-precipitates embed in straight γchannels.…”

Section: Resultsmentioning

confidence: 99%

Topologically inverse microstructure in single-crystal superalloys: microstructural stability and properties at ultrahigh temperature

Zhao

et al. 2021

Materials Research Letters

View full text Add to dashboard Cite

Topological phase inversion, in which γ '-precipitate becomes topological matrix phase, is a typical 'detrimental' microstructural degradation in Ni-based single-crystal superalloys. Here, a topologically inverse structure without service-induced damages is proposed. This structure exhibits excellent stress rupture properties at 1200°C and great microstructural stability, characterized by high, steady two-phase interface density. The relationship of the interface density to microscopic dislocation motion and macroscopic plastic deformation has been established, which reveals possible strengthening effect. These results will help understanding the benefit from this 'degraded' but quite stable microstructure and guide microstructure tuning against long-termed heat-resisted service. IMPACT STATEMENTTopological phase inversion achieved after heat treatment exhibits great microstructural stability and enhanced 1200°C stress rupture properties of single-crystal superalloys. The mechanism behind this beneficial effect is uncovered.

show abstract

Section: Resultsmentioning

confidence: 99%

Topologically inverse microstructure in single-crystal superalloys: microstructural stability and properties at ultrahigh temperature

Zhao

et al. 2021

Materials Research Letters

View full text Add to dashboard Cite

show abstract

“…16 Although Re increases dendrite segregation, 16 it enhances long-term stability by segregating to and thereby stabilizing the γ/γ′ interfaces, hence reducing coarsening of γ′ during creep. 52,53 However, this effect may be the result of a combination of Re with other alloying elements. 49 The comparatively low diffusivity of Re and W impedes precipitate coarsening.…”

Section: Chemistry Tailoring For Optimized Materials Propertiesmentioning

confidence: 99%

A review on atom probe and correlative microscopy studies of corrosion in nickel-based superalloys

et al. 2022

View full text Add to dashboard Cite

This article discusses challenges faced in the development of new Ni-based superalloys for applications in the hottest sections of turbine engines and the use of atom probe tomography and correlative microscopy for characterization of these complex alloys with regards to microstructural and compositional design. The two strengthening phases γ and γ′ are introduced and the precipitation of topologically close-packed phases and their potential detrimental effects on superalloy properties are reviewed. Mechanisms of environmental degradation, namely oxidation and hot corrosion, are elucidated and recent research studies on a new phenomenon of hot corrosion at relatively low temperatures below 600°C are discussed. The effect of individual alloying elements on superalloy properties is reviewed, with a focus on Mo and W. The use of atom probe in correlation with state-of-the-art microscopy, spectroscopy and diffraction techniques to study and understand oxidation and corrosion of Ni-based superalloys, including crack tip investigations, is presented. Graphical abstract

show abstract

“…Figure 6c also shows the γ 0 phase precipitated in the two-step aged atomized powder of Ni-based superalloy with the similar composition. Except some larger coarsened γ 0 discussed widely in the literature by the Ostwald ripening effect, [24][25][26][27][28] the main precipitates have near-spherical morphology in submicrometer size. As both solution-aged and atomized Ni-based superalloy powders have the same spherical morphology of γ 0 , it clearly suggests that severe plastic deformation during mechanical alloying change γ 0 morphology to irregular-shaped morphology in microscale characterization.…”

Section: Comparison Of Maed and Atomized Conditionsmentioning

confidence: 99%

“…Ni‐based superalloys are advanced engineering materials for hot sections in gas turbine applications due to their excellent high‐temperature properties. [ 1–4 ] These materials achieve their high temperature strengthening by precipitation of the ordered γ′ phase in an austenitic γ matrix. One special category of Ni‐based superalloys has the advantage of secondary strengthening mechanism by dispersion of fine oxide particles, the so‐called “Ni‐based oxide dispersion strengthened (ODS) superalloys.” [ 5–10 ] The typically yttrium‐based oxide particles dispersed in the superalloy matrix are highly stable beyond 1000 °C and promote the high‐temperature performance of ODS superalloys.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Processing Conditions on the γ′ Morphology of an Oxide Dispersion Strengthened Ni‐Based Superalloy

et al. 2020

View full text Add to dashboard Cite

Herein, the evolution of the microstructure of a newly developed oxide dispersion strengthened (ODS) Ni‐based superalloy with emphasis on γ′ morphology during different processing conditions is investigated. X‐ray analysis of severely deformed mechanically alloyed (MAed) powders shows that the as‐milled nano‐sized crystallite size increases with annealing associated with the sharp drop of dislocation density. At the same time, by annealing MAed powders γ′ precipitates above 300 °C, and depending on the aging treatment regime, Vickers microhardness changes mainly due to γ′ distribution and dislocation release. The thorough evaluation of γ′ morphology in the microscale shows that in contrast to the spherical shape of γ′, after heat treatment of solutionized MAed ODS superalloy, irregular‐shaped γ′ exist in the MAed ODS superalloy due to severe plastic deformation during mechanical alloying. However, a unique nanostructured lamellar morphology forms in the γ′ precipitates with different lamellae directions. This structure is stable in all subsequent processing steps with γ′ lamellae of (011true¯) planes and intervals of 20–30 nm. The scanning transmission electron microscopy (STEM)–high‐angle annular dark‐field (HAADF) composition analysis clarifies that the nanostructured lamellar morphology shows no partitioning of alloying elements, and its origin may be attributed to the formation of antiphase domain boundaries.

show abstract

Microstructural evolution and creep mechanisms in Ni-based single crystal superalloys: A review

Cited by 112 publications

References 175 publications

Topologically inverse microstructure in single-crystal superalloys: microstructural stability and properties at ultrahigh temperature

Topologically inverse microstructure in single-crystal superalloys: microstructural stability and properties at ultrahigh temperature

A review on atom probe and correlative microscopy studies of corrosion in nickel-based superalloys

Evaluation of Processing Conditions on the γ′ Morphology of an Oxide Dispersion Strengthened Ni‐Based Superalloy

Contact Info

Product

Resources

About