Stress relaxation behavior in single crystal superalloys

Nathal, M. V.; Bierer, J.; Evans, Laura J.; Pogue, E.A.; Ritzert, Frank J.; Gabb, Timothy P.

doi:10.1016/j.msea.2015.05.102

Cited by 19 publications

(10 citation statements)

References 12 publications

(31 reference statements)

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“…at higher strain rates, as the temperature increases. Similar behavior has been reported by Nathal et al [53] for the first-, second-, and fourth-generation single-crystal superalloys, NASAIR 100, CMSX-4, and EPM-102. These authors showed that the effect disappears if the specimens are crept prior to stress relaxation, as the pre-rafted microstructure offers higher resistance to primary creep.…”

Section: Stress Relaxation Testssupporting

confidence: 87%

“…This reduction has been shown to be related to directional coarsening of precipitates at higher temperatures. [53] It should be noted that these figures cannot be readily related to effective stress exponents used in creep models, as explained by Carry and Strudel for both primary [44] and tertiary creep. [45] Discrepancies between apparent and effective exponents were also confirmed by the experimental results of Dupeux et al from stress relaxation [55] and conventional creep tests [57] on CMSX-2.…”

Section: Stress Relaxation Testsmentioning

confidence: 95%

“…As opposed to a standard creep test, the driving force for directional coarsening and creep strain accumulation decreases with time during SRT and exceedingly tends towards zero. Nathal et al [53] observed no further microstructural changes when comparing specimens relaxed at 982°C for 100 and 370 hours. As such, once a steady-state stress value has been reached, the results from SRT are increasingly affected by mechanical noise and provide little further insight into high-temperature damage accumulation mechanisms.…”

Section: Stress Relaxation Testsmentioning

confidence: 96%

“…[24] Several recent studies have made use of SRT for the mechanical characterization of superalloys and have shown results consistent with conventional creep data from the literature, thus enabling accelerated testing campaigns of new alloys. [52][53][54] Here, in common with such approaches, it is assumed that the total strain rate of the system remains in equilibrium as crosshead displacement is fixed, consistent with:…”

Section: Stress Relaxation Testsmentioning

confidence: 99%

See 3 more Smart Citations

On the Rapid Assessment of Mechanical Behavior of a Prototype Nickel-Based Superalloy using Small-Scale Testing

Sulzer

Alabort

Németh

et al. 2018

Metall Mater Trans A

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An electro-thermal mechanical testing (ETMT) system is used to assess the mechanical behavior of a prototype single-crystal superalloy suitable for industrial gas turbine applications. Miniaturized testpieces of a few mm 2 cross section are used, allowing relatively small volumes to be tested. Novel methods involving temperature ramping and stress relaxation are employed, with the quantitative data measured and then compared to conventional methods. Advantages and limitations of the ETMT system are identified; particularly for the rapid assessment of prototype alloys prior to scale-up to pilot-scale quantities, it is concluded that some significant benefits emerge.

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Section: Stress Relaxation Testssupporting

confidence: 87%

Section: Stress Relaxation Testsmentioning

confidence: 95%

Section: Stress Relaxation Testsmentioning

confidence: 96%

Section: Stress Relaxation Testsmentioning

confidence: 99%

See 2 more Smart Citations

On the Rapid Assessment of Mechanical Behavior of a Prototype Nickel-Based Superalloy using Small-Scale Testing

Sulzer

Alabort

Németh

et al. 2018

Metall Mater Trans A

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“…Polycrystalline: any study that deals with a superalloy having a polycrystal grain structure [3,5,7,12,33,46,47,53,55,57,67] Comparative studies: any study that has done a comparison on different properties, manufacturing methods, casting conditions, alloys, or any other parameters [1-3, 10, 11, 13, 16, 19-23, 25, 30, 33-36, 39, 45, 47, 52, 53, 57, 66, 74-78] 1 st generation superalloy: any study that has used a 1 st generation superalloy [1, 3, 5-7, 10, 11, 13, 30-35, 40, 42, 43, 49, 79] 2 nd generation superalloy: any study that has used a 2 nd generation superalloy [16, 19, 20, 22, 23, 28, 29, 33, 36-38, 43, 56, 68] 3 rd generation superalloy: any study that has used a 3 rd generation superalloy [8,21,50] 4 th generation superalloy: any study that has used a 4 th generation superalloy [23,51,77] 4…”

Section: Research Areamentioning

confidence: 99%

Recent Advancements in the Field of Ni‐Based Superalloys

Selvaraj

Sundaramali

Dev

et al. 2021

Advances in Materials Science and Engineering

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In this review article, research papers related to recent developments in Ni-superalloy technologies have been reviewed in order to provide an insight into recent achievements and the potential for further study, research, and development in this field. In this paper, studies on various aspects of Ni-based superalloys are reviewed, such as production methods, which include widely used casting methods, as well as unconventional alternative procedures, novel techniques, or simulation and prediction of certain alloy casting properties. Reviewing was done by categorising the papers into 4 major categories: manufacturing of Ni-based superalloys, effects of alloying elements, physical and mechanical properties of Ni-based superalloys, and defects in Ni-based superalloys. The process used to make Ni-superalloy parts can have a huge impact on the production process efficiency, the final product’s quality and properties, and the defects formed in it. Investment casting is one of the most common methods for making Ni-superalloy parts. Manufacturing covers studies on various casting methods used to make Ni-based superalloy components, novel techniques and methods developed to improve casting procedures to produce better products, and alternative manufacturing methods like AM and HIP processing. Similar to production process, the role of alloying elements is also very important. Even minor changes in their compositions can cause significant changes in the final product. Simultaneously, these alloying elements appear to be more efficient in the development of new methods to control product quality, suppress defect formation, and improve material properties such as the creep and fatigue. As a result, the effects of various alloying elements used in castings of Ni-based superalloys are thoroughly examined. A material’s properties are its most important components. They assist the industrialist in selecting or developing a material based on the needs of the application/use. With this in mind, many researchers have conducted extensive research on physical and mechanical properties, as well as how to improve them. Fatigue life, stress rupture, creep properties, impact ductility, strain response, stress relaxation behaviour, and so on are some of the most important physical and mechanical properties of Ni-superalloys. This article thoroughly reviews various studies on these properties, how and by what factors they are affected, and how they can be improved. Another important factor to consider when making Ni-superalloy castings is defect formation, which can affect the properties of the final product. Freckle defects, hot tears, porosities, and slivers are some of the major defects that occur in Ni-superalloys during the casting process. This article also reviews in detail about these defects, how they form, and how they affect the final product. These defects were found to have a significant influence on a variety of properties, such as creep, fatigue behaviour, and fracture mechanism. Topics and areas such as reinforcement of Ni-superalloys with the help of CNCs and 3D printing of Ni-superalloys that can provide scope for potential future research are highlighted based on the above-reviewed papers.

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Metallurgical Mechanisms upon Stress Relaxation Annealing of the AD730TM Superalloy

Durand

Cormier

Villechaise

et al. 2020

The Minerals, Metals &Amp; Materials Series

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Tout d'abord, je remercie mes encadrants académiques Nathalie BOZZOLO et Jonathan CORMIER ainsi que mon encandrant industriel Jean-Michel FRANCHET pour toute l'énergie investie, votre soutien et la grande disponibilité dont vous avez su faire preuve tout au long de ces trois belles années. Je suis ravi d'avoir travaillé en votre compagnie car outre l'appui scientifique, vous avez toujours été là pour me soutenir et me conseiller au cours de la construction de cette thèse. Vos futurs doctorants ne savent pas encore la chance qu'ils auront de vous côtoyer.Ce travail n'aurait pu être mené à bien sans les collaborations, la disponibilité et l'accueil des personnes qui ont gravité autour de sujet. Je tiens donc à remercier chaleureuse-

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Stress relaxation behavior in single crystal superalloys

Cited by 19 publications

References 12 publications

On the Rapid Assessment of Mechanical Behavior of a Prototype Nickel-Based Superalloy using Small-Scale Testing

On the Rapid Assessment of Mechanical Behavior of a Prototype Nickel-Based Superalloy using Small-Scale Testing

Recent Advancements in the Field of Ni‐Based Superalloys

Metallurgical Mechanisms upon Stress Relaxation Annealing of the AD730TM Superalloy

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