Microstructure and creep behavior of DMS4-type nickel based superalloy single crystals with orientations near 〈001〉 and 〈011〉

Chatterjee, Dibyendu; Hazari, N.; Das, Niranjan; Mitra, Rahul

doi:10.1016/j.msea.2010.09.083

Cited by 50 publications

(25 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar as in the case of fatigue properties, the creep performance of superalloys is strongly dependent on the crystal orientation in which the material is loaded, see for example [76]. Literature studies often conclude that the 011 direction has worse creep properties than the 001 and 111 directions, see for example [55,[77][78][79]. One explanation for this is the orientation of the rafted γ -particles.…”

Section: Creepmentioning

confidence: 99%

“…A decrease of the overall γ/γ interfacial energy is attributed to both an elastic interaction between the internal stresses at the γ/γ interface, [48], and the interaction of dislocations relaxing the lattice misfit [49,50]. Generally, the rafting phenomenon is connected to creep deformation at elevated temperatures, see for example [8,33,[51][52][53][54][55]. According to Matan et al [56] rafting may occur without any external loading, if a critical amount of plastic strain has been introduced in the material and that the temperature is high enough.…”

Section: Raftingmentioning

confidence: 99%

“…• from the stress axis while for 001 oriented specimens the rafting is either parallel or perpendicular to the stress axis [55]. The γ -rafts oriented 45…”

Section: Creepmentioning

confidence: 99%

See 2 more Smart Citations

On Thermomechanical Fatigue of Single-Crystal Superalloys

Segersäll¹

2014

Linköping Studies in Science and Technology. Dissertations

View full text Add to dashboard Cite

Thesis cover: Design by Maria J. SegersällPrinted by: LiU-Tryck, Linköping, Sweden, 2014 ISBN 978-91-7519-211-6 ISSN 0345-7524 Distributed by: Division of Engineering Materials, Department of Management and Engineering Linköping University SE-58183, Linköping, Sweden © 2014 Mikael SegersällThis document was prepared with L A T E X, October 17, 2014 AbstractThanks to their excellent mechanical and chemical properties at temperatures up to 1000°C, nickel-based superalloys are used in critical components in high-temperature applications such as gas turbines and aero engines. One of the most critical components in a gas turbine is the turbine blade, and to improve the creep and fatigue properties of this component, it is sometimes cast in single-crystal form rather than in the more conventional polycrystalline form. Gas turbines are most commonly used for power generation and the turbine efficiency is highly dependent on the performance of the superalloys.Today, many gas turbines are used as a complement for renewable energy sources, for example when the wind is not blowing or when the sun is not shining, which means that the turbine runs differently compared to earlier, when it ran for longer time periods with a lower number of start-ups and shutdowns. This new way of running the turbine, with an increased number of start-ups and shut-downs, results in new conditions for critical components, and one way to simulate these conditions is to perform thermomechanical fatigue (TMF) testing in the laboratory. During TMF, both mechanical strain and temperature are cycled at the same time, and one fatigue cycle corresponds to the conditions experienced by the turbine blade during one start-up and shut-down of the turbine engine.In the work leading to this PhD thesis, TMF testing of single-crystal superalloys was first performed in the laboratory and this was then followed microstructure investigations to study the occurring deformation and damage mechanisms. Specimens with different crystallographic directions have been tested in order to investigate the anisotropic behaviour shown by these materials. Results show a significant orientation dependence during TMF in which specimens with a low elastic stiffness perform better. However, it is also shown that specimens with a higher number of active slip systems perform better during TMF compared to specimens with less active slip sysiii tems. This is because a higher number of active slip systems results in a more widespread deformation and seems to be beneficial for the TMF life. Further, microscopy shows that the deformation during TMF is localised to several deformation bands and that different deformation and damage mechanisms prevail according to in which crystal orientation the material is loaded. Deformation twinning is shown to be a major deformation mechanism during TMF and the interception of twins seems to trigger recrystallization. This is certainly negative for the mechanical properties of single-crystal superalloys since no grain boundary strengthening elemen...

show abstract

Section: Creepmentioning

confidence: 99%

Section: Raftingmentioning

confidence: 99%

See 1 more Smart Citation

On Thermomechanical Fatigue of Single-Crystal Superalloys

Segersäll¹

2014

Linköping Studies in Science and Technology. Dissertations

View full text Add to dashboard Cite

show abstract

“…Literature often concludes that the h011i direction has worse creep properties compared to the h001i and h111i directions. [22][23][24][25] One explanation for this is the orientation of the rafted c¢-particles. [22] In h011i oriented specimens, the orientation of the rafting is 45 deg from the stress axis while for h001i specimens the rafting is either parallel or perpendicular to the stress axis.…”

Section: Introductionmentioning

confidence: 99%

“…[22][23][24][25] One explanation for this is the orientation of the rafted c¢-particles. [22] In h011i oriented specimens, the orientation of the rafting is 45 deg from the stress axis while for h001i specimens the rafting is either parallel or perpendicular to the stress axis. The c¢-rafts oriented 45 deg from the stress axis do not act as good obstacles for dislocation motion as the parallel or perpendicular c¢-rafts, this is therefore one reason why the h011i direction show less creep strength than the h001i direction.…”

Section: Introductionmentioning

confidence: 99%

Creep and Stress Relaxation Anisotropy of a Single-Crystal Superalloy

Segersäll

Moverare

Leidermark

et al. 2014

Metall Mater Trans A

View full text Add to dashboard Cite

In this study, the TMF stress relaxation and creep behavior at 1023 K and 1223 K (750°C and 950°C) have been investigated for a Ni-based single-crystal superalloy. Specimens with three different crystal orientations along their axes were tested; h001i, h011i, and h111i, respectively. A highly anisotropic behavior during TMF stress relaxation was found where the h111i direction significantly shows the worst properties of all directions. The TMF stress relaxation tests were performed in both tension and compression and the results indicate a clear tension/compression asymmetry for all directions where the greatest asymmetry was observed for the h001i direction at 1023 K (750°C); here the creep rate was ten times higher in compression than tension. This study also shows that TMF cycling seems to influence the creep rate during stress relaxation temporarily, but after some time it decreases again and adapts to the pre-unloading creep rate. Creep rates from the TMF stress relaxation tests are also compared to conventional constant load creep rates and a good agreement is found.

show abstract

Anisotropic Tensile Properties of Ni-Based Single-Crystal Superalloys: A Phase-Field-Informed Crystal-Plasticity Finite-Element Investigation

Harikrishnan,

le Graverend

2024

The Minerals, Metals &Amp; Materials Series

View full text Add to dashboard Cite

Microstructure and creep behavior of DMS4-type nickel based superalloy single crystals with orientations near 〈001〉 and 〈011〉

Cited by 50 publications

References 32 publications

On Thermomechanical Fatigue of Single-Crystal Superalloys

On Thermomechanical Fatigue of Single-Crystal Superalloys

Creep and Stress Relaxation Anisotropy of a Single-Crystal Superalloy

Anisotropic Tensile Properties of Ni-Based Single-Crystal Superalloys: A Phase-Field-Informed Crystal-Plasticity Finite-Element Investigation

Contact Info

Product

Resources

About