Effect of ruthenium on the precipitation of topologically close packed phases in Ni-based superalloys of 3rd and 4th generation

Matuszewski, Kamil; Rettig, Ralf; Matysiak, H.; Peng, Zirong; Povstugar, Ivan; Choi, Pyuck‐Pa; Müller, Julian; Raabe, Dierk; Spiecker, Erdmann; Kurzydłowski, Krzysztof J.; Singer, Robert F.

doi:10.1016/j.actamat.2015.05.033

Cited by 135 publications

(22 citation statements)

References 27 publications

(75 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In bulk transformation the σ‐phase is formed at the beginning of transformation. Moreover, the bulk precipitation originates in the dendrite cores, as it is described in detail in a related publication of present authors . A strong influence of Re and Ru was found on both types of TCP phase precipitation.…”

Section: Resultssupporting

confidence: 72%

“…The present paper is part of a larger effort to clarify the effect of Re and Ru on the precipitation of TCP phases. Recently, we have published results based on microscopic observation and quantitative analysis that lead to the conclusion that Ru influences precipitation of TCP phases mainly due to thermodynamic reasons, i.e., Ru decreases the driving force for TCP phase precipitation. However, the experiments did not show good agreement with CALPHAD (CALculation of PHAse diagrams) thermodynamic calculations.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

On the Thermodynamics and Kinetics of TCP Phase Precipitation in Re‐ and Ru‐ Containing Ni‐base Superalloys

et al. 2015

View full text Add to dashboard Cite

Three experimental Ni-base superalloys of the second, third and fourth generation are studied in this work to clarify the effect of Re and Ru on the precipitation of TCP phases. Thermodynamic calculations using the CALPHAD method are performed based on the local chemical composition obtained with the use of electron probe microanalysis. The effects of microsegregation and g 0 -precipitation are taken into account. The results, complemented with scanning electron microscopy observations, show that Re increases, while Ru decreases the inclination of the material to precipitate TCP phases. The effect of both elements is assigned to thermodynamic rather than kinetic reasons. The CALPHAD-calculations do predict the effect of Re on the TCP phase formation in the investigated alloys correctly, but not the effect of Ru.

show abstract

Section: Resultssupporting

confidence: 72%

Section: Introductionmentioning

confidence: 99%

On the Thermodynamics and Kinetics of TCP Phase Precipitation in Re‐ and Ru‐ Containing Ni‐base Superalloys

et al. 2015

View full text Add to dashboard Cite

show abstract

“…The r phase often forms first and acts as a site for secondphase nucleation [54]. The orientations of these phases with the matrix and their morphologies were studied extensively [55][56][57][58]. However, the r and P phases are yet to be observed both in our alloys as well as in Co-Al-W alloys.…”

Section: Phase Stability and Decomposition Behavior Of Co-30ni-10al-5mentioning

confidence: 96%

Phase evolution and crystallography of precipitates during decomposition of new “tungsten-free” Co(Ni)–Mo–Al–Nb γ–γ′ superalloys at elevated temperatures

et al. 2016

View full text Add to dashboard Cite

This article reports the microstructural stability and consequent phase decomposition including the appearance of topologically close-packed (TCP) phases at high temperature of recently discovered tungsten-free c-c 0 alloys of base composition Co-10Al-5Mo-2Nb with or without the addition of Ni and Ti. On prolonged aging at 800°C of the Co-10Al-5Mo-2Nb alloy, needle-shaped DO 19 -ordered precipitates with stoichiometry of Co 3 (Mo, Nb) start appearing in the microstructure. In addition, growth of cellular domains from the grain boundaries featuring a three-phase composite lamellar structure could be observed. These phases are fcc c-Co with composition different from the original matrix, CoAl with B2 ordering and Co 3 (Mo, Nb) with DO 19 ordering. All the phases exhibit well-defined crystallographic orientation relationships. The decomposition of the alloys depends on the solvus temperature of the c 0 phase. The Nicontaining alloy exhibits no phase decomposition until 100 h of aging at 800°C without any significant effect on c 0 volume fraction (76 %). However, at 950°C, the alloy decomposes leading to the appearance of four different phases including TCP phases: a Cr 3 Si-type cubic phase, a hexagonal Laves phase, rhombohedral l phase, and solid solution of Co phase. The c-c 0 microstructure in the Co-10Al-5Mo-2Nb and Co-30Ni-10Al-5Mo-2Ta alloys is not stable at 800 and 950°C, respectively, on long-term aging. This shows that the measured solvus temperatures (i.e., 866 and 990°C) are metastable solvus temperatures. We also report that the Ti-containing alloy exhibits superior stability with no evidence of either TCP phase formation or any other decomposition of c 0 precipitates, even after aging at 950°C for 100 h.

show abstract

“…This is in accordance with the results of previous works (e.g. Rae & Reed, ; Matuszewski et al ., ).…”

Section: Resultsmentioning

confidence: 97%

“…Therefore, SC superalloys contain refractory elements, such as Mo, W and Re, which diffuse slowly in nickel and thus provide solid solution strengthening of the γ phase. Unfortunately, the presence of heavy elements promotes the precipitation of brittle TCP phases after long exposure at high temperatures above 900°C (Darolia et al, 1988;Rae et al, 2000;Rae & Reed, 2001;Cheng et al, 2011;Matuszewski et al, 2015). To describe the structure of TCP phases, several approaches, such as Kasper coordination polyhedra, atomic layers, structural units, etc., have been employed (Tan et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Characterization of the μ and P phase precipitates in the CMSX‐4 single crystal superalloy

Dubiel

Indyka

Moskalewicz

et al. 2017

Journal of Microscopy

View full text Add to dashboard Cite

A combination of scanning electron microscopy (SEM), transmission electron microscopy (TEM) and scanning-transmission electron microscopy (STEM) using high-angle annular-dark-field (HAADF) imaging, focussed ion beam- scanning electron microscopy (FIB-SEM) tomography, selected area electron diffraction with beam precession (PED), as well as spatially resolved energy-dispersive X-ray spectroscopy (EDS) and electron energy loss spectroscopy (EELS), was used to investigate topologically close-packed (TCP) phases, occurring in the CMSX-4 superalloy subjected to high temperature annealing and creep deformation. Structural and chemical analyses were performed to identify the TCP phases and provide information concerning the compositional partitioning of elements between them. The results of SEM and FIB-SEM tomography revealed the presence of merged TCP particles, which were identified by TEM and PED analysis as coprecipitates of the μ and P phases. Inside the TCP particles that were several micrometres in size, platelets of alternating μ and P phases of nanometric width were found. The combination of STEM-HAADF imaging with spatially resolved EDS and EELS microanalysis allowed determination of the significant partitioning of the constituent elements between the μ and P phases.

show abstract

Effect of ruthenium on the precipitation of topologically close packed phases in Ni-based superalloys of 3rd and 4th generation

Cited by 135 publications

References 27 publications

On the Thermodynamics and Kinetics of TCP Phase Precipitation in Re‐ and Ru‐ Containing Ni‐base Superalloys

On the Thermodynamics and Kinetics of TCP Phase Precipitation in Re‐ and Ru‐ Containing Ni‐base Superalloys

Phase evolution and crystallography of precipitates during decomposition of new “tungsten-free” Co(Ni)–Mo–Al–Nb γ–γ′ superalloys at elevated temperatures

Characterization of the μ and P phase precipitates in the CMSX‐4 single crystal superalloy

Contact Info

Product

Resources

About