TCP-phases in nickel-base alloys with elevated chromium content

Pigrova, G. D.

doi:10.1007/s11041-006-0029-7

Cited by 6 publications

(3 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Meanwhile, as a solid solution strengthening element, the alloying of Ta also improves the hot-corrosion and oxidation resistance [10,11]. However, the stabilization of topologically close packed (TCP) phase will deteriorate the mechanical properties of the superalloys for excessive addition of Cr and Ta elements [12,13]. Therefore, it is of significant necessity to investigate the phase diagram of the ternary Ni-Cr-Ta system, not only for the future thermodynamics assessment, but also enhancing the potential practical applications.…”

Section: Introductionmentioning

confidence: 99%

Isothermal Sections of the Ni-Cr-Ta Ternary System at 1200 °C and 1300 °C

Wang

Liang

Yang

et al. 2019

Metals

View full text Add to dashboard Cite

Two isothermal sections of the Ni-Cr-Ta ternary system at 1200 °C and 1300 °C have been determined by using electron probe microanalysis, energy dispersive spectroscopy and differential scanning calorimeter. A Laves phase (Ni, Cr)2Ta(HT)(C14 structure) with large solid solubility stabilized by the Ni addition was determined in both two isothermal sections. The composition range of this phase was about 25.8–66.0 at.% Cr, 2.5-44.3 at.% Ni, and 24.0-40.0 at.% Ta at 1200 °C, which increased with raising temperature. The melting point of the Ni-Cr alloys decreased with the addition of Ta. No ternary compound was found in both these two isothermal sections. The present work could be significant for practical application of nickel-based alloys and future thermodynamics assessment of the Ni-Cr-Ta ternary system.

show abstract

Section: Introductionmentioning

confidence: 99%

Isothermal Sections of the Ni-Cr-Ta Ternary System at 1200 °C and 1300 °C

Wang

Liang

Yang

et al. 2019

Metals

View full text Add to dashboard Cite

show abstract

“…Also, the appearance of the σ phase is observed at high concentrations of Cr. This last phase has been widely reported experimentally and is characterized as detrimental, so it should be avoided in alloy design [39]. Therefore, based on the above, the possible phases in the quaternary alloys studied can be considered analogous to the Ni-Cr-C system.…”

Section: Thermodynamic Study Of the Phases In Ni-cr-fe-c Alloysmentioning

confidence: 94%

Hydrogen Diffusion in Nickel Superalloys: Electrochemical Permeation Study and Computational AI Predictive Modeling

Román-Sedano,

Campillo,

Villalobos

et al. 2023

Materials

View full text Add to dashboard Cite

Ni-based superalloys are materials utilized in high-performance services that demand excellent corrosion resistance and mechanical properties. Its usages can include fuel storage, gas turbines, petrochemistry, and nuclear reactor components, among others. On the other hand, hydrogen (H), in contact with metallic materials, can cause a phenomenon known as hydrogen embrittlement (HE), and its study related to the superalloys is fundamental. This is related to the analysis of the solubility, diffusivity, and permeability of H and its interaction with the bulk, second-phase particles, grain boundaries, precipitates, and dislocation networks. The aim of this work was mainly to study the effect of chromium (Cr) content on H diffusivity in Ni-based superalloys; additionally, the development of predictive models using artificial intelligence. For this purpose, the permeability test was employed based on the double cell experiment proposed by Devanathan–Stachurski, obtaining the effective diffusion coefficient (Deff), steady-state flux (Jss), and the trap density (NT) for the commercial and experimentally designed and manufactured Ni-based superalloys. The material was characterized with energy-dispersed X-ray spectroscopy (EDS), atomic absorption, CHNS/O chemical analysis, X-ray diffraction (XRD), brightfield optical microscopy (OM), and scanning electron microscopy (SEM). On the other hand, predictive models were developed employing artificial neural networks (ANNs) using experimental results as a database. Furthermore, the relative importance of the main parameters related to the H diffusion was calculated. The Deff, Jss, and NT achieved showed relatively higher values considering those reported for Ni alloys and were found in the following orders of magnitude: [1 × 10−8, 1 × 10−11 m2/s], [1 × 10−5, 9 × 10−7 mol/cm2s], and [7 × 1025 traps/m3], respectively. Regarding the predictive models, linear correlation coefficients of 0.96 and 0.80 were reached, corresponding to the Deff and Jss. Due to the results obtained, it was suitable to dismiss the effect of Cr in solid solution on the H diffusion. Finally, the predictive models developed can be considered for the estimation of Deff and Jss as functions of the characterized features.

show abstract

“…The TCP phases have different crystal structures than the matrix and more complex morphology, like tessellated layers of arrays stacked into a polyhedral coordination, i.e., hexagons, pentagons or triangles, with a high and uniform packing density of atoms. They are also detrimental because of the strengthening elements depletion from the γ phase, such as Mo and Cr, becoming a probable crack initiation site during cyclic loading [4,[6][7][8]13,[17][18][19][20][21][22][23].…”

Section: Introductionmentioning

confidence: 99%