Microstructure Formation in Cast TiZrHfCoNiCu and CoNiCuAlGaIn High Entropy Shape Memory Alloys: A Comparison

Kosorukova, Tetiana; Gerstein, Gregory; Odnosum, V. V.; Koval, Yu. N.; Maier, Hans Jürgen; Firstov, G.S.

doi:10.3390/ma12244227

Cited by 19 publications

(11 citation statements)

References 23 publications

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“…In the majority of cases, multicomponent alloys are synthesized by crystallization from the melt (arc or induction melting in vacuum or argon [5][6][7][13][14][15][16][17][18][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43], plasma spark sintering [19], electric current assisted sintering [20,21], laser or plasma cladding deposition of coatings [44][45][46][47][48][49][50][51][52][53][54][55], additive manufacturing by the laser-powder bed fusion [56,57] or laser-metal deposition [58], self-propagating high-temperature synthesis (SHS) [59], and by brazing within the brazing joints [60,61]). Figure 1 shows a schematic phase diagram for the simplest case when there are on...…”

Section: Grain Boundary Wetting By the Liquid Phasementioning

confidence: 99%

The Grain Boundary Wetting Phenomena in the Ti-Containing High-Entropy Alloys: A Review

Straumal

Korneva

Kuzmin

et al. 2021

Metals

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In this review, the phenomenon of grain boundary (GB) wetting by melt is analyzed for multicomponent alloys without principal components (also called high-entropy alloys or HEAs) containing titanium. GB wetting can be complete or partial. In the former case, the liquid phase forms the continuous layers between solid grains and completely separates them. In the latter case of partial GB wetting, the melt forms the chain of droplets in GBs, with certain non-zero contact angles. The GB wetting phenomenon can be observed in HEAs produced by all solidification-based technologies. GB leads to the appearance of novel GB tie lines Twmin and Twmax in the multicomponent HEA phase diagrams. The so-called grain-boundary engineering of HEAs permits the use of GB wetting to improve the HEAs’ properties or, alternatively, its exclusion if the GB layers of a second phase are detrimental.

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Section: Grain Boundary Wetting By the Liquid Phasementioning

confidence: 99%

The Grain Boundary Wetting Phenomena in the Ti-Containing High-Entropy Alloys: A Review

Straumal

Korneva

Kuzmin

et al. 2021

Metals

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“…The SEM observations show dendritic globular phase and an interdendritic phase for the as-cast state (Fig. 4a [31].…”

Section: Preliminary Experimental Resultsmentioning

confidence: 99%

Investigation and Composition Characterization of a “NiTi-like” Alloy Combining High Temperature Shape Memory and High Entropy

Peltier

Lohmuller

Meraghni

et al. 2020

Shap. Mem. Superelasticity

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New high temperature shape memory alloys with five or more elements are under development and present attractive performances for several functional applications. These active metallic materials are called high entropy and high temperature shape memory alloys (HE-HT-SMAs). This work deals with the characterization of an alloy that combines high temperature shape memory effect and high entropy effect features, a NiCuTiHfZr alloy. The evolution of the phase transformation and the shape memory effect during thermal fatigue was compared with a ternary alloy NiTiZr. Ingots were prepared in a cold crucible and alloys were characterized after thermal cycling at 600 K without a protective gas atmosphere. Optical microscope, X-ray diffraction, and scanning electron microscopy observations showed the presence of martensite in this unpublished alloy at room temperature. The differential scanning calorimetry (DSC) tests showed that martensitic transformation takes place at high temperature. High temperature thermal cycling was performed during a three-point bending tests under constant load without a protective atmosphere. Thermomechanical results showed that high entropy effects increase the operating behavior at high temperature. Hence this new composition of NiCuTiHfZr alloy can be used as an actuator for aerospace and aeronautic application.

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“…Usually, HEAs synthesis is based on the crystallization from the melt by induction or arc melting [5][6][7][8][9][10][11][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35], plasma spark [36] or electric current assisted sintering [37,38], additive manufacturing by laser metal deposition [39], laser powder bed fusion [40,41] or laser or plasma cladding deposition of coatings [42][43][44][45][46][47][48][49][50][51][52][53], self-propagating high-temperature synthesis (SHS) [54], or brazing of dissimilar materials [55,56]. However, several HEA manufacturing technologies are based exclusively on the processes occurring in the solid state, such as solid-phase sintering [57]...…”

Section: Grain Boundary Wetting Phenomenamentioning

confidence: 99%

Grain Boundary Wetting Phenomena in High Entropy Alloys Containing Nitrides, Carbides, Borides, Silicides, and Hydrogen: A Review

et al. 2021

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In this review, we analyze the structure of multicomponent alloys without principal components (they are also called high entropy alloys—HEAs), containing not only metals but also hydrogen, nitrogen, carbon, boron, or silicon. In particular, we discuss the phenomenon of grain boundary (GB) wetting by the melt or solid phase. The GB wetting can be complete or incomplete (partial). In the former case, the grains of the matrix are completely separated by the continuous layer of the second phase (solid or liquid). In the latter case of partial GB wetting, the second solid phase forms, between the matrix grains, a chain of (usually lenticular) precipitates or droplets with a non-zero value of the contact angle. To deal with the morphology of GBs, the new GB tie-lines are used, which can be constructed in the two- or multiphase areas of the multidimensional HEAs phase diagrams. The GBs in HEAs in the case of complete or partial wetting can also contain hydrides, nitrides, carbides, borides, or silicides. Thus, GB wetting by the hydrides, nitrides, carbides, borides, or silicides can be used in the so-called grain boundary chemical engineering in order to improve the properties of respective HEAs.

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Microstructure Formation in Cast TiZrHfCoNiCu and CoNiCuAlGaIn High Entropy Shape Memory Alloys: A Comparison

Cited by 19 publications

References 23 publications

The Grain Boundary Wetting Phenomena in the Ti-Containing High-Entropy Alloys: A Review

The Grain Boundary Wetting Phenomena in the Ti-Containing High-Entropy Alloys: A Review

Investigation and Composition Characterization of a “NiTi-like” Alloy Combining High Temperature Shape Memory and High Entropy

Grain Boundary Wetting Phenomena in High Entropy Alloys Containing Nitrides, Carbides, Borides, Silicides, and Hydrogen: A Review

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