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Journal articles on the topic 'Spinodal material'
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1
Vanegas, Juan M., David Peterson, Taras I. Lakoba, and Valeri N. Kotov. "Spinodal de-wetting of light liquids on graphene." Journal of Physics: Condensed Matter 34, no. 17 (2022): 175001. http://dx.doi.org/10.1088/1361-648x/ac4f7e.
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Abstract We demonstrate theoretically the possibility of spinodal de-wetting in heterostructures made of light–atom liquids (hydrogen, helium, and nitrogen) deposited on suspended graphene. Extending our theory of film growth on two-dimensional (2D) materials to include analysis of surface instabilities via the hydrodynamic Cahn–Hilliard-type equation, we characterize in detail the spatial and temporal scales of the resulting spinodal de-wetting patterns. Both linear stability analysis and direct numerical simulations of the surface hydrodynamics show micron-sized (generally material dependent) patterns of ‘dry’ regions. The physical reason for the development of such instabilities on graphene can be traced back to the inherently weak van der Waals interactions between atomically thin materials and atoms in the liquid. Thus 2D materials could represent a new theoretical and technological platform for studies of spinodal de-wetting.
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Ahmad, Owais, Rakesh Maurya, Rajdip Mukherjee, and Somnath Bhowmick. "Integrated Phase Field and Machine Learning Study of Microstructure Evolution during Interface-Controlled Spinodal Decomposition." Solid State Phenomena 357 (June 11, 2024): 101–6. http://dx.doi.org/10.4028/p-6w4ixl.
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This study leverages artificial intelligence (AI) to advance materials science, focusing on microstructural evolution in binary alloys during spinodal decomposition. Following the formulation of Zhu et al., we explore the microstructure evolution during interface-controlled spinodal decomposition. A comprehensive dataset captures the dynamic microstructural changes, highlighting the model's efficiency in analyzing complex data. The innovative use of an Autoencoder- ConvLSTM model enables precise, low-error microstructural transformation predictions, demonstrating AI’s potential in materials science research. This work provides a deeper understanding of material behaviors and offers new research directions.
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Moskvin, Pavel, Sergii Skurativskyi, Wojciech Sadowski, Barbara Koscielska, Petro Melnychuk та Oleksandr Prylypko. "Resonance of mixing energy and energy of elastic deformations during spinodal decomposition and the composition modulation effect in ZnхCd1-ХTe solid solutions". Metallurgical and Materials Engineering 27, № 3 (2021): 385–96. http://dx.doi.org/10.30544/614.
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The Cahn-Hilliard equation is adapted to consider the spinodal decomposition of A2B6 semiconductor solid solutions. This approach is used to analyze the process of spinodal decomposition of ZnхCd1-хTe solid solution, which is accompanied by the appearance of the composition modulation effect during its low-temperature synthesis. Numerical simulations of the spinodal decomposition of the ZnхCd1-хTe solid solution are performed. It is shown that micro-variations of the material composition are related by the resonance phenomenon between the excess mixing energy and the energy of elastic strains arising in the inclusions of the new phase, which are coherently conjugated with the initial crystal lattice. It is revealed that such resonance phenomena are most intense when the conditions for the material synthesis are located in close proximity to the spinodal curves on the phase state diagram of the system.
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Hanna, James A., Ian Baker, Markus W. Wittmann, and Paul R. Munroe. "A new high-strength spinodal alloy." Journal of Materials Research 20, no. 4 (2005): 791–95. http://dx.doi.org/10.1557/jmr.2005.0136.
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Preliminary investigations of a new high-strength alloy of composition Fe30Ni20Mn25Al25 (at.%) are described in this paper. The as-cast alloy consisted of a periodic two-phase microstructure of interconnected, ∼50-nm-wide rods with fully coherent {100} interfaces, strongly suggestive of formation by a B2 to [(B2 + body-centered cubic (bcc)] spinodal decomposition. The (Ni,Al)-rich B2 and (Fe,Mn)-rich bcc phases differed in lattice parameter by <0.5%. Hardness and yield strength of the as-cast alloy were found to be approximately 500 VPN and 1500 MPa, respectively, and increased by more than 50% after annealing at 550 °C for several days. (Fe,Mn)-rich precipitates with a β–Mn structure were observed in the annealed material.
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Kuznetsov, V. V., P. P. Moskvin, and S. I. Skurativskyi. "Composition modulation in the GaxIni-xPyAs1-y - InP heterostructure during spinodal decomposition under the conditions of internal energy resonance." Journal of Physics: Conference Series 2103, no. 1 (2021): 012117. http://dx.doi.org/10.1088/1742-6596/2103/1/012117.
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Abstract The Cahn-Hilliard concepts are generalized and used to the description of the spinodal decomposition of A3B5 quaternary semiconductor solid solutions, when the mixing of components occurs simultaneously in the metallic and metalloid sublattices of the sphalerite structure. The resulting system of differential equations for material decomposition was used to describe the effect of composition modulation observed in the synthesis of GaxIn1-xPyAs1-y - InP heterostructures. Numerical simulation of the spinodal decomposition of the GaxIm-xPyAsuy solid solution is carried out. The intervals of the thermodynamic parameters of the technological process of the synthesis of structures, in which the effect of modulation of the composition should be manifested, are found.
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Sakakibara, Keita, Hideki Kagata, Norio Ishizuka, Takaya Sato, and Yoshinobu Tsujii. "Fabrication of surface skinless membranes of epoxy resin-based mesoporous monoliths toward advanced separators for lithium ion batteries." Journal of Materials Chemistry A 5, no. 15 (2017): 6866–73. http://dx.doi.org/10.1039/c6ta09005b.
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In this article, we propose a versatile method to prepare epoxy resin-based monolith membrane without any surface skin layer through polymerization induced spinodal type phase separation using a poly(vinyl alcohol) sacrificial film, where the monolith is a porous material with a bicontinuous skeletal structure.
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Radune, Maya, Michael Zinigrad, David Fuks, S. Hayun, and Nachum Frage. "Thermal Decomposition of Supersaturated Ti1-xAlxN Solid Solution Synthesized by High-Energy Milling." Diffusion Foundations 9 (October 2016): 82–89. http://dx.doi.org/10.4028/www.scientific.net/df.9.82.
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Supersaturated titanium-aluminum nitride (Ti1-xAlxN) is a very attractive material for a wide range of applications due to its high oxidation and wear resistance accompanied by high strength, hardness, thermal conductivity and thermal shock resistance. Currently, its applications are limited to coatings obtained by physical or chemical deposition. Bulk materials based on Ti1-xAlxN may be fabricated by powder metallurgy approach using powders synthesized by high-energy ball milling (HEBM), which composition corresponds to supersaturated Ti1-xAlxN solid solution. In the present study, thermal stability of the supersaturated Ti1-xAlxN solid solution was investigated. According to the quasi-binary TiN-AlN phase diagram, constructed using density functional theory (DFT) analysis, the concentration ranges, where decomposition takes place through spinodal decomposition or through nucleation and growth, were determined. Experimental study on thermal stability of solid Ti1-xAlxN solution powder was conducted by means of differential scanning calorimetry (DSC), Brunauer-Emmited-Teller (BET) and XRD. The results indicated that spinodal decomposition of Ti1-xAlxN starts at 800°C, while at temperature higher than 1300°C regular decomposition (nucleation and growth) is occur.
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Takezawa, Kazuhiro, Shigeharu Ukai, and Shigenari Hayashi. "Microstructure Control of Co-Base ODS Alloys." Advanced Materials Research 239-242 (May 2011): 864–67. http://dx.doi.org/10.4028/www.scientific.net/amr.239-242.864.
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As high-temperature metallic materials, Co-base ODS alloys were produced by means of mechanical alloying, spark plasma sintering and hot rolling. Co-3wt%Al-1.2wt%Hf-ODS alloy was found to be an attractive composite like material, which is formed by spinodal like decomposition. The metastable phases were traced by hard phase containing dense oxide particles and soft one containing less oxide particles. Their tensile stress at 1,000 °C was improved by Hf addition that forms Y2Hf2O7type oxide particles and shortens their space distance.
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Akbar, S., Z. Ahmad, M. S. Awan, M. N. Sarwar, and M. Farooque. "Single Step Heat Treatment Cycle for Development of Isotropic Fe-Cr-Co Magnets." Key Engineering Materials 510-511 (May 2012): 315–20. http://dx.doi.org/10.4028/www.scientific.net/kem.510-511.315.
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This study is focused on the development of isotropic Fe-Cr-Co based permanent magnets. Two compositions Fe-25Co-30Cr-3.5Mo-0.8Ti-0.8 and Fe-24 Co-32Cr-0.5Si-0.8V-0.8Ti were tried to optimize by adjusting heat treatment cycle. A modified single step heat treatment cycle was established which made processing easy and quick. Alloys were prepared in tri-arc melting furnace under inert atmosphere of Argon. Samples were solution treated at 1250 °C for 5 hours followed by water quenching. Then a spinodal decomposition heat treatment cycle in the temperature range 620 645 °C was applied in order to produce magnetism in this material. Samples were characterized for metallographic, chemical, structural and magnetic properties using Optical microscope, Scanning electron microscope equipped with Energy dispersive spectrometer, X-ray diffractometer and DC magnetometer. This study reveals that magnetic properties are sensitive to the spinodal decomposition temperature. Only + 5 °C change in temperature from optimum temperature can cause remarkable attenuation in magnetic properties. Magnetic properties of the alloys were achieved by controlling the spinodal decomposition temperature and subsequent cooling rate. The best magnetic properties in Mo and V containing alloys were obtained as 880 Oe (Hc), 7960 G (Br), 2.3 MGOe (BHmax) and 700 Oe (Hc), 7750 G (Br), 1.8 MGOe (BHmax), respectively.
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Minati, L., Giorgio Speranza, Yoann Jestin, et al. "Structural and Spectroscopic Assessment of Er3+-Activated SiO2-HfO2 Glass Ceramics Planar Waveguides." Advances in Science and Technology 55 (September 2008): 56–61. http://dx.doi.org/10.4028/www.scientific.net/ast.55.56.
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Two series of xHfO2 - (100-x) SiO2 (x=10, 20, 30 mol%) glass-ceramics planar waveguides doped with 0.3 mol% Er3+ ions were prepared by the sol-gel route. A thermal treatment at 1000°C was applied to the second series of samples to nucleate HfO2 crystals. The waveguides were analyzed by X-ray photoelectron spectroscopy to study the effect of the Hf concentration and of the annealing on the material structure. XPS shows that in the first series of samples a Hf concentration threshold exists. Above this threshold the material undergoes a spinodal decomposition with formation of HfO2 rich domains. In the second series of samples the presence of thermal treatment lowers the concentration threshold so that the phase separation occurs also at a Hf concentration of 10%mol. In the waveguides where spinodal decomposition in present, the emission spectra from the Er3+ ions reveal a sensible narrowing of the 4I13/2 → 4I15/2 line. This demonstrates the presence of a crystalline environment for the Er3+ ions since the inhomogeneous broadening due to the disordered glassy network is suppressed. These results may have important implications for the fabrication of photonic devices with increased efficiency.
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Marques, Ana C., and Mário Vale. "Macroporosity Control by Phase Separation in Sol-Gel Derived Monoliths and Microspheres." Materials 14, no. 15 (2021): 4247. http://dx.doi.org/10.3390/ma14154247.
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Macroporous and hierarchically macro/mesoporous materials (mostly monoliths and microspheres) have attracted much attention for a variety of applications, such as supporting or enabling materials in chromatography, energy storage and conversion, catalysis, biomedical devices, drug delivery systems, and environmental remediation. A well-succeeded method to obtain these tailored porous materials relies on the sol-gel technique, combined with phase separation by spinodal decomposition, and involves as well emulsification as a soft template, in the case of the synthesis of porous microspheres. Significant advancements have been witnessed, in terms of synthesis methodologies optimized either for the use of alkoxides or metal–salts and material design, including the grafting or immobilization of a specific species (or nanoparticles) to enable the most recent trends in technological applications, such as photocatalysis. In this context, the evolution, in terms of material composition and synthesis strategies, is discussed in a concerted fashion in this review, with the goal of inspiring new improvements and breakthroughs in the framework of porous materials.
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Teter, D. F., R. D. Field, and D. J. Thoma. "Hydrogen-Induced Phase Separation of Palladium-Rhodium Alloys Using an Environmental Cell TEM." Microscopy and Microanalysis 3, S2 (1997): 591–92. http://dx.doi.org/10.1017/s1431927600009843.
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The palladium-rhodium system has been extensively studied for its hydrogen absorption characteristics. However, the phase diagram of the palladium-rhodium system has not been conclusively determined below 800 K. Shield and Williams have experimentally determined the incoherent miscibility gap in Pd-Rh alloys using electrical resistivity studies, however the coherent miscibility gap and spinodal have not been determined. Recently work by Noh and Flanagan has suggested that hydrogen enhances metal atom mobility and may increase the kinetics of phase separation in Pd-Rh alloys. Field and Thoma found that hydrogen causes a Pd-10%Rh alloy to decompose during an in situhydrogen charging experiment in an environmental cell TEM. According to the calculations by Gonis et al. of the miscibility gap for the palladium-rhodium system, the Pd-10%Rh alloy may be within the chemical spinodal at room temperature.In this work, two palladium-rhodium compositions were investigated. The first was a Pd-10 at.% Rh alloy produced by melt-spinning, and the second was a Pd-30at.%Rh alloy which had been arc-melted and cold rolled followed by an annealing treatment to homogenize the material. TEM specimens were prepared by punching 3 mm disks from the material.
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Pacheco Rocha Lima, Emmanuel, Ricardo Artur Sanguinetti Ferreira, Ney Freitas de Quadros, and Yogendra Prasad Yadava. "Estudo dos aspectos cinéticos e morfológicos durante recristalizaçao da liga de alumínio AA 8011." Revista Iberoamericana de Ingeniería Mecánica 10, no. 1 (2006): 131–37. https://doi.org/10.5944/ribim.10.1.43081.
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A liga de alumínio AA 8011 foi recozida em temperaturas e tempos variados e, em seguida, submetida a ensaios mecânicos para a determinação da cinética de recristalização. Os resultados mostraram que a cinética pode ser descrita pelo modelo proposto por J-M-A e as modificações microestruturais que ocorrem, excluindo-se a recristalização, são decorrentes da decomposição spinodal e das transformações de fase por nucleação e crescimento, influenciando a plasticidade do material.
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Guo, W. H., L. F. Chua, C. C. Leung, and H. W. Kui. "Formation of Bulk Nanostructured Materials by Rapid Solidification." Journal of Materials Research 15, no. 7 (2000): 1605–11. http://dx.doi.org/10.1557/jmr.2000.0230.
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When a eutectic melt is undercooled below its liquidus T1 by a critical amount, it undergoes metastable liquid-state spinodal decomposition. The resulting morphologies can be described as intermixing undercooled liquid networks of characteristic wavelength λ. At a temperature substantially below T1, λ can be <100 nm. When λ ≤ 100 nm, the undercooled liquid networks break up into nanometer-size droplets/strips driven apparently by surface tension. The morphologies of the tiny droplets/strips can be frozen by subsequent crystallization. The as-crystallized specimen is a nanostructured material. It is microvoid free and the size of the constituent grains is rather uniform. Two systems, Pd40.5Ni40.5P19 and Pd82Si18, were chosen to illustrate the synthesis process.
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Herny, Emilie, Eric Andrieu, Jacques Lacaze, Frédéric Danoix, and Nicolas Lecoq. "Study by Differential Thermal Analysis of Reverse Spinodal Transformation in 15-5 PH Alloy." Solid State Phenomena 172-174 (June 2011): 338–43. http://dx.doi.org/10.4028/www.scientific.net/ssp.172-174.338.
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Alloy 15-5 PH is a stainless steel with 15 wt.% Cr and 5 wt.% Ni that is precipitation hardened by addition of Cu. In its semi-finished state, this alloy consists in Cu-supersaturated soft martensite; its high specific properties come from a final tempering consisting in a heating to 550-600°C, holding for 4 hours, and then air cooling. This treatment leads to nanometric Cu precipitation that hardens the material and to transformation of some martensite to reverted austenite which is then stable and provides ductility. While a' embrittlement of such steels is known to occur at temperature in the range 450-520°C, it has been reported that they can be sensitive to the same phenomenon after long term ageing at temperature as low as 300°C, with a significant loss of ductility and an increase of the ductile-to-brittle transition temperature. Atom probe studies showed that this degradation is related to demixtion of martensite into Fe-rich and Cr-rich phases. Depending on the ageing temperature, demixtion can proceed through a nucleation and growth precipitation or by spinodal decomposition of the martensitic matrix. The present study reports differential thermal analyses (DTA) performed upon heating samples of material held at various temperatures (290-525°C) for various times (410 h to 8500 h) that have been characterized by atom probe. A clear DTA signal is obtained upon the reverse spinodal transformation that is further found to depend on ageing conditions.
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Shepilov, Michael, Olga Dymshits, Valerii V. Golubkov, and Alexander A. Zhilin. "Anomalously Low Light Scattering in the Na2O-Nb2O5-SiO2 Glass-Ceramics." Advanced Materials Research 39-40 (April 2008): 273–76. http://dx.doi.org/10.4028/www.scientific.net/amr.39-40.273.
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An evolution of the structure of three glasses of Na2O-Nb2O5-SiO2 system in the course of isothermal heat treatments at 660–700°C and the extinction coefficient of the material were studied. Spinodal phase separation was found to be a primary process followed by precipitation of nano-sized NaNbO3 crystalline phase. It was found that the spectral dependence of the extinction coefficient in the wavelength range λ= 400–800 nm corresponds to light scattering by spinodal structure at the phase separation stage and by independent Rayleigh scatterers (NaNbO3 nanocrystals) at the early stage of crystallization. The extinction coefficient increases at the first half of the crystallization stage and then decreases. At the late stage of crystallization and for the final glass-ceramics, the extinction coefficient α is 10–20 times smaller than that calculated for independently scattering nanocrystals and is characterized by anomalous wavelength dependence (α ∝ λ−6). The model for calculation of extinction coefficient is proposed, in which the interference effects in light scattering by nanocrystals are taken into account. On this basis, the variation of extinction coefficient in the course of crystallization and its wavelength dependence are explained.
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Spooner, S., L. L. Horton, and M. K. Miller. "Characterizatiom of spinodally decomposed Fe-30.1% Cr-9.9% Co: Part 2." Proceedings, annual meeting, Electron Microscopy Society of America 44 (August 1986): 582–83. http://dx.doi.org/10.1017/s0424820100144383.
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Characteristic distances describing the scale of the spinodal microstructure obtained from Transmission Electron Microscopy (TEM), Atom Probe Field Ion Microscopy (APFIM), and Small Angle Neutron Scattering (SANS) are described and compared. These techniques provide a view of the microstructure either directly in real space or indirectly in reciprocal space. The material and its general microstructure are described in Part 1, elsewhere in these proceedings. Only the decomposition of the ferrite phase into a modulated isotropic microstructure consisting of a chromium-enriched α' phase and an iron-rich a phase is considered in this presentation.
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Han, Yongming, Xinyuan Cao, Yonghao Lu, and Tetsuo Shoji. "Deformation Properties of Thermally Aged E308L Stainless Steel During Tensile Test with Carbide Effects." Materials 17, no. 24 (2024): 6070. https://doi.org/10.3390/ma17246070.
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Microstructure and deformation properties of both unaged and aged cladding material were studied at 400 °C for 10,000 h. The results indicated that carbide formation occurred in the cladding material, while thermal aging treatment resulted in spinodal decomposition and G-phase formation in the aged ferrite phase. Furthermore, intensive straight slip bands formed in both unaged and aged austenite phases. Continual straight slip bands formed in the unaged ferrite phase, while curvilinear slip bands formed in the aged ferrite phase during the plastic deformation process. Microcracks preferred to nucleate at the points of interaction between phase boundaries and carbides, while the aged ferrite phase experienced lowered microcrack formation along the carbide/ferrite phase boundary. Microcracks propagated along the straight slip bands in the unaged ferrite phases and curvilinear slip bands in the aged ferrite phases.
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Böhme, Thomas, and Wolfgang H. Müller. "On the simulation of the spinodal decomposition process and phase growth in a leadfree brazing material." Computational Materials Science 39, no. 1 (2007): 166–71. http://dx.doi.org/10.1016/j.commatsci.2006.01.027.
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Lin, Le-Chi, Sheng-Jer Chen, and Hsiu-Yu Yu. "Connecting Structural Characteristics and Material Properties in Phase-Separating Polymer Solutions: Phase-Field Modeling and Physics-Informed Neural Networks." Polymers 15, no. 24 (2023): 4711. http://dx.doi.org/10.3390/polym15244711.
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The formed morphology during phase separation is crucial for determining the properties of the resulting product, e.g., a functional membrane. However, an accurate morphology prediction is challenging due to the inherent complexity of molecular interactions. In this study, the phase separation of a two-dimensional model polymer solution is investigated. The spinodal decomposition during the formation of polymer-rich domains is described by the Cahn–Hilliard equation incorporating the Flory–Huggins free energy description between the polymer and solvent. We circumvent the heavy burden of precise morphology prediction through two aspects. First, we systematically analyze the degree of impact of the parameters (initial polymer volume fraction, polymer mobility, degree of polymerization, surface tension parameter, and Flory–Huggins interaction parameter) in a phase-separating system on morphological evolution characterized by geometrical fingerprints to determine the most influential factor. The sensitivity analysis provides an estimate for the error tolerance of each parameter in determining the transition time, the spinodal decomposition length, and the domain growth rate. Secondly, we devise a set of physics-informed neural networks (PINN) comprising two coupled feedforward neural networks to represent the phase-field equations and inversely discover the value of the embedded parameter for a given morphological evolution. Among the five parameters considered, the polymer–solvent affinity is key in determining the phase transition time and the growth law of the polymer-rich domains. We demonstrate that the unknown parameter can be accurately determined by renormalizing the PINN-predicted parameter by the change of characteristic domain size in time. Our results suggest that certain degrees of error are tolerable and do not significantly affect the morphology properties during the domain growth. Moreover, reliable inverse prediction of the unknown parameter can be pursued by merely two separate snapshots during morphological evolution. The latter largely reduces the computational load in the standard data-driven predictive methods, and the approach may prove beneficial to the inverse design for specific needs.
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Xu, Si Yang, Ying Long Li, Mu Xin Zhang, Yi Fu Jiang, and Hua Ding. "Effect of Heat Treatment Conditions on Microstructures and Mechanical Properties of Cu-9Ni-6Sn-0.22Nb Alloy." Key Engineering Materials 904 (November 22, 2021): 124–30. http://dx.doi.org/10.4028/www.scientific.net/kem.904.124.
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Due to its high strength, excellent electrical conductivity and high resistance to stress corrosion, Cu-Ni-Sn alloy has been selected as a kind of advanced metal material which can be used as the manufacture of springs, connectors, bearings and so on. In addition, the addition of Nb can efficiently improve the comprehensive properties of the alloy. In the present work, the effect of heat treatment conditions on microstructure and mechanical properties were studied in a Cu-9Ni-6Sn-0.22Nb alloy by means of optical microscopy (OM), transmission electron microscopy (TEM), tensile test and microhardness tests. The results show that before ageing, a large number of fine γ precipitates with DO22 type structure are distributed on the matrix. With the prolongation of ageing time, the ultimate tensile strength (UTS), yield strength (YS) and Vickers hardness increased firstly, and then decline. The reason can be attributed to the occurrence of spinodal decomposition and the formation of discontinuous precipitation (DP). At first, spinodal decomposition induced the enhanced interaction between dislocations and internal stress field, resulting in an increase of mechanical properties. Then the increased DP at grain boundaries leads to the decline of strength in the material. Finally, the relationship between the microstructure and the electrical conductivity was also analyzed, and the results show that the electrical conductivity increased with ageing time/ageing temperature increasing for the present alloy. Through the analysis of Matthiessen’ s rule, the variation of electrical resistivity depends on precipitates, solute atoms, dislocations, vacancies and grain boundaries, and the precipitates play an important role among them. Besides, more precipitates improve electrical conductivity. Therefore, the increase of ageing time/ageing temperature induced the increase of DP, resulting in an increase of electrical conductivity.
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Silva, Rodrigo, Carlos Alberto della Rovere, and Sebastião Elias Kuri. "Effect of Thermal Aging at Low Temperature on the Mechanical Properties and Corrosion Resistance of LDX 2404 Duplex Stainless Steel." Materials Science Forum 869 (August 2016): 705–10. http://dx.doi.org/10.4028/www.scientific.net/msf.869.705.
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It is well known that when duplex stainless steels (DSS) are subjected to temperatures ranging from 300 to 1000 °C they may undergo precipitation of several phases, which can seriously impair their mechanical properties and corrosion resistance. The present work studied the effect of thermal aging (up to 2000 h) at 475 °C on the corrosion and mechanical properties of the newly developed 2404 DSS. The evaluation was based on potentiodynamic polarization in 3.5% NaCl solution and on Charpy tests. The pitting corrosion resistance was found to decrease significantly with aging time at 475 °C. In addition, Charpy tests revealed that after 100 h of thermal aging the material becomes brittle due to the spinodal decomposition of ferrite.
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Han, Bing Q. "Cracking Mechanism of High-Strength Cu-15Ni-8Sn C72900 Alloy." Materials Performance 60, no. 8 (2021): 38–41. https://doi.org/10.5006/mp2021_60_8-38.
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Intergranular cracking was evident in the fracture surface and adjacent areas of Cu-15Ni-8Sn (UNS C72900) alloy (ToughMet 3†, AT110 the material under discussion) with 758 MPa (110 ksi) minimum yield strength after downhole sour applications. A survey of literature indicated that selective corrosion at grain boundaries played a role in the corrosion cracking of high-strength Cu-Ni-Sn alloys. It is well-accepted that age strengthening by spinodal decomposition together with thermomechanical processing is the dominant strengthening mechanism of high-strength Cu-Ni-Sn alloys. However, the aging process could lead to discontinuous precipitation at grain boundaries, which is considered to be one of the main reasons for the loss of ductility, leading to selective corrosion at grain boundaries and even brittle failure.
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Eder, Alexander, Rudolf Königshofer, and Walter Lengauer. "Nitrogen-Induced Formation of Nano-Structured Precipitations in the Ti-W-C-N System." Defect and Diffusion Forum 237-240 (April 2005): 1121–28. http://dx.doi.org/10.4028/www.scientific.net/ddf.237-240.1121.
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A general trend in the field of hardmetals is to achieve a refinement of the microstructures, usually by using sub-micron powders as raw materials. In this study, an alternative route to produce fine structures within the fcc hard phase (W,Ti)(C,N) is investigated: nitrogen indiffusion into (W,Ti)C leads to precipitation of tungsten-rich phases. The mechanism of precipitation (lamella- and labyrinth-like structures with a size of 100-400nm) is thought do be discontinuous segregation on the one hand and spinodal decomposition on the other hand. Hot-pressed (W,Ti)(C,N) samples of different compositions were annealed at different temperatures and C activities in high-pressure N2 atmosphere. The composition and resulting structures of the precipitates were correlated with composition of the (W,Ti)(C,N) phase as well as with annealing conditions. An outlook of a possible application of the observed phenomena to powder particles is given to achieve micron-sized particles of this hard phase with nanometer-sized structures as a raw material for fine-grained hardmetals.
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Portela, Carlos M., A. Vidyasagar, Sebastian Krödel, et al. "Extreme mechanical resilience of self-assembled nanolabyrinthine materials." Proceedings of the National Academy of Sciences 117, no. 11 (2020): 5686–93. http://dx.doi.org/10.1073/pnas.1916817117.
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Low-density materials with tailorable properties have attracted attention for decades, yet stiff materials that can resiliently tolerate extreme forces and deformation while being manufactured at large scales have remained a rare find. Designs inspired by nature, such as hierarchical composites and atomic lattice-mimicking architectures, have achieved optimal combinations of mechanical properties but suffer from limited mechanical tunability, limited long-term stability, and low-throughput volumes that stem from limitations in additive manufacturing techniques. Based on natural self-assembly of polymeric emulsions via spinodal decomposition, here we demonstrate a concept for the scalable fabrication of nonperiodic, shell-based ceramic materials with ultralow densities, possessing features on the order of tens of nanometers and sample volumes on the order of cubic centimeters. Guided by simulations of separation processes, we numerically show that the curvature of self-assembled shells can produce close to optimal stiffness scaling with density, and we experimentally demonstrate that a carefully chosen combination of topology, geometry, and base material results in superior mechanical resilience in the architected product. Our approach provides a pathway to harnessing self-assembly methods in the design and scalable fabrication of beyond-periodic and nonbeam-based nano-architected materials with simultaneous directional tunability, high stiffness, and unsurpassed recoverability with marginal deterioration.
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Kudryavtsev, P. G. "Main routes of the porous composite materials creation." Nanotechnologies in Construction A Scientific Internet-Journal 12, no. 5 (2020): 256–69. http://dx.doi.org/10.15828/2075-8545-2020-12-5-256-269.
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This paper is devoted to an overview of the main ways of creating porous composite materials. Porous materials are solids containing free space in the form of cavities, channels, or pores, which determine the presence of an internal interfacial surface. The analysis of the general methods of obtaining porous materials. A deposition is one of the most common methods for producing porous materials. Thermal decomposition, as a method used to obtain porous oxide materials by thermal decomposition of various compounds. Hydrothermal synthesis is widely used to produce zeolites. Selective dissolution of individual components of a substance using chemical reactions is also one of the effective methods for creating or increasing porosity. The paper discusses the methods of forming highly porous refractory materials. There are two main ways of forming refractory ceramic products. The first way is the direct sintering of dispersions of ceramic fibers. The second method is the use of a binder, which can significantly reduce the temperature of obtaining a porous product. The possibilities of obtaining porous nanocomposites based on aerogels are shown. Composite materials are usually obtained by combining two different materials. In general, the creation of composites is used to take advantage of each type of material and to minimize their disadvantages. Aerogels are fragile substances. But with the introduction of another component into their structure, it is possible to increase the strength of the material. Such materials have the desired optical properties, high surface area, and low density like silica aerogel. A review of methods for obtaining porous materials using the phenomenon of spinodal decomposition has been carried out. Materials whose structure is formed in microphase separation during polymerization or polycondensation have high permeability and a sufficiently large specific surface. A significant advantage of such materials is high porosity, which can reach 80% or more
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Zhu, Gang, Shao Xia Sun, Jia Lin Chen, Ming Xie, and Jie Qiong Hu. "Enhanced Mechanical Properties of Ti(C,B)-Based Cermets with Multi-Component AlCoCrFeNi High-Entropy Alloys Binder." Key Engineering Materials 727 (January 2017): 149–53. http://dx.doi.org/10.4028/www.scientific.net/kem.727.149.
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In this study, Ti (C,N)-based cermets with multi-component AlCoCrFeNi high-entropy alloys binder were successfully fabricated by mechanical alloying and low pressure sintering. The results indicate that the introduction of AlCoCrFeNi HEAs binder extended the formation process of (W,M)C rim phase by WC diffusion-solution mechanism, and repressed the precipitation process of the outer rim phase. On the other hand, the TEM micro-area analysis revealed a lath modulated structure, which massive nanoparticles are precipitated in the spinodal plate zone, 3-20nm in diameter. The nanocrystalline dispersion would provide an effective precipitation strengthening effect. The results of mechanical properties revealed that the cermets with AlCoCrFeNi HEAs binder achieved the co-enhancement of hardness and toughness. The novel material exhibits a high Vickers hardness of 1787 MPa, along with a good fracture toughness value of 11.4 MPa m1/2.
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Herny, E., P. Lours, E. Andrieu, J. M. Cloué, and P. Lagain. "Evolution of microstructure and impact-strength energy in thermally and thermomechanically aged 15-5 PH." Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 222, no. 4 (2008): 299–304. http://dx.doi.org/10.1243/14644207jmda190.
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Due to its outstanding mechanical resistance and resistance to corrosion, alloy 15-5 PH can be beneficially used for manufacturing aerospace structural parts. Following exposure to intermediate temperature, from 300°–400 °C, the alloy embrittles through the decomposition of the martensite into iron-rich and chromium-rich domains. Depending on the ageing time, these domains are either interconnected or unconnected with each other. The embrittlement results in a drastic drop of the impact strength-energy and an increase of the ductile-to-brittle transition temperature. The initial microstructure and mechanical properties can be recovered through a re-homogenization of the distribution of chromium and iron atoms in the material in the case where the decomposition of the matrix is not too pronounced. The application of a stress higher than 60 per cent of the yield strength further enhances the ageing kinetics in the case where the combined effect of temperature and time results in the spinodal decomposition of the martensite.
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Deibuk, V. G. "Phase stability of thermoelectric ZnSb-SnTe thin films." Journal of Thermoelectricity, no. 1 (March 25, 2023): 14–23. https://doi.org/10.63527/1607-8829-2023-1-14-23.
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The article theoretically studies the phase stability of thin films of pseudobinary semiconductor alloys ZnSb–SnTe. The obtained T – x phase diagrams made it possible to predict the existence of a wide miscibility gap. Taking into account small internal stresses and the influence of the quartz substrate did not lead to significant changes in the phase diagram depending on the film thickness. It has been shown that spinodal decomposition processes caused by annealing at T = 225 °C in (ZnSb)1-х(SnTe)х alloys at x = 0.27 lead to microstructural evolution with the formation of precipitates of the SnSb metal phase. This fact is in good agreement with the experimental studies of the thin films considered and is the reason for the sharp increase in the power factor to 3383 μWm-1K-1 at 300 °C. The described recrystallization processes are the main mechanism for the high thermoelectric characteristics of this material. Bibl. 20, Fig. 3.
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Cordoba, Antoine, Marion Chandesris, and Mathis Plapp. "Intercalation Pathway in Graphite Particles Analyzed with a Multi-Layer Phase Field Model." ECS Meeting Abstracts MA2023-02, no. 5 (2023): 889. http://dx.doi.org/10.1149/ma2023-025889mtgabs.
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Graphite is today the most common negative electrode material in commercial cells, alone or blended with silicon, thanks to its relatively high specific capacity of 372 mAh·g−1, its excellent cycling stability, its low thermodynamic potential, and relatively low cost compared to alternative materials. The increase in the energy densities, power capabilities, and durability of lithium-ion batteries using this conventional cost-effective active material is possible through an optimization of the electrode and material designs. Such optimization requires, however, knowledge of the fundamental mechanisms that govern both the lithium transport inside graphite particles and the electrochemical transfer at the electrolyte / active material interface. Graphite has an ideal lamellar structure made of graphene sheets. During intercalation, the lithium atoms insert between the graphene planes, with almost no lithium transport across the graphene sheets. The interactions between lithium atoms in adjacent galleries leads to the formation of structures with filled layers separated by a number of empty layers, known as stages. Given this phenomenon, graphite active material undergoes phase separation between successions of several stable phases during lithium intercalation. This staging phenomenon influences the critical properties of graphite like its equilibrium potential, lithium diffusion or lithium insertion kinetics. In the present work, we use a Cahn-Hilliard type model, adapted to multi-layered materials1 and study the influence of the parameters in the underlying free-energy models. We focus first on the intra-layer and inter-layer lithium interaction contributions. Free-energy models with increasing complexity of inter-layer interactions are introduced and discussed based on their corresponding phase diagrams. In particular, we show that occurrence of fractional 3/2 stage, observed for potassium or rubidium intercalation in graphite at high pressure, requires an interlayer interaction effective at second neighbor, while a continuous screening effect of the intercalant is necessary to predict the occurrence of stages greater than 2 without the occurrence of the fractional 3/2 stage, as observed for lithium2. The kinetics of stage formation and evolution is also greatly affected by the interaction parameters of the free-energy model. A linear stability analysis (LSA) is performed to investigate the impact of the free energy model parameters on the stage formation dynamics and growth rates. In particular, the LSA shows that stage 2 grows the fastest, even for low lithium filling fraction. In accordance with this result, simulations of spinodal decomposition from moderate homogeneous lithium filling fraction (c=0.3) shows the formation of stage 2 at early times before an evolution towards stage 3 (See figure 1). This higher growth rate of stage 2 seems to have an impact on lithium intercalation pathway. Indeed, during simulations of lithium intercalation in a graphite particle at different C-rates, stage 2 tends to form very early at the electrolyte/particle interface, even when stage 3 and dilute stage 1 dominates inside the particle. The simulation of lithium intercalation also provides access to the effective exchange current density as function of the averaged surface concentration. The presence of the stages at the surface of the particles directly affects this averaged exchange current density. It results in non-symmetric exchange current density profiles, in coherence with operando X-ray micro-diffraction measurement in thick graphite electrodes3. Figure 1: Snapshots of a spinodal decomposition at different times. The initial average filling fraction is c=0.3 and the system has six layers. For each subfigure, top: lithium content in each layer, bottom: coefficients of the Fourier transform used to track the stages Smith, R. B. et al. Intercalation Kinetics in Multiphase-Layered Materials. J. Phys. Chem. C 121, 12505–12523 (2017). Chandesris, M., et al. Thermodynamics and Related Kinetics of Staging in Intercalation Compounds. J. Phys. Chem. C 123, 23711–23720 (2019) Tardif, S. et al. Combining operando X-ray experiments and modelling to understand the heterogeneous lithiation of graphite electrodes. J. Mater. A 9, 4281–4290 (2021) Figure 1
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Korneva, A., M. Bieda-Niemiec, G. Korznikova, A. Korznikov, and Krzystof Sztwiertnia. "Gradient Microstructure of FeCr30Co8 Hard Magnetic Alloy Subjected to Plastic Deformation by Complex Loading." Materials Science Forum 702-703 (December 2011): 344–47. http://dx.doi.org/10.4028/www.scientific.net/msf.702-703.344.
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Magnetically hard Fe-Cr-Co-based alloys are distinguished by their good ductility, excellent magnetic properties and low cost. Their superior magnetic properties are obtained by magnetic treatment and multistage tempering, which results in spinodal decomposition of the solid solution into the isomorphous α1 and α2 phases. However, the α1+α2 microstructure causes a reduction in the plasticity and strength of the material. It can often be advantageous for permanent magnets to maintain fine magnetic properties throughout their volume along while retaining good mechanical properties only in the subsurface layer. To improve the mechanical properties of the latter, FeCr30Co8 samples were deformed in tension combined with torsion. Loading was applied at 750°C, which ensured that the conditions for superplastic deformation were fulfilled. Here, we present the results of microstructure investigations of the samples treated in the aforementioned manner. Observations of the longitudinal section of the samples showed the formation of a gradient microstructure with the maximum grain refinement in the surface layer and the characteristic rotation of the elongated α phase grains from positions nearly perpendicular to the tension axis at the surface to positions tilted at approximately 45º to the tension axis inside the material. Deformation at superplastic conditions also activated precipitation of the σ intermetallic phase, particularly in the areas of highest deformation. The refinement of the microstructure and precipitation of the σ-phase resulted in a significant increase in hardness at the surface of the FeCr30Co8 samples.
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Yan, Fuyao, Jiawei Yao, Baofeng Chen, et al. "A Novel Decarburizing-Nitriding Treatment of Carburized/through-Hardened Bearing Steel towards Enhanced Nitriding Kinetics and Microstructure Refinement." Coatings 11, no. 2 (2021): 112. http://dx.doi.org/10.3390/coatings11020112.
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Decarburization is generally avoided as it is reckoned to be a process detrimental to material surface properties. Based on the idea of duplex surface engineering, i.e., nitriding the case-hardened or through-hardened bearing steels for enhanced surface performance, this work deliberately applied decarburization prior to plasma nitriding to cancel the softening effect of decarburizing with nitriding and at the same time to significantly promote the nitriding kinetics. To manifest the applicability of this innovative duplex process, low-carbon M50NiL and high-carbon M50 bearing steels were adopted in this work. The influence of decarburization on microstructures and growth kinetics of the nitrided layer over the decarburized layer is investigated. The metallographic analysis of the nitrided layer thickness indicates that high carbon content can hinder the growth of the nitrided layer, but if a short decarburization is applied prior to nitriding, the thickness of the nitrided layer can be significantly promoted. The analysis of nitriding kinetics shows that decarburization reduces the activation energy for nitrogen diffusion and enhances nitrogen diffusivity. Moreover, the effect of decarburization in air can promote surface microstructure refinement via spinodal decomposition during plasma nitriding.
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Yuan, Xiaobo, Ping Zhang, Jianxiang Wang, Biaobiao Yang, and Yunping Li. "Influences of Fe Content and Cold Drawing Strain on the Microstructure and Properties of Powder Metallurgy Cu-Fe Alloy Wire." Materials 16, no. 14 (2023): 5180. http://dx.doi.org/10.3390/ma16145180.
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To study the effects of Fe content and cold drawing strain on the microstructure and properties, Cu-Fe alloys were prepared via powder metallurgy and hot extrusion. Scanning electron microscopy was applied to observe the Fe phase, and the ultimate tensile strength was investigated using a universal material testing machine. Alloying with an Fe content below 10 wt.% formed a spherically dispersed Fe phase via the conventional nucleation and growth mechanism, whereas a higher Fe content formed a water-droplet-like Fe phase via the spinodal decomposition mechanism in the as-extruded Cu-Fe alloy. Further cold drawing induced the fiber structure of the Fe phase (fiber strengthening), which could not be destroyed by subsequent annealing. As the Fe content increased, the strength increased but the electrical conductivity decreased; as the cold drawing strain increased, both the strength and the electrical conductivity roughly increased, but the elongation roughly decreased. After thermal–mechanical processing, the electrical conductivity and strength of the Cu-40Fe alloy could reach 51% IACS and 1.14 GPa, respectively. This study can provide insight into the design of high-performance Cu-Fe alloys by tailoring the size and morphology of the Fe phase.
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Mohri, Tetsuo. "First-principles Calculation for Spinodal Ordering." Materia Japan 53, no. 9 (2014): 394–99. http://dx.doi.org/10.2320/materia.53.394.
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TANAKA, HAJIME. "Spinodal decomposition of high polymer mixtures." Materia Japan 33, no. 4 (1994): 417–19. http://dx.doi.org/10.2320/materia.33.417.
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Su, Shen. "Prediction of the Miscibility of PBAT/PLA Blends." Polymers 13, no. 14 (2021): 2339. http://dx.doi.org/10.3390/polym13142339.
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Designing polymer structures and polymer blends opens opportunities to improve the performance of plastics. Blending poly(butylene adipate-co-terephthalate) (PBAT) and polylactide (PLA) is a cost-effective approach to achieve a new sustainable material with complementary properties. This study aimed to predict the theoretical miscibility of PBAT/PLA blends at the molecular level. First, the basic properties and the structure of PBAT and PLA are introduced, respectively. Second, using the group contribution methods of van Krevelen and Hoy, the Hansen and Hildebrand solubility parameters of PBAT and PLA were calculated, and the effect of the molar ratio of the monomers in PBAT on the miscibility with PLA was predicted. Third, the dependence of the molecular weight on the blend miscibility was simulated using the solubility parameters and Flory–Huggins theory. Next, the glass transition temperature of miscible PBAT/PLA blends, estimated using the Fox equation, is shown graphically. According to the prediction and simulation, the blends with a number-average molecular weight of 30 kg/mol for each component were thermodynamically miscible at 296 K and 463 K with the possibility of spinodal decomposition at 296 K and 30% volume fraction of PBAT. This study contributes to the strategic synthesis of PBAT and the development of miscible PBAT/PLA blends.
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Renbaum-Wolff, L., M. Song, C. Marcolli та ін. "Observations and implications of liquid–liquid phase separation at high relative humidities in secondary organic material produced by α-pinene ozonolysis without inorganic salts". Atmospheric Chemistry and Physics Discussions 15, № 22 (2015): 33379–405. http://dx.doi.org/10.5194/acpd-15-33379-2015.
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Abstract. Particles consisting of secondary organic material (SOM) are abundant in the atmosphere. To predict the role of these particles in climate, visibility, and atmospheric chemistry, information on particle phase state (i.e. single liquid, two liquids, solid and so forth) is needed. This paper focuses on the phase state of SOM particles free of inorganic salts produced by the ozonolysis of α-pinene. Phase transitions were investigated both in the laboratory and with a thermodynamic model over the range of < 0.5 % to 100 % relative humidity (RH) at 290 K. In the laboratory studies, a single phase was observed from 0 to 95 % RH while two liquid phases were observed above 95 % RH. For increasing RH, the mechanism of liquid–liquid phase separation (LLPS) was spinodal decomposition. The RH range at which two liquid phases were observed did not depend on the direction of RH change. In the modelling studies at low RH values, the SOM took up hardly any water and was a single organic-rich phase. At high RH values, the SOM underwent LLPS to form an organic-rich phase and an aqueous phase, consistent with the laboratory studies. The presence of LLPS at high RH-values has consequences for the cloud condensation nuclei (CCN) activity of SOM particles. In the simulated Köhler curves for SOM particles, two local maxima are observed. Depending on the composition of the SOM, the first or second maximum can determine the critical supersaturation for activation. The presence of LLPS at high RH-values can explain inconsistencies between measured CCN properties of SOM particles and hygroscopic growth measured below water saturation.
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Soriano Vargas, Orlando, Erika O. Avila Davila, Victor M. Lopez-Hirata, and Maribel L. Saucedo-Muñoz. "Spinodal Decomposition in Fe-Cr Alloys." Solid State Phenomena 172-174 (June 2011): 443–48. http://dx.doi.org/10.4028/www.scientific.net/ssp.172-174.443.
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The hardening behavior of precipitation was studied during aging of Fe-Cr alloys. This mechanical behavior is associated with the nanometric modulation structure of the coherent decomposed Fe-rich and Cr-rich phases formed by the spinodal decomposition of the supersaturated solid solution. The growth kinetics of spinodal decomposition was very slow and it increased during coarsening stage. The morphology of decomposed phases consisted of an interconnected irregular shape with no preferential alignment for short aging times and a further aging caused the change to a plate shape of the decomposed Cr-rich phase aligned in the <110> directions of the Fe-rich matrix. The rapid increase in hardness and embrittlement seem to be associated with the coherency and nanometer size of the spinodally-decomposed phases in the aged alloys.
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Mohsan, Aziz Ul Hassan, Mina Zhang, Menggang Zhai, et al. "Effect of Dilution on Microstructure and Phase Transformation of AlCrFeMnNi High-Entropy Alloy by Resonant Ultrasonic Vibration-Assisted Laser Cladding." Materials 18, no. 3 (2025): 695. https://doi.org/10.3390/ma18030695.
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The present study effectively produced a high-entropy alloy (HEA) coating of AlCrFeMnNi on AISI 304L steel using resonant ultrasonic vibration-assisted laser cladding (R-UVALC). An investigation was conducted to examine the impact of dilution rate on the phase composition, microstructure, and mechanical and tribological properties of AlCrFeMnNi coatings. The coating, which was created utilizing the appropriate dilution rate, was thoroughly characterized using EDS mapping and TEM investigation. The results suggest that a higher dilution rate causes a change in the AlCrFeMnNi coating, transforming it from a single solid solution phase (BCC) into a two-phase solid solution containing both FCC and BCC phases. The analysis conducted using transmission electron microscopy (TEM) reveals that the AlCrFeMnNi coating, when diluted at an optimal rate of around 37%, is predominantly composed of a disordered body-centered cubic (BCC) phase and an ordered BCC (B2) phase featuring a spinodal decomposition structure. The AlCrFeMnNi coating has an average microhardness of approximately 540 HV, which is over 2.5 times higher than the microhardness of the substrate. Additionally, it was also established that the dilution rate has an impact on the occurrence of phases, which subsequently affects the mechanical and antifrictional properties of the coating. The integration of ultrasonic vibration in laser cladding enhances quality and improves mechanical and tribological properties, thereby reducing material costs and promoting an environmentally friendly process when compared to conventional cladding.
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Nguyen, Thao A., and Linn W. Hobbs. "Studies of phase transformation of Fe1-xS by in Situ TEM." Proceedings, annual meeting, Electron Microscopy Society of America 47 (August 6, 1989): 648–49. http://dx.doi.org/10.1017/s0424820100155219.
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The transformation from Fe1-xS (IC) phase to a mixture of FeS (2C) and iron poor Fe1-xS (IC) phases has been investigated by a series of in-situ heating experiments. The purpose of this study is to resolve the controversy over the mechanism of phase transformation (spinodal decomposition versus nucleation and growth) and to explain the different microstructures observed in the two phase mixture of FeS and Fe1-xS (Figure 1).In-situ heating experiments were carried out using a JEOL JEM EM-SHTH double tilt heating holder. Synthetic “single” Fe0.97S crystals were cut into 3 mm disks, mechanically and ion thinned to electron transparency. In all cooling experiments, the sample was first held at 390 K, a temperature above the transition temperature in order to generate an initial single phase material; then, the temperature was quickly reduced to the temperature of interest.Figure 2a shows the development of a lamellar type microstructure after the sample's temperature was reduced from 390 K to 363 K and then held at this temperature for ten minutes. At 363 K, the undercooling is 27 K. The troilite FeS (2C) phase heterogeneously nucleates and grows along the edge of the sample. Diffraction analysis shows that the FeS (2C) phase is embedded in the iron-poor Fe1-x,S matrix with a rod-like structure.
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Lee, K. L., and H. W. Kui. "Crystallization of undercooled liquid spinodals: Part II." Journal of Materials Research 14, no. 9 (1999): 3663–67. http://dx.doi.org/10.1557/jmr.1999.0494.
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We demonstrated in “Phase separation in undercooled molten Pd80Si20: Part I” that when a molten Pd80Si20 ingot is undercooled into its undercooling regimen with ΔT ≥ 220 K (ΔT = T1 – T, where T1 is the liquidus and T is the temperature of the undercooled melt), liquid-state phase separation by spinodal decomposition occurs. On crystallization, one of the metastable liquid spinodals becomes Pd3Si, whereas the other one turns into Pd9Si2. In both cases, Pd particles precipitate out. Microstructural analysis indicates the Pd3Si subnetwork forms first. It then acts as a seed for the subsequent crystallization of the remaining undercooled melt, which finally forms the Pd9Si2 dendrites. As crystallization proceeds, latent heat and volume contraction bring about morphological changes.
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Fiantok, Tomáš, Viktor Šroba, Nikola Koutná, et al. "Structure evolution and mechanical properties of co-sputtered Zr-Al-B2 thin films." Journal of Vacuum Science & Technology A 40, no. 3 (2022): 033414. http://dx.doi.org/10.1116/6.0001802.
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Zirconium diboride (ZrB2) represents a promising hard coating material for demanding high-temperature applications and could provide an excellent basis for fine-tuning mechanical properties via the concept of alloying. Here, combining density functional theory and experiments, we investigate the effect of aluminum alloying on thermally induced structure evolution and mechanical properties of α-structured Zr1 − x Al x B2 + Δ. Ab initio calculations predict a strong tendency for spinodal phase separation of hexagonal Zr1 − x Al x B2 solid solution into isostructural binaries. Experimental results confirm predictions of the insolubility of aluminum in the ZrB2 phase when the structure of magnetron co-sputtered Zr0.72Al0.28B2.64 films with an aluminum content of 8 at. % has a nanocomposite character consisting of hexagonal α-ZrB2 nanocolumns surrounded by an amorphous Al-rich tissue phase. The films are structurally stable up to 1100 °C but out-diffusion of Al atoms from boundary regions during annealing was observed. Al alloying causes a significant decrease in hardness when the hardness of the reference as-deposited ZrB2.2 and Zr0.72Al0.28B2.64 is 39 and 23 GPa, respectively. Low hardening effect in ternaries was observed after annealing at 1000 °C when the hardness increased from 23.5 to 26.5 GPa due to the locally increased concentration of point defects at the boundaries of the nanocolumns and Al-rich tissue phases. Young's modulus decrease from 445 (ZrB2.2) to 345 GPa (Zr0.72Al0.28B2.64) indicates a change in the mechanical response of the ternary film toward more ductile behavior.
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SAKUMA, Taketo. "Spinodal Decomposition in Ceramic Materials." Tetsu-to-Hagane 73, no. 11 (1987): 1453–60. http://dx.doi.org/10.2355/tetsutohagane1955.73.11_1453.
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Labisz, Krzysztof. "Comparison of Long-Term Ageing Duration of Binary Ag-Cu Alloys." Advanced Materials Research 1036 (October 2014): 128–33. http://dx.doi.org/10.4028/www.scientific.net/amr.1036.128.
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Silver alloys, due to its specific properties are widely used in different branches of industry, with approximately 95% of the world silver production is used in the photographic industry and for jeweller production. Moreover Poland is a significant producer of silver in the world, and takes the 6th place on the list of the world's silver producers with the KGHM Polish Copper Company production on the first place among global companies providing silver on the market, with an annual production at 1281 tones. Because of this impotent role of silver, this work presents microstructure and mechanical properties investigations results of the long aged Ag-Cu alloys used mainly for mint monetary production. The purpose of this work was to determine the microstructural changes after 32 and 40 year of natural ageing time, with appliance of transmission electron microscopy as well as light microscopy. A very important issue - one of the investigations directions is also the possibility of study of spinodal decomposition process, which occurred in this alloy. After the long-time ageing of the material, there are detected morphological different areas of the Ag-α and Cu-β phase. As an implication for appliance in real conditions - as coin metal, or in electronic and chemical industry branches, there is the possibility of application of long term ageing for mechanical properties improvement by natural ageing method. Some other investigations should be performed in the future, but the knowledge found in this research shows an interesting investigation direction, where a low cost but long term treatment operations can be applied.
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Renbaum-Wolff, Lindsay, Mijung Song, Claudia Marcolli та ін. "Observations and implications of liquid–liquid phase separation at high relative humidities in secondary organic material produced by <i>α</i>-pinene ozonolysis without inorganic salts". Atmospheric Chemistry and Physics 16, № 12 (2016): 7969–79. http://dx.doi.org/10.5194/acp-16-7969-2016.
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Abstract. Particles consisting of secondary organic material (SOM) are abundant in the atmosphere. To predict the role of these particles in climate, visibility and atmospheric chemistry, information on particle phase state (i.e., single liquid, two liquids and solid) is needed. This paper focuses on the phase state of SOM particles free of inorganic salts produced by the ozonolysis of α-pinene. Phase transitions were investigated in the laboratory using optical microscopy and theoretically using a thermodynamic model at 290 K and for relative humidities ranging from < 0.5 to 100 %. In the laboratory studies, a single phase was observed from 0 to 95 % relative humidity (RH) while two liquid phases were observed above 95 % RH. For increasing RH, the mechanism of liquid–liquid phase separation (LLPS) was spinodal decomposition. The RH range over which two liquid phases were observed did not depend on the direction of RH change. In the modeling studies, the SOM took up very little water and was a single organic-rich phase at low RH values. At high RH, the SOM underwent LLPS to form an organic-rich phase and a water-rich phase, consistent with the laboratory studies. The presence of LLPS at high RH values can have consequences for the cloud condensation nuclei (CCN) activity of SOM particles. In the simulated Köhler curves for SOM particles, two local maxima were observed. Depending on the composition of the SOM, the first or second maximum can determine the critical supersaturation for activation. Recently researchers have observed inconsistencies between measured CCN properties of SOM particles and hygroscopic growth measured below water saturation (i.e., hygroscopic parameters measured below water saturation were inconsistent with hygroscopic parameters measured above water saturation). The work presented here illustrates that such inconsistencies are expected for systems with LLPS when the water uptake at subsaturated conditions represents the hygroscopicity of an organic-rich phase while the barrier for CCN activation can be determined by the second maximum in the Köhler curve when the particles are water rich.
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Ten Bosch, A. "Spinodal decomposition in liquid crystalline materials." Journal de Physique II 1, no. 8 (1991): 949–58. http://dx.doi.org/10.1051/jp2:1991119.
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Ramanarayan, H., and T. A. Abinandanan. "Spinodal decomposition in fine grained materials." Bulletin of Materials Science 26, no. 1 (2003): 189–92. http://dx.doi.org/10.1007/bf02712811.
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Suzuki, Masanori, and Toshihiro Tanaka. "Thermodynamic Prediction of Spinodal Decomposition in Multi-component Silicate Glass for Design of Functional Porous Glass Materials." High Temperature Materials and Processes 31, no. 4-5 (2012): 323–28. http://dx.doi.org/10.1515/htmp-2012-0086.
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AbstractThe authors have investigated metastable phase separation in multi-component silicate glass for the fabrication of porous glass from multi-component slag. Spinodal decomposition forms an interconnected microstructure in glass spontaneously, and porous glass is obtained by leaching one of the decomposed phases with an acid solution. This porous glass can be used for a filter to remove impurities in polluted water or air. In this study, the metastable miscibility gap was predicted in multi-component silicate glass using thermodynamic analyses where glass was regarded as a super-cooled liquid phase. Occurrence of spinodal decomposition was observed in annealed glass, and it corresponded to the predicted miscibility gap. Then, we fabricated porous glass using spinodal decomposition in multi-component borosilicate glass and by removing one of the decomposed phases. Furthermore, for the creation of functional porous glass applicable for environmental purification, the spinodal decomposition was prepared in multi-component borosilicate glass containing titanium oxide based on the predicted metastable miscibility gap in multi-component silicate glass.
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Li, Yuanfei, Jianchao Peng, Jian Yin, et al. "Effect of proton irradiation dose rate and implanted hydrogen ions on spinodal decomposition in thermally aged EQ308L stainless steel weld metal." Journal of Physics: Conference Series 2783, no. 1 (2024): 012053. http://dx.doi.org/10.1088/1742-6596/2783/1/012053.
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Abstract Stainless steel welds with a ferritic phase are extensively utilized in nuclear power plants. Spinodal decomposition stands as the primary factor contributing to the degradation of their service performance. Ion irradiation has been widely employed to investigate the damage behavior of materials. However, varying irradiation parameters, such as dose rate and implanted ions, are believed to result in significant differences in the extent of spinodal decomposition. In this paper, proton irradiation experiments were conducted at different dose rates on thermally aged EQ308L stainless steel welds. Spinodal decomposition within the ferrite at various radiation depths was compared and analyzed by using atom probe tomography to unveil the effects of dose rate and implanted hydrogen ions. The results reveal that, under conditions of high dose rate irradiation, spinodal decomposition can be partially alleviated when compared to the initial thermally aged state. Conversely, under low dose rate irradiation conditions, spinodal decomposition exhibits an enhancement trend. This difference may be attributed to the interplay between irradiation-enhanced diffusion and atomic mixing. Therefore, the dose rate significantly influences the progression of spinodal decomposition. Furthermore, implanted hydrogen ions may also inhibit spinodal decomposition within the ferrite, potentially by promoting the recombination of irradiation defects.
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Guo, Can, Yu-Ping Zhao, Ying-Yuan Deng, Zhong-Ming Zhang, and Chun-Jie Xu. "A phase-field study on interaction process of moving grain boundary and spinodal decomposition." Acta Physica Sinica 71, no. 7 (2022): 078101. http://dx.doi.org/10.7498/aps.71.20211973.
Full textAbstract:
The grain boundary-directed spinodal decomposition has a substantial effect on the microstructure and properties of polycrystalline materials. However, due to the fact that the spinodal decomposition is usually too fast to be captured in experiments, our understanding of the grain boundary-directed spinodal decomposition process is still very limited. In this work, we simulate the spinodal decomposition process of a polycrystalline system by the phase-field model, check the influences of the curvature and the atom diffusion constant inside the grain boundary (<i>M</i><sub>t</sub>) on the phase decomposition patterns, and discuss the interaction between the moving grain boundaries and spinodal decomposition. The simulation results indicate that the velocity of spinodal decomposition near the grain boundary is faster, and the spinodal morphology at the grain boundary presents the anisotropic bicontinuous microstructures different from the isotropic continuous microstructures in the bulk phase. Further, we find that the spinodal pattern is parallel to the grain boundaries with larger curvatures, and it will perpendicular to the grain boundaries with smaller curvatures. We also find that the spinodal decomposition velocity increases with the augment of <i>M</i><sub>t</sub> , while the grain boundary migration velocity will first decrease and then increase with the augment of <i>M</i><sub>t</sub> under the effect of spinodal decomposition. Finally, we simulate the spinodal decomposition process of two-grain system in three dimensions, and we obtain the results consistent with the two-dimensional simulations.