Mathematical modeling of melting of nano-sized metal particles

Федоров, А. В.; Shul’gin, A. V.

doi:10.1134/s001050821102002x

Cited by 16 publications

(18 citation statements)

References 6 publications

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“…To compare the results of MMD simulations with the predictions of the phenomenological approach previously used in [1,2], we introduce a comparison parameter, namely, the specific energy pumped into the system…”

Section: Comparison Of Results Predicted By the Phenomenological Apprmentioning

confidence: 99%

“…It turned out that the melting times predicted by the two approaches are approximately identical (t m,S /t m,M = 1.045-1.062) if the amounts of energy pumped into the system are approximately identical in the MMD and phenomenological computations: L S /L M = 1.075-1.082. As was mentioned above, in our previous study we determined the times of nanoparticle melting within the framework of the non-classical Stefan problem [1,2] where the thermophysical parameters were taken to be equal to those of microparticles. To estimate the influence of this choice, we performed additional computations of the melting time by the model of [1,2], but the values of the specific heat were now taken from refined data obtained by the MMD (see Fig.…”

Section: Comparison Of Results Predicted By the Phenomenological Apprmentioning

confidence: 99%

“…It can be expected to play an important role in ignition and combustion of continua consisting of nanoparticles. In [1,2], we constructed a mathematical model of nanoparticle melting, based on the experimental fact that the melting temperature of nanoparticles depends on their size. The solution of this problem was reduced to the numerical solution of the non-classical Stefan problem, where the thermophysical parameters were assumed to have the same values as those of microparticles (i.e., particles with the microscopic characteristic scale).…”

Section: Introductionmentioning

confidence: 99%

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Complex modeling of melting of an aluminum nanoparticle

Федоров

Shul’gin

2013

Combust Explos Shock Waves

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A semi-empirical model of molecular dynamics is proposed within the molecular dynamics approach. The model is verified against the experimental dependence of the melting temperature of aluminum nanoparticles on their size. The specific heat of the particle and the phase transition heat are determined as functions of the initial size and temperature of the particle. It is demonstrated that these dependences tend to the limiting dependences, which describe the particle size in the volume phase, as the particle size increases. A comparison of the aluminum nanoparticle melting characteristics calculated by the model of molecular dynamics and by the phenomenological model reveals reasonable agreement in terms of the melting time.

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Section: Comparison Of Results Predicted By the Phenomenological Apprmentioning

confidence: 99%

Section: Comparison Of Results Predicted By the Phenomenological Apprmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Complex modeling of melting of an aluminum nanoparticle

Федоров

Shul’gin

2013

Combust Explos Shock Waves

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“…1,b). (More extended model based on data [25] for 80-nm aluminum particle combustion has been developed in [29]). …”

Section: Nanosized Particle Ignition and Combustionmentioning

confidence: 99%

Physical and mathematical model of detonation in aluminum gas suspensions with regard for transition processes of nanosized particle flow, heat transfer and combustion

Khmel

Федоров

2017

AIP Conference Proceedings

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“…The appearance of sections with local melting could be associated with the fact the nanosize fractions of the powder (especially in the interval 1-10 nm) have a considerably lower melting temperature than the bulk of the larger particles [16]. Apparently, local melting is responsible for open porosity in the compacts obtained by mechanical activation of the powders for 40 and 50 h (marked by the arrow in Fig.…”

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confidence: 97%

Optimization of Electric-Pulse Consolidation Regimes to Obtain High-Density Dispersion-Hardened Reactor Steel

et al. 2016

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Research on the development of EP-450 high-density, Y 2 O 3 -oxide dispersion-hardened, reactor ferritemartensite steel is described. All available parameters infl uencing the fi nal density of the compacts were varied in the course of the preparation of the powders and electric-pulse consolidation. The research established that samples with density equal to 99% of the theoretical value can be obtained for the following optimized mechanical activation and electric-pulse consolidation parameters: mechanical alloying time 30 h, optimal Y 2 O 3 amount 0.2-0.5 wt.%, sintering temperature 825-890°C, climb rate to the prescribed temperature >300°C/min, load 70-80 MPa, holding time at the load -without isothermal holding or holding for ≥3 min.Intense research and development work has been conducted in the last few decades on chromium steel because the swelling of such steel is signifi cantly smaller than that of austenitic steel. The main drawback of chromium steel is low high-temperature strength under operating conditions in the core of a fast reactor. The aim of this research is to develop oxide dispersion-hardened chromium steel [1-6], since its mechanical properties and high-temperature strength are better than those of the conventionally used steel [1,4,5]. The main method of producing such steel is powder metallurgy and the commonly used methods of powder consolidation (in decreasing order) -hot extrusion, hot isostatic pressing, and the electric-pulse method [7][8][9][10][11].Two basic problems must be solved in order to produce oxide-dispersion-hardened steel: obtaining a uniform volumetric distribution of hardening nanoparticles and obtaining high-density compacts. This can be accomplished in two basic ways: optimization of the mechanical alloying regime (time, mill rotation speed, and avoidance of overheating of the powder) and optimization of the electric pulse consolidation regimes. The dispersity of the oxide particles has been studied previously and it has been shown that even during mechanical alloying the Y 2 O 3 particles are quite uniformly distributed in the powder within 15 h [10] and they are uniformly distributed in the volume of the sample during grinding in optimized regimes [11].The aim of the present work is to determine the regularities of the structure formation in dispersion-hardened reactor ferrite-martensite steel depending on the electric pulse consolidation regimes.Materials and Procedure. Reactor ferrite-martensite steel EP-450 (12Kh13M2BFR) in the form of brittle fl akes was fi rst ground for 2 h in a MTI SFM-1 (USA) planetary mill and then mixed with yttrium oxide powder followed by alloying conducted in an optimized regime in a Pulverizette-5 (Germany) planetary ball mill (argon atmosphere) [11]. The basic parameters of the process were varied in order to obtain blanks with the maximum density: grinding time 30, 40, and 50 h;

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Mathematical modeling of melting of nano-sized metal particles

Cited by 16 publications

References 6 publications

Complex modeling of melting of an aluminum nanoparticle

Complex modeling of melting of an aluminum nanoparticle

Physical and mathematical model of detonation in aluminum gas suspensions with regard for transition processes of nanosized particle flow, heat transfer and combustion

Optimization of Electric-Pulse Consolidation Regimes to Obtain High-Density Dispersion-Hardened Reactor Steel

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