Modeling Enhanced Diffusion Mass Transfer in Metals during Mechanical Alloying

Хина, Б. Б.; Lovshenko, G. F.

doi:10.5772/14152

Cited by 1 publication

(16 citation statements)

References 81 publications

(111 reference statements)

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“…The general form for thermal self-diffusion is written as , D k * = D normalk , 0 * 0.25em exp ( − E normalk italicRT ) where D k,0 * is the preexponential term, E k is the atom migration activation energy, R is the universal gas constant, and T is temperature. The equilibrium vacancy concentration is described as , c v 0 = exp ( − Δ H normalv normalf italickT ) where Δ H v f is the vacancy formation energy. This equation describes the concentration of vacancies with no external effects.…”

Section: Methodsmentioning

confidence: 99%

“…The coupled effect on species diffusion is implemented in the models through the modification of diffusivities in eqs – . The effect of amorphization is considered by multiplying the diffusivity terms with the amorphous fraction α, ensuring that the materials do not interdiffuse or alloy until sufficient amorphization has occurred.…”

Section: Methodsmentioning

confidence: 99%

“…This type of annihilation is dependent on the defects’ ability to diffuse to each other. The rate of this process is proportional to the recombination rate coefficient, which can be written as K iv = ( 2 π b / a 0 3 ) ( D normali + D normalv ) where a 0 is the lattice parameter and b is the burgers vector.…”

Section: Methodsmentioning

confidence: 99%

“…During this motion, the grinding balls collide with each other, transferring kinetic energy to the powders caught between the ball–powder–ball impacts. This energy accumulates in the powders as milling progresses, causing deformation of the powder to an amorphous state when the strain energy exceeds the amorphization energy. ,− , Excess defects are generated in the powders, enhancing the transport of atoms within the solid powders through defect-coupled diffusion. ,,, The ball-milling process is considered completed when diffusing species become fully saturated in the domain, and no further diffusion occurs.…”

Section: Introductionmentioning

confidence: 99%

“…Khina et al. advanced the models by incorporating the interdiffusion of two adjacent phases enhanced by ball milling . They considered the generation and annihilation of vacancies, as well as the diffusion of atoms coupled with those of vacancy and interstitial defects, which were absent in the aforementioned models by Pabi and Robson models. , These defects exhibit heterogeneous distributions of concentration alongside atoms, as illustrated in Figure , and may diffuse across the 1D interdiffusion couple.…”

Section: Introductionmentioning

confidence: 99%

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Modeling Analysis of Ball-Milling Process for Battery-Electrode Synthesis

Welch,

Cho,

Srinivasan

2024

Chem. Mater.

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The mechanical alloying process is a promising method for synthesizing electrode materials for batteries owing to its benefits such as the ability to produce nanostructured, high-performing electrode alloys, no adverse effects on the solid electrolyte for solid-state batteries, stable production of thick electrodes, simple processing steps, and low processing costs. It is gaining intensive attention in the battery industry as one of the best methods to replace the conventional wet-slurry-solvent method, and its application is rapidly increasing these days. However, the operation is currently conducted purely based on trial-and-error methods without fully utilizing the features of its functions. This may be attributed to a lack of understanding of the effect of operating parameters on the alloying process and final products. Surprisingly, there is a scarcity of the literature conducting fundamental research to comprehend the underlying physics of the entire mechanical alloying process, resulting in a significant knowledge gap. To address this knowledge gap, extensive research was conducted. The existing literature on mechanical alloying was reviewed to comprehend the current state of understanding and to discuss the direction for future research. Mathematical expressions were developed to create physics-based models capable of capturing the entire mechanical alloying process, including milling kinetics and defect-enhanced phase evolution. These methods were then applied to investigate the impact of operating parameters such as milling frequency, initial mole ratio of the alloyed materials, density of grinding balls, and energy required for the powders to become amorphous (i.e., the amorphization energy threshold). This research aimed not only to comprehend the direct effects of these operating parameters but also to unveil the physics underlying the ball-milling process. The results of our study can serve as crucial information for the battery industry in designing or operating the ball-milling process.

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