Synthesis of Aluminum-Aluminum Nitride Nanocomposites by Gas-Liquid Reactions I. Thermodynamic and Kinetic Considerations

Borgonovo, Cecilia; Makhlouf, Makhlouf M.

doi:10.1007/s11661-016-3665-6

Cited by 8 publications

(8 citation statements)

References 25 publications

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“…If the alloy contains Mg, the formation of Mg 3 N 2 is also probable. 43 In fact, N 2 gas can be utilized in the synthesis of Al-AlN composites, [44][45][46] thus the general assumption, that N 2 is an inert purging gas is not well supported. The purging gas bubbles with their nitride or oxide inner surface act as bifilm inclusions in the melt if they are not fully removed during the treatment.…”

Section: Introductionmentioning

confidence: 99%

The Effects of Rotary Degassing Treatments on the Melt Quality of an Al–Si Casting Alloy

et al. 2020

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In order to produce cast components, which meet the quality requirements of the automotive and aerospace industries, the control of liquid metal quality prior to the casting process is essential. Rotary degassing is the most commonly used melt treatment method in the foundry industry, which can effectively reduce the inclusion and solute hydrogen content of the metal. This procedure is often combined with fluxing, which allows more efficient inclusion removal during melt processing. In this study, the effects of rotary degassing treatments executed with and without flux addition on the melt cleanliness were compared. The quality of the molten metal was characterized by the microscopic inspection of K-mold specimens, X-ray computed tomography of reduced pressure test samples, and by Density-Index evaluation. The inclusions found on the fracture surfaces of K-mold samples were analyzed with energy-dispersive X-ray spectroscopy. Based on the results, rotary degassing coupled with flux addition can be an effective inclusion and solute hydrogen removal technique that can significantly improve melt quality. On the other hand, rotary degassing executed without flux addition can increase the inclusion content of the melts. This can be attributed to the chemical reaction between the liquid alloy and the N 2 purging gas during the degassing process. It was also found that inclusion content highly influences the tendency to porosity formation.

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Section: Introductionmentioning

confidence: 99%

The Effects of Rotary Degassing Treatments on the Melt Quality of an Al–Si Casting Alloy

et al. 2020

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“…The obtained information here is helpful to get insight into not only the role of AlN particles in heterogeneous nucleation of Al-based metals/alloys, further into designing of new grain refiners, but also the chemistry of AlN-containing nano-composites. [18][19][20][21][22][27][28][29]…”

mentioning

confidence: 99%

Atomic Ordering at the Interfaces Between Liquid Aluminum and Polar AlN{0 0 0 1} Substrates

Fang

Fan

2022

Metall Mater Trans A

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AlN particles are formed in liquid Al metals/alloys during liquid-dealing and casting. They may act as potential nucleation sites during solidification. Along its [0 0 0 1] axis, AlN consists of Al3+N3- dipolar double-atom layers in the ionic model. Thus, the AlN{0 0 0 1} substrates are terminated by either an Al3+ or a N3- layer, being polar. Here we investigate the atomic ordering at the interfaces between liquid-aluminum and AlN{0 0 0 1} using an ab initio molecular dynamics technique. We have observed a rich variety of interfacial chemistry and identified an ordered Al layer terminating the substrates. The newly formed terminating Al atoms are positively charged. The liquid Al adjacent to the interfaces exhibit strong layering but weak in-plane ordering. The obtained information helps get insight into the role of aluminum nitride as potential nucleation sites in solidification of Al-metals, and further enriches our knowledge about nucleation

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“…It should be noted that this is the fundamental difference between anode evaporation and widely used magnetron sputtering where the decrease in the flux density of sputtered particles with an increase in the pressure of the reactive gas is caused by the growth of compounds with a low ion sputtering coefficient on the metal surface [18]. The relatively small effect of such compounds on the rate of anodic evaporation is due to the high rate of diffusion of metal atoms through the growing nitride layer at high temperatures [19] and the discontinuity of this layer during evaporation (due to the significant difference between the thermal expansion coefficients of liquid metal and solid oxide) [20,21].…”

Section: Resultsmentioning

confidence: 99%

Diagnostics of a low-pressure arc plasma (N2, 0.1–1 Pa) in the mode of aluminum anodic evaporation

Ershov¹,

Kamenetskikh²

2022

8th International Congress on Energy Fluxes and Radiation Effects

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The use of an arc with a thermionic cathode burning in vapors of the anode material for the coating deposition provides high deposition rates, a controlled level of ion assistance, and the absence of microdroplets characteristic of a cathode arc. The use for this purpose of a low-pressure arc with a self-heating hollow cathode makes it possible to use an active gaseous medium for the synthesis of binary coatings, for example, nitride or oxide coatings. The rate of deposition of such coatings, their structure, and properties depend on such parameters of the discharge plasma as the plasma density and its electron temperature, the anode potential drop, the mass composition of the plasma, the degree of vapor ionization, and the degree of reactive gas dissociation. In this work, to diagnose the discharge plasma, probe diagnostics and optical emission spectroscopy were used. The results of measurements obtained in wide ranges of discharge current (5–30 A), reactive gas pressure (N2, 0.1–1 Pa), and evaporation rate of Al ((1.4–18)·10-5 g/cm2·s) are presented.

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Synthesis of Aluminum-Aluminum Nitride Nanocomposites by Gas-Liquid Reactions I. Thermodynamic and Kinetic Considerations

Cited by 8 publications

References 25 publications

The Effects of Rotary Degassing Treatments on the Melt Quality of an Al–Si Casting Alloy

The Effects of Rotary Degassing Treatments on the Melt Quality of an Al–Si Casting Alloy

Atomic Ordering at the Interfaces Between Liquid Aluminum and Polar AlN{0 0 0 1} Substrates

Diagnostics of a low-pressure arc plasma (N2, 0.1–1 Pa) in the mode of aluminum anodic evaporation

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