• Journal of Powder Materials
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• v.26 no.2
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• pp.101-106
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• 2019

Ni-based oxide dispersion strengthened (ODS) alloys have a higher usable temperature and better high-temperature mechanical properties than conventional superalloys. They are therefore being explored for applications in various fields such as those of aerospace and gas turbines. In general, ODS alloys are manufactured from alloy powders by mechanical alloying of element powders. However, our research team produces alloy powders in which the $Ni_5Y$ intermetallic phase is formed by an atomizing process. In this study, mechanical alloying was performed using a planetary mill to analyze the milling behavior of Ni-based oxide dispersions strengthened alloy powder in which the $Ni_5Y$ is the intermetallic phase. As the milling time increased, the $Ni_5Y$ intermetallic phase was refined. These results are confirmed by SEM and EPMA analysis on microstructure. In addition, it is confirmed that as the milling increased, the mechanical properties of Ni-based ODS alloy powder improve due to grain refinement by plastic deformation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.37 no.1
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• pp.43-53
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• 2011

The conditions in fluid-bed processor for nanoencapsulation of azelaic acid-milk nano powder for acne nanocosmetics were optimized by response surface methodology (RSM). The maximum value of yield was 70.97 %. The yield was appreciably influenced by inlet air temperature, atomizing pressure, and feeding speed. The particle size increased with an increase in the feeding speed and a decrease in the atomizing pressure. The elution rate in saline solutions was appreciably influenced by inlet air temperature and atomizing pressure. The moisture content increased with higher atomizing pressure, which was demonstrated to be similar to the nanoencapsulation characteristics related to water activity. The Hunter's L and b values increased with an increase in the inlet air temperature. The optimum conditions estimated by RSM for the maximized values of yield, moisture content, particle size and elution rate in skin suitability were $67{\sim}73^{\circ}C$ of inlet air temperature, 0.6 ~ 0.8 mL/min feeding speed and 1.8 ~ 2.0 kg/$cm^2$ of atomizing pressure, respectively. These estimated values were in agreement with those measured by real experiments.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1994.04c
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• pp.8-8
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• 1994

• Journal of Biosystems Engineering
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• v.21 no.4
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• pp.467-473
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• 1996

Ultrasonic energy was applied for atomizing rice-bran oil which is a highly viscous bio fuel. Six different nozzles, an injection simulator, and an ultrasonic generator system were designed and constructed for the experiment. An immersion liquid method was used for the measurement of injection droplet sizes. The characteristics of injection droplets was investigated with respect to the numbers of the droplets with diameters ranging from 5$\mu$m 50$\mu$m and to the Sauter mean diameter. The results showed that the ultrasonic energy was effective for the improvement of the atomization of the injection droplets for all the factors such as type of nozzles, nozzle opening pressures, and collection distances.

• Journal of the korean Society of Automotive Engineers
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• v.14 no.5
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• pp.41-53
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• 1992

The main purpose of this study is to investigate the atomizing characteristics of a two phase spray by using a liquid column type coaxial nozzle. The experiments have been carried out to analyze the atomization behavior, the droplet size distributions, and the statistical properties of droplet size distributions. Immersion sampling method and the image processing technique were adapted for the measurements of particles, and the distributions of the droplet sizes were statistically analyzed. In the experiments, the mass ratio defined as Mr= $M_{\sigma}$/ $M_{1}$ has been changed from 1.0 to 3.4 and the measurements have been performed along the axis of the spray. As a result of this experimental study, the distributions of droplet size were satisfied with the Log-Normal distributions and arithmetic mean diameter and deviation of mass ratio. Droplet volume-surface mean diameter was denoted by a exponential function of mass-ratio and the exponent was denoted by linear relation according to the central axis from the nozzle. Dispersions, skewness factors and flatness factors had comparatively constant values regardless of mass ratio and location.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.348-351
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• 2006

This paper presents preliminary laboratory investigations on the electrokinetic (EK) remediation coupled with permeable reactive barrier (PRB) system. Atomizing slag was adopted as a PRB reactive material for remediation of groundwater contaminated with inorganic and/or organic substances. A series of laboratory experiments were performed with variable conditions such as (i) type of contaminant, (ii) applied electric field strength, (iii) processing time, and (iv) the application of PRB system. From the preliminary investigations, the coupled technology of EK with PRB system would be effective to remediate contaminated grounds without the extraction of pollutants from subsurface due to the reactions between the reactive materials and contaminants.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.155-156
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• 2006

Developed and conducted a performance test of the Water mist system that is satisfied with the requirement of a fire test requiring Class 3 Engine Mock-up exceeding net volume $3,000m^3$ as per IMO's MSC/Circ. 668 Appendix B(Test method for fire testing equivalent water-based fire-extinguishing systems for machinery spaces of category A and cargo pump rooms).Even though fuel atomizing was continued for 15 sec. after stopping of the system according to the test method relating to the atomizing fire type, no fire was reignited. This result shows the excellence of the system. There was no damage to the contents of the system after the test.

• Journal of Powder Materials
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• v.1 no.2
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• pp.145-152
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• 1994

Atomizing mode and powder characteristics of CuA1Ni base shape memory alloy in rotating disk atomization were investigated in accordance with disk materials and additional elements. Produced powders were classified into two types of spherical and flake shape. In the case of CuAlNiBTi and CuAlNiZr alloy, high yield rate and fine powder were obtained. This tendency was same when we used oxide coated disks. We concluded that this results were steno from the wetting characteristics change between molten metal and disk surface. Especially, due to the reactive properties of Ti and Zr with ceramic disk, the change of atomizing appearance and powder characteristics were noticeable.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1184-1189
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• 2008

This paper is a study about characteristics of the SSC-1 nozzle, which is used in a fire extinguishing system in a ship. Through this paper, we can find that the traces and elements’ distributions obtained from experiments are as the same as the simulation analysis results of CFD program. At the point of 100mm, the $\alpha$ is 34.9 in the CFD analysis, and it is 32.5 in the experiment. This shows that there is no big different between the CFD analysis and the experiment result. And the average elements velocity is similar to the SMD.

• Advances in materials Research
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• v.6 no.4
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• pp.343-348
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• 2017

High-pressure gas atomization was employed to prepare the Fe-based $Fe_{50}Cr_{24}Mo_{21}Si_2B_3$ alloy powder. The effect of flow rate of atomizing gas on the median powder diameter was studied. The results show that the powder size decreased with increasing the flow rate of atomizing gas. Fe-based alloy coatings with amorphous phase fraction was then prepared by high velocity oxygen fuel spraying (HVOF) of gas atomized $Fe_{50}Cr_{24}Mo_{21}Si_2B_3$ powder. Microstructural studies show that the coatings present dense layered structure and low porosity of 0.17% in about $200{\mu}m$ thickness. The Fe-based alloy coating exhibits an average hardness of about 1230 HV. Our results show that the HVOF process results in dense and well-bonded coatings, making it attractive for protective coatings applications.