• Proceedings of the KSME Conference
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• 2000.11b
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• pp.168-173
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• 2000

Flame aerosol synthesis technology refers to the formation of fine particles from gases in flame and is widely used in practical materials processing. In this paper, an experimental investigation was performed on growth of the silica particles that were generated in $H_2/O_2$ Diffusion Flame by the direct injection or TEOS using Electro-spraying method. in this flame aerosol synthesis, four main parameters or nos interaction (flame temperature, residence time or particle in flame, TEOS flow rate, applied voltage) for particle generation and growth was investigated along the axial direction above the burner. A fairly monodisperse non-aggregated particles were successfully obtained.

• Journal of the Korean institute of surface engineering
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• v.22 no.1
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• pp.26-42
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• 1989

It has between investigated that the optimum spaying conditions, such as, spraying distance, fusing temperature and fusing time, ect, in a Ni-cr base self fluxing alloy sprayed on the mild steel substrate by oxygen-acetylenc flame spraying. Sprayed specimens on various conditions were fuused in a vacuum furnace and the results were as follows. The optimum spraying condition for excellent coating layer are obtained under spraying distances, fusing temperature and fusing and time ; 180~240mm,1050~110$0^{\circ}C$and 15~30min, respectively. The adhesive strength and surface hurface hardness of the as sprayed specimens were very low by mechanical bonding becaus of the diffusion layer during process. The carbides and borides and formed in the sprayed coating layer and densification of the layer was resulted from the elimination of pores and oxides. The hardness of sprayed coating layer, particularly in the high temperature, was superior to ordinary tool steels.

• Journal of Advanced Marine Engineering and Technology
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• v.15 no.3
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• pp.39-44
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• 1991

The purpose of this investigation is to examine the effects of spraying conditions on the mechanical properties of flame-sprayed titania ceramic coating layer. Titania ceramic was sprayed onto the mild steel substrate under the various spraying conditions. Spraying distances were 100, 150, 200, 250mm respectively and pinch air pressures were 0.2 0.3, 0.4 MPa at each spraying distance. The mechanical properties such as microhardness, adhesive strength and erosion wear resistance were tested for the specimens sprayed under the various spraying conditions above mentioned. The optimum operational conditions obtained through the experimental results were 150mm of spraying distance and 0.3 MPa of pinch air pressure.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.1
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• pp.49-58
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• 2000

Thermal spraying is one of the most common surface coating techniques to be used for many applications and flame spraying covers a wide range of different materials which can be coated onto various substrates. The purpose of this study is to investigate the effects of mixed ratio in composite coatings on the mechanical and anti-corrosion properties. The five different types of composite coatings were made with $Al_2O_3$ ceramic and Ni-alloy powder on the mild steel substrate by flame spraying method. The mechanical properties such as microhardness, adhesive strength and erosion resistance and corrosion resistance were tested for the sprayed coating specimens. The results obtained are summarized as follows; 1. The composite coating layers greatly improve the microstructure, erosion resistance and adhesive strength by increasing the content of Ni-Al alloy. 2. Microhardness of the compsite coating layer is decreased by increasing the content of Ni-Al alloy. 3. The anti-corrosion properties is considerably improved by increasing the compsite rate of Ni-Al alloy.

• Fire Science and Engineering
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• v.23 no.5
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• pp.66-71
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• 2009

In this study, I evaluated toxicity that analyze performance of flame-retardant about flame-retardant painting wood and combustion gas that is based on the toxicity index. Processing condition of flame retardant solution and treatment method of samples didn't affect greatly to performance of flame retardant. Occurrence of combustion gas showed a almost similar result from the sample which spraying flame retardant solution and toxicity corresponds to high level, Hazard Class III, and the flame retardant solution saturation sample which makes put out Hazard Class II which is a low toxicity relatively.

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.05a
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• pp.107-107
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• 2002

• Journal of Power System Engineering
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• v.1 no.1
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• pp.70-79
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• 1997

Ni-base self-fluxing alloy powder particles were flame sprayed onto the SS400 mild steel substrate surface. The effects of both substrate temperature and spraying distance on the splat behavior of sprayed particles were examined. The results obtained are summarized as follows: 1) In the splat behavior of Ni-base self-fulxing alloy particles sprayed onto the SS400 mild steel substrate, splashing was observed under the room temperature condition. On the contrary, it showed circular plate pattern in the substrate temperature range over 373K. 2) It was cleared that there was close relationship between mechanical properties of coating layer and splat behavior of sprayed particles. 3) From the experimental results, optimum spraying conditions showed excellent mechanical properties in the case of Ni-base self fluxing alloy sprayed onto the SS400 mild substrate were 473K of substrate temperature and 250mm of spraying distance.

• Journal of ILASS-Korea
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• v.16 no.1
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• pp.37-43
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• 2011

The present study conducted computational simulation for multiphase flow in the flame spray coating process with commercially available Ni-Cr powders. The flows in a flame spray gun is characterized by very complex phenomena including combustion, turbulent flows, and convective and radiative heat transfer. In this study, we used a commercial computational fluid dynamics (CFD) code of Fluent (ver. 6.3.26) to predict gas dynamics involving combustion, gas and particle temperature distributions, and multi-dimensional particle trajectories with the use of the discrete phase model (DPM). We also examined the effect of particle size on the flame spray process. It was found that particle velocity and gas temperature decreased rapidly in the radial direction, and they were substantially affected by the particle size.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.509-510
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• 2006

Correlations between in-flight particle, splat and coating microstructure of thermally sprayed Ni20Cr were investigated. Flame spray and arc spray systems were employed for spraying Ni20Cr powder and Ni20Cr wire, respectively. The results showed that the arc spray process produced a broader size distribution for both in-flight particles and splats compared to flame process. Flower-like splat morphology was obtained from the arc spray whereas a pancake-like splat was obtained by flame spray. Ni20Cr coating sprayed by arc process had a denser microstructure, lower porosity and better adhesion at the interface.

• Journal of the Korea Institute of Building Construction
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• v.13 no.2
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• pp.122-130
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• 2013

One of recent methods to protect wooden cultural assets from fire, there is the flame retardation which is applied directly to wood and it is to prevent fire through securing flame resistance for the material and delaying combustion when failed fire in advance and then to gain time for people in the room to evacuate and it has same goal with the Korean Fire Service Act by protecting life and property. However, in case of spraying flame retardant on the colored surface of the wooden cultural assets, there are continuous problems of decoloration, efflorescence and water absorbtion after sometime and accordingly there increases danger of damages of cultural assets. So when treating with flame retardant on wooden cultural assets, there has to be no problems on dancheong after sometime and securing sustainable methods for flmae retardation should be preceded. Accordingly, this study aims to provide basic sources for selecting proper flame retardation methods by evaluating and analyzing flame retardation capabilities according to types of flame retardants which are frequently used nowadays and spraying them on the dancheong-painted surface and confirming if there is no problem on the dancheong and wood after sometime and if flame retardation effect is sustainable with its quality and capability through precise analysis.