• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2014.11a
• /
• pp.213-213
• /
• 2014

$300^{\circ}C$와 $500^{\circ}C$에서 아크 이온 증착된 도포층의 조성은 각각 Fe : Al : Ti : Si : N = 1.31 : 36.52 : 31.31 : 0.48 : 30.38 [wt.%]와 Fe : Cr : Al : Ti : Si : N = 1.24 : 0.56 : 36.82 : 32.72 : 0.59 : 28.07 [wt.%] 이었다. 0.1N $H_2SO_4$ 수용액과 인공해수 (ASTM D1141-98) 분위기에서 $300^{\circ}C$, $500^{\circ}C$에서 증착된 도포층의 부식전압과 부식속도는 각각 $-0.2787V_{SHE}$, $0.002A/cm^2$, $-2.764V_{SHE}$, $0.002A/cm^2$ 와 $-0.2799V_{SHE}$, $0.002A/cm^2$, $-0.0394V_{SHE}$, $0.002A/cm^2$이었다. 나노 경도값은 각각 23.6, 25.8 GPa 이었다. 이는 각각 2208.2, $2434.2H_V$에 해당되었다.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2012.11a
• /
• pp.179-180
• /
• 2012

Aluminum alloys are widely known as non-ferrous metal with light weight and high strength. Consequently, these materials take center stage in the aircraft and automobile industry. The Al7075 aluminum alloy is based on the Al-Zn-Mg-Cu and one of the strongest wrought aluminum alloys. Aluminum nitride has ten times higher thermal conductivity($319W/m{\cdot}K$) than Al2O3 and also has outstanding electric insulation($1{\times}1014{\Omega}{\cdot}cm$). Furthermore, it has high mechanical property (430 MPa) even though its co-efficient of thermal expansion is less than alumina For these reasons, it has great possibilities to be used for not only the field which needs high strength lightweight but also electronic material field because of its suitability to be applied to the insulator film of PCB or wafer of ceramic with high heat conduction. This paper investigates the mechanical properties and corrosion behavior of aluminum alloy Al7075 deposited with aluminum nitride thin films To improve the surface properties of Al7075 with respect to hardness, and resistance to corrosion, aluminum nitride thin films have been deposited by pulsed DC reactive magnetron sputtering. The pulsed DC power provides arc-free deposition of insulating films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.11a
• /
• pp.216-219
• /
• 2002

Much quantity of anti-tracking agent, ATH is added to the silicone rubber for the protection of silicone rubber against surface discharge. Hydrophobicity recovery properties of silicone rubber could be different by the content, surface treatment state and particle size of ATH. Because hydrophobicity of silicone rubber is depend much on the surface state of ATH. In this paper, the properties of silicone rubber is investigated according to the addition of different particle size of ATH to the silicone rubber. Hydrophobicity recovery properties and arc resistance of silicone rubber were investigated according to the addition of different particle size of ATH. Hydrophobicity recovery properties of silicone rubber were evaluated by the measurement of contact angle.

• Journal of the Korean Applied Science and Technology
• /
• v.2 no.2
• /
• pp.47-53
• /
• 1985

Correlation among the wax-pigment composites which is base vehicles for the crepas was investigated in terms of fadeness. The base wax synthesized and pigments are compounded with petroleum lubricant and exposed under carbon arc individually. The yellowing phenomenon was appeared on the reference papers coated with the spindle oil which was then exposed. The papers were again extracted with distilled water and pH of them were ranged between 6.2-6.5. Color difference from Adam-Nickerson equation, ${\vartriangle}E$ of base wax is 0.15 and that of spindle oil are varied from 0.66 to 15.62. Since the main components of the petroleum lubricant are aromatic hydrocarbons which have absorptions characteric of UV ranging from 240 to 280 nm, fadeness characteristics of the composites are largely depend upon the change of molecular structure of spindle oil by absorbing UV. Thus the spindle oil having the following physical properties has the better resistance of fadness and is recommended to use in compounding the base wax-pigment composites: ${\cdot}$ main component: paraffinic hydrocarbon ${\cdot}$ pour point: below - $15^{\circ}C$ ${\cdot}$ UV absorption characteristics: ${\lambda}max.$ : 268-290nm ${\cdot}$ absorbancy: below 0.1(0.03ml of sample/50ml of $CHCl_3$)

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2013.05a
• /
• pp.53-54
• /
• 2013

Nano-multilayered CrAlSiN films consisting of crystalline CrN nanolayers and amorphous AlSiN nanolayers were deposited by cathodic arc plasma deposition. Their oxidation characteristics were studied between 600 and $1000^{\circ}C$ for up to 70 h in air. During their oxidation, the amorphous AlSiN nanolayers crystallized. The formed oxides consisted primarily of $Cr_2O_3$, ${\alpha}-Al_2O_3$, $SiO_2$. The outer $Al_2O_3$ layer formed by outward diffusion of Al ions. Simultaneously, an inner ($Al_2O_3$, $Cr_2O_3$)-mixed layer formed by the inward diffusion of oxygen ions. $SiO_2$ was present mainly in the lower part of the oxide layer due to its immobility. The CrAlSiN films displayed good oxidation resistance, owing to the formation of oxide crystallites of $Cr_2O_3$, ${\alpha}-Al_2O_3$, and amorphous $SiO_2$.

• Journal of the Korean institute of surface engineering
• /
• v.47 no.2
• /
• pp.57-62
• /
• 2014

The biogas holder is composed of an outer membrane and an inner membrane which are subject to outdoor exposure and gas exposure respectively. The influence of weathering conditions on the photo-degradation of a biogas holder was investigated. Tests were performed under three different methods - outdoor exposure tests (Seosan, Arizona), accelerated tests (Xenon-are lamp) with the outer-membrane of biogas. Moreover, the changes in the aging process were monitored using color difference, gloss, the contact angle and an optical microscope. Changes in physical properties, such as decrease reduction in gloss, decrease in the contact angle, increase in color difference were observed in the aging process. The comparison between membrane 3B, 4B and membrane 5B under xenon-arc were discussed. Membrane 5B was very sensitive to ultraviolet (UV) ray. There were many difficulties in the outdoor exposure test due to acid rain, dust, and stain resistance.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2004.11a
• /
• pp.234-238
• /
• 2004

Inconel 625 is useful in variety of industrial applications because of the resistance to attack in various corrosive media at temperatures from $200^{\circ}C$ to aver $1090^{\circ}C$, in combination with good law- and high temperature mechanical strength. Rencently, this material is also used widely in offshore processing piping in order to extend the maintenance term and improve the quality of anti-corrosion. In general, high quality weldments for this material are readily produced by commonly used processes. Not all processes are applicable to this material group, Ni-alloys. Metallurgical characterictics or the unavailability of matching, position or suitable welding processes. Nowadays, the flux cored wire is developed and applied for the better productivity in several welding position including the vertical position. in this study, the weldability and weldment characteristics (mechanical properties) of inconel 625 are considered in FCAW(Flux Core Arc Welding) associated with the several shielding gases($80\%Ar\;+\;20\%CO_2,\;50\%Ar+50CO_2,\;100CO_2$) in viewpoint of welding productivity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.4
• /
• pp.390-395
• /
• 2004

In order to analyze the physical and chemical characteristics of home production porcelain insulators by change of the alumina addition amount, 360001bs ball socket type suspension insulators which were manufactured in 1989, 1995 and 2001 removed in transmission line and an experiment was performed. By the result, 8 wt.％ alumina that influences the mechanical properties and arc resistance properties in case of insulators that were manufactured in 1989 was contained, and the relative density and the fracture toughness of insulators appeared by 94.2％ and 1.4 ㎫$.$ $M^{\frac{1}{2}}$, respectively. However, 12 wt.％ alumina was contained in case of insulators that were manufactured in 1995, and the relative density and the fracture toughness of insulators appeared preferably lower by 92％ and 1.3㎫$.$ $M^{\frac{1}{2}}$, respectively. Amount of alumina was contained most by 17 wt.％ in case of insulators that were manufactured in 2001. It was confirmed that the electrical and mechanical characteristics such as the relative density and the fracture toughness appeared excellently by 96％ and 1.7㎫$.$ $m^{\frac{1}{2}}$, respectively.

• Journal of the Korean Ceramic Society
• /
• v.35 no.10
• /
• pp.1061-1069
• /
• 1998

The thermal instability of Al2TiO5 Ceramics was contrlled by solid solution with MgO SiO2 and ZrO2 through electrofusion in an arc furnace. The thermal expansion properties of Al2TiO5 composites show the hysteresis due to the strong anisotropy of The crystal axes of these material. These phenomena are ex-plained by the opening and closing of microcracks. The difference in microcracking temperatures e.g 587.6(ATG2), 405.9(ATG3) and 519.7$^{\circ}C$(ATG4) is caused by the difference in grain size and stabilizer type. The thermal shock behaviour under cyclic conditions between 750-1400-75$0^{\circ}C$ show no change in mi-crostructure and phase assemblage for all three stabilized specimens. After the thermal loading test at 110$0^{\circ}C$ for 100hrs. ATG1 and ATG2 materials decomposes completely to its components corundum and ru-tile in both cases. However with approximatelly 20% retention of the Al2TiO5 Thus in order to prevent decomposition of the stabilized material in the critical temperature range 800-130$0^{\circ}C$ it must be traversed within a short period of time.

• Journal of Ocean Engineering and Technology
• /
• v.18 no.6 s.61
• /
• pp.96-100
• /
• 2004

Inconel 625 is useful in a variety of industrial applications because of the resistance to attack in various corrosive media at temperatures from $200^{\circ}C$ to over $1090^{\circ}C$, in combination with good low and high temperature mechanical strength. Rencently this material has also been widely used in offshore processing piping in order to extend the maintenance term and improve the quality of anti-corrosion. In general, high quality weldings for this material are readily produced by commonly used processes. How, not all processes are applicable to this material group of Ni-alloys. Metallurgical or the unavailability of matching, position or suitable welding processes produce a lower quality. Nowadays, the flux cored wire is developed and applied for increased productivity in several welding positions, including the vertical position. In this study, the weldability and weldment characteristics(mechanical properties) of inconel 625 are considered in FCAW(Flux Core Arc Welding) associated with the several shielding gases$(80\%Ar+20\%CO2,\;50\%Ar+50CO2,\;100CO2)$ in view of welding productivity.