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In this study, we tried to form the calcareous deposit films by the electrodeposition process. The uniform and compact calcareous deposit films were formed by electrodeposition process and their crystal structure and characteristics were analyzed and evaluated using various surface analytical techniques. The mechanism of formation for the calcareous deposit films could be confirmed and the role of magnesium was verified by experiments in artificial and natural seawater solutions. The highest amount of the calcareous deposit film was obtained at 5 A/m2 while current densities between 1–3 A/m2 facilitated the formation of the most uniform and dense layers. In addition, the adhesion characteristics were found to be the best at 3 A/m2. The excellent characteristics of the calcareous deposit films were obtained when the dense film of brucite-Mg(OH)2 and metastable aragonite-CaCO3 was formed in the appropriate ratio.

Carbon Fiber Reinforced Plastic (CFRP) has strong and superb material properties, especially inmechanical and heat-resisting aspects, but the drawback is its high price. In this study, we made a hybrid compositeusing carbon fiber and basalt fiber, which is expected to attribute to its strong material properties and its financialbenefits. We found out that the higher the content of basalt fiber included, the lower the intensity, and carbon'sintensity contents of 80% showed the similar intensity level as that of CFRP. Besides it was possible to get a bettermechanical properties using the composite that included the mixed fiber, instead of using a composition of separatefibers filed.초록 : 탄소섬유 복합재료는 내열성 및 우수한 기계적 특성을 가지고 있는 우수한 재료이지만 가격이 비싼 결점이 있다. 따라서 본 연구에서는 높은 기계적 강도를 가지며, 가격이 비싸지 않은 재료의 개발을 위해 탄소섬유에 현무암 섬유를 첨가하여 하이브리드 복합재료를 제작하였다. 현무암 섬유의 함유 비율이 높아질수록 강도는감소하였으며, 탄소의 강화재 비율이 80% 정도에서 CFRP와 유사한 강도를 얻을 수 있었다. 또한 섬유 각각을 적층하여 복합재료를 제작하는 것 보다 섬유사를 혼합시켜 제작한 복합재료에서 더 우수한 기계적 특성을 얻을 수 있었다.

To improve the corrosion resistance of an electro-galvanized steel sheet, we deposited magnesium film on it using a vacuum evaporation method and annealed the films at 250–330°C. The zinc–magnesium alloy is consequently formed by diffusion of magnesium into the zinc coating. From the anodic polarization test in 3% NaCl solution, the films annealed at 270–290°C showed better corrosion resistance than others. In X-ray diffraction analysis, ZnMg 2 was detected throughout the temperature range, whereas Mg 2 Zn 11 and FeZn 13 were detected only in the film annealed at 310°C. The depth composition profile showed that the compositions of Mg at 270–290°C are evenly and deeply distributed in the film surface layer. These results demonstrate that 270–290°C is a proper temperature range to produce a layer of MgZn 2 intermetallic compound to act as a homogenous passive layer.