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.

Cathodic protection is widely recognized as the most cost effective and technically appropriate corrosion prevention methodology for the port, offshore structures, ships. When applying the cathodic protection method to metal facilities in seawater, on the surface of the metal facilities a compound of calcium carbonate(CaCO 3 ) or magnesium hydroxide(Mg(OH) 2 ) films are formed by Ca 2+ and Mg 2+ ions among the many ionic components dissolving in the seawater. And calcareous deposit films such as CaCO 3 and Mg(OH) 2 etc. are formed by the surface of the steel product. These calcareous deposit film functions as a barrier against the corrosive environment, leading to a decrease in current demand. On the other hand, the general calcareous deposit film is a compound like ceramics. Therefore, there may be some problems such as weaker adhesive power and the longer time of film formation uniting with the base metal. In this study, we tried to determine and control the optimal condition through applying the principle of cathodic current process to form calcareous deposit film of uniform and compact on steel plate. The quantity of precipitates was analyzed, and both the morphology, component and crystal structure were analyzed as well through SEM, EDS and XRD. And based on the previous analysis, it was elucidated mechanism of calcareous deposit film formed in the sacrificial anode type (Al, Zn) and current density (1, 3, 5 A/m 2 ) conditions. In addition, the taping test was performed to evaluate the adhesion.

Carbon Fiber Reinforced Plastic (CFRP) has strong and superb material properties, especially in mechanical and heat-resisting aspects, but the drawback is its high price. In this study, we made a hybrid composite using carbon fiber and basalt fiber, which is expected to attribute to its strong material properties and its financial benefits. We found out that the higher the content of basalt fiber included, the lower the intensity, and carbon's intensity contents of 80% showed the similar intensity level as that of CFRP. Besides it was possible to get a better mechanical properties using the composite that included the mixed fiber, instead of using a composition of separate fibers filed.

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This study was intended to investigate the effect of the amount of magnesium addition and heat treatment in the Al-Mg coating film in order to improve corrosion resistance of aluminum coating. Al-Mg alloy films were deposited on cold rolled steel by physical vapor deposition sputtering method. Heat treatment was fulfilled in an nitrogen atmosphere at the temperature of 400°C for 10 min. The morphology was observed by SEM, component and phase of the deposited films were investigated by using GDLS and XRD, respectively. The corrosion behaviors of Al-Mg films were estimated by exposing salt spray test at 5 wt.% NaCl solution and measuring polarization curves in deaerated 3 wt.% NaCl solution. With the increase of magnesium content, the morphology of the deposited Al-Mg films changed from columnar to featureless structure and particle size was became fine. The x-ray diffraction data for deposited Al-Mg films showed only pure Al peaks. However, Al-Mg alloy peaks such as Al 3 Mg 2 and Al 12 Mg 17 were formed after heat treatment. All the sputtered Al-Mg films obviously showed good corrosion resistance compared with aluminum and zinc films. And corrosion resistance of Al-Mg film was increased after heat treatment.