Formation of Corrosion Resistant Mg-Al Layered Double Hydroxide Contained Mg(OH)2 Film on Mg Alloy by Steam Coating
In recent years, a reduction in weight of materials is highly desirable in the fields of transport industry and information technology devices. Magnesium (Mg) alloys have excellent physical and mechanical properties such as low density, good electromagnetic shielding, and high strength/weight ratio. Unfortunately, they have a great default that is low corrosion. Thus, it is very important to develop surface treatment technologies to improve the corrosion resistance of magnesium alloys. Many surface treatments such as chemical conversion, anodic oxidization, electroless plating, and electroplating have been developed. However, these processes require multi-step pretreatments and waste liquid treatments. Thus, the development of a simple, easy, and low-cost surface treatment is highly desirable. In this paper, we report a novel preparation method of corrosion resistant film on Mg alloy by steam coating. The prepared films were characterized by XRD, SEM, EDX, FT-IR, and electrochemical measurements. Polarization curve measurements demonstrated that the Ecorr and icorr values were found to be shifted to positive direction and to lower current density with an increase in the film thickness, indicating that the corrosion resistant Mg-Al layered double hydroxide (LDH)contained Mg(OH)2 Filmimparted superior corrosion resistant performance to Mg alloy.
Keywords - Mg alloy, Corrosion Resistant Film, Mg (OH)2, LDH, Technology.