Improvement of Corrosion Behavior of Al7075 by Applied Ti/TiN Multilayer Coating with High Vacuum Magnetron Sputtering

7075 aluminum alloys are widely used in industry, due to their properties such as specific strength and good fatigue resistance. The nitride multilayer coating, which applied by physical vapor deposition (PVD) process have shown good improvement in abrasive resistance, but their columnar structure led to decreasing corrosion resistance behaviors. In this paper, multilayer coatings of Ti/TiN with 6 layers applied on Al 7075 as a substrate by high vacuum magnetron sputtering. Then GIXRD, FESEM and AFM were used to assessed phase behavior, structure and morphology of the coating, respectively. As well as the corrosion behavior of coating was investigated by using electrochemical impedance in simulated body fluid such as Ringer’s solution at 37 ºC. The results show production of homogeneity and uniformity multilayer coating, with cutting the column structure of titanium nitride, which increasing the charge transfer resistance by 56 times compared with Al 7075 and also no pitting was seen at the coated samples after 72 hours of immersion, with enhancing of corrosion resistance by 284 % compare to 48 h of immersion.