Dayauc, Aysenur Keles; Acimert, Ozlem Baran; Senocak, Taha Cagri

Al-5083 alloys are used as a marine part due to resistance to harsh environment. However, mechanical and corrosion resistance to seawater is not sufficient. For this purpose, many different surface treatments, electrochemical coatings, etc. are used to increase the mechanical, wear and corrosion resistance of the surface of Al-5083. This works aims to enhance mechanical, corrosion and tribological properties of Al-5083. Therefore, in this study, the oxide surface was enlarged on the Al-5083 alloy by anodisation and MAO techniques. Three different current densities (25 mA/cm2, 50 mA/cm2 and 75 mA/cm2) were used in the anodisation process. In the MAO process, three different voltages (400 V, 420 V and 440 V) were used. SEM, XPS and AFM were used for microstructure after anodisation and MAO processes. Scratch and hardness test were used to determine mechanical properties, and pin-on-disc was used to determine tribological properties. Also, electrochemical test was used to evaluate the corrosion properties. According to studies compared, it has been observed that the anodisation technique in Al-5083 alloy is better than the MAO technique. Corrosion and mechanical strengths decreased with increasing voltage and current density in both techniques.

Dayauç, Ayşenur Keleş; Acımert, Özlem Baran

MoS2 is one of the widely known solid lubricants. However, it cannot be used in atmospheric environment due to its affinity for oxygen. The best way to reduce oxygen affinity is to add elements or compounds to the MoS2 film. For this reason, in this study MoS2 coatings were doped with Graphite-like carbon (GLC) using CFUBMS method. The MoS2 film was doped by using different C2H2 ratios. The mechanical and electrochemical properties of the films for both undoped and doped coatings were examined. The results of the study have shown that undoped MoS2 film has the worst mechanical and electrochemical properties. On the other hand, with the increasing flowrate of C2H2, an improvement was observed in the mechanical properties, thickness and electrochemical properties of the films. Moreover, at the highest C2H2 ratio used in this work, the highest adhesion value of 90 N was observed.