The effect of NiCrN coating by Arc-PVD method on the corrosion behavior and hydrophobicity of the low-density AlCrFeMnTi high entropy alloy

An effective coating method for creating hydrophobic and corrosion-resistant surfaces is the physical vapor deposition (PVD) method. For this, NiCrN coating was applied by Arc-PVD method on the surface of AlCrFeMnTi high entropy alloy samples and also on the anodized surface of the high entropy alloy. After coating, FE-SEM results show the formation of micro-nano scale protrusions that increase the surface roughness. EDS results also show the successful and correct formation of NiCrN coating on the alloy surface as well as on the anodized surface of the alloy. Then, in a weight loss test, the corrosion resistance of this alloy was examined by immersing the alloy samples in a Simulated Body Fluid solution for 4 weeks, and 2.44 mpy was obtained. Next, the corrosion resistance of NiCrN coating in two solutions 3.5 wt.% NaCl and Simulated Body Fluid was investigated and compared using linear polarization test. In the case of applying NiCrN coating on anodized surface in 3.5 wt.% NaCl solution, the corrosion current density reached 3×10 -7 A.cm -2 and in Simulated Body Fluid solution, the corrosion current density reached 1.66×10 -8 A.cm -2 . Profilometry also shows that by applying a coating, especially to the anodized surface of the samples, the surface roughness has increased significantly. Regarding the hydrophobicity, the results show that the contact angle in the two cases of coating application on the anodized surface and on the substrate is 143.1° and 112.8°, respectively. So this work is an effective coating method for creating a hydrophobic and corrosion-resistant surface and has been able to improve hydrophobicity and corrosion resistance parameters.