Plasma nitriding is a treatment process of metals by depositing nitrogen into metal that considered to be nitrided by mean of increasing the mechanical, physical, and chemical properties of the metal. This treatment will form a hard layer compund of Al-N on the surface of the sample. In this study, aluminium alloy 7075 was nitrided which the application of it to structural part of aircraft makes it vulnarable to not only corrosion and wear attack but also decreasing the hardness of the material. One method to overcome these issues is plasma nitriding. The purpose of of this research is to do the characterizations of plasma nitrided aluminium alloy 7075 regarding its microstructure, mechanical, and chemical properties. The characterizations that had been done were microhardness Vickers testing, SEM-EDX, and electrochemical corrosion testing Potensiostat. The hardness of the sample increased 55% from 75,88 VHN (raw material) to 117,68 VHN (at optimum parameter). The depth of the white layer of plasma nitriding is approximately 6 µm, while the EDX result reported carbon, oxygen, and nitrogen presence. Corrosion testing showed that the highest corrosion rate is on the raw material, 0,15393 mpy. While the optimum one is 0,07184 mpy.

The present work reports the effect of nitrogen ion implantation on aluminum alloy 7075. The microhardness, corrosion resistance, and surface nanostructure were investigated. The implantation was carried out at energy 60 keV with the ion doses used were 1.70 × 1017 ion/cm2, 1.86 × 1017 ion/cm2, 2.02 × 1017 ion/cm2, 2.17 × 1017 ion/cm2, and 2.33 × 1017 ion/cm2. The microhardness test was performed to study the hardness of the implanted layer which was characterized by X-ray Diffraction (XRD). The potentiodynamic corrosion test was performed in a 0.5 mol/l NaCl solution. The surface nanostructure was investigated by atomic force microscopy (AFM) to study the surface roughness after implantation. The results showed that the microhardness after implantation at 2.17 × 1017 ion/cm2 increased by 90.81%. The increase was attributed to the formation of the AlN phase. The AlN phase was confirmed at 2-theta peaks of 39.53°, 45.84°, 66.90°, and 80.54°. The corrosion test showed the improvement of corrosion resistance by the decrease of corrosion rate from 4.49 mpy to 1.43 mpy. The atomic force microscopy showed the arithmetical mean height (Sa) value was 37.5 nm and the root means square (Sq) value was 47.6 nm. The ion implantation induced the change of material surface due to the penetration of nitrogen ion into the material.