چكيده به لاتين
In this project, the effect of copper-titanium combined nano-metallic coatings on the
corrosion of the inner surface of pipes and structures in contact with wastewater of sewage
treatment plants has been investigated. For this purpose, different thicknesses of the
mentioned coating were applied by sputtering on the surface of L304 stainless steel. Then the
effect of the atomic percentage of copper on things such as the structure and properties
related to the electrochemical corrosion resistance of the steel substrate by analyzes such as:
X-ray diffraction analysis (XRD), X-ray energy diffraction spectroscopy analysis (EDS),
scanning electron microscope (SEM), force microscope Atomic force (AFM), Tofel
extrapolation analysis (LSV) and impedance spectroscopy (EIS) were investigated. The
results of XRD showed that the size of the crystals increases with the increase in the weight
percentage of copper. But increasing the amount of copper will decrease the size of the
crystals. SEM images showed that the thickness of the layers was in the range of 197.4 to
206.7 nm. The results of measuring the polarization of chemical corrosion show that the
corrosion current decreases from 7.28 x 10-6 to 8.69 x 10-9 with increasing copper weight
percentage. But with the increase in temperature in the corrosion current layer, it increases up
to 7-10 x 8.45. The results of the impedance analysis also show that with the increase in the
percentage of copper in the layer, the load transfer resistance against corrosion increases from
13.74 to 550.66 kilohms. But with the excessive increase in temperature, the load transfer
resistance decreased to 6.146 kilohms.
Also, the AFM images showed that the uniformity of the surface of the steel coated with
TiCu layer has significantly improved compared to the raw steel and the surface roughness
has decreased from 27.64 nm to 5.69 nm. By increasing the weight percentage of copper, the
uniformity of the surface has increased. The detailed study and analysis of the results of the
analyzes show that the combined thin layer of copper and titanium is very effective in
protecting 304 L stainless steel against chemical corrosion and has significantly reduced the
rate of corrosion in this type of steel.
