PROPANOYL(1Z)-N-(2,6-DIMETHYLPHENYL)-2- OXOPROPANEHYDRAZONOATE AS INHIBITOR FOR CORROSION OF 6061 AL ALLOY15 % (V) SIC(P) COMPOSITE IN HYDROCHLORIC ACID MEDIA

The corrosion inhibition effect of Propanoyl(1Z)-N-(2,6-dimethylphenyl)- 2-oxopropanehydrazonoate (PDOH) in the corrosion of 6061 Aluminium alloy-15%(v) SiC(p) composite in 0.5 and 1M hydrochloric acid medium at four different temperatures (30, 40, 50 and 60 ⁰C) was investigated using potentio-static polarization (Tafel extrapolation and Linear polarization) and weight loss methods. The results obtained reveal that PDOH is an efficient corrosion inhibitor with around 96% inhibition efficiency within the range of temperature studied. Leftward and downward shifts in Tafel plots were observed with the addition of the inhibitor, indicating that PDOH inhibits the corrosion process effectively, and that it is a cathodic inhibitor. Corrosion rate increases and inhibition efficiency decreases with increase in temperature. Results obtained by Tafel extrapolation, linear polarization, and weight loss methods are in agreement. The adsorption of the inhibitor onto the surface of the 6061 Al alloy 15 % (v) SiC(p) composite is found to obey Temkins adsorption isotherm that verifies the assumption of mono-layer adsorption on a uniform homogeneous composite surface with an interaction in the adsorption layer. The inhibition is therefore governed by the physisorption mechanism.