Anticorrosion Behaviour of a Hydrazide Derivative on 6061 Al-15%_(v) SiC_(P) Composite in Acid Medium: Experimental and Theoretical Calculations

The present work describes the evaluation of anticorrosion property of 4-hydroxy-N′-[3-phenylprop-2-en-1-ylidene] benzohydrazide (HBH) on 6061 Al-15%_(v) SiC_(P) composite (Al-CM) in 0.5 M hydrochloric acid medium. The results of electrochemical measurement and specimen morphology study are discussed in this work. The adsorption of HBH over the Al-CM surface is through physisorption and obeys the Langmuir’s isotherm model. Potentiodynamic polarization study showed that the HBH acted as mixed inhibitor. The electrochemical impedance spectroscopy (EIS) study showed that the increase in the adsorption tendency of HBH on to the metal surface is due to increase in the polarization resistance. Density functional theory (DFT)-based calculations were carried out for both neutral and protonated HBH molecules which is well supported by the experimental observations.