Evaluation of extract of Caesalpinia pulcherrima flower as corrosion inhibitor for Al-Si-Mg/SiC composite in 0.5M HCl Solution
Authors: Asuke F, Abdulwahab M, Musa AA, Haruna IM
Gravimetric-based mass loss and potentiodynamic polarization method of corrosion measurement were employed to study the effect of extract of Caesalpinia pulcherrima flower as inhibitor in the corrosion of Al-Si-Mg/SiC composite in 0.5M HCl solution at room temperature. Different concentrations of inhibitor (0, 1.5. 3.0, 4.5, 6.0, 7.5%v/v) with time of two (2) to ten (10) hours at an interval of two hours were used for the weight loss method. The results showed a decrease in corrosion rate with increase in inhibitor concentration. The maximum inhibitor efficiency (IE) of 88.87% was obtained at a concentration of 6.0 and 7.5%v/v with exposure time of two hours followed by 81.21% inhibitor efficiency (IE) at 7.5% v/v after six hours for the weight loss method. The potentiodynamic polarization technique recorded 77.679% and 79.381% inhibitor efficiency (IE) for 6.0 and 7.5%v/v respectively. The results of the weight loss and potentiodynamic polarization technique were found to be in agreement. Microstructural observation of the samples revealed the effect of inhibitor on the test samples.
Affiliations: Department of Metallurgical and Materials Engineering, Ahmadu Bello University, Zaria, Nigeria.
Keywords: Al-Si-Mg/SiC Composite, Caesalpinia Pulcherrima, Potentiodynamic Polarization, Thin Film, Adsorption
Published date: 2019/06/30