2455-0205 / JACS Directory©2016. All Rights Reserved Cite this Article as: M. Abdulwahab, O.S.I. Fayomi, F.E. Awe, Anti-corrosion and passivation potential of AA6063-type Al-Mg-Si alloy with Avogadro natural oil in HCl solution, J. Adv. Electrochem. 2(2) (2016) 75–77. Journal of Advanced Electrochemistry 2(2) (2016) 75–77 Contents List available at JACS Directory Journal of Advanced Electrochemistry journal homepage: http://www.jacsdirectory.com/jaec Anti-Corrosion and Passivation Potential of AA6063-Type Al-Mg-Si Alloy with Avogadro Natural Oil in HCl Solution M. Abdulwahab 1,2, *, O.S.I. Fayomi 2,3 , F.E. Awe 4 1 Department of Metallurgical and Materials Engineering, Ahmadu Bello University, Zaria, Nigeria. 2 Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Pretoria, South Africa. 3 Department of Mechanical Engineering, Covenant University, Ota, Ogun State, Nigeria. 4 Department of Applied Chemistry, Federal University Dutsinma, Katsina, Nigeria. A R T I C L E D E T A I L S A B S T R A C T Article history: Received 29 December 2015 Accepted 31 March 2016 Available online 27 April 2016 The electrochemical study of the passivation potential of AA6063-type Al-Mg-Si alloy in Avogadro Natural Oil/HCl Interface was studied using weight loss and potentiodynamic techniques. The result shows that the corrosion rate increases with an increase in exposure time but decrease as the concentration of inhibitor increases. The result of both weight loss and potentiodynamic show good agreement as can been seen that the inhibition efficiencies was found to increase as concentration of inhibitor increases. Equally the additive helps to retard the rate of corrosion and increase the polarization resistance thereby lowering the corrosion density of the system. The presence of the additive was also seen to affect both the cathodic and anodic half which shows that the inhibitor acts as a mixed-type inhibitor. The surface morphology of as-corroded samples assessed with scanning electron microscopy show that the attack was severely reduce in the presence of the Avogadro natural oil. Keywords: Avogadro Oil Corrosion Rate Inhibition Efficiency SEM 1. Introduction Aluminium has a versatile application in the industries owing to it numerous characteristics such as: thermal and good electrical conductivities, high ductility, low cost, availability for its fabrication, shiny appearance and excellent properties [1-4]. It has wide application in automobile, roofing, aviation, electronic devices, pipe, machinery and chemical batteries [3]. In most cases, contact between the metal and aggressive medium (such as acid, base and salt) is unavoidable [5]. In view of the industrial facilities exposed to corrosion are often protected against such attack by adopting several options including painting, oiling, cathodic and anodic protections etc. However, the use of inhibitors has been found to be one of the best options available for the protection of metals against corrosion [6-8]. Most of the effective and efficient chemical inhibitors are those compounds containing hetero-atoms such as oxygen, nitrogen, sulphur, and olefins which allowed adsorption on the metal surface. However, using these inhibitors for corrosion control, factors such as cost, toxicity, availability, and environmental friendliness are very important. Numerous studies have been carried out on the corrosion of metals in different environments and their inhibition and most of the well-known inhibitors suitable for the inhibition of the corrosion of metals in acidic medium are heterocyclic compounds [9-18]. In view of this, environmentally friendly and non-toxic inhibitors have been the focus in recent research. This study is therefore aimed at determining the electrochemical behavior of the passivation potential of AA6063-type Al- Mg-Si alloy in Avogadro natural oil/HCl interface using both gravimetric and potentiodynamic measurement. 2. Experimental Methods The aluminium alloy specimen was cut into dimension of 20 mm x 10 mm x 3 mm with the chemical composition shown in Table 1. The entire specimen were immersed in ethanol to degrease it dried, weighed and later stored in a desiccator. Each alloy initial weight were taken and recorded. 0.5 M HCl was prepared fresh as required for the experiment. Avogadro oil used for the analysis was obtained from chemical shop in Pretoria, South Africa. The measurements were conducted at room temperature (25 °C) under static condition. Table 1 Chemical composition of aluminium alloy used Element wt% Element wt% Al 99.01 Ca 0.0012 Si 0.157 Na 0.001 Mn 0.025 Fe 0.281 Mg 0.5 Ti 0.0046 Sr 0.0001 P, Cr, Zr,Cu,Zn 0.01 Bi 0.0024 B,Ni,Ag, Co 0.004 2.1 Weight Loss Measurement Weight loss measurement was carried out on a previously weighed aluminium alloy in the presence and absence of inhibitor at 25 °C. The volume of the solution prepared were 100 mL with and without inhibitor. The Avogadro natural oil as inhibitor concentrations were 1.5, 3.0 and 4.5 g/v in 100 mL of 0.5 M HCl solution. On each sample with Avogadro oil inhibitor using weight loss after the corrosion test, samples were washed, dried and weight taken at interval of 96, 192, 288 and 384 h of immersion. The corrosion rate (mm/day), inhibition efficiencies (IE%) and degree of surface coverage (θ) were determined. 2.3 Potentiodynamic Corrosion Measurement Potentiodynamic polarization measurement was used to determine the rate of corrosion of the alloy in the presence of the oil-HCl solution. All the measurement was done in an Auto lab frequency response analyzer (FRA) coupled to potentiostat that was connected to a computer system. A glass corrosion cell kit with a platinum counter electrode a saturated Ag/Ag reference electrode and aluminium alloy sample as working electrode. The working electrodes samples were positioned at the glass corrosion cell kit, leaving 1 cm 2 surfaces in contact with the solution. Polarization test were carried out in 0.5 M HCl solution at room temperature under static solution using a potentiostat (model: AuT71791 and PGSTAT 30) with a scan rate of 0.003 V/sec. From the Tafel corrosion results, the inhibition efficiencies, corrosion rate and linear polarization resistance were obtained. The *Corresponding Author Email Address: mabdulwahab@abu.edu.ng (M. Abdulwahab) ISSN: 2455-0205