Corrosion inhibition of aluminium radiators by iron-stabilized Moringa Oleifera and Newbouldia Laevis Bio-additives: A weight loss study

¹ Department of Mechanical Engineering, Covenant University, Ota, Ogun State, Nigeria
² Department of Mechanical Engineering, School of Engineering and Applied Sciences, Kampala International University, Uganda

^* Corresponding author: Aanuoluwa D. Ayoola 1 aanuoluwa.ayoolapgs@stu.cu.edu.ng

Abstract

In corrosion research, iron is a paradoxical element since it may promote film formation in some situations while speeding up dissolution in others. This study set out to examine how iron(II) sulfate can alter the behaviour of plant-based inhibitors when applied in radiator coolants. Extracts of Moringa oleifera and Newbouldia laevis were blended in equal ratios and stabilised with FeSO₄ at 0.1 M and 1.0 M concentrations. Aluminium coupons were immersed in the prepared formulations for 576 hours, and mass loss was used to calculate corrosion rates. The 0.1 M system produced measurable inhibition, reducing the final corrosion rate to 0.61 mm/year compared with 5.07 mm/year in the control. By contrast, the 1.0 M solution triggered an aggressive onset of corrosion before gradually levelling off. These findings suggest that iron-stabilized bio-additives can both protect and destabilise, with their performance hinging on dosage and exposure time.