Corrosion inhibition of aluminium radiators by zinc-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

Concerns about the toxicity and biodegradability of conventional glycol coolants have led to the hunt for environmentally preferable substitutes. In this work, a green coolant made from leaf extracts of Moringa oleifera and Newbouldia laevis stabilised with zinc sulphate was used to investigate the corrosion inhibition of aluminium radiators. Extracts were prepared in a one-to-one blend and tested with zinc sulfate at 0.1 M and 1.0 M concentrations, dosed at 0.25 g and 1.0 g per 15 L of distilled water. Aluminium coupons were immersed for 24 days under controlled conditions, and corrosion rates were determined by the gravimetric weight loss method. Results showed significant inhibition compared with distilled water, with inhibition efficiencies exceeding 80 percent at optimal zinc dosage. As an alternative to hazardous glycol-based coolants, the study shows that zinc-stabilized Moringa-Newbouldia bioadditives offer aluminium radiators efficient, long-lasting corrosion protection.