A comprehensive review of corrosion inhibition of aluminium alloys by green inhibitors

Corrosion is a spontaneous process that affects many industrial materials and processes. It may lead to severe damages and economic losses. Aluminium and its alloys are extensively employed in industries because of their unique properties. Aluminium and aluminium alloys are quite stable towards degradation, due to the presence of their inherent γ alumina oxide film. However, under an aggressive medium they too will undergo corrosion. When in contact with hydrochloric acid (HCl) and sodium chloride (NaCl) they will undergo severe pitting corrosion. Addressing corrosion mitigation is of prime importance, mainly in metallurgical operations. In addition to this, corrosion control is of aesthetic, economic, ecological and academic interest. Several techniques have been adopted to inhibit the corrosion of aluminium and aluminium alloys. One such method is the use of corrosion inhibitors. The toxicity, harmful effect on the environment and expensiveness of synthetic inhibitors resulted in the diversion of interest towards environment-friendly green inhibitors. Human health and safeguard of the environment is of utmost importance. Even though the use of different classes of inhibitors is reported in the literature, a comprehensive, updated review that includes all types of green inhibitors use to attenuate the corrosion of aluminium and its alloys is very rare.