Development of advanced smart self-healing coatings for magnesium alloys for anti-corrosion applications

Smart material, also called intelligent material, can change its structure and/or chemical/physical properties in response to one or more external stimuli such as light, pH, c...chemicals, temperature, humidity, mechanical force, electrical fields, and magnetic fields. This project aims to develop novel and more efficient smart anti-corrosion self-healing coatings for magnesium alloys. A self-healing material demonstrates an ability to restore its properties after mechanical and functional damages. These materials have applications in several areas, including smart anti-corrosion coatings, self-healing electronics, smart textiles, artificial muscles, etc. The metallic material used in this study is magnesium alloy. Magnesium and its alloys have found intense topical research attention due to their exceptional qualities like higher specific strength, excellent vibration/shock absorption, good thermal/electrical conductivity, biodegradability and biocompatibility; making them suitable for several industrial applications, including automotive, electronics, biomedical, aerospace, and defence. The feeble aqueous corrosion resistance is the most crucial shortcoming of Mg alloys that hinder its extensive utilization. When compared to aluminium and titanium alloys having robust passive surface film, magnesium forms a less corrosion resistant film made up of inner Mg-O and outer porous Mg(OH)2 layer. The most practical corrosion protection method for Mg alloys is protective surface coatings. Compared to the conventional active corrosion protection (by the embedded inhibitors in the coating matrix) offered by the protective barrier coatings, a smart coating normally employs inhibitors/antibiofouling agents loaded onto nanocarriers, facilitating the on-demand release of the encapsulants, providing the self-healing effect. A smart coating typically relies on supramolecular chemistry-based extrinsic/intrinsic self-healing. The intrinsic self-healing depends on the inherent covalent/non-covalent interactions within the polymer coating matrix, whereas the extrinsic self-healing utilize external added nano/microcarriers loaded with corrosion inhibitors/antibiofouling agents. In this context, the project aims to develop advanced self-healing coatings for magnesium alloys via an extrinsic self-healing approach by incorporating corrosion inhibitor encapsulated nanocontainers in a polymer coating matrix. The proposal's first phase (six months) focuses on acquiring the required materials and chemicals. The base material for the study is AZ 31 Mg alloy. The expected duration of the complete project is 2 years. The PI has published papers in this area.