Polymer-based coatings are a long-established category of protective coatings for metals and alloys regarding corrosion inhibition. The polymer films can degrade, and when coated on metallic substrates, the degradation facilitates moisture and oxygen penetration, reducing the polymer film’s adhesion to the metallic substrate and exposing the substrate to extreme conditions capable of corrosion. For this reason, pigments, inhibitors, and other compatible blends are added to the polymer coating formulations to enhance adhesion and protection. To prevent the possible deterioration of inhibitor-spiked polymer coatings, inhibitors are encapsulated through diverse techniques to avoid leakage and to provide a controlled release in response to the corrosion trigger. This review discusses polymer-based coating performance in corrosion-causing environments to protect metals, focusing more on commercial steels, a readily available construction-relevant material used in extensive applications. It further beams a searchlight on advances made on polymer-based coatings that employ metal–organic frameworks (MOFs) as functional additives. MOFs possess a tailorable structure of metal ions and organic linkers and have a large loading capacity, which is crucial for corrosion inhibitor delivery. Results from reviewed works show that polymer-based coatings provide barrier protection against the ingress of corrosive species and offer the chance to add several functions to coatings, further enhancing their anti-corrosion properties.

Boron carbide is one of the potential neutron-shielding materials and its use can be maximized for structural shielding application by dispersing it into metal matrixes such as aluminum. Dispersion of B₄C and its interfacial stability is a major issue during its processing. This investigation is on the synthesis of B₄C-reinforced 6061 aluminum matrix composite by liquid–metal stir-casting technique under optimized conditions after solving the issues related to the processing, and evaluation of the structural, mechanical, and interfacial characteristics. During processing of composites, pretreatment of B₄C particles is necessary to improve its dispersion. However, higher preheating temperatures above 300°C lead to particle agglomeration in the matrix due to the formation of B₂O₃ phase during preheating. B₂O₃ is formed due to the surface oxidation of B₄C particles above 300°C and this glassy phase leads to particle sintering and lump formation. Incorporation of particles preheated at 250°C has shown uniform distribution of particles in the composite. Interfacial characterization of the composite and the extracted B₄C particles from the matrix has shown the presence of interfacial reaction products such as AlB₂, Al₃BC, AlB₁₂, and AlB₁₀.