A review of next-generation coatings for automotive systems: From corrosion protection to multifunctional performance

Objectives This review examines the evolution of automotive coatings from conventional corrosion barriers to multifunctional systems for electrified and lightweight vehicles. It evaluates structure–property–performance relationships across metallic, polymeric, ceramic, nanostructured, smart, and multifunctional coatings and identifies barriers to industrial implementation. Methods A systematic literature search was conducted using the Clarivate Web of Science database with a defined Boolean search strategy and screening criteria. The selected literature was critically synthesized to compare reported corrosion resistance, hardness, adhesion strength, thermal performance, deposition approaches, and indicators of scalability and technology readiness. Because testing conditions and reporting practices varied substantially, quantitative values were interpreted as comparative evidence rather than direct head-to-head measurements. Results The review identifies substantial advances in multifunctional coatings, including graphene- and nitride-reinforced nanocomposites that combine corrosion protection, mechanical enhancement, and flame retardancy, as well as titanium nitride coatings for corrosion-resistant proton exchange membrane fuel-cell components. However, chromium-free conversion coatings continue to face performance challenges relative to hexavalent chromium systems, while reported performance of zinc–magnesium–aluminum coatings varies with accelerated test protocols. Emerging giga-cast aluminum architectures and electrified-vehicle components introduce additional thermal, electrical, mechanical, and corrosion requirements. The analysis also highlights persistent gaps in standardized testing, scale-up, long-term validation, and cross-study comparability . Conclusions Future development should prioritize application-representative and standardized testing, scalable processing, AI-assisted predictive design, durability validation, and lifecycle assessment. Integrating materials selection, coating architecture, processing, performance, and sustainability at the systems level will be essential for translating promising laboratory-scale coating technologies into reliable automotive applications.