Optimizing stealth thin films: Nanoindentation and nanoscratch testing for enhanced mechanical properties

Abstract

The study provides a comprehensive mechanical assessment of thin film coatings using nanoindentation and nanoscratch testing to analyze the effects of composition, microstructure, and testing conditions on their mechanical properties. A diverse range of materials, such as ZrAlN, TiCrN, and reduced graphene oxide-functionalized epoxy coatings, was systematically evaluated under varying test conditions. Nanoindentation revealed critical parameters such as hardness, elastic modulus, and plasticity index, underscoring the influence of filler content and matrix interactions in determining mechanical performance. ZrAlN thin films exhibited exceptional thermal stability and resilience, making them ideal for high-temperature stealth applications. Meanwhile, TiCrN coatings with optimized nitrogen stoichiometry demonstrated enhanced adhesion strength, scratch resistance, and elastic recovery, emphasizing the significance of precise compositional control in aerospace and defense systems. Nanoscratch testing further validated the improved performance of these coatings, showcasing their ability to withstand mechanical stresses while maintaining structural integrity. Comparative tables and graphical interpretations were utilized to reveal intricate relationships between material compositions, testing parameters, and mechanical properties. The study highlights the critical importance of optimizing material composition and microstructure to develop multifunctional coatings that meet the stringent demands of modern stealth technology. Future research should address the long-term performance of these coatings under cyclic loading and extreme environmental conditions while exploring novel material systems that offer enhanced radar absorption and low infrared emissivity. These findings provide a robust framework for advancing thin film technologies tailored to next-generation defense applications.