Evaluation of a Local Acoustic Resonance Method for Coating Thickness Determination on Stochastic Metal Hybrid Foams

Novel cellular materials promise a combination of high strength and low specific weight for sustainable and energy-efficient material design. Inhomogeneities of the materials, such as varying coating thickness, are inherent to the production process but require advanced characterization in order to better understand mechanical properties. Herein, global and local acoustic analysis for nondestructive characterization of local coating thickness on an open-porous hybrid metal foam system is studied. Experiments and numerical simulations are carried out to evaluate vibration behavior stimulated by a low-energy impact. The novelty of the work is the use of local excitation and analysis of decay times to determine coating thickness gradients. This qualitative measurement can inform and speed up the material development process due to its simplicity, speed, and low cost. Furthermore, it provides a basis for quality control when scaling up the technology of metal hybrid foams for industrial applications. Hybrid metal foams are natural, lightweight construction materials with great application potential, which are produced by electrodeposition. This work presents a nondestructive acoustic characterization method for the qualitative determination of the coating thickness. The combination of experiments and numerical simulations enables the identification of factors influencing the results.image (c) 2024 WILEY-VCH GmbH