Understanding Deformation Processes of a Rolled Aluminum Sheet Using Instrumented Indentation

This study employs instrumented indentation testing (IIT) in combination with finite element (FE) modeling to analyze the deformation processes of an aluminum AA 3003-H14 sheet. IIT, commonly known as nanoindentation, is an effective method for evaluating the mechanical properties of materials such as thin films, coatings, and bulk materials at very small scales. The load-displacement curve obtained from nanoindentation provides insight into the stress-strain characteristics of an elastic-plastic material. However, establishing an analytical relationship between these parameters is complex due to the localized stress fields generated during indentation. This work implements a combined experimental and numerical approach to understand the material deformation under the localized stress conditions induced by a nanoindenter probe pressing into the material’s surface. The experimental component of this study involves measuring nanoindentation responses of the sheet surface by using a three-sided diamond pyramid Berkovich indenter. By measuring the load and displacement during the indentation process, critical mechanical properties, such as yield strength, hardness, and elastic modulus are estimated at the nanoscale level. This method reveals material behavior under concentrated stress, allowing assessment of both elastic and plastic properties. The numerical approach uses FE simulations of instrumented indentation tests to validate experimental load-displacement responses. An axisymmetric model is employed for efficient, preliminary analysis under symmetrical loading, aiding in quick parameter identification and optimization. In contrast, the three-dimensional (3D) model is utilized to capture localized stress and strain fields in greater detail, essential for refining the understanding of material deformation mechanisms. By comparing simulated and experimental results, the accuracy of FE models is confirmed, providing a robust framework for material deformation and property analysis at small scale, aiding in the optimization of manufacturing processes.