Nanoindentation Study of Intermetallic Particles in 2024 Aluminium Alloy

Nanoindentation tests are useful for determining the local mechanical properties of materials. However, the method has its limitations, and its accuracy is strongly influenced by the nano-scale geometry of the indented area. The authors chose to perform measurements of the hardness and elastic modulus of intermetallic particles in 2024 aluminium alloys. The objective of this study was to investigate the influence of the particles’ depth and shape on the accuracy of the nanoindentation result. Several simulations were performed with the use of the finite element method on different geometries mirroring possible real-life configurations of the particle and matrix. The authors compared the force vs. deformation curves for all of the variants. The results showed that the nanoindentation process is different for a particle with the same mechanical properties depending on its depth under the investigated surface. Therefore, the measured values of hardness and elastic modulus for intermetallic particles are partly the result of interaction with a matrix.