Prediction of the elastic properties profile in glass-alumina functionally graded materials

Glass-alumina functionally graded materials were obtained by percolation and alternatively by plasma spraying. The paper develops a reliable model to predict the functional gradient of the analysed systems. A finite element code, which was able to handle microstructural images, was employed to estimate the effective elastic properties along the gradient direction. The calculated values were compared with experimental data acquired by means of systematic microindentation tests. The computational approach was compared with analytical tools such as the rule of mixture. The results revealed that the elastic properties were significantly influenced by microstructural features such as the shape of the ingredient materials domains and the presence of pores at the grain boundaries. This was particularly evident in the sprayed FGMs, due to their peculiar lamellar microstructure. Even if the coating–substrate interface properties were difficult to include in the model, the numerical simulations fitted fairly well the experimental data.