Estimation of the elastic modulus of the alumina coated AA1050 aluminum: Modeling and experiments

This paper deals with the prediction of the elastic modulus of alumina coating deposited on an aluminum substrate. Three- and four-point bending tests were used for the mechanical characterization. Three configurations were retained: a sandwich model, a model with coating subjected to tensile and model with coating placed in the state of compression. For the prediction of the elastic modulus of anodic oxide layer, an inverse method based on a numerical/experimental comparison was used. From the main results, it was found that: Finite element (FE) simulations of three- and four-point bending tests have been successfully conducted. In particular, both numerical 2D and 3D models were considered to be compared with the experimental results. The predicted elastic modulus was found to largely depend on the coating thickness. The elastic modulus was found to be around 15 GPa for a thickness of 20-50 µm and 20 GPa for an alumina coating of 80 µm. The numerical/experimental correlation allowed to conclude that when the alumina coating was subjected to compression it was more resistant than in tensile.