Experimental and Finite Element Simulation of Nano-indentation on Metal Matrix Composites: Hardness Prediction

The scientific importance of nanocomposites is being increased due to their improved properties. This paper is divided into two parts. First, Al-Al2O3 nanocomposite was produced by using ball milling technique followed by cold compaction and sintering. Microstructure and morphology studies were done through SEM, TEM, and EDX analyses on the produced powder. The mechanical properties of the produced composite were determined by the tensile test. Also, nano-indentation experiment was conducted on the produced composite to determine its hardness. Second, a 2-D axisymmetry model was implemented in ANSYS software to simulate the nano-indentation experiment on pure aluminum and Al-Al2O3 nanocomposite. A conical indenter with 70.3◦ was considered in simulations. The results show that, a homogenous distribution of the reinforcement in the matrix was achieved after 20 h milling. The elastic modulus, yield strength, and the hardness of the produced composite were increased compared to the pure metal. The finite element (FE) simulation results showed a good agreement with the experimental results for nano-indentation experiment. The scatter of the FE results from the experimental results in the pure metal was smaller than that observed for the nanocomposite.