Experimental investigation and FE simulation of nano-indentation on Al-Al2O3 nanocomposites

The main purpose of this paper is to investigate the nano-indentation test method and validation of its finite element simulation (FE). In the first stage, a series of nano-indentation tests were performed on the Al-Al2O3 nanocomposites by using Triboscope system and Berkovich indenter to obtain its hardness. To prepare the Al-Al2O3 nanocomposites, a pre-alloyed powder was milled in a planetary ball mill followed by cold compaction and sintering. Then in the second stage, the nano-indentation process on Al-Al2O3 nanocomposites was simulated by a 2D axisymmetric finite element (FE) model. Using the same projected area to depth function as the standard Berkovich indenter, a conical indenter with half angle 70.3°was considered in simulations. The results showed that, a homogenous distribution of the nano-sized Al2O3 particles in the Al matrix was achieved after 20 h milling. The young's modulus, yield strength, and hardness of the produced nanocomposite were increased than the pure aluminum. The results of load-displacement curve obtained from the finite element simulation of non-sharp indenter showed a good agreement with that obtained from the nano-indentation experiment. The scatter of the FE results than the experimental results in the pure aluminum is smaller than that observed for the nanocomposite.