Experimental investigation and FE simulation of spherical indentation on nano-alumina reinforced copper-matrix composite produced by three different techniques

Preparation of metal matrix composites with homogenously distributed reinforcement is a difficult process. The process can be even more complex when the reinforcement particles are nano-particles. In this paper, three different techniques (dry mixing, mechanical alloying and mechanochemical) were applied to produce Cu-Al2O3 nano composite with three different Al2O3 content (2.5, 7.5 and 12.5.wt.%). XRD, SEM and EDX analysis were conducted to analyse the physical and structural properties of the produced samples. Rockwell hardness test and compression test were applied to determine the mechanical properties of the produced composites. A 2D axisymmetric FE model was implemented using commercial software to predict the Rockwell hardness of the prepared samples. The results show that dry mixing and mechanical alloying techniques are valid for production of metal matrix composites with large reinforcement particle size and low reinforcement content. However, mechanochemical technique can be used to produce Cu-Al2O3 nano composite with high reinforcement weight fractions. Homogenously distributed dispersed nano alumina copper matrix can be achieved by applying mechanochemical technique and as a result, the mechanical and physical properties can be improved. The hardness predicted by the presented FE model correlates well with the experimental observation. (C) 2017 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.