Development of a high wear resistance aluminium matrix nanoreinforced composite

Because of the present economic conditions, the great energetic dependence on petroleum derivatives and the restrictive regulations of environmental pollution, development of new materials and processing methods has become a very important technological challenge. 7075 aluminium alloys (Al-Mg-Zn-Cu) have been widely used as structural materials in the aeronautics industry because of their attractive properties such as very low density and high specific strength, ductility, toughness and resistance to fatigue. In the last few years many studies have been carried out to enhance these properties by developing aluminium matrix microparticulate reinforced composites. These properties can be improved by the use of nanoparticulate reinforcements. In this work, some steps of the fabrication of a new advanced aluminium matrix nanoreinforced composite are analyzed. A powder metallurgy 7075 aluminium alloy was chosen as the matrix and TiC nanoparticles were used as reinforcement material. Although the manufacturing process consists of many stages (mechanical alloying, sintering, extrusion, aging treatment, etc.), in this work only mechanical alloying and sintering are considered. Microstructural characterization of samples was carried out by means of optical microscopy and SEM techniques. Transmission electron microscopy was used to determine the adequate distribution of the reinforcement material. Vickers hardness tests were carried out and structural changes were studied by X-ray diffraction tests. Copyright (c) 2012 John Wiley & Sons, Ltd.