Synthesis of graphite reinforced aluminum nanocomposite by mechanical alloying

Abstract

Aluminum nanocomposite was obtained through mechanical alloying process using elemental powders of aluminum, copper and magnesium of high purity with the aim to obtain the 2024 aluminum alloy composition. Elemental powders and reinforcement particles were milled in a simoloyer mill for different times from 1 to 5 h. X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) results indicated that even for milling time of 5 h some elemental copper remained in the microstructure and has not been incorporated completely in solid solution into the aluminum lattice. Furthermore, it was not observed formation of any second phase, however when the specimens were subjected to Differential Thermal Analysis (DTA), it was observed in the microstructure the presence of Al2Cu, Al4C3 and some oxide of the type CuO and CuO2. It was also demonstrated that average crystallite size of milled powders was refined to nanometric level while microhardness values were arising continuously with the milling time and were a maximum in the 2 mass% graphite specimen. © 2010 The Japan Institute of Metals.