Experiments on surface hardening of aluminum components by high-energy centrifugal milling

This work investigates a surface-hardening technique applied to pure aluminum rods via dry centrifugal milling. The intrinsically hard binary Fe-Cu material powder, also produced by high-energy ball milling, is incorporated into the surface of the samples to enhance their mechanical properties. The process has the rods and Cu-Fe powder placed in the grinding bowl so the deposition takes place under high centrifugal forces. These forces cause the particles integrate uniformly with the surface of the rods according to the process parameters, such as rotational speed, filling ratio, and time. Various microstructural characterization techniques (X-ray diffraction, scanning electron microscopy, and glow discharge analysis) are applied to investigate the deposition quality, as well as standard tests conducted to assess the improvement of mechanical properties, such as the compression and the micro hardness tests. The results show tangible benefits to the mechanical properties and a significant increase in hardness using this facile process.