Effect of milling speed and shaping method on mechanical properties of nanostructure bulked aluminum

Nanostructured bulk Al was successfully fabricated by conventional powder metallurgy, hot press and extrusion. Effect of milling speed on mechanical properties was investigated. Morphology of milled powders was monitored by scanning electron microscope (SEM). The relative density and hardness were measured by Archimedes and Vickers methods, respectively. Tensile and compression experiments were used for the measurement of mechanical properties. Results showed that a nanostructured Al powder was obtained after ball milling. Maximum relative density and hardness were procured for hot press (HP) samples at 360 rpm milling speed. There is a considerable improvement in yielding point (YP) at higher milling speed in both HP and extrude (EX) methods. Maximum YP of 315 MPa was obtained for EX samples that are larger than YP in HP samples (243 MPa).