Development of new materials by mechanical alloying

The synthesis of materials by high-energy ball milling or mechanical alloying (MA) of powders was first developed by John Benjamin and his co-workers to produce fine and uniform dispersions of oxide particles in nickel-base superalloys. Nowadays MA is being used to produce numerous materials and alloys. The aim of this work is to demonstrate that MA allows for the production of composite powders and materials with better structural properties than alternative routes. Alloys AA6061 and AA2014, reinforced with different particles, have been produced by MA and a conventional milling process. All of the powders produced were cold pressed and subsequently extruded with an extrusion ratio of 25/1 at 500 degrees C. The powders and extruded bars were characterised by means of microstructural analysis, microhardness testing, and tensile testing. This work shows that MA can be used to produce composite powders with enhanced properties. With finer and more uniformly distributed the reinforcing particles, the MA extruded composites show improve mechanical properties.