High ductility aluminum alloy made from powder by friction extrusion

Friction extrusion has been used to consolidate and extrude aluminum alloy powder into bulk nanostructured rods. Extrudates exhibited 450 MPa ultimate tensile strength, 380 MPa yield strength, and 15.7% elongation at ambient temperature. Twice the elongation was achieved compared to conventional direct extrusion of the same material, with similar ultimate and yield strengths, and is attributed to extensive reduction of the matrix grain size and refinement and redistribution of nanoscale second phases. Quasicrystalline approximants within the starting powder were not observed in the extrudate, indicating shear processing was effective in solutionizing some fraction of the alloying elements and re-precipitating them as second phase nanoscale intermetallics.