Strengthening and grain refinement in an Al-6061 metal matrix composite through intense plastic straining

1. Significant grain refinement, down to the submicrometer level, was achieved in an Al-6061 metal matrix composite reinforced with 10 vol % Al2O3 particulates using both the torsion straining and ECA pressing procedures. 2. The strength of the composite, as estimated from microhardness data, was increased by almost a factor of ∼2 by ECA pressing and close to a factor of ∼3 by torsion straining. 3. After ECA pressing to a strain of ∼10, quantitative metallography revealed no evidence for any breaking of the Al2O3 particulates. 4. These results confirm the potential for significant grain refinement and strengthening in metal matrix composites using intense plastic straining techniques.