STRENGTHENING OF METALS THROUGH SEVERE PLASTIC DEFORMATION

The processing of bulk metals through the application of severe plastic deformation (SPD) provides an opportunity for achieving excellent grain refinement to the submicrometer or even the nanometer range. These SPD procedures produce materials exhibiting improved mechanical properties including very high strength. This report describes recent results demonstrating the strengthening of conventional metallic alloys processed by high-pressure torsion (HPT). It shows also that exceptionally high strength may be achieved by synthesizing a metal matrix nano-composite using HPT to simultaneously process two different metal disks. Special emphasis is placed on the significance of grain refinement in producing strengthening by HPT.