Achieving High-Strain-Rate Superplasticity in Al-Mg-Sc-Zr Alloys after Severe Plastic Deformation

摘要

The application of severe plastic deformation to metallic alloys via the procedure of equal-channel angular pressing (ECAP) leads to significant grain refinement and an opportunity for achieving superplastic deformability at very high strain rates (>=10~(-2) s~(-1)) The development of high-strain-rate superplastic alloys is important because it provides the possibility for making use of superplastic forming for the rapid fabrication of complex components. Experiments were conducted to evaluate the mechanical properties of a series of Al-Mg Sc-Zr alloys after ECAP. The results demonstrate that some of these alloys exhibit exceptionally high tensile ductilities (elongations up to >2000 percent) at very rapid strain rates.