The Effect of Strain Rate on the Tensile Behavior of Electrodeposited Nanocrystalline Ni-Co Alloy

摘要

A fully dense nanocrystalline Ni-Co alloy with 18 nm grain size exhibited high strength of about 2200 MPa and ductility of 8.1-9.2% at strain rates of 1.04×10~(-5) to 1.04 s~(-1) and room temperature. The alloying of Co element induces the grain refinement, solid solution hardening and decrease of stacking fault energy should contribute to the favorable combination of mechanical performance. The obvious distinctions of fracture-surface morphologies with strain rate alteration were attributed to underlying deformation mechanism transition. The high strain rate sensitivity exponent and small activation volume indicate that grain boundary activity may be expected in this alloy.