Superplasticity in Pd₄₀Ni₄₀P₂₀ Metallic Glass

Abstract

We have investigated the deformation behavior of a Pd 40 Ni 40 P 20 (at.%) metallic glass ribbon that has a wide supercooled liquid region of 73 K The supercooled liquid above the glass transition temperature exhibited large elongation exceeding 1000% over a wide range of strain rate (10 -4 s - to 10° s -1 ), which was similar to a high-strain-rate superplasticity in polycrystalline materials. On the tensile test at 620 K (1.07T g , 0.64T m ) and at 1.7×10 -1 s -1 , no fracture occurred at the elongation limit (1260 %) of the tensile test setup used in this study. The metallic glass, moreover, has many advantages as compared with the polycrystalline superplastic materials. We can say that the metallic glasses with a wide supercooled liquid region are a new type of high-strain-rate superplastic materials.