Superplastic deformation of supercooled liquid in Zr-based bulk glassy alloys containing nano-quasicrystalline particles

The tensile deformation behavior of the supercooled liquid in the bulk glassy Zr65Al7.5Ni10Cu12.5Ag5 and Zr65Al7.5Ni10Cu12.5Pd5 alloys was investigated in comparison with the glassy Zr65Al7.5Ni10Cu17.5 alloy. An icosahedral phase precipitated as the primary precipitation phase from the supercooled liquid in the Ag- or Pd-containing alloy. The deformation behaviors of both the alloys were similar to that of the Zr65Al7.5Ni10Cu17.5 alloy at relatively high strain rates of about 1 x 10(-2) s(-1). While the largest elongation of the Zr65Al7.5Ni10Cu17.5 alloy, 270%, was obtained at 3 x 10(-3) s(-1), those of the alloys containing Ag or Pd were about 400% at 1 x 10(-3) s(-1). Apparent strain hardening due to the growth of the icosahedral particles wag observed during the deformation of both the alloys at lower strain rates. The plastic deformation of the supercooled liquid continues even after the precipitation of the icosahedral particles, while the deformation of the Zr65Al7.5Ni10Cu17.5 alloy is inhibited by the onset of crystallization.