Indentation characteristics of metallic glass and nanoquasicrystal-glass composite in Zr-Al (Ga)-Cu-Ni alloys

Abstract

Indentation characteristics of melt-spun Zr69.5Al 7.5-xGaxCu12Ni11 (x = 0-2.5; in at %) metallic glasses have been investigated. Formation of a nano-quasicrystalline phase by annealing the glass has been found only upto x = 1.5. The substitution of Ga changes the size and shape of this phase. The load dependent hardness behaviour of metallic glasses and nanoquasicrystal-glass composites are reported in detail. It has been observed that substitution of 1.5 at % Ga improved microhardness property of Zr-Al-Cu-Ni alloy. The value of yield strength of the materials was estimated with the help of hardness values based on the empirical correlations available in literature. It has been found that microstructural and morphological changes alter the Meyer exponent. Pile up parameters seems to be sensitive to structural and microstructural details. © 2010 Elsevier Ltd. All rights reserved.