Synthesis and characterization of bulk amorphous Zr65Cu18Ni9Al8 and [Zr0.65Cu0.18Ni0.09Al0.08]98Er2 alloys

Bulk metallic glasses (BMGs), especially Zr-based BMGs, have attracted lot of attention of materials scientists because of their very attractive physical, thermal and mechanical properties and a few unique applications. In the present study, Zr65CU18Ni9Al8 alloy was designed according to the criterion of conduction electron/atom (e/a ratio) similar to 1.395 and average atomic size of alloy (R-a) similar to 0.1498 nm. Addition of 2 at.% Er was carried out in the base alloy to investigate its effect on thermal and mechanical properties. Characterization of alloys was performed using the techniques of XRD, DSC, and SEM/EDS. Mechanical properties like Vicker's microhardness, nanohardness, elastic modulus, density and fracture strength were measured. Average shear angle was found to be similar to 35 +/- 1 degrees for base alloy and about 31 +/- 1 degrees for alloy containing 2 at.% Er. Wide supercooled liquid regions of 129 K and 119 K were found for the base alloy and the alloy containing 2 at.% Er. (c) 2006 Elsevier B.V. All rights reserved.