Formation, thermal stability and mechanical properties in Zr-Al-Co bulk glassy alloys

Abstract

A Zr-Al-Co ternary alloy was investigated in order to clarify the glass-forming ability, thermal stability and mechanical properties. The Zr55Al20Co25 alloy was found to be fabricated in bulk glassy alloy rods with diameters up to at least 2.5 mm. The glassy alloy rod of 2.5 mm in diameter exhibits a large supercooled liquid region of 79 K, followed by a nearly single exothermic peak due to the precipitation of ZrCo + ZrAlCo + Zr6Al2Co phases. The glassy alloy rod exhibits Young's modulus of 114 GPa, high compressive fracture strength of 1900 MPa and total fracture elongation of 1.7%. The finding of forming the bulk glassy alloy at the new ternary composition of Zr55Al20Co25 by the copper mold casting method is encouraging for future search of a new glassy alloy composition.