Alloy with metallic glass and quasi-crystalline properties

US6692590B2 · kind B2 · utility

Assignee

• THE JOHNS HOPKINS UNIVERSITY · US

Inventors

• Li Xing · Davis, US
• Todd Hufnagel · Baltimore, US
• Kaliat T. Ramesh · Baltimore, US

Key dates

• Filing date: Sep 25, 2001
• Grant date: Feb 17, 2004
• Expiry date: Sep 25, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C22C45/10
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

An alloy is described that is capable of forming a metallic glass at moderate cooling rates and exhibits large plastic flow at ambient temperature. Preferably, the alloy has a composition of (Zr, Hf)a TabTicCudNieAlf, where the composition ranges (in atomic percent) are 45≦a≦70, 3≦b≦7.5, 0≦c≦4, 3≦b+c≦10, 10≦d≦30, 0≦e≦20, 10≦d+e≦35, and 5≦f≦15. The alloy may be cast into a bulk solid with disordered atomic-scale structure, i.e., a metallic glass, by a variety of techniques including copper mold die casting and planar flow casting. The as-cast amorphous solid has good ductility while retaining all of the characteristic features of known metallic glasses, including a distinct glass transition, a supercooled liquid region, and an absence of long-range atomic order. The alloy may be used to form a composite structure including quasi-crystals embedded in an amorphous matrix. Such a composite quasi-crystalline structure has much higher mechanical strength than a crystalline structure.