ALLOY WITH METALLIC GLASS AND QUASI-CRYSTALLINE PROPERTIES

摘要

An alloy is described that is capable of forming a metallic glass at mdoerate cooling rates and exhibits lareg plastic flow at ambient temperature. Preferably, the alloy has a composition of (Zr, hf)a TabTicCudNicAlf, 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 &le 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 grass, 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 mechanica l strength than a crystalline structure.