metalglass

Metalglass, or metallic glass, refers to a class of metals whose atoms are arranged in an amorphous, non-crystalline structure. This glassy state is achieved when a molten alloy is cooled rapidly enough to suppress crystalline formation, trapping the atoms in a disordered arrangement. Alloys with high glass-forming ability can form bulk metallic glasses in relatively thick sections, enabling practical uses.

Composition and processing: Metallic glasses are typically based on transition metals such as iron, nickel, cobalt, zirconium, titanium, and copper, often with metalloids like boron or silicon. They are produced by rapid solidification methods such as melt spinning or copper mold casting, or by thermomechanical processing to form bulk specimens.

Properties: The amorphous structure yields high yield strength, high hardness, and often good wear and corrosion resistance. Fe- and Ni-based amorphous alloys can show soft magnetic behavior with low coercivity and high permeability. Common drawbacks include brittleness at ambient temperatures and limited ductility, along with processing challenges to avoid crystallization.

Applications: Metglas and related soft magnetic alloys are widely used in transformer cores, magnetic shielding, and other electrical components. Other metallic glasses serve as wear-resistant coatings, tooling, or lightweight structural parts where high strength and elasticity are beneficial. Ongoing research seeks to expand ductility, thermal stability, and cost-effective production.

History: The concept emerged in the 1960s from rapid quenching of molten alloys to create non-crystalline metals; later advances yielded bulk metallic glasses, expanding the range of usable compositions.