Metglas

Metglas is a brand of amorphous metal alloys, also known as metallic glasses, produced as thin ribbons and foils by rapid solidification. These materials lack long-range crystalline order, which gives them unique magnetic properties that are advantageous for soft magnetic applications, including low core losses and high permeability.

Most Metglas alloys are based on iron with boron and silicon, and may include small amounts of carbon or phosphorus; cobalt-containing variants are also available for higher saturation levels and temperature stability. The amorphous structure yields high magnetic permeability, low coercivity, and good electrical resistivity, making the materials suitable for magnetic cores and related components.

Manufacturing uses rapid quenching of molten alloy to form ribbons, commonly by melt-spinning or planar flow casting onto a rotating copper wheel. The resulting amorphous ribbons are typically very thin and flexible; they are often annealed to relieve stresses and optimize magnetic properties before being assembled into cores or laminations.

Primary applications include transformer cores, inductors, high-frequency cores for switch-mode power supplies, pulsed-power devices, and magnetic shielding. Metglas materials enable compact, energy-efficient components due to their low core losses at elevated frequencies and their ability to operate at relatively high magnetic flux densities.

Metglas products have been marketed since the 1980s by Metglas, Inc., and are supplied to manufacturers of electrical and electronic equipment worldwide. The technology continues to evolve with new compositions and processing methods to extend operating temperature ranges and mechanical robustness.