Melt Spinning

Melt spinning is a metal-forming technique that produces thin ribbons of metal alloy by jetting molten metal onto the surface of a rapidly spinning, internally cooled metal wheel, so that the stream solidifies within a fraction of a second of touching the wheel while the wheel's rotation continuously carries the finished ribbon away and presents fresh cold surface to the incoming melt, allowing continuous production. Because the metal cools at a rate on the order of ten thousand to a million degrees Kelvin per second, its atoms have no time to arrange into an ordered crystal lattice and instead freeze in the disordered arrangement of a liquid, producing an amorphous metal, or metallic glass, ribbon with magnetic and mechanical properties that ordinary crystalline metal does not have. The modern melt-spinning technique traces to patents filed by Robert Pond between 1958 and 1961 and further work by Pond and Robert Maddin published in 1969, and it was developed into a practical continuous-casting process by Howard Liebermann and Charles Graham by 1976, whose refinements eventually allowed commercial production of amorphous ribbon several inches wide, now used in high-efficiency transformer cores and other magnetic components.