Amorphous metals, also known as metallic glasses, are metallic materials that have a non-crystalline structure. Most amorphous metals are alloys rather than pure metals. These materials have atoms of varying sizes in random arrangement in the solid. They exhibit a high viscosity in molten form which prevents proper molecular alignment, giving them better resistance to plastic deformation.
Types of Amorphous Metals
There are two types of metallic glasses: metal and metalloid metallic glasses.
- Metal metallic glasses are formed with combinations of metals. Combinations include nickel and niobium, magnesium and zinc, copper and zirconium, and hafnium and vanadium.
- Metalloid metallic glasses are formed with combinations of metals such as iron, cobalt, and nickel with metalloids such as boron, silicon, carbon, and phosphorous.
Advantages of Metallic Glass
Metallic glasses possess high physical and tensile strength superior to that of common steels. They also are very ductile, exhibit good corrosion and wear resistance, and have high electrical resistivity. Some metallic glasses also have soft or strong magnetic properties.
Selecting amorphous metals requires an analysis of the desired dimensions and specifications. Dimensions to consider include outer diameter (OD), inner diameter (ID), overall length, and overall thickness. Other specifications of importance (based on application) include product shape, tensile strength, yield strength, melting point, conductivity, corrosion resistance, ductility, and malleability. These properties differ based on the forming method and alloy composition.
Video from University of Maryland on Amorphous Metals
Applications and Uses
Due to their many advantages over crystalline metals, amorphous solids are used in a number of fields. Applications include electronics, nuclear reactor engineering, medical industries, structural reinforcement, and razor blades.