What is Indium?
Indium is a relatively rare post-transition metal with a bright luster. It is also known for its very soft and malleable properties. In fact, it is so soft that the metal can even be cut with a knife. If drawn across a piece of paper, it will leave a mark like a lead pencil. Indium is silvery-white and resembles Tin in appearance. When bent, Indium emits a high-pitched “cry” like Tin.
Indium material properties
Some of Indium’s characteristic properties are that it is easily fusible, as well as highly ductile. Indium is also a metal with high thermal conductivity and low thermal resistance.
Other key features are that it is recyclable and resistant to oxidation. With a melting point higher than Sodium, but lower than Lithium or Tin, it is of considerable industrial importance, most notably in low melting point metal alloys. When pure, it sticks very tightly to itself or to other metals, which makes it useful as a solder (a material used to join two metals to each other). The material also dissolves in acids but does not react with oxygen at room temperature. Like Gallium, Indium is able to wet glass. It has the ability of a liquid, enabling it to spread out and leave a trace on a solid.
Indium foil uses
The primary use of Indium is in making alloys. It has been called a “metal vitamin” in alloy usage, due to the fact that by adding very small amounts of Indium, the properties of an alloy can be greatly modified. For example, very small amounts of Indium are sometimes added to Gold alloys to make them much harder. Such alloys are used in electronic devices and dental materials. Another important use of Indium is in the making of coatings that are applied, for example, to aircraft parts. The Indium prevents them from wearing out or reacting with oxygen in the air.
The semiconductor industry finds Indium useful in the synthesis of semiconductor materials for the manufacture of thin film solar cells. A principal use is in the forming of electrodes for touchscreens and liquid crystal displays. A transparent conductive coating of Indium oxide and Indium Tin oxide may also be applied as a substrate to glass in the manufacture of electroluminescent panels. Indium is especially suited to being used in vacuum systems due to its sealing properties and as bonding material in acoustic transducers.
As a foil or a sheet, Indium is regularly used as an extremely efficient heat sink for high temperature and cryogenic applications. A heatsink is a device or substance for absorbing excessive or unwanted heat. It is typically a metallic part that is attached to a device releasing heat, with the aim of transferring that heat to a surrounding fluid in order to prevent the device overheating.
In art and design, Indium Foil is sometimes used for its bright aesthetic and flexibility. Metal sculptors, for example, have expressed great interest in the material. In addition, by adding Indium to Gold, an intermetallic compound can be produced having a slight blue colour, which is called blue Gold. It’s even been known to be used in wallpapers – great for interior walls that need a sleek, shiny finish!