Bismuth Metal Applications
What are the uses of bismuth?
Pure bismuth's brittleness makes it ineffective in metallurgical applications. However, small amounts are used as additives in copper, aluminum, iron, and steel to toughen and make alloys that are more machineable.
Since the 1970s, bismuth has increasingly been used as a substitute for lead in everything from water pipes to fishing weights and solders to bullets. Lead-free plasma TVs and plasma displays also incorporate bismuth.
The eutectic alloy known as Wood's Metal, which is used to manufacture triggering devices for fire sprinklers and holding devices for grinding optical lenses or turbine blades, makes use of bismuth due to its low melting point and unique thermal expansion properties
Bismuth alloys, such as bismuth telluride, are also used for thermal electricity generation, as coolants for compact discs and semiconductors and in high-temperature superconductors.
Lead-bismuth eutectic (LBE) alloys containing 44.5% lead and 55.5% bismuth are used as the coolant in some nuclear reactors.
Despite the range of end-uses, metallurgical applications account for only about one-third of bismuth's total annual demand. Chemicals of bismuth are used in large quantities in the pharmaceutical (nitrate and carbonate), cosmetic (bismuth oxychloride) and pigment industries (bismuth subsalicylate).
Other uses for bismuth include:
- In brass alloys
- In thermocouples
- In alloys for drop hammer and embossing dies
- In fuel tank safety plugs alloys
- In catalysts for making acrylic fibres (various chemicals)
- In bismanol permanent magnets (Manganese Bismuth - MnBi)
- In low melt alloys (e.g. Wood's metal)
- In malleable iron and machineable aluminum or copper
- In lead-acid batteries