The Element Tantalum:  History, Information, Uses and Properties

Tantalum, a rare and versatile metal, has become an unsung hero in modern metallurgy. It was first discovered by the Swedish chemist Anders Ekeberg in 1802, and since then, it has become essential to numerous industries.

While raw tantalum rarely occurs in nature, it is typically found in the ore columbite-tantalite, also known as coltan. Once extracted, pure tantalum is a hard blue-gray lustrous metal that possesses several unique properties, making it an ideal choice for a wide range of applications.

Tantalum is used in various industries, with over 75% of electronics containing tantalum in some form. Engineers have been able to take advantage of some of tantalum’s unique properties to make capacitors and other components smaller and more efficient.

One of tantalum’s most remarkable properties is its high stability. It is almost immune to chemical degradation at temperatures lower than 302 °F (159 °C) and exhibits high levels of corrosion resistance when it comes into contact with air and moisture. When exposed to the atmosphere, tantalum forms a thin but dense protective oxide layer (Ta2O5) that firmly adheres to the surface of the metal, acting as a barrier that protects the underlying metal from further corrosion.

Tantalum is classified as a refractory metal, which means it has a strong resistance to heat and wear. It has a melting point of 5,463 °F (2,996 °C), making it the fourth highest of all metals. Tantalum is also highly ductile, making it suitable for processes such as bending, stamping, and pressing. When combined with other metals, it can produce alloys with enhanced strength and higher melting points.

Tantalum is commonly used in applications that require increased heat, corrosion, and chemical resistance. For example, in sheet form, it is commonly used in linings for columns, vessels, tanks, heat exchangers, and vacuum furnace parts. Thin sheets can also be used for anti-corrosion cladding, repairs, and reinforcement of existing structures.

Tantalum wires are known for their biocompatibility, making them a popular material for prosthetic implants and other medical devices. Tantalum wires are also commonly used in vacuum furnace heating elements, chlorinator springs, light bulb elements, and chemical processing equipment.

In its powder form, tantalum is used to produce electrical circuits, capacitors, and resistors. Its superior capacitance allows it to hold more charge per gram than other materials, making it possible to develop smaller electrical parts and, by extension, smaller electrical devices.

Tantalum tubes are often employed in the chemical, petrochemical, and pharmaceutical industries for the processing of compounds that may weaken or destroy other metals. Columns, stacks, and piping are just some of the products constructed from tantalum tubing in these industries.

Finally, tantalum strips and foils can be used as liners in vacuum furnaces and heat insulation applications. Thin-gauge tantalum strips can also be deep drawn to manufacture crucibles, cups, and other inert laboratory equipment.

In conclusion, tantalum is a versatile and remarkable metal that has become essential to various industries due to its unique properties. From electronics to medical devices, tantalum’s excellent heat, corrosion, and chemical resistance has made it an ideal choice for various applications. As technology continues to evolve, tantalum is likely to play an increasingly important role in our lives.

PHYSICAL PROPERTIES

PHASE — Solid
STD ATOMIC WEIGHT — 180.94788(2) g-mol -1
MELTING TEMPERATURE — 3290K, 3017C, 5463F
BOILING TEMPERATURE — 5731K, 5458C, 9856F
CRYSTAL STRUCTURE — Body Centered Cubic
ELECTRICAL RESISTIVITY — (20 °C) 131 nΩ·m
THERMAL CONDUCTIVITY — (300 K) 57.5 W·m−1·K−1
THERMAL EXPANSION — (25 °C) 6.3 µm·m−1·K−1

GENERAL PROPERTIES

SYMBOL — Ta
NUMBER — 73
ELEMENT CATEGORY: — Transition Metals

KEY FACTS

  • Discovered in 1802 in Sweden by Anders Ekeberg
  • Closely related to niobium
  • Density and melting points halfway between Mo and W
  • Easily worked at room temperature
  • Excellent corrosion resistance, especially in acids, caustics, and glass

MAJOR APPLICATIONS

  • Capacitors and capacitor wire
  • Barrier layers in semiconductor products
  • Nuclear shielding
  • Heat exchangers and vessels in the chemical processing industry

COMMON ALLOYS

  • Tantalum
  • Tantalum 2.5% Tungsten
  • Tantalum 7.5% Tungsten
  • Tantalum 10% Tungsten
  • Tantalum 40% Niobium