History of Tantalum
Anders Gustaf Ekeberg discovered niobium in 1802, but many chemists thought niobium and tantalum were one and the same. Some felt that perhaps tantalum was an allotrope of niobium. Later, Rose, in 1844, and Marignac, in 1866, showed that niobic and tantalic acids were two different acids. The word Tantalum comes from the Greek word “tantalos” meaning “father of Niobe” (Greek mythology, (tantalum is closely related to niobium in the periodic table) the first relatively pure tantalum was produced by von Bolton in 1907.
Special Qualities of Tantalum Products:
- Corrosion Resistance
- Thermal Conductivity
- Melting Point
- “Getter” Characteristics
- “Valve Action”
Tantalum works similar to copper in forming operations it can be cold-formed in both the grain direction and in the cross grain direction. It can be spun, drawn, and hydro-formed. Like copper, it work-hardens and when this occurs, it requires annealing in inert gas or a vacuum before further working. If annealed in the presence of hydrogen I any amount embrittlement will occur. An Electron Beam can weld tantalum or if care is taken by TIG. The welds are strong and can be stress-relieved by annealing. Welded tantalum can be further formed and even drawn.
Tantalum has gained wide acceptance for use in electronic components, chemical equipment, missile technology, and nuclear reactors. The electronics industry consumes the majority of tantalum produced for capacitors. Other industries concerned with corrosion, especially the chemical processing industry are accounting for an increasingly larger percentage of the market. Tantalum can be used to fabricate valves for corrosive liquids and to manufacture heaters for acids and heat shields for rocket motors. It is also used as a component of ion implanters in the manufacture of semiconductors. Also, because tantalum does not have a low neutron absorption cross-section it is used for radiation shielding. Tantalum mill products are used in the fabrication of corrosion resistant process equipment including reaction vessels, columns, bayonet heaters, shell and tube heat exchangers, diaphragms and orifices. The metal offers excellent “getter” properties, making it popular in vacuum tubes to absorb products of out-gassing upon heat up of the tube components. It is also used to getter potential contaminants of niobium and its alloys as well as titanium during vacuum heat-treating operations. Tantalum is used in vacuum furnaces where very high temperatures must be attained and where there can be no residual oxygen or hydrogen present during the cycle.
Tantalum is almost completely immune to attack by acids and liquid metals. It equals glass in resistance to acids and it is impervious to liquid metals up to 1650°F. Few chemicals such as hydrofluoric acid, fuming sulfuric acid, and strong alkalis will begin to break through tantalum’s corrosion barrier. This ability to resist practically everything has won tantalum favor among manufacturers of chemical equipment, instruments, heating elements, and surgical implants.
Tantalum conducts heat better than the nickel alloys, ductile irons, and stainless/high temperature steels. Therefore, tantalum has become the efficient heat transfer surface, especially in acidic or corrosive environments. The corrosion-proof surfaces of tantalum remain smooth and clean under conditions that foul or scale so-called acid resistant materials.
Of the refractory metals, tantalum is outranked only by tungsten at 6170°F and rhenium at 5732°F. The high temperature strength of tantalum, combined with its workability, has resulted in the fabrication of superior heat shields, heating elements, electrodes, and other high temperature parts.
Tantalum absorbs surrounding gases and vapors extremely well at elevated temperatures. Electronic tube manufacturers have long-recognized the ability of tantalum to maintain high vacuum inside the tubes.
Tantalum forms highly stable anodic films and combined with its acid resistance can be used in the manufacture of rectifiers, capacitors, lightning arrestors and surge suppressors.
H. Cross Company can supply tantalum products in wire, rod, ribbon, strip, sheet and foil forms at 99.95% purity and in wire, strip and ribbon at 99.995% purity for specialized applications such as filament materials. We also handle 90/10 tantalum tungsten products in wire, strip, ribbon, sheet and foil forms for higher strength at high temperatures. Please email or call with your specific requirements.