Exotic & Refractory Metals

Like niobium, tantalum is a heat-tolerant refractory exotic metal with excellent corrosion resistance. Often alloyed with other metals, tantalum is used to make super alloys used in chemical processing, jet engines and nuclear reactors. Its oxidation properties also make it an excellent choice for many electronic applications, including electrolytic capacitors and high-power resistors. Tantalum is also highly bio-compatible and used extensively for medical applications, such as skull plates, hip joints, suture clips and stents.

Tungsten has the highest melting point of all metals and, at temperatures greater than 1650°C, the highest tensile strength. Its thermal expansion rate is like that of borosilicate glass and silicon. Tungsten’s good thermal and electrical conductivity make it an excellent choice for microprocessor applications. It is also used in electron emitters, heater coils, cathode ray tubes, electrical contacts and a variety of high-heat applications such as vacuum furnaces and fusion reactor chambers.

Heavy exotic metal alloys are pseudo-alloys of tungsten with a nickel-iron or nickel-copper matrix. They are produced by powder metal pressing and sintering processes. Tungsten Heavy Alloys have a high density of 17-19 g/cm³. Comparable densities are only reached by gold or platinum. These tungsten alloys are used as mass balancing weights and attenuators in aircraft construction, in motors and power trains, as oscillating weights and centrifugal weights in machines and in equipment construction, and in medical technology for both protection from and focusing of ionizing radiation in x-ray and measuring devices. New applications in the Fusion Energy industry for plasma facing components will ensure a reliable low cost energy solution in the future.

Molybdenum is a plentiful, cost-effective refractory metal known for its strength and stability in high-heat applications. Softer and more ductile than tungsten, it is often alloyed with other compounds to improve corrosion resistance and strength at high temperatures.

Molybdenum TZM is an established Molybdenum alloy (0.50 Ti, 0.08 Zr, balance Mo), which is consolidated by either the P/M or vacuum arc-casting processes. It gives excellent service in applications that require high strength and creep resistance at elevated temperatures. Molybdenum TZM Alloy also permits higher service temperatures without softening or weakening.

Niobium (also known as columbium) is a shiny, ductile exotic metal primarily used in high strength alloys. It improves the properties of steel and is often used in gas pipelines, jet engines and structural applications. Because of its corrosion resistance and ability to perform at high temperatures, niobium metal plates, rods and sheets are used in sputtering targets and chemical processing equipment. The growing space/launch industry is utilizing the high temperature strength of Niobium alloy C-103 for the critical application of the upper stage rocket engine nozzle skirts on many new designs.

Composed of iron, nickel and cobalt, Kovar^® (ASTM F15) has thermal expansion characteristics similar to hard glass, making it an excellent choice for glass-to-metal hermetic seals. Kovar^® is widely used in the electronics industry for these electronic packaging applications.

With an extremely low coefficient of thermal expansion, approximately one-tenth that of carbon steel at temperatures up to 400° F, Invar^® is often thought of as the material of choice for low expansion nickel alloy applications. The ability to maintain strength at very low temperatures also makes it the optimum exotic metal choice for containing some liquid gasses.

Titanium 6AL-4V is a silvery-white, corrosion-resistant refractory metal with a high strength-to weight ratio. Because it is both light and strong, it is used extensively throughout the automotive and aerospace industries. Its ability to maintain strength even with prolonged exposure to saltwater also makes it perfect for marine applications. Titanium is also biocompatible, making it an excellent choice for medical implants.

200 Series are chromium-manganese-nickel alloys, which maximize the use of manganese and nitrogen to minimize the use of nickel. 200 Series Nickel has good mechanical properties and excellent corrosion resistance to alkalis. It also has good electrical, thermal and magneto-strictive properties.

Zirconium is an exotic metal mainly used as a refractory and opacifier, although small amounts are used as an alloying agent for its strong resistance to corrosion. Zirconium alloys can be found in pipes, fittings and heat exchangers, catalytic converters, furnace bricks, lab crucibles, surgical instruments, television glass, and removing residual gases from vacuum tubes.