Tungsten Metal: Definition, Composition, Properties, and Applications
Tungsten is the heaviest known engineering metal with an astounding density of 19.35 g/cm3. It is a bright white metal in its purest state. However, the presence of carbon and oxygen traces causes it to break easily under shock loading. Tungsten is notable for its remarkable tensile strength and resilience to high temperatures.
Tungsten carbide's abrasiveness and tolerance to high temperatures make it an excellent choice for a variety of applications, including cutting and drilling tools. Furthermore, tungsten is an essential component in many industrial fields due to its exceptional electrical and thermal conductivity.
This article explores the essential contributions of tungsten as we delve into its composition, applications, and unique qualities.
What Is Tungsten?
Tungsten is a chemical element with the atomic number 74 and the symbol W. It is a transition metal with a strong atomic structure on the periodic table. Its tensile strength and high melting point (3,422 °C) are two of its most notable characteristics. These attributes help explain why tungsten is so important to so many different industrial uses.
Is Tungsten the Same as Wolfram?
Yes, tungsten and wolfram refer to the same chemical element. The terms are used interchangeably, with "tungsten" more common in modern usage and "wolfram" originating from its earlier discovery and historical nomenclature.
What Is the Origin of Tungsten?
Spanish mineralogists Juan and Fausto Elhuyar discovered tungsten in 1783. An important development in the history of the element was the isolation of tungsten oxide and its subsequent reduction to tungsten metal by heating it with carbon as a result of their research at the Seminary at Vergara.
What Is Tungsten Made Of?
Tungsten is not naturally found in its pure form but is primarily present in minerals such as wolframite and scheelite. Wolframite is a solid solution of ferberite and hübnerite, composed of iron–manganese tungstate (Fe,Mn)WO4. Scheelite, another tungsten-bearing mineral, is identified as calcium tungstate (CaWO4).
How Is Tungsten Made?
The process of removing tungsten from its ores involves multiple processes. Crushing and gravity concentration are the initial steps for the ores. The process for handling scheelite, a tungsten ore, involves: flotation, fine grinding, and if required, leaching, roasting, and magnetic or high-tension separation. The extraction process of ammonium paratungstate (APT) uses methods including acid leaching and autoclave-soda processes. Liquid ion exchange makes the solution even purer. APT uses evaporation to crystallize. Tungsten powder is produced by breaking down APT and reducing the blue oxide with carbon or hydrogen. The powder is then sintered into bars or billets by compressing it.
What Is the Melting Point of Tungsten?
Tungsten possesses the highest melting point among all pure metals, reaching 3,422 °C. This exceptional property is attributed to its strong metallic bonds. This makes tungsten a crucial material in applications requiring high-temperature stability, such as aerospace and industrial processes.
What Is the Color of Tungsten?
Tungsten is hard, brittle, and has a steel-gray color when it is raw. However, pure tungsten appears as a gleaming white metal. This color variability is what makes it useful in so many various industries.
What Does a Tungsten Look Like?
Tungsten is a shiny silvery-white metal. Historically, it was used in incandescent-light-bulb filaments. However, it is not energy efficient due to high heat production. Figure 1 below shows tungsten metal:
Tungsten metal.
Image Credit: Shutterstock.com/AkulininaOlga
| Chemical Properties | Description |
|---|---|
Chemical Properties Acid Resistance | Description Resistant to nitric acid, hydrofluoric acid, hydrochloric acid, sulfuric acid, and aqua regia at low temperatures; weakly affected by some acids at elevated temperatures |
Chemical Properties Dissolution in Mixed Acid | Description Quickly dissolves in a mixed acid of hydrofluoric acid and concentrated nitric acid at normal temperatures |
Chemical Properties Reaction with Oxidants | Description Intense reaction with oxidants (NaNO3, NaNO2, PbO2, KClO3) to produce tungstate |
Chemical Properties Alkali Resistance | Description Does not dissolve in alkaline solutions |
Chemical Properties Reaction with Carbon | Description Reacts with carbon at high temperatures to produce tungsten carbide, known for its hardness and wear resistance |
Chemical Properties Combination with Elements | Description Can combine with chlorine, nitrogen, oxygen, fluorine, bromine, iodine, carbon, and sulfur at high temperatures; does not undergo hydrogenation |
Chemical Properties Oxidation in Air | Description Molten alkali in the presence of air can oxidize tungsten to tungstate |
Chemical Properties Dissolution in Mixed Acid | Description Quickly dissolves in a mixed acid of hydrofluoric acid and concentrated nitric acid at normal temperatures |
| Physical Properties | Description |
|---|---|
Physical Properties Appearance | Description Silver-white metal with a steel-like appearance. |
Physical Properties Group | Description Belongs to group VIB of the periodic table. |
Physical Properties Melting Point | Description High melting point of 3,422 °C. |
Physical Properties Boiling Point | Description The boiling point can reach 5,927 °C. |
Physical Properties Atomic Number | Description 74 |
Physical Properties Density | Description 19.35 g/cm³, 2.5 times that of steel, equivalent to gold. |
Physical Properties Electrical Conductivity | Description Exhibits good electrical conductivity |
Physical Properties Elastic Modulus | Description High elastic modulus of 35,000–38,000 MPa (Wire). |
Is Tungsten the Hardest Metal on Earth?
Yes, tungsten is the strongest natural metal with a tensile strength of 142,000 psi. However, it is brittle and prone to shattering upon impact, limiting its overall durability. So, while it's incredibly hard, its brittleness prevents it from being crowned the most durable or “strongest” metal for most (ambient-temperature) purposes.
Can Tungsten Be Processed by Laser Cutting?
Yes, tungsten can be processed by laser cutting. Laser cutting is effective for tungsten due to its high melting point and excellent absorption of laser energy, allowing precise and efficient material removal.
Is Tungsten Magnetic?
No, tungsten itself is not magnetic. It has a low susceptibility to magnetism. However, tungsten carbide, an alloy of tungsten and carbon, exhibits magnetic properties due to magnetically susceptible elements in the alloy.
What Are the Applications of Tungsten?
Some common applications of tungsten are:
1. Electronics
Tungsten is essential to electronics as an interconnecting material for integrated circuits. Tungsten is prominent for its elevated electrical conductivity and resilience. This guarantees effective signal transfer among diverse constituents in electronic apparatuses, hence augmenting their dependable functionality and bolstering the complex interconnectivity indispensable for contemporary technologies.
2. Alloys
It is common practice to combine tungsten with refractory metals to create alloys with qualities appropriate for a variety of uses, such as turbine blades and rocket-engine nozzles, as well as fine darts.
3. Fusion Power
In fusion power, tungsten surpasses carbon for plasma-facing materials (PFM) in upcoming nuclear reactors. Its exceptional high-temperature strength, minimal erosion, efficient thermal conductivity, low tritium retention, and relatively low activation under neutron irradiation make tungsten the preferred choice for ensuring the viability and safety of future fusion reactors.
4. Permanent Magnets
Applications for tungsten include improving the magnetic characteristics of SmFeN–α-Fe permanent magnet nanocomposites. Tungsten is added in the 0–17% range to modify the microstructure and magnetic behavior. This is accomplished by mechanically alloying Sm, Fe, and W powders, then annealing and nitriding the mixture. As a result, permanent magnets operate and perform better.
5. Medical Applications
Tungsten alloys are integral in diverse medical applications, offering strength and protection. They serve in gamma radiography, oncology instruments, and as containers for radioactive sources. Additionally, tungsten-alloy syringe shields provide a robust defense against radiation exposure, ensuring safety and efficacy in medical procedures.
6. Nanowires
Tungsten oxide nanowires, composed of tungsten and oxygen atoms, demonstrate excellent electrical conductivity and unique optical properties, finding applications in sensing, electronics, optoelectronics, and energy storage.
7. Military Materials
Tungsten, prized for its high hardness and temperature resistance, is used in military applications such as: tungsten-alloy bullets, shrapnel heads, and armor-piercing projectiles.
8. Chemical Applications
In the chemical industry, tungsten compounds are essential because they help produce a wide range of materials. These compounds take advantage of the special qualities of tungsten to influence the formulation of a wide range of chemical products necessary in diverse industrial applications, from pigments and paints to catalysts, inks, and lubricants.
How Is Tungsten Metal Used in TIG Welding?
Tungsten is used in TIG (tungsten inert gas) welding as a non-consumable electrode. In TIG welding, an electric arc between the tungsten electrode and the workpiece generates heat, creating a molten weld pool to fuse metal joints. Tungsten's high melting point and stability make it ideal for this non-consumable role.
What Are the Advantages of Tungsten?
Some advantages of tungsten include:
- Tungsten's lowest coefficient of thermal expansion among pure metals provides stability under extreme heat, making it essential for tools like tungsten-carbide cutting tools and jet-engine turbine blades.
- Tiny kinetic munitions and racing car ballast are two examples of applications in which tungsten shines. Its density is around 1.7 times higher than lead and 19.3 times higher than water.
- Due to its conductive properties and inertness, tungsten is widely used in electronics and high-radiation environments. It serves as a key source for X-ray targets and finds applications in electrodes, conductors, and metallic films.
- Due to its great corrosion resistance, tungsten can be exposed to corrosive materials including solvents, water, and acid for extended periods. Its resilience increases its applicability in maritime settings, including: jewelry, fishing lures, and shipbuilding.
- Tungsten boasts the highest melting point among pure metals (3,422 °C), making it crucial for applications in high-temperature environments, particularly in aerospace and construction.
What Are the Disadvantages of Tungsten?
Some disadvantages of Tungsten include:
- Tungsten's hardness, while advantageous in some applications, makes it more brittle and prone to breakage than softer metals like gold. A tungsten ring can crack or shatter upon impact, rendering it permanently unwearable.
- Tungsten’s very high density means that even small items are weighty. While some people enjoy wearing heavy jewelry, others could find it unpleasant, which could affect personal choice.
- Tungsten's high melting point and unique properties make welding challenging, limiting its ease of use in certain fabrication processes.
- Owing to its hardness, tungsten wedding bands are not resizable. Not only is it not possible to modify the band over time to achieve the ideal fit, but attempting to adjust them risks the danger of breakage.
- Tungsten is considered a toxic metal and exposure to it may lead to health issues, including respiratory problems and skin irritation. This aspect requires careful handling to avoid potential health risks.
What To Know More About Tungsten?
Is Tungsten Expensive?
Yes, tungsten can be expensive. The cost depends on raw material expenses and production complexity. Finished tungsten product prices vary widely, ranging from $25 to $2,500 per kilo. The majority falls within the $100–350 per kilo range, reflecting the influence of raw material costs and manufacturing processes.
Is Tungsten Stronger Than Steel?
Yes, tungsten is stronger than steel. With a tensile strength exceeding 600 MPa, tungsten is approximately three times stronger than steel.
Is Tungsten a High-Quality Metal?
Yes, tungsten is a high-quality metal. In its pure form, it boasts the highest melting point at 3,422 °C, the lowest vapor pressure above 1,650 °C, and exceptional tensile strength. These characteristics make tungsten a valuable material in various high-performance applications.
Is Tungsten Metal Valuable?
Yes, tungsten metal is valuable. Its scarcity, combined with exceptional properties such as high melting point and tensile strength, contribute to its significant economic importance and widespread use in various industries.
What Is the Difference Between Tungsten and Titanium?
Titanium is a hypoallergenic, lightweight, and corrosion-resistant metal. Tungsten, on the other hand, is denser and heavier than other metals, making it more resistant to scratches but also more prone to fracture. Often made of a tungsten and carbon combination, tungsten carbide alloy gives tungsten rings special qualities not found in titanium.
What Is the Difference Between Tungsten and Stainless Steel?
Tungsten steel excels in wear resistance and heat resistance but is more expensive. Stainless steel is magnetic, offers better oxidation resistance, and has higher ductility for shaping.
Summary
This article presented tungsten metal, explained it, and discussed its composition and properties. To learn more about tungsten metal, contact a Xometry representative.
Xometry provides a wide range of manufacturing capabilities and other value-added services for all of your prototyping and production needs. Visit our website to learn more or to request a free, no-obligation quote.
Disclaimer
The content appearing on this webpage is for informational purposes only. Xometry makes no representation or warranty of any kind, be it expressed or implied, as to the accuracy, completeness, or validity of the information. Any performance parameters, geometric tolerances, specific design features, quality and types of materials, or processes should not be inferred to represent what will be delivered by third-party suppliers or manufacturers through Xometry’s network. Buyers seeking quotes for parts are responsible for defining the specific requirements for those parts. Please refer to our terms and conditions for more information.