Pure tungsten

Types of Pure Tungsten

Tungsten, known for its density, hardness, and high melting point is a strategic metal that has a myriad of industrial applications. Widely used to create alloys with steel to increase its hardness and strength, tungsten is also used in mining, aerospace, and electronics, as well as in bullet and armour-piercing projectiles.

While there are numerous types of tungsten, pure tungsten refers to tungsten that contains a minimal amount of impurities, like rare earth metals. Mostly classified based on the degree of oxidation, here are some of the prominent types of pure tungsten:

• W1

  W1 tungsten contains less than 0.5% of carbon and nontime metals, along with traces of iron and thorium. Renowned for its ultra-fine grain structure, the alloy is used in a wide variety of applications, such as electronics and X-ray tubes, where strength and corrosion resistance are critical.

• W2

  W2 tungsten contains slightly higher amounts of impurities (like iron and thorium), which lead to a coarser grain structure compared to W1 tungsten. This makes it more suited for high-temperature applications, such as furnace components and aerospace engineering.

• Lutetium tungsten

  Usually marked by a low oxidation state and an ultra-high degree of purity, this tungsten type is a staple in chemical catalysis. Stocked with co-factors that give it the ability to resist oxidation, lutein tungsten is a popular metal used in chemical reactions where other metals wear out quickly.

• Thoriated tungsten

  Containing a small amount of thorium, it’s a radioactive metal with the ability to increase the electrode’s lifespan and resistance to wear. Because of its composition, this type of alloy is used in TIG welding, planetary gears, and space applications to withstand extreme conditions.

Besides these, there are several other types of tungsten, such as W3, W4, W5, and W6, with the latter three being mostly X-ray screen tungsten. W2 is also used in furnace components and aerospace engineering. But as noted earlier, all these were still classified based on the degree of impurities they contained, as well as oxidation states.

Features of Pure Tungsten

Tungsten is a coveted strategic metal that shares numerous industrial applications, from aerospace to chemical catalysis. Known for its outstanding density, hardness, and ultra-high melting point, the metal has variegated features that make it stand out. Here are some:

• High melting point

  Tungsten has a melting point of 3422°C (6192°F), which is higher than any other atom in the periodic table. This makes it ideal for applications in extreme temperature environments, ranging from X-ray tubes and light bulbs to rocket engines.

• Density

  While it is rare, tungsten is one of the densest metals, only behind osmium and iridium. At 19.3 g/cm3, it is 1.7 times denser than gold and gives it the weight and feel of a heavy-looking “nobody” or “screamer” metal. It is 1.7 times denser than gold and 8 times heavier than steel. This high density makes it ideal for applications that require weight and balance, like fishing lures, beauty products, and firearm ammunition.

• Hardness

  Tungsten is the hardest metal on Earth, measuring 7.5 on Mohs scale for hardness. Tungsten carbide, the most popular form used in jewelry, rates at 9-9.5 on the scale, making it extremely scratch-resistant and durable. This property makes it suitable for mining tools, industrial machinery, and jewelry that must withstand everyday wear.

• Low coefficient of expansion

  Tungsten has a low thermal expansion coefficient, meaning it doesn’t expand or contract much when heated or cooled. This helps preserve its shape and size in variable temperatures. Due to this property, tungsten is used in rocket engines and high-performance heat shields.

• Chemical inertness

  Tungsten is highly resistant to chemical reactions, especially with acids and bases. This makes it ideal for use in environments where it must withstand chemical corrosion, such as in mining tools and chemical processing equipment. This also means that tungsten will stay intact and “forever” in its original form when used in jewelry.

• Electrical conductivity

  Tungsten has good electrical conductivity, making it useful for electrical applications. According to scholars, tungsten's conductivity is about half that of copper, but its density and other properties make it ideal for specialized applications like electrodes in gas tungsten arc welding (GTAW) and incandescent light bulbs.

Uses of Pure Tungsten

Tungsten is a strategic metal with a myriad of applications. Its outstanding hardness, density, purity, and high melting point make it valuable in various settings, such as:

• Aerospace

  Tungsten is commonly used in aerospace components due to its ability to withstand high temperatures and extreme conditions in space. Tungsten’s purity and density also make it suitable for rocket engine nozzles and heat shields, ensuring they maintain structural integrity under intense heat and pressure.

• Jewelry

  Tungsten is popularly used in jewelry, especially wedding bands and engagement rings. Tungsten's hardness and scratch resistance make tungsten jewelry exceptionally durable, even with daily wear. It’s also weighty, giving the pieces a sense of heft and luxury. Tungsten jewelry is cobalt-free to avoid allergic reactions and comes in various colors.

• Electronics

  Pure tungsten is used in the electronics industry for filaments, contacts, and other components. In particular, tungsten's high melting point makes it ideal for light bulb filaments, in which it provides long-lasting illumination without burning out quickly. It is also used in semiconductors and as a bonding wire in chips, ensuring the wires withstand heat without melting.

• Medical equipment

  It is used in medical applications like radiation shielding and cancer treatment. Its density and purity make it effective at blocking harmful radiation. In particular, its non-reactive nature ensures it doesn't interfere with medical imaging or cause adverse reactions in patients.

• Industrial

  Tungsten is used to make tungsten carbide tools for drilling, cutting, and mining machinery because they’re durable and long-lasting. Their hardness offers significant advantages in reducing wear and extending the lifespan of cutting tools, which in turn increases efficiency in industrial processes. Tungsten’s heavy weight is also used for balance in machinery and equipment, ensuring stability during operation. Examples of tools this property is used for include turbine blades, and metalworking and mining tools, which must endure extreme conditions.

• Defense

  In defense, tungsten is used in armor-piercing ammunition and penetration bombs. Its density, hardness, and purity make tungsten munitions capable of penetrating enemy armored targets, whether vehicles or structures.

How to Choose Jewelry Tungsten

There are several factors buyers need to consider when choosing tungsten as an investment or for various industrial applications. Here are the key ones:

• Purity

  This is arguably the most important consideration. Buyers should look for tungsten with at least 99.9% purity. Anything less than this might compromise its quality and properties, such as hardness, density, and scratch resistance.

• Grain size

  The tungsten's purity as well as how it was processed and manufactured primarily affect its grain size, which in turn affects its hardness and toughness. Generally, tungsten with a finer grain structure is harder and more durable. Tungsten with a more refined grain, for example W1 tungsten, is often used to manufacture industrial machinery and jewelry because it makes them extra durable and harder.

• Alloys

  Some jewelry tungsten may be alloyed with small amounts of other metals like titanium or nickel to enhance certain properties like strength, corrosion resistance, or scratch resistance. Buyers should focus on how these alloys might affect the metal's quality. For instance, while nickel enhances strength, it could cause allergic reactions in some people if the alloy is bought for jewelry.

• Finish and craftsmanship

  Different finishes on tungsten give it different aesthetics for jewelry. More importantly, however, the quality of the craftsmanship can significantly affect the alloy's durability and appeal. Therefore, buyers should ensure that the tungsten jewelry is well-crafted to avoid potential wear and tear or discomfort if it's for personal use.

• Refinisher and dealer reputation

  The reputation of the dealer goes hand in hand with the jeweler and the quality of tungsten carbide jewelry they create. Buyers should work with reputable jewelers and dealers that sell authentic tungsten of high quality in jewelry to ensure the quality of the product they’re getting is premium. Still, they should find ones that offer certificates of authenticity to verify the tungsten's purity and quality. This also protects against counterfeit products.

Q&A

Q1: What makes tungsten an industrial metal?

Often called Screamer metal, Tungsten is a strategic and rare heavy-looking metal with numerous industrial applications. It has an extremely high melting point, which makes it an ideal metal for high-temperature applications.

Q2: What is the difference between tungsten and tungsten carbide?

Tungsten consists of pure tungsten metal, while tungsten carbide is an alloy of tungsten (which may contain trace amounts of other metals). Tungsten exposes the raw element, while tungsten carbide fabricates a dense, tough material. Tungsten is heavier and stronger, while tungsten carbide is more scratch-resistant.

Q3: Why is tungsten in jewelry a prominent investment?

Tungsten in jewelry is often a foray for retailers into tungsten investment since jewelry creates demand for tungsten in a more direct consumer way. Also, because tungsten is a precious metal with a high density, heavy looking, and difficult to mine, this creates a supply constraint, thus increasing its value. Further, because tungsten in jewelry is durable and has a scratch-resistance finish, it makes the jewelry pieces forever beautiful and valuable to the user or a potential buyer in the resale market.

Q4: How can buyers verify the authenticity of tungsten jewelry?

They can verify certificates of authenticity to verify the tungsten's purity and quality. Moreover, working with reputable jewelers can also help verify the authenticity of tungsten jewelry since they follow ethical and legal standards to sell the product.