All About Tungsten, Including its Use in Construction
Do you still remember some of the elements found in the periodic table? Unless you’re dealing with this table every day, it’s likely that you don’t, save for some elements that are quite common.
You might remember that ‘O’ stands for oxygen, ‘H’ is for hydrogen, and ‘K’ is for potassium. But what about W?
If you really don’t have a clue, W stands for tungsten.
What is Tungsten?
Tungsten is one of those elements you may have heard of but have no idea what it actually is. To give you an idea, it is a metal known for its stability, melting point, density, and tensile strength. In fact, its high melting point makes it much more difficult to melt compared to other metals. This is why despite its rarity, tungsten is used for a variety of things.
What is ironic about tungsten is that it only gets the tensile strength it is known for when it is formed into different compounds. But at its pure form, it is actually really soft.
If you recall your lessons involving the periodic table, you know that the positioning of these elements in the table has something to do with their properties. Tungsten has an atomic number of 74, atomic volume of 9.53, and atomic weight of 183.84, which means it can be found somewhere in the middle of that table.
One of the most notable things about this metal is its melting point. While the boiling point of tungsten is already remarkable at 5,555 ˚C or 3,068.3 ˚F, its melting point is even more so at 3,422 ˚C or 6,191.6 ˚F. This metal is also known to have the highest tensile strength among other materials, especially at 1,650 ˚C or higher, even only coming second to diamonds.
Tungsten also has the following classifications or scores on the different hardness scales: 7.5 for the Mohs Scale of Hardness, 3,430 for the Vickers hardness number, and 2,570 for the Brinell scale. All these numbers simply prove that tungsten is one very tough metal. Its toughness even makes it resistant to the effects of combining it with alkalis, acids, and oxygen.
The atomic symbols of the elements are usually the first letters or a combination of the letters found in its name, but tungsten is one those that does not really follow this standard. To understand why, we need to trace its origins.
In the past, tungsten was known as Wolfram, hence the use of W as its atomic symbol. It was the German smelters of the medieval period who coined this term, since they worked with tin ores that contain tungsten because it has a yield that is much lower than usual. They noticed that tungsten ‘ate up’ the tin components of the ore, just like how a wolf devoured its prey.
It was not until 1779 that tungsten was discovered to be a new type of metal by Peter Woulfe, after examining a mineral that came from Sweden but without isolating it. Two years later, Wilhelm Scheele tried to isolate an acidic oxide that was white in color and was successful in it, and even concluded that this oxide came from a new metal.
Tungsten was officially discovered as a new metal only in 1783 by Juan and Fausto Elyuhar in Spain. They successfully reproduced the acidic metal oxide discovered by Scheele and, after heating it up using carbon, they were able to isolate this new metal. Wolfram was later given the new name of ‘tungsten’ after the Swedish term ‘tung sten,’ which translates to “heavy stone.”
Although it is a fairly recent discovery, historical records show that this was already in use for hundreds of years. In particular, some Chinese porcelain dating back to more than 350 years ago were discovered to incorporate tungsten pigments. These pigments resulted to a shade of peach that was unique back then.
What is the Color of Tungsten?
Earlier, we talked about tungsten having an oxide that is whitish in color. We also mentioned that tungsten pigments were used in making a unique color that has a shade of peach used in Chinese porcelain centuries ago. But what is the actual color of tungsten?
Tungsten is more commonly found in shades within the range of gray to white, reminiscent of nickel, in the color spectrum. When used in jewelry, white tungsten has a whiter hue than platinum. However, you can also find tungsten in the colors pale yellow, pale orange, yellow orange, red, green, and even colorless, depending on the ore it is extracted from.
Despite its commonly gray or nickel-white color, tungsten can be quite a chameleon when coated with gold. This is because it has the exact same density as that of a gold bar when it is formed into a brick. Just cover it with gold paint and no one can mistake it for a gold bar. This is why it is the most common material used for counterfeiting gold bars.
Where Can It Be Found?
The irony is that despite being used for so many products, tungsten is considered as a rare metal. It is also never extracted alone; it always comes from ores, particularly from scheelite and wolframite. Tungsten can also be recycled and this process actually provides around 30% of the total supply of tungsten worldwide.
According to data, China is the leading supplier of tungsten, followed by Russia and Bolivia. Other countries that also produce tungsten are South Korea, Vietnam, Canada, Portugal, and Great Britain. In the United States, tungsten can be found in Colorado and California. AT present, most tungsten reserves are held by China, Russia, and the US.
Tungsten is one of those metals that are used in a wide variety of fields. In fact, it is common to find it being used in electrical, chemical, manufacturing, military, and construction industries. Here we list down some of the known products that incorporate tungsten.
The most common use for tungsten is for making light bulb filaments, due to its low vapor pressure and being nearly impossible to melt. These result in a longer lifespan and increased brightness of the light bulbs. Tungsten was also used to create incandescent light bulb filaments, before being phased out in favor of more energy-efficient bulbs.
Tungstates that are made up of magnesium or calcium are also used in the fabrication of fluorescent lights. Other types of lamps, such as those used in vehicles, reflectors, floodlights, and domestic lights, also use tungsten. And if you combine tungsten powder with a tiny amount of potassium-aluminum silicate at high temperature, it produces the wire filament placed in the middle of light bulbs.
Filaments made up of tungsten are also used to create x-ray tubes, electron tubes, and cathode-ray tubes, better known as CRTs. You may be familiar with CRTs, since they are commonly used in television sets and computer monitors.
Chemical laboratories also make use of tungsten, particularly for biochemical analysis. This metal is also used to separate various minerals by density using mineralogy. Tungsten, when used in high purity and in granule form, can also speed up the process of identification of sulfur and carbon in the different metals.
Paint is another by-product of various tungsten compounds and tungsten bronzes and this explains why pigments of tungsten were found in some ancient Chinese porcelain. Tungsten can also be found in different enamels and textile dyes.
Jewelers now make use of tungsten as well, most often when creating rings. It is becoming a popular choice, especially of men, because of its affordability and customizability. Their durability is also a key selling point, especially for those who want to own jewelry that hardly gets scratches.
The heat-resisting ability of tungsten, which is one of the things it is known for, makes it ideal for use with tools and equipment that get exposed to intense heat. These include the heating elements commonly used in spacecraft applications, microwave ovens, and furnaces.
The military industry also makes use of tungsten-based equipment. Being very dense, tungsten is used to make bullets and missiles, substituting for lead, because this metal allows them to penetrate various materials. On the other hand, they are also used for different protective equipment, such as armors, since they do not easily allow anything to penetrate it.
Tungsten is also combined with other types of metals to produce different alloys and superalloys. These alloys are used to create tools and other products that are resistant to corrosion and wear and tolerate extreme heat well. Among these are valve seats, pistons, and turbine blades found in engines of aircrafts and on stationary power supplies.
These tungsten alloys are also used to fabricate counterweights and weights, and other materials that take advantage of its density. Common examples of it are darts and sinkers used in fishing.
In the Construction Industry
We cannot emphasize enough the strength and durability of tungsten, even more so when it is used in combination with other metals to form various compounds. This is the primary reason why using tungsten-based materials is common in construction. There is always no room for weak tools and equipment in construction and tungsten fulfills that requirement.
One of the most common compounds produced in mass quantities that involve tungsten is tungsten carbide. This particular compound is known for its hardness, making it one of the best materials to use in mining, manufacturing, and metalwork. It even has a score of 9.5 in the Mohs scale. Tungsten carbide is commonly used for creating various drilling and cutting tools, such as saw blades, dental drills, and drill bits.
You know that cement, asphalt, gravel, and the like are difficult to penetrate and you would need special tools to make even just a small dent on it. If you have seen demolition works, you may have noticed all those tools that demolition contractors and their workers use, such as jackhammers, pulverizers, and cutters. These demolition tools are infused with tungsten carbide, that’s why they can withstand those strong repeated vibrations and hits.
The tungsten carbide, when combined with cobalt powder, produces cemented carbide. This material is excellent at resisting wear and tear, making it ideal for the fabrication of heavy-duty tools and equipment, including those used in mining. In fact, the tunnel-boring machine used to create the tunnel that links Great Britain to the rest of Europe has cemented carbide tips.
Most road maintenance contractors use heavy equipment that have tungsten carbide and cemented carbide. While steel-based equipment is available, those that contain cemented and tungsten carbides are much tougher and are ideal for road maintenance works regardless of seasons. The various blades used in road maintenance, such as plow blades, snowplowing blades, and grader blades, are known to contain these compounds.
Also, expect to have these blades replaced less often if they are made up of tungsten carbide. Not only do they last long but they also resist crowning, which is important if you are doing grading operations that require even leveling. The heat-resisting ability of tungsten also makes it an ideal material for construction tools that will handle materials with high temperatures.
The same goes for contractors involved in road construction and building construction. The tools they commonly use, such as blades, knives, grippers, inserts, and punches, are known to be tungsten-carbide-based because of its durability. Tungsten carbide in powder form is also used in the creation of bits for road construction.
There is a certain type of welding called Tungsten Inert Gas welding, or TIG welding, which is used for various construction projects. This kind of welding is often used to join aluminum and its alloys together, as well as stainless steel. Some contractors also use this method for connecting pipelines, due to the superior result it provides, compared to the more traditional kind of welding. Now you know about its use the next time you talk with a construction contractor.
Titanium Versus Tungsten
Titanium and tungsten are often pitted together, especially when jewelry is concerned. This comparison is due to the fact that they are quite similar to each other. In fact, someone with an untrained eye may not even know the difference between them. So, how are they different from each other?
- Weight – tungsten is a very dense material and as a result, it is much weightier. Titanium, on the other hand is a very lightweight material. Weight differences are quite obvious between these two.
- Resistance to Corrosion – both titanium and tungsten are tough and will resist contact with various acids and bases. However, titanium is much more resistant when corrosion is concerned.
- Melting Point – tungsten and titanium are both sturdy when it comes to heat. This is due to the fact that they both have high melting points. What you need to remember is that tungsten needs a higher temperature to melt, compared to titanium that only requires 3034 ˚F to melt, which is nearly half of tungsten’s melting point.
- Cost – surprisingly, both tungsten and titanium are quite affordable. However, titanium has a slight edge when it comes to pricing, because tungsten is a bit more expensive compared to it.
- Scratch resistance – these two are known to withstand scratches very well. But between tungsten and titanium, tungsten is much more resistant to scratch.
- Brittleness – despite its grade of hardness, tungsten is much more brittle than titanium. Hit or even drop tungsten hard enough and it will already break, but titanium will only bend.
- Hardness – when differentiating tungsten and titanium, you are probably much more concerned about their respective durability. After all, they are both known for their strength. Ultimately, their difference lies in their hardness and tungsten easily beats titanium in this aspect, owing to the fact that it has a higher grade in various hardness scales compared to titanium.
In the end, using either tungsten or titanium is just a matter of preference. What is important is that you can rely on the durability if you use any of these two.
The Use of Tungsten in Wire and How it is Produced
You may think that all wires are basically the same, since they all seem to look alike. That’s where you are mistaken; there are actually different kinds of wires. In fact, there is even a type of wire that is made of tungsten.
We discussed earlier that tungsten is used for a wide variety of products and equipment, but what you need to know is that the form of tungsten they use is already in wire form. Have you noticed the incandescent light bulbs and the wires found inside these bulbs? Those wires are actually tungsten wires. You might also recall us mentioning it previously.
Like most metal wires, tungsten wires also come in different sizes. The diameter of this type of wire ranges from as thin as 0.0005 inches to as thick as 0.06 inches. However, what sets them apart is their price; tungsten wires are generally much more expensive because of the intricate process needed to produce it.
Making tungsten wires is much more complex, compared to the process of making the more common ones, such as copper wires. This is mainly due to the higher resistance of tungsten to heat, requiring it to skip the traditional way of making wires through smelting. Tungsten also has to undergo various chemical processes before it can be usable for producing wires.
In reality, extracting tungsten from ores is not the hardest part. What follows is even more complicated, since anyone producing this type of wire needs to make sure that it follows the exact processes. This makes sure that the right chemical composition of the tungsten wire would be produced.
Are you curious about how tungsten wires are made?
- The production of tungsten wires starts with turning raw tungsten into powder form, which is then sifted.
- The sifted tungsten powder will be mixed. Adding binders to it is optional.
- An exact amount of the mix will be placed in the steel mold, which will then be compacted to solidify it.
- After compacting, the powder will turn into a bar and will then be removed from the mold and placed in a boat specifically for refractory metals.
- This boat will then be placed inside a hydrogen-filled furnace. The hydrogen and heat combined will bind the entire tungsten bar together.
- This bar will then be placed inside a specially-treated bottle that has undergone a cooling process, specifically involving water.
- Once inside this bottle, the bar will receive electric currents that will make it much denser and shrink it at the same time. This process also results in the formation of tungsten crystals inside it.
- The resulting tungsten bar has now increased in strength but has also become much more brittle, especially when placed at room temperature.
- For an increased malleability, this bar will be placed inside a swager, which will hammer it out and decrease its diameter as it passes through it.
- The tungsten crystals will have a much more fibrous structure as it gets elongated while passing through the swager, increasing its length.
- This tungsten bar-turned-rod will then be reheated to lessen the amount of stress it received.
- The process of passing this rod through the swager needs to be repeated until the rod measures somewhere between 0.25 to 0.10 inches. The rod has now become a wire.
- This tungsten wire will be lubricated and then undergo another reduction of its diameter. This is done by drawing it with the use of dies that have either diamond or tungsten carbide, until the desired diameter is acquired.
At first glance, the steps may seem simple enough. However, the entire process needs to meet the strictest standards; there is absolutely no room for error when producing tungsten wires. Even one small mistake somewhere will produce a tungsten wire that has a poor quality.
Is Tungsten Harmful to Use?
You may have heard of some elements posing risks to both humans and the environment. If you have prolonged exposure to them, you can get sick or worse, have fatal consequences. Some are also known to do more harm than good when they come into contact with the environment. Fortunately, tungsten is not one of those.
Even with prolonged exposure to tungsten, you will not get sick. However, there may be people who are sensitive to it and may show allergic symptoms, such as itching and redness and watering of eyes. This only often happens when tungsten is combined with other metals and already formed into a compound, and not in its pure form.
The same goes with nature. If you release pure tungsten in the environment, it poses little to no environmental hazard at all, as studies have shown. Animals, however, may have a reaction to it when ingested.