Tungsten Carbide Chemical Properties

There are two well-characterized compounds of tungsten and carbon, WC and tungsten semicarbide, W2C. Both compounds may be present in coatings and the proportions can depend on the coating method.

At high temperatures tungsten carbide decomposes to tungsten and carbon and this can occur during high-temperature thermal spray, e.g., in high velocity oxygen fuel (HVOF) and high energy plasma (HEP) methods.

Oxidation of tungsten carbide starts at 500–600 °C (932–1,112 °F). It is resistant to acids and is only attacked by hydrofluoric acid/nitric acid (HF/HNO) mixtures above room temperature. It reacts with fluorine gas at room temperature and chlorine above 400 °C (752 °F) and is unreactive to dry H2 up to its melting point. Finely powdered WC oxidizes readily in hydrogen peroxide aqueous solutions. At high temperatures and pressures it reacts with aqueous sodium carbonate forming sodium tungstate, a procedure used for recovery of scrap cemented carbide.

Tungsten Copper Block Picture

If you have interest in tungsten carbide products, please do not hesitate to e-mail us by : sales@chinatungsten.com.

Tungsten Carbide Physical properties

Tungsten carbide has a high melting point at 2,870 °C (5,200 °F), a boiling point of 6,000 °C (10,830 °F) when under a pressure equivalent to 1 standard atmosphere (100 kPa), a thermal conductivity of 110 W·m?1·K?1,and a coefficient of thermal expansion of 5.5 μm·m?1·K?1.

Tungsten Carbide Plate Picture

Tungsten carbide is extremely hard, ranking about 9 on Mohs scale, and with a Vickers number of around 2600.It has a Young's modulus of approximately 530–700 GPa, a bulk modulus of 630–655 GPa, and a shear modulus of 274 GPa. It has an ultimate tensile strength of 344 MPa, an ultimate compression strength of about 2.7 GPa and a Poisson's ratio of 0.31.

The speed of a longitudinal wave (the speed of sound) through a thin rod of tungsten carbide is 6220 m/s.

Tungsten carbide's low electrical resistivity of about 0.2 μΩ·m is comparable with that of some metals (e.g. vanadium 0.2 μΩ·m).

Tungsten carbide is readily wetted by both molten nickel and cobalt. Investigation of the phase diagram of the W-C-Co system shows that WC and Co form a pseudo binary eutectic. The phase diagram also shows that there are so-called η-carbides with composition (W,Co)

6C that can be formed and the brittleness of these phases makes control of the carbon content in WC-Co hard metals important.

 If you have interest in tungsten carbide products, please do not hesitate to e-mail us by : sales@chinatungsten.com

Tungsten Carbide Products

Tungsten carbide is a material used for a number of industrial applications and it is characterised by its high strength, toughness and hardness. Its name derives from the Swedish for tung (heavy) and sten (stone) and it is mainly used in the form of cemented tungsten carbides. Cemented carbides (also known as hardmetals) are made by 'cementing' grains of tungsten carbide into a binder matrix of cobalt or/and nickel.

Tungsten carbide as a material can vary in carbide grain size (0.2 – 50 microns) and by binder contents (up to 30%), as well as by the addition of other carbides. By varying the grain size of the tungsten carbide and the binder content in the matrix, engineers have access to a class of materials whose properties can be tailored to a variety of engineering applications. This includes high-tech tools, wear parts and tools for the construction, mining and oil and gas sector.

Tungsten carbide products typically have a high resistance to wear and can be used at high temperatures, allowing tungsten carbide's combined hardness and toughness to significantly outperform its steel product equivalents.

What is Tungsten Carbide

Tungsten carbide is an inorganic chemical composited by equal parts of tungsten and carbon atoms. In its most basic form, tungsten carbide is a fine gray powder, but it can be pressed and formed into shapes for use in industrial machinery, cutting tools, abrasives, armor-piercing rounds, other tools and instruments, and jewelry. In its most basic form, it is a fine gray powder, but it can be pressed and formed into shapes for use in industrial machinery, tools, abrasives, as well as men's jewelry.
The notable and rare combination of physical properties possessed by tungsten carbide makes it useful for a variety of applications. It is extremely strong and wear-resistant. There are only a few materials on earth that can be used to cut or engrave it, with industrial diamond abrasives being one of these. Its tensile strength is very high, but it is brittle under high pressures as a result. The melting point is also very high, at 5,200°F (2,870°C). To boil, it must be heated much further, to 10,382°F (6,000°C).
This compound can be made by reacting tungsten and carbon at temperatures of around 2,552 to 3,632°F (1,400 to 2,000°C). It is then often made into mills and cutting tools for industrial use, which are able to withstand heavy use and high temperatures. Military organizations also use it in armor-piercing ammunition as an alternative to depleted uranium because of its very high density and hardness level. Some sporting goods are made stronger and more durable by the addition of carbide. Trekking poles used by hikers, for instance, use carbide tips in order to gain traction on hard or rocky surfaces.
Several common consumer goods contain tungsten carbide, including razor blades and the rotating tips of ballpoint pens. It has also become increasingly common for it to be used in men's wedding bands. When used in this way, the bands have a dark hue that can be polished to a mirror-like shine. Due to the toughness of the material, these rings will remain shiny and scratch-free for decades.
Wedding bands made of carbide also contain other materials known as binders, usually metals such as nickel and cobalt. Cobalt has been known to cause allergic reactions on the skin of the wearer, so many manufacturers are turning toward substitute materials. Despite the common misconception that carbide rings cannot be removed in emergency situations, the jeweler's saws used in emergency rooms and jewelry shops can cut through any material that a ring might be made of.
It is important to note that tungsten carbide is made in nearly two dozen different grades that have different properties, depending on what each will be used for. They are almost all variations of just a few parameters: grain size, hardness, and the degree to which a binder is used. Generally, the higher the percentage of the finished product that is composed of binding materials like nickel, the softer it will be and the more it will wear. The size of the original powder grains makes slightly less difference, but can affect the amount of shock that the product will be able to withstand.

Ultra-Precision Aspheric Grinding System Simplifies Optical Productivit

The Nanotech 100UPG brings a new generation of accuracy, productivity, and simplicity in ultra-precision aspheric grinding. The system is available in either a XZ or XZB configuration. Although its primary application is the grinding of Tungsten Carbide and Silicon Carbide aspheric optical mold inserts used in glass press molding or the grinding of glass lenses directly, it also provides a 250mm diameter capacity for diamond turning applications.

Swanzey, NH — Moore Nanotechnology Systems, LLC, a global supplier of ultra-precision machining systems, introduces the all new Nanotech 100UPG Ultra-Precision Aspheric Grinder at SPIE Optifab in Rochester, NY the week of October 14th, 2013.

Nanotech has continued its history of setting new industry standards in the ultra-precision machining systems field with their latest innovation. The Nanotech 100UPG is the most technically advanced aspheric grinder available, with a great emphasis having been placed on making operation of this system easy and intuitive. Whether the application is Tungsten Carbide / Silicon Carbide precision optical mold inserts or aspheric glass lenses, this total flood coolant containment design has been engineered to add value to the process in terms of both efficiency and performance. Available in either XZ or XZB configurations, the machine offers a 100mm diameter swing capacity for optical grinding. It can also serve as an ultra-precision diamond turning system with a 250mm diameter capacity.

“One of the shortcomings with more traditional ultra-precision machining/grinding systems has been in offering customers the complete manufacturing solution. When we started this development project our goal was to not only design a superior grinding platform with state-of-the-art mechanics and control, but to also design and implement the tools and devices required for turnkey manufacturing. This included such features as in-situ automated wheel dressing and probing, in-situ metrology and correction, process monitoring with vision techniques, as well as touch probing for dimensional control. Our goal was to incorporate all this into a single system. I am pleased to say that our team here at MNTS has not only met this challenge, but they exceeded our expectations,” notes Tom Dupell, Vice President & Chief Operating Officer for Nanotech.

What is Tungsten Carbide or Hard Metal?

Tungsten Carbide is often referred to as a Hard Metal due to it’s very high hardness in relation to other metals.
Typically a Tungsten Carbide Hard Metal can have a hardness value of 1600 HV, whereas mild steel would be in the region of 160 HV a factor of 10 lower.
Although called a hard metal, Tungsten Carbide is actually a composite material with hard particles of Tungsten Carbide embedded in a softer matrix of metallic Cobalt .
What is the Chemical Formula for Tungsten Carbide?
The chemical formula for Tungsten Carbide is WC.
What is the History of Hard Metals or Tungsten Carbide?
Tungsten Carbide was originally developed in Germany in the 1920’s as there was a requirement for die materials that were able to stand up to the high wear encountered in the drawing of tungsten filaments for light bulbs
How is Hard Metal or Tungsten Carbide Made?
Tungsten Carbide Hard Metals are primarily produced using a Powder Metallurgy process, whereby the powdered forms of tungsten carbide and cobalt are mixed using ball mills, a binder material is added to hold the powders together during the next stage of the process which is compaction or pressing.
During the compaction processes, hydraulic presses or isostatic presses are used to compact the powders into a shape which approximates the design of the finished product.

Tungsten Carbide

We use Tungsten Carbide everyday in a variety of products, for use in a number of different applications throughout many industries. It is an incredibly versatile and useful material due to its unique properties which are outlined below:
General
When evaluating or finding equivalents of Tungsten Carbide grades the important criteria is to specify two of three factors. Binder content, hardness or grain size. In straight matrix materials any two of these will match the third. A 15% binder with hardness of 88.0 RA would have to be fine grain material whereas with a hardness of 86.0 RA would need a very coarse grade to achieve it. Specifying cobalt binder only can be a dangerous game. Take control of each situation and ensure you know what you are using and why so that consistency of specification can be obtained from whatever source. We can achieve hardness differential on 15% cobalt: purely by varying the grain size, that would need a spread of 11% cobalt over same gain size materials. I.e. We can manufacture 15% material with a hardness of a 6% or 18% grade just by using sub micron or coarse grains !!
The Tungsten Carbide properties chart below shows basic data for each grade manufactured. All specifications are designed and engineered for a purpose and rigid controls are kept throughout production processes to ensure adherence to grade engineering.
Quality control properties such as hardness, density, and minimum transverse rupture strength were determined from tests made on each batch of powder before it is used in the manufacturing process. Other properties such as Young's modulus of Elasticity , Poisson's ratio , Coefficient of Thermal Expansion, Thermal Conductivity and Electrical Conductivity are used by engineers for design calculations. Properties such as compressive strength, grain size and abrasion resistance give the designer additional information about the suitability of the grade for the part being designed.
Binder
The binder in most grades of Tungsten Carbide is cobalt. The other binder used is nickel. The binder is added as a percentage by weight varying from 3% to 30%. The amount of binder used is a very important factor in determining the properties of each grade. As a rule of thumb the lower the cobalt content the harder the material will become. However variation in grain size and additives can upset this rule.
Density
Determined by comparison of mass with volume and usually stated in g/cm3.
Grain Size
The majority of grades we machine are made with standard size grains varying between 1 and 3 microns in size. Using larger grains of 2 - 6 microns will greatly increase the strength and toughness of the material because the larger grains interlock better. The trade off is that larger grain materials do not offer as much resistance to wear as finer grain sized materials. Sub micron materials that vary between 0.4 and 1.0 micron grain size are harder than standard grain materials with the same cobalt content. The sub micron grains are much more uniform in size and hence give improved hardness as well as increased carbide strength. However, as specs show the transverse rupture strength is perhaps 20% improved on 15% sub micron compared to 15% fine grain material but this can give a false impression as sub micron carbide is not as resistant to impact and may chip more easily.
Rockwell Hardness
The hardness of Tungsten Carbide grades is determined by using the Rockwell hardness tester. A pointed diamond indenter is forced into the carbide. The depth of the hole is a measure of the hardness. The Rockwell "A" scale is used for tungsten carbide. Rockwell "C" readings are only shown on the data sheet so that tooling people can compare values of carbide against tool steel. The "A" scale is used on tungsten carbide because the lower indenting force of 60 KGs is less likely to damage the diamond than the 150 KGs force used on the "C" scale.
Minimum Transverse Rupture Strength (TRS)
TRS is a measure of the strength of Tungsten Carbide. Tensile strength is not used on tungsten carbide because it is too brittle and accurate readings cannot be obtained. As a rule of thumb the tensile strength of tungsten carbide is approx. half of the transverse rupture strength.
Transverse rupture strength values are determined by the amount of force needed to break standard test pieces under the same test conditions.
Compressive Strength
Compressive strength is measured by compressing a right cylinder test piece between two tungsten carbide blocks held in line by an outer sleeve assembly. The CS of Tungsten Carbide is higher than for virtually all metals and alloys. This high compressive strength makes it possible to compress carbon at one million P.S.I. from man made diamonds.

How hard is Tungsten Carbide

Tungsten carbide is hard. Very hard. But how hard is very hard? Hardness is measured on the Moh’s scale. You probably haven’t heard of it before, but we can easily use it to compare some common metals and materials to give you an idea just how hard Tungsten Carbide is.
As you can see in the chart, Diamond is the only thing you’d recognize which is harder than Tungsten Carbide. Gold as you know is a softer metal which is why it only scores a six on the mohs scale. This is why you’ll notice gold rings getting scratched, having any hard edges smoothed over as time goes on and generally losing that ‘new’ appearance. In fact, the harder variations of gold are LESS pure, meaning if you want it to last you will have to choose an alloy anyways.

Tungsten Carbide

Tungsten carbide is an inorganic chemical compound that contains equal numbers of tungsten and carbon atoms. It is sometimes colloquially referred to as simply "carbide." In its most basic form, it is a fine gray powder, but it can be pressed and formed into shapes for use in industrial machinery, tools, abrasives, as well as men's jewelry.

The notable and rare combination of physical properties possessed by tungsten carbide makes it useful for a variety of applications. It is extremely strong and wear-resistant. There are only a few materials on earth that can be used to cut or engrave it, with industrial diamond abrasives being one of these. Its tensile strength is very high, but it is brittle under high pressures as a result. The melting point is also very high, at 5,200°F (2,870°C). To boil, it must be heated much further, to 10,382°F (6,000°C).

This compound can be made by reacting tungsten and carbon at temperatures of around 2,552 to 3,632°F (1,400 to 2,000°C). It is then often made into mills and cutting tools for industrial use, which are able to withstand heavy use and high temperatures. Military organizations also use it in armor-piercing ammunition as an alternative to depleted uranium because of its very high density and hardness level. Some sporting goods are made stronger and more durable by the addition of carbide. Trekking poles used by hikers, for instance, use carbide tips in order to gain traction on hard or rocky surfaces.

Tungsten carbide

Tungsten carbide
Tungsten carbide is an inorganic chemical compound which contains equal numbers of tungsten and carbon atoms. It is sometimes colloquially referred to as simply "carbide." In its most basic form, it is a fine gray powder, but it can be pressed and formed into shapes for use in industrial machinery, tools, abrasives, as well as men's jewelry.
It is important to note that tungsten carbide is made in many different grades, which have different properties depending on what each will be used for. There are nearly two dozen different grades of carbide, but they are almost all variations of just a few parameters: grain size, hardness, and the degree to which a binder is used. Generally, the higher the percentage of the finished product that is composed of binding materials like nickel, the softer it will be and the more it will wear. The size of the original powder grains makes slightly less difference, but can affect the amount of shock that the product will be able to withstand.

New Era of Tungsten Carbide as Cutting Material

In recent years, all kinds of new cutting tools that were launched by the manufacturer of cutters have caught people’s attention in hardware machine tool exhibition. In order to reach the goal and lay a foundation for long-term development of “twelfth five-year”, importance of hardware industries should be attached to product structure adjustment, diamond cutter innovation and industry restructuring.

Experts believed that tungsten carbide used as cutting materials would create a new era. Compared with the high speed steel, tungsten carbide performs better properties and owns higher cutting efficiency. It is an important guarantee to realize efficient process of modern cutting technology when it combined with super hard materials. Now, the proportion of tungsten carbide cutting tool in our country reaches 40%, far below the level of developed country, which has seriously restricted the improvement of cutter products? Better cutting materials, more solid foundation for the adjustment of cutting tools. Without better cutting materials, the reform of increasing proportion of cutting material would not be achieved. Therefore, tungsten carbide as cutting material would be catalyst for the reformation of cutting industries.

Tungsten Carbide

Tungsten carbide is sometimes colloquially referred to as cement carbide or simply "carbide." Its general definition is described as: Tungsten carbide is an inorganic chemical compound which contains equal numbers of tungsten and carbon atoms. It is also caled tungsten cemented carbide. Tungsten cemented carbide can be pressed and formed into shapes from fine gray powder, which is considered to be its most basic form. The applications of tungsten cemented carbide are widely reflected in industrial machinery, wear resistent tools, abrasives as well as men' s jewelry.

Chinatungsten Online of tungsten carbide manufacturer can offer different kinds of tungsten cemented carbide products based on our customers' requirements.

Tungsten cemented carbide is the preferred material for parts that must withstand all forms of wear (including sliding abrasion, erosion, corrosion/wear and metal-to-metal galling) and exhibit a high degree of toughness. It exhibits high compressive strength, resists deflection, and retains its hardness values at high temperatures, a physical property especially useful in metal-cutting applications. It provides long life in applications where other materials would not last or would fail prematurely.