What is Cemented Carbide or Hard Metal?

Cemented Carbide is usually referred to as a Hard Metal due to its very high hardness rather than other metals. Typically, a Cemented Carbide product can have a hardness value of 1600 HV30, however mild carbon steel would have a hardness value of only 160 HV30, a factor of 10 times lower.
Although called a hard metal, Cemented Carbide is actually a composite material with hard particles of Cemented Carbide embedded in a softer matrix of metallic Cobalt, Nickel or other metals.

What is the Chemical Formula for Cemented Carbide?

The chemical formula for Cemented Carbide is WC, which means wolfram carbide’s abbr.

What is the History of Cemented Carbide?

Cemented Carbide was originally developed in Germany in the 1920’s, coz there was a huge requirement for die materials that were able to stand up to the high wear encountered in the drawing of tungsten filaments for light bulbs. You know, the bulbs are used by everyone, so there needs lots of tungsten filaments for production. Afterwards, people developed many other application of the cemented carbide.

How is Cemented Carbide Made?

Cemented Carbide are primarily produced by using a Powder Metallurgy process, whereby the powdered forms of WC and Cobalt are mixed by using ball mills, a binder material is added to hold the powders together during the next stage of the process which is pressing process.
During the pressing processes, hydraulic presses or isostatic presses are used to compact the powders into a shape which approximates the design of the finished product.

Whilst in this condition, the powder compact can be easily machined using conventional metal working tools. This process is often referred to as “Half-Machining”, we usually call it this way. Operators must be very careful with the removal of the fine powder particles, as they can pose a health hazard so effective extraction methods are required.
Following “Half-Machining”, the half-finished carbide product is then ready to be Sintered. Typically this is done in a vacuum or HIP furnace at temperatures between 1300 and 1700°C. The sintering process causes the Cemented Carbide and cobalt matrix to fuse together to produce a dense “Hard Metal”.
After sintering, the product is so hard that it can only be machined by diamond grinding, a specialized form of micro machining that is really expensive, as it is not possible to remove large amounts of materials by this process, and the cost is much higher than machining steel or other metals.

 

Typical Properties of Cemented Carbide Hard Metals

ISO Class	Cemented Carbide WC %	Cobalt Co %	Hardness HV 30	Transverse Rupture Strength MPa	Density g/cm3	Grain Size µm	Description
K05	97	3	2050	1800	14.95	0.5	Ultra-fine grained material with very high hardness
K10	94	6	1810	2800	14.85	1.0	Fine grain size “workhorse” grade
K20	92	8	1710	3200	14.75	1.0	Fine grain size good hardness and wear resistance

You can see from above table for the basic parameters of common cemtend carbide grades. For more info, you can refer to our website and the exact product’s page. You will find more related info you want.
Tungsten Rings Don't Scratch

Applications of Cemented Carbide and Hard Metals

Cemented Carbides have a wide range of application in many industry sectors. We call it’s the teeth of all our industry today, coz almost every industry will use it. Such as aerospace, military, oil and gas, mining, construction, cutting tools, and so on.
No matter what you want to use for, welcome to talk to Zhuzhou Hongtong or Arris.