What is cemented carbide?

Cemented carbide is an alloy composed of hard metal carbide and iron based metal.
The most typical composition of cemented carbide is WC-Co alloy.
Made by sintering compound of WC and Co powder at 1,400 degrees celsius, cemented carbide possess hardness following diamond and high modulus of elasticity. Due to such high hardness and elastic modulus, cemented carbide is used for machining tools and press dies that require wear resistance.

Characteristics of cemented carbide

Other than cemented carbide, high speed tool steel is also a common material for working tools.
We will explain below the characteristics of cemented carbide in comparison with high speed tool steel.
Cemented carbide has higher values in hardness, elastic modulus, compressive strength, thermal conductivity and specific gravity compared with high speed tool steel, while values such as thermal expansion coefficient, impact strength and fracture toughness are lower.
However, the characteristics of cemented carbides are not all the same. As cemented carbides are manufactured by powder metallurgy, it is possible to produce alloys with a variety of properties through a combination of material selection. Therefore, it is possible to manufacture tools that match the characteristics of the workpiece.

超硬合金のメリット・デメリット

超硬合金のメリット

• 超硬合金は非常に硬いという特長があります。ハイス鋼やダイス鋼と比べ耐摩耗性は非常に優れたものがあるため金型部品、治具などの長寿命化を図ることができます。長寿命化されることでメンテナンス回数が削減され生産性の向上につながります。
• 超硬合金は弾性係数や圧縮強度が高く変形しにくいため、金型部品として使用する場合、高い寸法精度の加工を行うことができます。
• 超硬合金はスクラップにならずリサイクルが可能です。環境への配慮が可能な材料です。

超硬合金のデメリット

• 超硬合金は非常に硬いため、脆いという部分も持ち合わせており、材種によっては欠け
  やすくなる場合や衝撃に弱くなることがあります。
• 超硬合金は希少金属のタングステンカーバイドやコバルトを使用するため非常に高額に
  なるというデメリットがあります。
• 超硬合金はダイヤモンドに次いで硬いという特長がありますが、その硬さゆえに加工するには特殊な工具や加工機を必要とします。ダイヤモンド砥粒をつかった砥石や、研削盤、放電加工機など高額な加工機が必要になります。

The hardness of cemented carbide is next to diamond, and the weight is the same as gold.

Cemented carbide is an extremely hard metal.
It is harder than iron and stainless steel, and the hardness is next to diamond.
Also, it weighs twice as much as iron, which is almost the same as gold.
Not only is it hard, but it also has excellent strength and elasticity.
Decrease in hardness at high temperatures is also small, and is not easily worn.
Because of those reasons, it is used for metal processing tools and dies.

超硬合金の組成

Cemented Carbide is not a natural metal, but an artificially made alloy.
It is composed of tungsten carbide (WC) and cobalt (Co).
Tungsten carbide has a high melting point (2900 degrees in Celsius,) and cannot be melted and made like iron.
Therefore, cemented carbide is manufactured by sintering and hardening blended powder at high temperatures from 1300 to 1500 degrees celsius.
Cobalt is used as a binder at that time.
Most of the tungsten is from China, and others places include Russia and South Korea.
Cobalt can be mined as ore from Finland, Canada, Australia and Congo.

Contributes to society in a wide range of applications

Given its hardness and strength, cemented carbide is used in cutting tools for metal processing such as drills, milling cutters, and lathes.
It is also used in molds for aluminum cans used for canned drinks, powder molding dies for making sintered automobile engine parts, and recently, molds for parts used in electronics like mobile phones.
It is also used for crushing hard rock in shield tunnelling and for cutting the surface of asphalt roads.
Due to its excellent properties, cemented carbide is used in a wide range of industrial fields such as manufacturing and public works for infrastructure development.

Types of cemented carbide

Function of cemented carbide can be broadly divided into 2 categories: cutting and wear resistance.
Cemented carbide for cutting can be divided into 3 types, P type (for steel), M type (general purpose), and K type (for cast iron), depending on the material of the workpiece. There are different types of wear-resistant cemented carbides, finely classified according to binder phase type, WC grain size and hardness. As a cemented carbide manufacturer, we developed grades focusing on specific issues, possess a wide variety of grades in order to meet the diverse demands of our customers.

Please contact us for material selection and processing of cemented carbide.

We selected and processed a large number of cemented carbides.
Among them, we have proposed solutions for customer’s various problems by selecting and processing the most suitable materials.
We will be able to select the appropriate cemented carbide for the intended application and perform the appropriate processing.
If you have any problems with the use of cemented carbide, please feel free to contact us.