how are tungsten carbide insert tips manufactured

When you need to choose a tool for metal processing, tungsten carbide (also known as cemented carbide or cemented carbide) is often the first choice.

But are you curious: How is this material, which is several times harder than steel, produced? Or, can the drill made of it efficiently process aluminum?

一. Revealing how tungsten carbide inserts are made

People call tungsten carbide inserts “industrial teeth” because of their complex manufacturing process and extreme performance.The following are the four core steps of cemented carbide inserts from powder to finished products:

1. Puwei preparation:

Active mixing: Workers mix tungsten carbide (WC) powder with a metal binder (usually cobalt, accounting for 6%-12%) in precise proportions.

You need to control the powder particle size between 0.5 and 2 microns. The finer the particles, the higher the hardness of the final product.

2. Forming and pressing:

You load the mixed powder into the mold and press it into a blade blank under a high pressure of 100–300 MPa.The blank density at this time is about 50% of the theoretical value.

You can manufacture blades with complex structures, such as chip breakers and holes (e.g., CNMG, WNMG models), through multi-directional pressurization technology.

3. High-temperature sintering:

You send the blank to a sintering furnace at 1,400–1,600°C and heat it continuously for 1–3 hours in a hydrogen or vacuum environment.

Passive densification: Cobalt melts and wraps tungsten carbide particles at high temperature, the material shrinks by about 20%, and the density increases to 14-15g/cm³.

4. Post-processing:

Grinding and polishing: Use a diamond grinding wheel to mirror the blade edge to ensure that the surface roughness Ra≤0.4μm.

You can coat the blade with materials like TiAlN or AlCrN through chemical vapor deposition (CVD) or physical vapor deposition (PVD), which increases the blade’s lifespan by 3–5 times.

The uniqueness of Puwei cemented carbide:

You can use gradient sintering technology to achieve a WC content of 94% on the blade surface (ultra-wear-resistant) while increasing the cobalt content in the core to 10% (impact-resistant), perfectly balancing hardness and toughness.

二. Can carbide drills be used for aluminum processing?

Yes, but you need to optimize the design and parameters.

Although cemented carbide excels at processing hard materials like steel and titanium alloys, it can also be applied in the aluminum field. The premise is to address the following two challenges:

Challenge 1: Aluminum sticks to the tool and causes poor chip removal

The essence of the problem: Aluminum has a low melting point (660℃), and it is easy to soften and adhere to the drill bit edge during cutting, forming a built-up edge.

Solution:

Choose uncoated or polished drill bits: reduce the surface friction coefficient (the surface roughness of the PW-AL series drill bits Ra is less than 0.2μm).

Increase the helix angle (30°-45°): speed up chip removal and avoid aluminum chip blockage.

Challenge 2: Edge collapse at high speed

The essence of the problem: Aluminum processing usually requires ultra-high speed (such as φ6mm drill bits up to 20000RPM), and the dynamic balance requirements of the drill bit are extremely high.

Solution:

Use unequal blade design: disperse cutting vibration and improve stability (such as PW-AD3 three-blade drill).

Optimize cooling method: use air cooling (pressure ≥ 6 bar) or minimal lubrication (MQL) to reduce cutting temperature.

Whether it is the precision manufacturing process of tungsten carbide inserts or the drill optimization solution in aluminum processing, Puwei Carbide always focuses on customer needs.