How to Achieve Efficient and Non-destructive Cutting of Cemented Carbide?

2026-03-06

Reading volume: 8

Key Challenges in Carbide Cutting

Carbide, particularly tungsten carbide (WC), is widely used in various industrial applications due to its excellent hardness and wear resistance. It is commonly used to manufacture cutting tools, molds, and wear-resistant parts. However, the unique properties of carbide also present some challenges to the cutting process.

1. Mismatched tool hardness

One of the main challenges in carbide cutting is the mismatch between the hardness of carbide and traditional cutting tools.

Problem: Traditional cutting tools, such as alumina or silicon carbide grinding wheels, typically have a much lower hardness than cemented carbide wheels. This difference causes the cutting tools to wear out rapidly during machining.
Consequences: Rapid wear leads to decreased cutting efficiency and significantly shortened tool life, requiring frequent tool replacements and increasing production costs. Manufacturers must invest in high-quality cutting tools capable of withstanding the hardness of carbide, which can be even more expensive.

2. Workpiece damage

The brittleness of cemented carbide presents another major challenge during the cutting process.

Problem: The material’s high brittleness means it is prone to chipping and microcracks, especially when the cutting force is unstable or the cutting tool is not sharp enough.
Consequences: This type of damage can compromise the integrity of the workpiece, affecting its performance and lifespan. This is especially critical in applications where precision and reliability are paramount, such as aerospace or medical device manufacturing.

3. Risk of thermal damage

The cutting process generates a lot of heat, which can lead to thermal damage if not handled properly.

Problem: If the heat generated during the cutting process cannot be effectively dissipated, it may lead to localized annealing of carbides, binder phase transformation, or thermal stress cracking.
Consequences: These thermal effects can significantly degrade the material properties of cemented carbide, leading to a decrease in hardness and wear resistance. Effective cooling strategies, such as using cutting fluid or optimizing cutting parameters, are crucial to mitigating this risk.

4. Machining accuracy is difficult to guarantee

Achieving high precision and good surface quality in the machining of cemented carbide is another challenge.

Problem: For precision cutting tools, such as PCB milling cutters and micro drills, the cutting process must meet stringent accuracy requirements. Due to the inherent properties of cemented carbide, traditional cutting methods often struggle to achieve the necessary precision.
Consequences: Failure to maintain tight tolerances leads to part defects, increased scrap rates, and ultimately higher production costs. While advanced machining techniques, such as electrical discharge machining (EDM) or laser cutting, may be required to achieve the necessary precision, these methods can also be more expensive and time-consuming.

Diamond: An Abrasive Used for Efficient Cutting of Cemented Carbide

Diamond is recognized as the hardest material, with a microhardness of approximately 10,000 HV, far exceeding that of tungsten carbide, which typically has a hardness between 2,600 and 3,000 HV. This exceptional hardness allows diamond abrasive grains to effectively “scratch” tungsten carbide particles during cutting, rather than being worn down by them. Therefore, diamond has become the abrasive of choice for cutting cemented carbide, especially in high-precision applications.

Advantages of diamond abrasives in carbide cutting

1. Extremely high cutting efficiency

Mechanism of Action: Diamond abrasives have sharp, angular particles that can quickly penetrate and remove material. This property enables them to cut cemented carbide quickly, thus significantly reducing machining time.
Impact: High cutting efficiency translates into increased productivity in the manufacturing process, enabling the company to complete tasks on time and improve overall operational efficiency.

2. Excellent wear resistance

Durability: Compared to other superhard abrasives such as silicon carbide and boron nitride, diamond has an extremely low wear rate. This durability means that the cutting edge of diamond tools can remain intact for a longer period of time, thereby reducing tool changes and downtime.
Cost-effectiveness: Diamond abrasives have a longer lifespan, thus reducing overall processing costs. Fewer replacements and lower maintenance frequency contribute to significant savings in production costs.

3. Good thermal conductivity

Heat management: Diamond’s excellent thermal conductivity helps dissipate the heat generated during cutting. This property is crucial for preventing thermal damage to the tool and workpiece.
Risk reduction: Diamond abrasives reduce the risk of carbide thermal stress cracking and localized annealing by lowering the temperature in the cutting zone, thereby maintaining the integrity and performance of the material.

The Key Role of Resin Binders in Diamond Cutting Discs

Diamond cutting discs are essential tools for machining hard materials, especially cemented carbide. While the diamond abrasive itself provides the hardness needed for effective cutting, the choice of bonding agent is equally crucial, directly determining the performance and efficiency of these tools. Resin-bonded diamond cutting discs, with their unique properties, have become the mainstream choice for machining cemented carbide. This article will explore the key role of resin bonds in diamond cutting discs and how they improve machining results.

1. Good toughness and cushioning

One of the outstanding characteristics of resin adhesives is their inherent toughness and cushioning ability.

Elasticity: The resin binder possesses a certain degree of elasticity, enabling it to absorb vibrations and impacts generated during cutting. This buffering effect reduces instantaneous stress on the workpiece, which is particularly important when cutting brittle materials such as cemented carbide.
Risk reduction: Resin-bonded diamond cutting discs help maintain workpiece integrity by minimizing the risk of chipping and cracking, ensuring the final product meets quality and performance requirements.

2. Excellent self-sharpening performance

The resin adhesive also exhibits excellent self-sharpening properties, which are crucial for maintaining cutting efficiency.

Moderate abrasion: During the cutting process, the resin bond wears away at a controlled rate. This abrasion causes the passivated diamond abrasive grains to fall off rapidly, exposing new, sharp abrasive grains.
Continuously sharp: This mechanism ensures that the cutting tool remains sharp throughout its use, thereby improving cutting stability and efficiency. Therefore, operators can achieve consistent cutting performance without frequent tool changes.

3. Thermal protection mechanism

The thermal management capabilities of resin adhesives play a crucial role in preventing damage during the cutting process.

Heat resistance: The heat resistance threshold of resin adhesives is typically around 250°C. When the cutting temperature exceeds this limit, the adhesive wears off more rapidly, prompting operators to adjust cutting parameters or enhance cooling measures.
Overheat protection: This thermal protection mechanism helps prevent workpiece overheating damage, maintains material properties, and ensures high-quality surface treatment.

4. High-precision narrow slot

Resin-bonded diamond cutting discs can be carefully designed to meet high-precision machining requirements.

Ultra-thin cutting discs: By adjusting the manufacturing process, ultra-thin resin-bonded diamond cutting discs with a thickness of less than 0.5 mm can be produced. These discs are ideal for machining precision parts and micro-tools, enabling narrow kerfs and minimal material loss.
Precision machining: In industries where material conservation and precision are critical, such as electronics and medical device manufacturing, the ability to achieve high-precision narrow cuts is essential.

5. High process flexibility

The versatility of resin adhesives allows for extensive customization to meet a wide range of processing needs.

Adjustable parameters: By changing the diamond concentration, particle size, binder hardness, and additives, manufacturers can optimize tools for different shapes (such as bars, plates, and cutting tools) and specific machining requirements.
Balanced performance: This flexibility allows for an optimal balance between processing efficiency, surface quality, and tool life, making resin-bonded diamond cutting discs suitable for a wide range of applications.

Technical Comparison of Other Cutting Methods

Electrical discharge machining

Overview: Electrical discharge machining is a non-traditional machining process that uses electrical sparks to remove material from conductive workpieces.
Advantages: Especially effective for complex shapes and hard materials.
Limitations: The processing speed is relatively slow, and a heat-affected zone (HAZ) may form on the surface, which may impair material properties and surface quality.

Laser cutting

Overview: Laser cutting utilizes a focused laser beam to melt or vaporize materials, thereby achieving precise cutting.
Advantages: High precision, capable of cutting complex geometric shapes.
Limitations: This process generates a large heat-affected zone, which may lead to localized melting or cracking of the carbides. Therefore, laser cutting is not suitable for applications requiring high precision and surface quality.

Metal/ceramic combined diamond tools

Overview: These tools combine diamond abrasive with metal or ceramic binders to enhance wear resistance.
Advantages: They have higher wear resistance compared to resin-bonded tools.
Limitations: However, their poor toughness and self-sharpening properties lead to increased cutting forces and a higher risk of workpiece damage.

In Conclusion

The high hardness and brittleness of cemented carbide, coupled with its stringent requirements for machining quality, pose a significant challenge to traditional cutting tools. Diamond cutting discs have emerged as a highly efficient, precise, and economical solution for cutting cemented carbide. They cleverly combine the extremely high hardness and wear resistance of diamond with the excellent toughness, self-sharpening properties, and thermal protection of resin bonds, making them particularly suitable for precision and semi-precision cutting of cemented carbide parts.

With continuous advancements in materials science and manufacturing processes, the performance of diamond cutting tools is expected to be further improved, opening up new possibilities for the machining of cemented carbide and other superhard materials. By leveraging the advantages of diamond cutting discs, manufacturers can achieve efficient, non-destructive cutting, ultimately improving productivity and product quality across a wide range of industrial applications.