Content Menu
● What is Tungsten Carbide?
● Understanding Plasma Cutting
● The Challenge of Plasma Cutting Tungsten Carbide
● Alternative Methods for Cutting Tungsten Carbide
● Step-by-Step Guide to Cutting Tungsten Carbide Rods with a Diamond Saw Blade
● Safety Precautions
● Cost Considerations
● Conclusion
● FAQ
>> 1. Can I use a regular metal cutting blade to cut tungsten carbide?
>> 2. What type of coolant should I use when cutting tungsten carbide?
>> 3. Is it safe to dry cut tungsten carbide without coolant?
>> 4. How do I prevent tungsten carbide from cracking during cutting?
>> 5. What should I do with the waste material generated during cutting?
● Citations:
Tungsten carbide is a compound renowned for its exceptional hardness, wear resistance, and high-temperature tolerance, making it a crucial material in various industrial applications[2][3]. Its properties make it ideal for cutting tools, molds, dies, and components in aerospace and automotive industries[2][3]. Plasma cutting, on the other hand, is a process that utilizes a high-temperature plasma arc to cut through electrically conductive materials[1]. This article explores the feasibility of using plasma cutting on tungsten carbide, the challenges involved, alternative methods, and safety considerations.
What is Tungsten Carbide?
Tungsten carbide (WC) is a composite material made from equal parts of tungsten and carbon[3]. It is produced by heating tungsten powder with carbon at high temperatures, resulting in a dense and hard material[3]. The resulting material is known for its exceptional hardness, surpassed only by diamond and cubic boron nitride[3]. Tungsten carbide ranks between 9 and 9.5 on the Mohs scale of hardness and has a Vickers hardness of approximately 2600[3].
Key Properties of Tungsten Carbide:
- Extreme Hardness: Tungsten carbide's hardness makes it highly resistant to wear, making it ideal for applications requiring durable materials[3].
- High Melting Point: With a melting point of approximately 2,870°C (5,198°F), tungsten carbide maintains its structural integrity even at high temperatures[3].
- Thermal Conductivity: Tungsten carbide has a thermal conductivity of 110 W/m·K, effectively dissipating heat[3].
- Low Thermal Expansion: Its low thermal expansion coefficient of 5.5 μm/m·K ensures minimal size changes with temperature variations[3].
- Chemical Resistance: Tungsten carbide is highly resistant to chemical corrosion, especially from acids[3].
Despite its beneficial properties, tungsten carbide is brittle and can crack or shatter under impact or excessive stress[3]. Therefore, handling and machining this material requires careful techniques[3].
Understanding Plasma Cutting
Plasma cutting is a thermal cutting process that uses a high-velocity jet of ionized gas (plasma) to transfer energy to the workpiece[1]. The basic plasma cutting process involves creating an electrical channel of superheated, electrically ionized gas[1]. This plasma is generated by passing a gas, such as compressed air, nitrogen, or argon, through a narrow nozzle at high speed and then applying an electrical arc to the gas[1].
The Plasma Cutting Process:
1. Arc Generation: A high-voltage electrical arc is struck between an electrode (cathode) and the workpiece (anode)[1].
2. Plasma Formation: The gas passing through the nozzle is ionized by the electrical arc, creating plasma[1].
3. Material Removal: The intense heat of the plasma melts the metal, and the high-velocity gas jet blows the molten material away, creating a clean cut[1].
Plasma cutting is effective for cutting various electrically conductive materials, including steel, stainless steel, aluminum, and copper[1]. It is valued for its speed, precision, and ability to cut through materials of varying thicknesses[1].
The Challenge of Plasma Cutting Tungsten Carbide
While plasma cutting is suitable for many metals, cutting tungsten carbide presents significant challenges due to the material's unique properties[3].
1. High Hardness: Tungsten carbide's extreme hardness makes it difficult to melt and remove with a plasma arc[3]. The energy required to cut through such a hard material is substantially higher than that needed for conventional metals like steel.
2. Brittleness: Tungsten carbide is brittle and prone to cracking under thermal stress[3]. The rapid heating and cooling cycles in plasma cutting can induce thermal shock, leading to cracks and material failure.
3. High Melting Point: The high melting point of tungsten carbide (approximately 2,870°C) requires extremely high energy input from the plasma arc[3]. Achieving and maintaining such high temperatures can be challenging and may exceed the capabilities of standard plasma cutting equipment.
4. Electrical Conductivity: While tungsten carbide is electrically conductive, its conductivity is lower than that of many metals commonly cut with plasma[3]. This can affect the stability and efficiency of the plasma arc during the cutting process.
5. Tool Wear: The abrasive nature of tungsten carbide causes accelerated wear and tear on cutting tools[3]. This necessitates frequent replacement of consumables, increasing operational costs.
Alternative Methods for Cutting Tungsten Carbide
Given the difficulties in plasma cutting tungsten carbide, alternative methods are often preferred for achieving precise and clean cuts[3].
1.Diamond Saw Blades:
Diamond saw blades are specifically designed for cutting hard and abrasive materials like tungsten carbide[3]. The blades are coated with diamond particles, which provide the necessary hardness to cut through the material effectively.
- Process: The tungsten carbide rod is securely clamped, and the diamond saw blade is used to make precise cuts. Cooling the blade with a coolant helps to reduce heat buildup and extend the blade's life.
- Advantages: High precision, clean cuts, and relatively low cost.
- Disadvantages: Slower cutting speed compared to other methods, potential for blade wear.
2. Carbide Grit Blades:
Carbide grit blades are another option for cutting tungsten carbide, particularly for rough cuts[3]. These blades have carbide particles embedded in the cutting edge, providing good abrasion resistance.
- Process: Similar to using diamond saw blades, the tungsten carbide rod is secured, and the carbide grit blade is used to make the cut.
- Advantages: Suitable for rough cuts, can handle harder materials.
- Disadvantages: Lower precision compared to diamond saw blades, potential for chipping.
3. Electric Discharge Machining (EDM):
EDM is a non-traditional machining process that uses electrical discharges to erode the material[3]. It is highly effective for cutting complex shapes and intricate details in hard materials like tungsten carbide.
- Process: The workpiece is submerged in a dielectric fluid, and an electrode is used to generate electrical sparks that erode the material.
- Advantages: High precision, ability to create complex shapes, minimal mechanical stress.
- Disadvantages: Slow cutting speed, high equipment cost.
4. Electrolytic Machining (ECM):
ECM is another non-traditional machining process that uses electrochemical reactions to remove material[3]. It is a non-contact method that reduces the risk of mechanical stress and cracking.
- Process: The workpiece is placed in an electrolytic solution, and an electrode is used to dissolve the material through electrochemical action.
- Advantages: Non-contact process, minimal mechanical stress, suitable for complex shapes.
- Disadvantages: High equipment cost, requires specialized electrolytes.
5. Laser Cutting:
Laser cutting is a non-contact thermal process that uses a focused laser beam to melt, burn, or vaporize the material[3]. It offers high precision and is suitable for creating intricate shapes in tungsten carbide.
- Process: A high-power laser beam is directed onto the tungsten carbide rod, causing it to melt or vaporize.
- Advantages: High precision, non-contact process, suitable for intricate shapes.
- Disadvantages: High equipment cost, potential for thermal stress.
6. Dremel Tool with Carbide Wheel:
For small-scale or intricate tasks, a Dremel tool equipped with a carbide wheel can be effective[3]. This setup is ideal for detailed work, such as cutting small sections or making fine adjustments.
- Process: The tungsten carbide rod is secured, and the Dremel tool with a carbide wheel is used to make precise cuts.
- Advantages: Suitable for small-scale tasks, provides good control for precision cuts.
- Disadvantages: Limited to small sections, requires careful handling to avoid cracks.
Step-by-Step Guide to Cutting Tungsten Carbide Rods with a Diamond Saw Blade
Using a diamond saw blade is a practical method for cutting tungsten carbide rods. Here is a step-by-step guide:
Materials and Tools:
- Tungsten carbide rod
- Diamond saw blade
- Vise or clamp
- Coolant (e.g., water or specialized cutting fluid)
- Safety glasses
- Gloves
- Marker or scribe
Procedure:
1. Safety First: Wear safety glasses and gloves to protect against flying particles and sharp edges[3].
2. Mark the Cutting Area: Use a marker or scribe to accurately mark the cutting area on the tungsten carbide rod[3].
3. Secure the Rod: Firmly secure the tungsten carbide rod in a vise or clamp to prevent movement during cutting[3]. Be careful not to apply excessive pressure to avoid cracking the material.
4. Mount the Diamond Saw Blade: Install the diamond saw blade on the cutting machine, ensuring it is properly aligned and securely attached.
5. Apply Coolant: Continuously apply coolant (water or cutting fluid) to the cutting area to dissipate heat and reduce thermal stress[3].
6. Start Cutting: Slowly and steadily start cutting along the marked line, allowing the diamond saw blade to gradually wear away the material. Avoid applying excessive force, which can cause the blade to bind or the material to crack.
7. Maintain Cooling: Ensure the cutting area remains cool by continuously applying coolant throughout the cutting process[3].
8. Complete the Cut: Continue cutting until the rod is completely separated.
9. Finishing: Use abrasion wheels or a Dremel tool with a carbide wheel to grind and smooth the cut edges[3].
Safety Precautions
Cutting tungsten carbide requires strict adherence to safety precautions to prevent injuries and ensure a safe working environment[3].
1. Personal Protective Equipment (PPE):
- Safety Glasses: Always wear safety glasses to protect your eyes from flying particles[3].
- Gloves: Use gloves to protect your hands from cuts and abrasions[3].
- Dust Mask: Wear a dust mask to avoid inhaling fine particles generated during cutting[3].
2. Secure Workpiece: Ensure the tungsten carbide rod is firmly secured in a vise or clamp to prevent movement during cutting[3].
3. Cooling: Use a coolant system (e.g., water or specialized cutting fluid) to prevent overheating of tools and the workpiece[3].
4. Ventilation: Work in a well-ventilated area to minimize inhalation of hazardous particles[3].
5. Tool Maintenance: Regularly inspect and maintain cutting tools to prevent wear and ensure optimal performance[3].
6. Avoid Overheating: Prevent overheating of tools by cooling the blade periodically[3].
7. Proper Handling: Handle tungsten carbide rods carefully to avoid dropping or subjecting them to impact, which can cause cracks or fractures[3].
Cost Considerations
The cost of cutting tungsten carbide depends on the method used, the size and complexity of the cut, and the equipment required[3].
1. Diamond Saw Blades: The initial cost of diamond saw blades can be higher than that of other cutting tools, but their longevity and precision can make them cost-effective in the long run[3].
2. EDM and ECM: EDM and ECM have high equipment costs and require specialized expertise, making them more expensive options[3].
3. Laser Cutting: Laser cutting also involves significant equipment costs and may require outsourcing, which can increase the overall cost[3].
4. Tool Maintenance: Regular maintenance and replacement of cutting tools are essential to maintain optimal performance[3].
5. Labor Costs: The time required to cut tungsten carbide can vary depending on the method used, affecting labor costs[3].
Conclusion
While plasma cutting tungsten carbide is theoretically possible, it is not practical due to the material's high hardness, brittleness, and high melting point[3]. Alternative methods such as diamond saw blades, EDM, ECM, and laser cutting offer more precise and efficient solutions[3]. When working with tungsten carbide, it is crucial to follow safety precautions and use appropriate tools and techniques to achieve the desired results while minimizing the risk of injuries and material damage[3].
FAQ
1. Can I use a regular metal cutting blade to cut tungsten carbide?
No, regular metal cutting blades are not suitable for cutting tungsten carbide[3]. Tungsten carbide's extreme hardness will quickly wear down or damage standard blades. Diamond saw blades or carbide grit blades are recommended for cutting tungsten carbide[3].
2. What type of coolant should I use when cutting tungsten carbide?
You can use clean water or a specialized cutting fluid as a coolant[3]. The primary purpose of the coolant is to dissipate heat and reduce thermal stress on the material and cutting tool.
3. Is it safe to dry cut tungsten carbide without coolant?
Dry cutting tungsten carbide without coolant is not recommended[3]. The heat generated during cutting can damage the cutting tool and induce thermal stress in the material, leading to cracks and reduced precision. Always use a coolant to maintain a safe and efficient cutting process[3].
4. How do I prevent tungsten carbide from cracking during cutting?
To prevent tungsten carbide from cracking during cutting, follow these tips[3]:
- Secure the rod firmly in a vise or clamp.
- Use a slow and steady cutting speed.
- Apply coolant continuously to dissipate heat.
- Avoid applying excessive force.
- Use appropriate cutting tools, such as diamond saw blades.
5. What should I do with the waste material generated during cutting?
The waste material generated during cutting, such as fine particles and debris, should be collected and disposed of properly[3]. Wear a dust mask to avoid inhaling particles and clean the work area thoroughly after cutting. Follow local regulations for the disposal of industrial waste.
Citations:
[1] https://www.thefabricator.com/thefabricator/article/plasmacutting/the-life-and-times-of-plasma-cutting
[2] https://www.calnanocorp.com/tungsten-carbide-tooling
[3] https://shop.machinemfg.com/how-to-cut-tungsten-carbide-rods-an-overview/
[4] https://www.shutterstock.com/search/tungsten-carbide
[5] https://www.cnczone.com/forums/cnc-plasma-oxy-fuel-cutting-machines/261594-cnc.html
[6] https://www.shutterstock.com/search/solid-tungsten-carbide
[7] https://www.everlastgenerators.com/forums/showthread.php/2772-Plasma-Cutting-Tungsten
[8] https://www.researchgate.net/figure/Photo-of-the-nano-crystalline-binderless-tungsten-carbide-nWC-cutting-inserts_fig1_352568741
