Wire-cut EDM is a technology that uses the principle of electric spark discharge to precisely cut metal materials. This processing technology plays an indispensable role in the manufacture of parts with complex shapes, especially in the fields of molds, aerospace and automobile manufacturing.

一. Working principle

The core principle of wire-cut EDM is to use the electric spark discharge generated by the pulse power supply in the electric field. The processing process is as follows:

1. Workpiece and electrode installation: The workpiece is connected to the positive pole of the pulse power supply, and the cutting wire is usually molybdenum wire or copper wire, which is connected to the negative pole of the pulse power supply. The molybdenum wire or copper wire is used as a tool electrode and moves continuously during the processing to form a cutting path.

2. Discharge process: Under the action of the electric field, a strong electric field is formed between the anode (workpiece) and the cathode (cutting wire), causing electrons and ions to flow between the two. This process causes the anode surface and the cathode surface to be bombarded respectively, generating instantaneous high temperature, causing the metal to melt or vaporize at the contact point.

3. Cutting process: As the cutting wire moves on the workpiece, the electric spark instantly bursts in the gap, forming a tiny cutting action to achieve high-precision cutting.

This processing method has high precision, good surface quality and complex shape cutting ability, and is suitable for processing materials with high hardness and strong toughness.

二. Conductivity requirements

In the process of wire cutting, in order to achieve effective spark discharge, the workpiece must have good conductivity. This is because the key to spark discharge lies in the electric field strength between the workpiece and the electrode. For metal materials, their conductivity is good, so they can easily meet the requirements of wire cutting. Relatively speaking, for some non-metallic or insulating materials, EDM may not be suitable.

三. Wire cutting of PCD materials

Polycrystalline diamond (PCD) is a composite material formed by combining diamond particles under high temperature and high pressure. It is widely used in high-end applications such as cutting tools and abrasives. The hardness of PCD materials is recognized to be very high, but its processability in wire cutting is relatively special.

1. Conductivity: Although PCD materials are mainly composed of diamonds and have relatively low conductivity, they can still be processed during wire cutting because they are semiconductor materials. In particular, PCD has a certain conductivity under certain conditions, but its processing speed is usually slow.

2. Processing speed: Generally speaking, the wire cutting processing speed of PCD materials is about 1mm/2min. This speed is much slower than the processing speed of traditional metal materials, mainly because the hardness and conductivity of PCD materials limit the processing efficiency. It is worth noting that the thickness of the PCD blade layer also has a significant impact on the cutting speed. The thicker the blade layer, the greater the processing difficulty and time.

3. Processing effect: Although the processing speed is slow, PCD materials can obtain relatively high surface quality after wire cutting. This makes PCD still an ideal choice in applications that require high-precision cutting.

四. Factors affecting processing efficiency

The efficiency of wire cutting EDM is related to many factors, especially when processing hard materials such as PCD, the following points should be paid more attention to:

1. Power supply parameters: The power supply settings such as current, pulse width, and pulse interval have a significant impact on processing efficiency and quality. These parameters need to be adjusted in detail according to the material characteristics to achieve the best processing effect.

2. Cutting wire material and diameter: The material of the cutting wire will also affect the processing process. Generally speaking, molybdenum wire and copper wire have their own advantages and disadvantages. Choosing a cutting wire with a suitable diameter can improve the processing accuracy and efficiency to a certain extent.

3. The nature of the coolant: The coolant plays a role in cooling and flushing during the processing. Reasonable use of the coolant can significantly improve the processing effect and tool life.

4. Workpiece fixing method: It is very important to ensure the fixation of the workpiece during the processing. Improper fixation may cause the movement of the workpiece during the processing, which in turn affects the cutting accuracy.

5. The influence of PCD layer thickness: We must pay close attention to the thickness of the PCD layer, because the thicker the knife layer, the more energy and time it takes to process. This requires manufacturers to fully consider the specific use occasions and processing needs when selecting tools, and reasonably match the thickness of the knife layer.

五. Summary

There is reason to believe that although there are processing difficulties in online cutting EDM of PCD materials, high-quality processing effects can be achieved with appropriate parameter settings and operating skills.

However, as the demand for efficient and high-precision processing equipment in the manufacturing industry continues to increase, laser processing technology has gradually become an effective alternative for processing PCD (polycrystalline diamond) materials. Compared with traditional wire-cut electrical discharge machining (EDM), laser processing has shown significant advantages in many aspects.

1. Processing speed

• Laser processing speed: The speed of laser processing PCD can reach 100~200mm/min, which is significantly higher than the 1mm/2min (about 30mm/min) of wire cutting. This means that laser processing can complete more cutting per unit time, greatly improving production efficiency.

• Market responsiveness: Due to the speed of laser processing, manufacturers can respond to market demand more quickly, improve order delivery capabilities, and bring competitive advantages to enterprises.

2. Processing quality

• Excellent cutting effect: Laser processing is not only fast, but also can achieve better cutting quality. Laser technology can achieve precise control, and the cuts after processing are smooth, reducing the need for subsequent processing.

• Small thermal impact: The heat input during laser cutting is low, and the thermal deformation of the workpiece is limited, which can maintain the stability and performance of PCD materials.

3. Flexibility and adaptability

• Diversified processing: Laser processing of PCD materials can flexibly handle workpieces of different shapes and sizes, and is suitable for processing complex geometric structures.

• Fewer processes: Laser processing can simplify the processing process, reduce the time for tool replacement and adjustment, and further improve production efficiency.

4. Cost-effectiveness

• Reduce production costs: Although the initial investment in laser equipment is high, the higher processing speed and lower post-processing requirements make the total production cost of laser processing more economical in the long run.

• Reduce material waste: Laser processing has high precision and small cutting format, which can effectively reduce material waste and improve material utilization.

5. Replacement trend

• Transition from EDM to laser processing: With the continuous development of laser processing technology, many companies have begun to gradually replace traditional EDM processes with laser processing. The high efficiency and excellent quality of laser make it an important trend in future PCD processing.

• Improve corporate competitiveness: Using laser processing technology, companies can not only improve their own production capacity, but also better adapt to market changes and meet the diverse needs of customers.

Conclusion

In summary, laser processing of PCD materials has significant advantages in speed, quality, flexibility and cost-effectiveness, and can completely replace traditional wire-cut electrical discharge machining (EDM). In the increasingly competitive market environment, companies should actively consider introducing laser processing technology to improve processing efficiency and market responsiveness and gain a larger market share.