Polycrystalline diamond (PCD) is a high-performance material with excellent hardness and wear resistance and is widely used in cutting tools, molds and other industrial fields. Since PCD materials are extremely expensive to manufacture, it is particularly important to maximize the use of PCD Blank during processing. An effective cutting strategy not only reduces material waste but also significantly improves the quality of the final product. In recent years, fiber laser cutting technology has gradually replaced traditional electric discharge machining (EDM) due to its obvious advantages such as high cutting efficiency, low pollution, and small thermal deformation.
Laser cutting is a method that uses high-energy laser beams to locally heat materials, so that the materials quickly reach melting or vaporization temperatures, thereby achieving material separation. Due to the non-contact nature of laser cutting technology, compared with traditional mechanical cutting, it can effectively reduce the mechanical stress and thermal impact on the workpiece. The flexibility of this processing method is reflected in the fact that it can easily cope with PCD Blanks of different thicknesses and materials by adjusting the cutting parameters of the laser, thereby significantly improving cutting efficiency.
The laser cutting process includes the following basic steps:
1. Laser generation: A high-energy laser beam is generated by a laser, usually a fiber laser, which has high optical efficiency and strong stability.
2. Laser focusing: The laser beam is focused into a small spot through a focusing mirror to increase the energy density and facilitate the melting or vaporization of the material.
3. Heat-affected zone heating: When the laser beam irradiates the PCD Blank surface, the material heats up rapidly under the influence of the powerful heat of the laser, and is cut after reaching the melting point.
4. Gas-assisted cutting: During the cutting process, blowing gas (such as oxygen, nitrogen) is usually used to blow away the molten material and keep the cutting area clean.
Advantages of laser cutting
Laser cutting has many significant advantages over traditional cutting methods:
1. High precision: Laser cutting can achieve high-precision cutting of less than 1 mm and is suitable for materials with complex shapes.
2. Non-contact processing: Since laser cutting does not require direct contact with the workpiece, mechanical damage and tool wear are reduced, thereby extending the service life of the workpiece and tools.
3. Processing flexibility: The cutting parameters of the laser cutting machine (such as laser power, cutting speed, etc.) can be flexibly adjusted to adapt to different materials and thicknesses, and have high adaptability.
Advantages of fiber laser cutting machine
After years of continuous innovation and optimization, TKD CO., Ltd brand fiber laser cutting machines have been widely used in global markets such as North America, the European Union, Southeast Asia, India, Russia and China. Its main advantages include:
• Low noise: The noise during laser processing is low, reducing noise pollution in the entire production environment.
• Small vibration: Since laser cutting is non-contact processing, the impact of vibration is almost non-existent, ensuring the processing stability of complex parts.
• Environmental protection: No harmful pollutants are produced during the cutting process, and the smoke and gas emissions are relatively small, helping to comply with environmental regulations.
• High processing efficiency: Laser cutting is extremely fast, which can significantly shorten the production cycle and improve manufacturing efficiency. The application of fiber laser cutting machines in production lines makes mass production possible.
Effect of process parameters on cutting quality
During the laser cutting process, multiple process parameters jointly affect the final cutting quality. The following are the core indicators that affect the quality of PCD Blank laser cutting:
1. Cutting seam width
The cutting slit width is one of the important indicators to evaluate the quality of laser cutting, which directly affects the surface quality and dimensional accuracy of the tool. The influencing factors of cutting slit width are as follows:
• Defocus: When the laser spot cannot be accurately focused on the workpiece surface, the transmission efficiency of laser energy will be significantly reduced. Larger negative defocus will reduce cutting accuracy, while positive defocus will quickly disperse the laser energy, resulting in unsatisfactory cutting results. Therefore, the best focusing position is the key to ensuring cutting quality.
• Pulse frequency: The pulse frequency directly affects the degree of overlap of light spots. The higher the pulse frequency, the energy density increases, and the cutting slit width decreases, improving the overall cutting accuracy.
• Laser power: The higher the laser power, the energy density of the laser beam also increases, thus affecting the control of the cutting slit width. Power needs to be chosen carefully to avoid wasting material due to excessive cutting kerf width.
2. Cutting surface quality
The surface roughness of the cutting surface is affected by many factors, including pulse frequency, defocus, laser power and cutting speed:
• Increasing the pulse frequency: Increasing the pulse frequency can increase the overlap of laser spots, reduce the energy of a single pulse, and improve the cutting quality. Higher frequency can effectively reduce cutting surface burrs.
• Laser power: Moderately increasing laser power can improve cutting stability and efficiency, but too high power may cause side burrs on the cutting surface, affecting the flatness and finish of the cutting surface. Therefore, the power needs to be carefully adjusted within the effective range.
3. Microcracks
Microcracks are one of the common defects during laser cutting. When the laser power is too high, the local heat load on the material surface will increase, and the concentration of thermal stress will cause the appearance of microcracks. Relevant factors include:
• Stress level: If the tensile stress is lower than the strength of the material, there should be no cracks during cutting. Therefore, stress control should be paid attention to when dealing with PCDs of different thicknesses and brands.
• Heat-affected zone: High laser power can accelerate material removal to form a good processing surface, but too high power will also expand the heat-affected zone, affecting crack generation and size control. Proper laser power selection and optimization of cutting speed are crucial.
4. Cutting speed
Cutting speed is another key process parameter that has a significant impact on cutting quality:
• Cutting speed is too fast: The energy of the laser beam may not be enough to fully melt the material, resulting in unsatisfactory cutting results. This condition is usually more noticeable when cutting thicker materials.
• Cutting speed is too slow: It may lead to a series of problems such as expansion of the heat-affected zone, material burning, and cutting angle deformation, thus affecting cutting quality and accuracy. Therefore, reasonable cutting speed selection can enhance the cutting stability of the material and ensure cutting quality.
As laser cutting technology becomes increasingly mature, PCD cutting has broad application prospects in the future. With the further development of laser technology, the following trends are expected to emerge:
1. Intelligent processing: Introducing artificial intelligence and machine learning technology to automatically adjust cutting parameters to optimize cutting effects and improve production efficiency and product quality.
2. Application of new materials: With the emergence of new composite materials, laser cutting will show greater adaptability and efficiency in the processing of these materials, promoting the development of material technology.
3. Green manufacturing: The environmentally friendly characteristics of laser cutting will promote its application in various industries and comply with global sustainable development goals.
Laser cutting technology provides an efficient and flexible solution for PCD Blank processing. By scientifically and rationally selecting laser cutting parameters, material waste can be effectively reduced and product quality improved. The key to ensuring the cutting effect is to appropriately adjust process parameters such as laser power, pulse frequency, defocus and cutting speed. With the continuous advancement and improvement of laser technology, laser cutting will continue to flourish in the field of PCD cutting, further promoting the advancement of high-performance material processing technology and the development of the industry.
