High-speed machining refers to the method of machining at a much higher speed than the conventional cutting speed and feed rate, and its speed is usually 5-8 times or more than the conventional machining. High-speed machining is an advanced manufacturing technology, which has significant advantages over conventional processing. This article will explain the high-speed machining.
What is High Speed Machining?
High Speed Machining (HSM) is an advanced manufacturing technique that utilizes high-speed rotating cutting tools and rapid movement of the workpiece to achieve fast and efficient machining processes. It is commonly applied to various materials including metals, plastics, and composite materials. The key to HSM lies in achieving faster and more precise machining by employing higher cutting speeds and feed rates, thereby enhancing production efficiency and part quality.
History of High Speed Machining
High Speed Machining technology emerged in the late 1960s and early 1970s, further popularized with the development of Computer Numerical Control (CNC) technology. Initially used primarily in the mold and die manufacturing sectors, advancements in tool materials, machine tool technology, and CAD/CAM software have expanded its applications across a wide range of manufacturing industries. Today, HSM is integral to modern manufacturing, prominently used in aerospace, automotive, medical equipment, and other critical sectors.
Characteristics of High Speed Machining
- By increasing the cutting speed and feed speed, the material removal rate can be significantly improved, for example, the cutting speed range of ultra-high speed cutting various materials has far exceeded the traditional processing, such as aluminum alloy has exceeded 1600m/min, cast iron is 1500m/min and so on.
- Due to the reduction of cutting force and the trend of cutting heat influence in the process of high-speed machining, the machining accuracy and surface quality of the workpiece are significantly improved. At the same time, due to the improvement of cutting speed, the heat taken away by the chips increases, which is conducive to reducing the thermal deformation and residual stress of the workpiece.
- High-speed machining technology has good machining performance for some difficult materials (such as titanium alloy, nickel-based alloy, etc.), and can solve the problems that are difficult to be solved by traditional processing methods.
Key Points of High Speed Machining
In high speed machining (HSM), several critical factors are essential to ensure successful and safe machining processes. Here are three main key points: rigidity, tool balancing, and appropriate clamping methods.
- Rigidity:
- Machine Tool Rigidity: High speed machining requires machine tools to have sufficient rigidity to minimize vibration and deformation. High rigidity enables better transmission of cutting forces, maintaining stability of the tool and workpiece.
- Workpiece Clamping: When securing the workpiece on the machine, it’s crucial that the clamping device provides adequate rigidity to prevent movement or vibration during machining.
- Tool Balancing:
- Dynamic Balancing of Tools: High-speed rotating tools must be dynamically balanced to avoid severe vibration and deterioration of machining quality. Tool balancing is typically performed using specialized equipment to ensure proper balance.
- Balance of Tooling Systems: This includes tool holders, cutting tools, and tool seats, where the balance of all components is critical to prevent excessive vibration and noise during high-speed operation.
- Appropriate Clamping Methods:
- Uniform Distribution of Clamping Force: When clamping the workpiece, it’s essential to ensure that the fixture or clamping system distributes clamping force evenly to prevent workpiece deformation or movement.
- Selection of Suitable Clamping Techniques: Depending on the geometric shape and material properties of the workpiece, choose appropriate clamping methods such as mechanical clamping, vacuum suction, or specialized fixtures.
High Speed Machining Tool Selection Tips
The selection of high speed machining tools is very important to ensure machining efficiency, accuracy and tool life. The following are some specific points about high-speed machining tool selection skills:
Tool geometry
Select the appropriate tool geometry based on the workpiece material, type of machining and machine conditions. For example, different types of cutting tools such as turning tools, milling cutters, and drills have their own characteristics in terms of the shape and Angle of their cutting edges. The parameters of cutting edge sharpness, front Angle and back Angle are considered. For example, in the high-speed processing of cast iron, if the use of carbide tools, the radius of the tool tip is about 0.2mm, and the back Angle is selected at about 12°, it can provide good cutting performance.
Material composition
Select tool materials with high hardness and high wear resistance to withstand the high cutting forces and high temperatures generated during high-speed cutting. For example, coating materials such as cemented carbide, cermet, non-metallic ceramics and CBN. Ensure that the tool material has good heat resistance and can withstand the high temperature environment during cutting.
Keep tools short
The vibration and centrifugal force generated by a shorter tool at high speed will be relatively small. This is because shorter tools are lighter and therefore easier to maintain stability at high speeds. The reduction of vibration and centrifugal force helps to reduce tool wear, extend tool life, and reduce machining errors.
In addition, shorter tools are also easier to control. This means that during the machining process, the operator can more easily adjust the position and Angle of the tool, resulting in more precise machining.
Use special tools
Specialized tools are designed according to the specific processing requirements, and they can better meet the specific processing requirements. For example, the milling cutter is suitable for the machining of flat surfaces and contours, the drill is suitable for drilling operations, and the turning tool is suitable for the machining of outer and inner circles. The use of specialized tools can increase processing efficiency and quality because their design is optimized for specific processing tasks.
High speed machine clamping mechanism
High-speed machine tool holding mechanism is a key component to ensure that the tool is stably fixed on the machine tool spindle when rotating at high speed. Select the high-speed clamping mechanism that matches the machine tool to ensure that the tool can be stably fixed on the machine tool spindle when rotating at high speed.
Balancing tool
It is a common practice to use a balancing machine to balance the action of the tool. By adjusting the weight distribution of the tool or using a balance block to balance the unbalance of the tool, the vibration and noise generated by the tool during high-speed rotation can be significantly reduced. This helps to improve machining accuracy and surface quality, as well as extend tool life.
Clean
Clean the cutting area regularly to remove impurities such as chips and oil to keep the cutting area clean. This helps reduce tool wear and machining errors. Clean and check the tool regularly to ensure that the tool is in good working condition. Check the wear of the tool, coating status, etc., timely replacement of severely worn tools.
High Speed Machining Technology
Trochoidal Machining
Trochoidal machining is a milling technique where the tool path is a series of circular arcs. This method allows for efficient cutting with reduced tool wear and improved chip evacuation. It is particularly effective in high speed machining to maintain consistent cutting forces and enhance surface finish.
Applications: Trochoidal machining is often used for roughing of difficult-to-cut materials like stainless steel and titanium alloys.
Radial Chip Thinning
Radial chip thinning refers to the phenomenon where the thickness of the chip is reduced due to the geometry of the cutter and the engagement of the tool with the workpiece. In high speed machining, this effect is utilized to increase feed rates without increasing cutting forces excessively, optimizing material removal rates.
Applications: Radial chip thinning is widely used in the machining of various metallic materials, especially where high precision and efficiency are required.
Side Steps
Side steps in machining involve moving the cutting tool sideways between successive passes to ensure an even distribution of tool wear and optimize surface finish. This technique is important in high speed machining to manage heat generation and maintain dimensional accuracy.
Applications: Side steps are commonly used in the machining of molds, cavities, and other complex-shaped workpieces.
Cornering
Cornering refers to the maneuvering of the cutting tool around sharp corners or edges of a workpiece during machining. In high speed machining, cornering techniques aim to minimize tool deflection and ensure consistent cutting performance while maintaining part geometry and surface quality.
Challenges: Machining corners and edges can be challenging due to the adverse cutting conditions that often occur in these areas.
Solutions: Optimizing tool paths, cutting parameters, and tool geometries can effectively improve cornering results, enhancing accuracy and surface quality.
Smart Machining
Smart machining involves the integration of advanced technologies such as real-time monitoring, adaptive control systems, and data analytics to optimize machining processes. This approach ensures efficient use of resources, enhances productivity, and improves overall machining quality in high speed machining applications.
Plunge Roughing
Plunge roughing is a machining strategy where the cutting tool plunges directly into the workpiece material, removing large volumes of material quickly. In high speed machining, plunge roughing techniques are optimized to reduce machining time and improve efficiency while minimizing tool wear and heat generation.
Challenges: Plunge roughing can be challenging due to difficulties in supplying coolant and evacuating chips in deep holes.
Solutions: Special cutting tools, optimized cutting parameters, and machining strategies can help improve the cutting conditions in plunge roughing, enhancing efficiency and quality.
Advantages of High Speed Machining
- Improved Production Efficiency: High speed machining utilizes higher cutting speeds and feed rates, significantly reducing machining cycles. This leads to faster part production and increased machine tool utilization, thereby enhancing overall productivity.
- Cost Reduction: Shorter machining times and higher machining efficiency lower production costs. By reducing machining cycles and saving energy, HSM can substantially decrease manufacturing costs per part.
- Enhanced Precision and Surface Quality: HSM enables more precise machining tasks to be completed in shorter times, reducing potential errors introduced during machining. Additionally, high-speed cutting often produces smoother and finer surface finishes, minimizing or eliminating the need for subsequent surface treatments.
- Extended Tool Life: Despite higher cutting forces and heat generation, optimized machining conditions in HSM can significantly prolong tool life. Advanced tool materials and coatings, coupled with effective tool management and maintenance strategies, maximize tool longevity and performance.
- Suitability for Complex Parts and Materials:HSM is applicable to a wide range of materials including metal alloys, titanium alloys, composites, and plastics. It is particularly effective for machining complex geometries and intricate structures found in aerospace components, medical devices, and automotive parts.
How to Optimize Feed and Speed in High Speed Machining?
Optimizing feed and speed in high-speed machining is a comprehensive process, and the following are some specific optimization methods:
Machine and spindle
- Choose a highly rigid and powerful machine tool, because high-speed machining requires the machine tool and control device to meet the requirements of high feed speed and high cutting speed.
- High speed spindle technology is introduced to reduce tool wear and improve machining surface quality by increasing spindle speed.
- Optimize spindle design, including selecting the right bearing type and specification, as well as optimizing spindle geometry, material selection and machining process to improve spindle rigidity and stability.
Materials and tools
- Select the appropriate tool materials according to the type of processing materials, such as diamond tools, cubic boron nitride tools, etc., these tools are suitable for different mold materials and working conditions.
- Choose the right blade grade to ensure that the blade can handle the workload, reducing tool changes, scrap and rework.
- Consider using a triangular blade because they provide a lower lead Angle and can produce thinner chips, requiring a higher feed rate to maintain the appropriate chip thickness.
- Select the appropriate tool geometry (such as tool Angle and blade design) and coating technology (such as TiAlN or TiCN coating) to improve the cutting performance and life of the tool.
Job holdings and types of instruments
- Use the appropriate fixture and tool holding system to ensure that the tool is stable and accurate during processing.
- Consider using high-speed tool systems such as HSK, which have high accuracy and stiffness to reduce tool vibration and displacement during high-speed rotation.
- Select the appropriate tool type according to the machining needs, such as end milling cutter, ball cutter or T-cutter, etc., according to the geometry of the workpiece and processing requirements to select the most appropriate tool type and size.
Depth of cutting
- In high-speed machining, using a smaller cutting depth (usually about 10% of the diameter of the tool) can reduce the cutting force, reduce the cutting temperature, and thus improve the machining quality.
- According to the requirements of the specific workpiece and tool, the cutting depth is adjusted to find the balance between the best processing efficiency and quality.
Calculate and adjust chip load
- In high speed machining, chip load is one of the key factors affecting machining quality and tool life. Therefore, it is necessary to accurately calculate and adjust the chip load.
- When programming, pay attention to the smooth transition of the tool path and avoid sharply changing paths to reduce the fluctuation of the cutting load.
- For steep, corner and other positions, the speed should be reduced reasonably to avoid overload and damage to the tool.
Programming optimization
Optimize the cutting path through appropriate programming to avoid unrealistic demands on the tool.
In programming, smooth transition and auxiliary trajectory transition are used to deal with the situation that two adjacent tool paths are not smooth.
In the programming, the appropriate adjustment ratio is set, and the cutting parameters are optimized reasonably to keep the reasonable load of the high-speed machine tool.
Process optimization
- Choose high-speed cutting, large feed, high efficiency processing mode to significantly improve the processing efficiency.
- According to different workpiece materials, the appropriate cutting process plan is adopted, including the optimization of cutting speed, feed rate, cutting depth and other parameters.
High Speed CNC Machining Materials
Metallic material
- Steel: Steel is one of the main materials for CNC machine tool processing, because of its moderate hardness, easy processing and widely used in machinery manufacturing, automobile manufacturing, aerospace and other fields.
- Aluminum: Aluminum is a high-strength, lightweight, corrosion-resistant metal material, often used in aviation, automotive, electronics, construction and other fields. CNC machine tool processing aluminum can improve the quality of parts and production efficiency.
- Copper: Copper has good ductility and electrical conductivity, and is often used in electrical appliance manufacturing, pipe manufacturing and other fields. CNC machine tools can efficiently process various copper parts.
- Alloy materials: Alloy materials such as aluminum alloy, stainless steel, titanium alloy, etc., with high strength, heat resistance, corrosion resistance and other advantages, suitable for aviation, aerospace, energy, chemical industry and other fields. CNC machine tools can accurately process various alloy materials.
Non-metallic material
- Plastic: Plastic is a lightweight, corrosion resistant, heat insulation, insulation of non-metallic materials, widely used in electronics, machinery, automotive, construction and other fields. CNC machine tools can accurately process all kinds of plastic products.
- Rubber: Rubber has the characteristics of good elasticity, strong wear resistance, good cold resistance, etc., often used in automobile manufacturing, machinery manufacturing, rubber products and other fields. CNC machine tools can efficiently process all kinds of rubber products.
Factors to Consider in Selecting High Speed Machining Materials
In the selection of high-speed CNC machining materials, the main factors to consider include the hardness of the material, processing performance, thermal conductivity, cost, working environment requirements and its matching with tools and machine tools. Hardness affects the cutting speed and tool life, machining performance determines the degree of ease of cutting, thermal conductivity affects the cutting temperature and tool wear, cost is an economic consideration, working environment requirements determine the applicability of materials. In addition, it is necessary to ensure that the selected materials can be well matched with existing tools and machine tools to achieve efficient, high-quality processing.
Machines for High Speed Machining
In high speed machining (HSM) operations, choosing the right machine is crucial. High performance machines such as Mikron Mill-S-400-U and Matsuura LX-160 are designed specifically for HSM with outstanding high-speed machining capabilities, high precision and surface finish. These machines use intelligent temperature management systems and optimized rigid construction to ensure thermal stability and high precision during processing. By choosing the right HSM operation strategy, these machines are able to process a wide range of materials efficiently and accurately, resulting in high-quality, precise parts.
Select Machine Requirements for High Speed Machining
When choosing a machine for high-speed processing, several key factors need to be considered to ensure smooth processing and efficient output.
- Advanced spindle technology: High-speed machining requires spindle with high speed, high rigidity and high precision. The maximum speed of the spindle needs to reach tens of thousands of RPM or more to meet the needs of ultra-high-speed processing.
- Robust construction: High-speed machining machines require a robust structure to withstand the vibrations and shocks generated during high-speed machining. Key components such as the bed body, spindle and guide rails require high-strength materials and advanced manufacturing processes to ensure the overall rigidity and stability of the equipment.
- Efficient chip removal system: The efficient chip removal system can discharge the chips generated in the processing process in time to avoid the accumulation of chips affecting the processing quality and machine performance.
- Spindle drive speed regulating device: The spindle drive speed regulating device needs to have a wide speed regulating range and stable speed regulating performance to meet the needs of different materials and processing conditions. Because of its wide speed range and stable output characteristics, DC spindle drive has become a common choice in high-speed machining.
- Still water and fluid power systems (usually not directly related to high-speed machining machines, but may be relevant if special applications or cooling requirements are involved) : In some special applications, such as high-precision cooling or special lubrication, still water and fluid power systems can play a key role. These systems need to ensure a stable fluid supply and precise control to meet the specific needs of the process.
- HSK spindle taper: HSK spindle taper is a high precision, high rigidity spindle interface standard, suitable for high-speed machining machines.
- High-speed machine tool clamping mechanism: high-speed machine tool clamping mechanism needs to have the characteristics of high precision, high rigidity and fast response to ensure the stability and accuracy of the workpiece during processing.
Configuration Tips for CNC High-Speed Machining Centers
Configuration tips for CNC high-speed machining emphasize the importance of high-speed spindles, efficient cutting tools, and advanced CNC systems. High-speed spindles should possess high rotational speed and rigidity, such as direct-drive spindles and electric spindles. Tools need to be suitable for high-speed cutting, like polycrystalline diamond and cubic boron nitride, with a focus on dynamic balance in tool structures.
High-speed CNC systems require robust data processing capabilities and functional attributes, preferably with 32-bit or 64-bit processors. During programming, special attention should be paid to the smoothness of cutting paths, avoiding sudden changes in direction and overcutting. CAM systems should be utilized to optimize tool paths, ensuring machining efficiency and accuracy. Brands like GF+ excel in high-speed machining, and strategies such as gradually entering and exiting the cutting layer and maintaining stable cutting parameters are recommended.
Application of High Speed Machining
High Speed Machining (HSM) has a wide range of practical applications in modern manufacturing, and its technologies and methods are used in multiple industries and applications to improve production efficiency, processing accuracy and material utilization. The following are several typical cases of high-speed machining in practical applications:
- Aerospace Industry: The aerospace industry requires high-precision, lightweight parts, such as aircraft structures, engine parts and aerospace equipment.
- Automotive manufacturing: High-speed machining technology is used to process key components such as engine parts, transmission parts and brake system components to improve the accuracy and reliability of parts.
- Medical device manufacturing: Medical device manufacturing requires parts with high precision and excellent surface quality, such as artificial joints, surgical tools and implants. High-speed machining technology enables precision machining of complex geometrics and maintains medical-grade cleanliness and smoothness of parts.
- Energy and Marine industries: In the energy industry, high-speed machining is used to manufacture high-performance bearings, turbomachinery and turbomachino-generator components to improve energy conversion efficiency and reliability.
- Electronic and communication equipment manufacturing: Used to process micro electronic components, PCB boards and precision optical components to improve the performance and reliability of equipment.
Difference Between Traditional Milling and High-Speed Machining
| Feature | Traditional Milling | High-Speed Machining (HSM) |
|---|---|---|
| Cutting Speed | Low (typically < 200 m/min) | High (typically > 200 m/min, up to several thousand m/min) |
| Feed Rate | Low | High |
| Cutting Depth | Generally large | Small |
| Surface Quality | Average, often requires post-processing | High, often requires little to no post-processing |
| Tool Life | Limited, wears quickly | Longer (under optimal conditions) |
| Material Removal Rate | Low | High |
| Heat Management | Heat concentrates, can cause workpiece deformation | Good heat dissipation, reduces workpiece deformation |
| Equipment Requirements | Standard machine tools | High-rigidity, high-precision, and high-speed machines |
| Workpiece Clamping | Standard clamping systems | High-rigidity clamping systems to reduce vibration |
| Applicable Materials | Common metals like steel, cast iron | Various materials, including hard-to-machine materials like titanium and nickel alloys |
| Machining Time | Long | Short |
| Production Efficiency | Low | High |
| Investment Cost | Relatively low | High (due to equipment and tooling requirements) |
| Vibration Control | Affected by vibrations, may impact surface quality and precision | Better vibration control, higher surface quality and precision |
What are the Challenges of High-Speed Machining?
The main challenges for high-speed machining include tool wear due to cutting heat, tool vibration and resonance, the need for high-performance tool materials, the lack of suitable machining parameter selection options, and the need for machine tools with excellent dynamic performance and efficient cooling and lubrication systems. These challenges need to be considered together to ensure stability and efficiency in high-speed machining. In the face of these challenges, it is necessary to consider multiple aspects such as material selection, cutting parameter optimization, machine tool performance improvement and cooling and lubrication system improvement to ensure the stability and efficiency of high-speed machining.
High-Speed Machining with BOYI
Our cutting-edge machines are engineered for high-rigidity, high-precision, and high-speed operations, ensuring optimal performance across a wide range of materials, from lightweight aluminum alloys to robust titanium and nickel alloys. With BOYI, you can effortlessly tackle complex geometries and intricate designs, delivering exceptional quality and consistency every time.
Elevate your manufacturing prowess and stay ahead of the competition with BOYI High-Speed Machining solutions. Discover the power of innovation and precision today. Contact us to learn more and schedule a demonstration.
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FAQ
High-speed machining offers several benefits, including improved surface finish, shorter cycle times, and the ability to machine hard materials. The high cutting speeds reduce the cutting forces, leading to less tool wear and improved dimensional accuracy.
Selecting the right cutting tool for high-speed machining involves considering factors such as tool material, geometry, coating, and balance. Tools should be designed specifically for high-speed applications and able to withstand the high temperatures and cutting forces.
Catalog: CNC Machining Guide
This article was written by engineers from the BOYI team. Fuquan Chen is a professional engineer and technical expert with 20 years of experience in rapid prototyping, mold manufacturing, and plastic injection molding.
