In the CNC machining industry, there are many ways to process parts, and grinding is one of the most typical processes. Many factories use this process to remove edge materials or create smooth surfaces. If you want to know whether grinding can improve the quality of your products, then read on! I believe you can learn everything about it.
What is Grinding?
Grinding is a precision machining process that requires the use of abrasive wheels as cutting tools. The rotary grinding wheel is made of many hard abrasive particles, such as: alumina, silicon carbide, cubic boron nitride CBN, diamond, etc.
During the grinding process the grinding wheel will run at high speed. When it comes into contact with the workpiece, the workpiece material will be removed to achieve the required shape and size. This process is often used to achieve strict tolerances, excellent surface quality, and specific shapes. At the same time, you need to know that grinding is very suitable for hard materials, and the actual effect will be compared with other processes.
Types Of Grinding Process
1. Surface Grinding
Surface grinding is the basic grinding process that uses the periphery of the grinding wheel or the end to finish the surface of the workpiece. This processing technology can obtain high planeness and parallelism, and is often the finishing of parts after heat treatment. During the process, the end face of the grinding wheel will come into contact with the workpiece in large areas, and you must also pay attention to controlling heat and deformation to complete the entire processing process.
2. Cylindrical Grinding
Cylindrical grinding is mainly used in rotary bodies, such as large shafts, sleeves, pins, etc., which can ensure that the diameter, roundness, cylindricality and surface roughness of these parts meet customer requirements. During the process, the workpiece is supported and rotated in a tip or chuck, while the grinding wheel does the cutting and longitudinal passes, gradually grinding the final product according to your program settings.
3. Internal Grinding
Internal grinding is used in the finishing holes and the inner surface of the sleeve. Give some product examples, such as bearing inner ring, hydraulic valve body mating hole, gear inner hole, fuel injector seat hole, etc. Through this process, the aperture accuracy, roundness, coaxiality and surface functional integrity of these products can be significantly improved. However, compared with external grinding, internal grinding wheels have poor system rigidity and heat dissipation due to their small diameter and long overhang, so they need to use high rotation speed and small single cutting depth to grind workpieces.
Centerless Grinding
Centerless grinding is a very practical grinding method for factories. It supports high-efficiency batch processing and is very easy to achieve automation. Does it sound very suitable for your wishes?
This process is suitable for a large number of small and medium-diameter shaft pins, needles, ferrules and other products. Since centerless grinding does not rely on the central hole or chuck of the workpiece, the stable support triangle formed by high-speed grinding wheels, low-speed adjustable guide wheels (speed control wheels) and support pallets can achieve efficient outer circumferential processing of medium and large products.
1. Form / Profile Grinding
Forming (contour) grinding is very suitable for making parts of complex geometric models, such as cams, scroll grooves, and precision mold cavity parts. It has two processing methods. One is to use a diamond roller or other trimming tool to make the surface of the grinding wheel into a reverse shape of the required contour of the workpiece. Then, aim the grinding wheel at the workpiece and slowly cut it in, and then you can grind out the contour at one time. The second type is that the grinding wheel grinds the part profile along the curve under the command of the CNC program. At the same time, the CNC system will control multiple axes so that the grinding wheel can rotate while trajectory, thereby gradually grinding the material off.
2. Thread Grinding
Thread grinding is mainly used for high-precision and high-hardness parts, such as ball screws, gauge threads, aviation fasteners, valve sealing threads, etc. According to the process path, there are also two types. The first is the forming method, which means that the tooth shape of the grinding wheel is consistent with the side profile of the thread, and the workpiece will be cut into one or more times to complete the production. The second method is the expansion method, which is to use the spiral movement of the grinding wheel to rotate synchronously with the workpiece to generate a section, similar to the development of the hobbing.
3. Gear Grinding
Gear grinding is the core method of hard tooth surface finishing, which can greatly improve the gear’s tooth shape, tooth direction and pitch accuracy. It is also mainly divided into two processing methods: forming method and continuous expansion method. The first is to match the tooth shape of the grinding wheel and grind each tooth and grind it, which is very suitable for small batch production or special tooth shape gear parts. The second type is to use threaded grinding wheels or grinding worms to combine movement with the gear workpiece. During this period, the grinding wheel will rotate at a high speed with the grinded gear at an accurate synchronous ratio, and will remain in a constant meshing state during the entire grinding stroke, thereby completing the production of parts. This method is very efficient, so it is very moderate to mass production.
4. Creep-feed Grinding
The last type is deep cutting and slow-moving grinding. This process is relatively more precise and complex. It achieves a millimeter-level large-cut depth through a single or a few strokes. It is naturally used in precision components such as aircraft engine turbine tongue and groove, difficult-to-process alloys (nickel-based, titanium alloys). Its main features are large cutting depth (ap can be 2–6 mm, locally even 20+ mm), extremely low workpiece feed speed (vf only a few mm/s), and high rigidity.
It is worth noting that deep and slow-moving grinding can complete product forming at one time, reducing multiple processes.
Grinding Process Steps
After talking about so many grinding processes, I will introduce you to the specific operation process of the grinding process.
1. Preparations
First of all, choose the right abrasive tool based on workpiece material and the required surface quality. Before all work begins, you should also pay attention to ensuring that the grinder and related equipment are in good condition and check whether the grinding wheel is intact.
2. Workpiece Clamping
Then you need to choose the right fixture based on the shape and size of the workpiece, and also securely secure the workpiece to prevent the workpiece from moving during grinding.
3. Set Grinding Parameters
Next, you need to set the appropriate spindle speed according to the material and abrasive type, and pay attention to adjusting the grinding feed speed to ensure grinding efficiency and surface quality.
4. Grinding Operation
At this point, the grinding operation is officially started. After starting the equipment, you need to contact the abrasive tool to the surface of the workpiece, and the grinding machine will complete the grinding of the entire workpiece according to the setting. During the grinding process, you must also pay attention to checking the grinding status regularly to ensure that there are no abnormalities.
5. Cooling And Lubrication
Similarly, during the grinding process, you should pay attention to using coolant to reduce the temperature and prevent both the workpiece and the abrasive tool from overheating. It is also necessary to ensure that the grinding area is sufficiently lubricated, reduce wear of parts and improve surface quality.
6. Grinding Completion
After the grinding process is completed, you can stop the working equipment and remove the workpiece. After that, check the surface quality of the grinded parts to ensure that they can meet the set requirements.
7. Post-Processing
This last step is also very important, which is to clean the surface of the workpiece and remove the residue generated during the grinding process. And if it is convenient, my suggestion is to record the grinding parameters and results for subsequent analysis and improvement.
Areas of Application of Grinding
Nowadays, grinding has been applied in many industries. If you want to know which industries there are, then let me introduce them one by one.
1. Mechanical Manufacturing
In the precision machining of mechanical parts, grinding can improve the dimensional accuracy and surface finish of parts, such as shafts, gears and bearings, etc.
2. Automotive Industry
Grinding can be used to process engine components, transmission parts and brake system components to ensure their accuracy and wear resistance.
3. Aerospace
In the aerospace field, grinding is used to manufacture high-precision and high-strength components, such as turbine blades and fuselage structural parts.
4. Mold Making
Grinding processing can manufacture and trim molds to ensure the accuracy and surface quality of the mold, thereby improving the quality of the molded product.
5. Electronics Industry
Grinding can be used to make precision electronic components and circuit boards to ensure their size and surface finish meet customer requirements.
6. Medical Devices
In the medical machinery industry, grinding can be used to process surgical instruments and implants to ensure the safety and accuracy of these medical devices.
7. Tool Making
Grinding supports the manufacture of a variety of cutting tools, such as drills, milling cutters and tools, ensuring their sharpness and durability.
8. Metalworking
During metalworking, grinding can remove defects and irregularities on the metal surface, thereby improving surface quality.
9. Ceramics And Glass Machining
Grinding can actually be used for the processing of ceramics and glass materials, thereby enabling cutting and polishing of complex shapes.
Advantages of Grinding
Since there are so many parts suitable for grinding, what are their advantages? I will tell you here.
1. High Precision And Smooth Surfaces
Grinding enables very high dimensional accuracy and surface finish, suitable for parts requiring strict tolerances.
2. Wide Range Of Applications
It is suitable for many materials, including metals, ceramics, plastics, etc., and has strong adaptability.
3. Minimal Material Removal
During the grinding process, the amount of material removed is very small, so it is very suitable for finishing and reduces material waste.
4. Enhanced Hardness
Grinding enhances the hardness of the material’s surface, thereby improving its wear resistance and service life.
5. Complex Shape Machining
Grinding can process workpieces of complex shapes such as gears, bearings and molds.
6. Minimal Heat Affect
The grinding process produces relatively little heat, which greatly reduces the heat impact on the workpiece and reduces the risk of deformation.
7. High Automation
Grinding equipment can achieve high automation, greatly improving production efficiency.
8. Suitable For Mass Production
Grinding processing can maintain consistent processing efficiency and product quality, so it is very suitable for mass production.
9. Improved Material Properties
You can improve the microstructure of the material and improve its physical and chemical properties through grinding.
Disadvantages of Grinding
The advantages have already been said, so what are the disadvantages? The following will explain it to you.
1. Higher Costs
Grinding equipment and abrasive tools are usually costly, especially high-precision grinders and specialty grinders.
2. Slower Processing Speeds
Compared with other processing methods (such as turning and milling), the removal rate of grinding is lower, so its processing speed is relatively slow.
3. Tool Wear
The abrasive tool will wear during use, so it needs to be replaced regularly, which also increases the cost.
4. Generate Dust And Waste Material
A large amount of dust and waste will be generated during the grinding process, which needs to be effectively eliminated and processed.
5. Unsuitable For Large Workpieces
A large amount of dust and waste will be generated during the grinding process, which needs to be effectively eliminated and processed.
6. High Technical Requirements For Operation
The grinding process requires high technical requirements for operators, which requires them to have proficient skills and experience.
Purpose Of Grinding
Well, I have said so much, so what are the purposes we use grinding? The answer will be told below.
1. Improve Dimensional Accuracy
Grinding can achieve very high dimensional accuracy to ensure that the workpiece meets design requirements and tolerance standards.
2. Improve Surface Finish
Through grinding, the surface finish of the workpiece can be significantly improved, and the appearance and performance of the product can be improved.
3. Remove Material Defects
Grinding can remove defects on the surface of the workpiece, such as scratches, oxide layers, etc., thereby improving the overall quality.
4. Enhance Hardness And Wear Resistance
Grinding can improve its hardness and wear resistance and extend service life by machining the surface of the workpiece.
5. Shape And Size Trim
Grinding allows fine shape and size trimming of workpieces to meet specific functional needs.
6. Process Complex Shapes
Grinding is suitable for machining workpieces of complex geometric shapes such as gears, molds and precision parts.
7. Improve material performance
Grinding can also improve the microstructure of materials and improve their physical and chemical properties, such as strength and toughness.
8. Reprocessing
Grinding can remachines and repair old parts to restore their original performance and functionality.
9. Achieve efficient production
Grinding can achieve mass production, provide consistent product processing quality, and greatly improve production efficiency.
In Conclusion
In short, grinding can be said to be a very important part of the processing technology, and can provide you with high precision, high efficiency and high quality production, thereby achieving valuable returns. As for our DSR company, we can also provide you with such excellent services. we believe that you will be very satisfied after cooperating with us!
FAQ
Q1: What is the difference between wet and dry grinding？
A: The difference between the two grinding methods you asked is whether or not to use liquid media.
During wet grinding, the grinding material is mixed with water or other liquids, which can reduce grinding temperature, reduce the wear of the abrasive, and also improve the surface finish and machining accuracy of the part. In addition, the liquid can help remove debris generated during the grinding process.
Dry grinding, as the name suggests, is processed without liquid and is usually suitable for certain specific materials or processes. Higher temperatures and wear are generated during work, but in some cases it can increase efficiency and processing speed.
So ultimately, you have to choose wet or dry grinding, which usually depends on the characteristics of the processed material, the required surface quality, and the production efficiency requirements.
Q2: What is the role of a grinding wheel in the grinding process?
A: What you need to understand is that the grinding wheel plays a crucial role throughout the grinding process. Firstly, it removes the workpiece material through the cutting of abrasive particles, forming the required size and surface finish. Secondly, the grinding wheels provide cutting force, stability and support, allowing the workpiece to be well positioned and fixed. Then, during wet grinding, the grinding wheel will also be combined with the coolant to help reduce the temperature of the workpiece and reduce the heat impact. At the same time, the design and material of the grinding wheel will directly affect the processing efficiency and economy, so a reasonable selection of grinding wheel can improve production efficiency and reduce production costs.
