In the modern process of mechanical manufacturing, grinding and machining is a high-precision cutting process, widely used in situations with high requirements for the surface quality of parts. Among them, surface roughness is one of the important indicators for measuring the quality of grinding and machining. Excessive surface roughness not only affects the appearance and performance of the parts but may also reduce their fatigue strength and wear resistance. Therefore, how to effectively control the surface roughness in the grinding and machining process has become a key link in improving product quality.



The causes of surface roughness



During the grinding process, the surface roughness is mainly caused by the following factors:



1. Abrasive cutting action: The various abrasive grains on the surface of the abrasive wheel cut, squeeze, and rub the workpiece at different cutting depths and angles, causing irregular wave peaks and troughs on the surface.

2. Abrasive wear and dulling: As the grinding process progresses, the abrasive grains in the abrasive wheel gradually wear, break, or become dull, leading to a decrease in cutting ability and thus deteriorating the surface quality.

3. Vibration and instability: Insufficient rigidity of the machine tool, loose fixture, and unbalanced workpiece and other factors can cause vibration, exacerbating the formation of surface roughness.

4. Cooling and lubrication conditions: Insufficient cooling fluid or poor lubrication will cause the temperature in the grinding zone to rise, leading to thermal deformation of the workpiece and clogging of the abrasive wheel, affecting the surface quality.

5. Inappropriate selection of processing parameters: Inappropriate selection of parameters such as grinding speed, feed rate, and abrasive grain size will directly affect the size of the surface roughness.



Section 2: Key Measures for Controlling Surface Roughness



To effectively control the surface roughness of grinding processing, attention should be paid to the following aspects:



# 1. Reasonably Selecting the Abrasive Wheel



The type, grain size, bond, and hardness of the abrasive wheel directly determine its cutting performance. Generally, a finer grain size, moderate hardness of the abrasive wheel, and a suitable bond are more conducive to achieving a smaller surface roughness. For example, fine-grained abrasive wheels (such as WAF, WA60K) with resin bonds can be selected for precision grinding.



# 2. Optimizing Grinding Parameters



- Grinding Speed: Increasing the linear speed of the abrasive wheel helps to reduce the surface roughness, but excessive speed may cause vibration, and it is necessary to choose rationally according to the machine tool performance.

- Feed Rate: Reducing the longitudinal and transverse feed rates can reduce the cutting depth and improve the surface quality.

- Workpiece Speed: Appropriately increasing the workpiece speed helps to achieve uniform cutting and reduce undulations.



# 3. Enhancing Cooling and Lubrication



Using sufficient cooling fluid can not only reduce the grinding temperature and prevent the workpiece from burning, but also effectively wash away the metal chips adhering to the surface of the abrasive wheel, maintain the sharpness of the abrasive wheel, and thus improve the surface roughness.



# 4. Improving the Rigidity of the Machine Tool and Fixture



Ensure that the key components such as the machine tool spindle, guide rail, and worktable have good rigidity and precision to avoid surface quality degradation caused by vibration or elastic deformation. At the same time, the workpiece clamping should be firm to avoid loosening causing irregular vibration.



# 5. Regularly Dressing the Abrasive Wheel



Regularly dressing the abrasive wheel with a diamond roller or a single-point diamond pen to restore its sharpness and flatness is an important means to maintain good surface quality. Reasonable dressing feed rate and frequency can significantly improve the condition of the grinding surface.



Conclusion



Surface roughness, as an important technical indicator for measuring the quality of grinding processing, is influenced by various factors such as abrasive wheel characteristics, processing parameters, equipment status, and process conditions. Only through scientific selection, reasonable adjustment, precise operation, and regular maintenance can the surface roughness be effectively controlled and the processing accuracy and performance of the parts be improved. In the future, with the development of intelligent manufacturing and precision processing technology, the surface quality of grinding processing is expected to achieve a higher level of control and optimization.