In modern manufacturing, polishing processing is one of the important processes to improve the surface quality, accuracy, and aesthetics of workpieces. During the polishing process, abrasive, as a key processing material, directly affects processing efficiency, surface roughness, and the performance of the final product. Therefore, how to scientifically and reasonably select abrasive particle size is the key to ensuring the polishing effect.



One, Basic concept of abrasive particle size



Abrasive particle size refers to the size of abrasive particles, which is usually expressed in mesh (Mesh) or micrometers (μm). Common abrasives such as diamond, silicon carbide, and alumina have particle size ranges from several micrometers to sub-micron levels. Generally, the larger the particle size, the stronger the abrasive force and the higher the removal efficiency; the smaller the particle size, the lower the surface roughness, and the better the precision processing effect.



Two, Factors affecting the selection of abrasive particle size



1. Initial surface condition

If the workpiece surface has many scratches, oxidation layers, or burrs, abrasive with larger particle sizes should be selected for preliminary grinding to improve removal efficiency. For surfaces that are already relatively smooth, finer abrasive should be selected for fine polishing.



2. Balancing processing efficiency and surface quality

During the production process, it is usually desired to achieve ideal surface quality in a short period of time. At this time, it is necessary to select an appropriate particle size according to the processing stage. For example, in the coarse polishing stage, abrasive with mesh sizes of 120-240 can be used, while for precision polishing, W20 (about 15μm) or even finer abrasive can be used.



3. Hardness and toughness of workpiece materials

Different materials react differently to abrasives. Hard materials such as ceramics and hard alloys are suitable for abrasives with high hardness and moderate particle size; while soft metals such as copper and aluminum require finer abrasives to avoid scratching the surface or causing excessive deformation.



4. Types and parameters of polishing equipment

The speed, pressure, and working mode (such as vibration, rotation, ultrasonic, etc.) of the polishing machine will also affect the selection of abrasive. High-speed rotating equipment can use finer particle sizes to improve surface quality, while low-speed heavy-pressure equipment is more suitable for coarse particle sizes to enhance removal efficiency.



Three, Practical suggestions for the selection of abrasive particle size



- Coarse polishing stage: It is suggested to use abrasive with particle sizes above 20μm (such as 36 mesh-120 mesh) for rapid removal of surface defects.

- Semi-precision polishing stage: Abrasive with particle sizes of 10-20μm (such as 180 mesh-400 mesh) should be selected to gradually reduce surface roughness.

- Precision polishing stage: It is recommended to use fine abrasive with particle sizes of 1-10μm (such as W20-W5) to achieve mirror-like effects or ultra-smooth surfaces.



In addition, in actual operation, a multi-stage gradual transition method can be adopted, that is, from coarse to fine, step-by-step polishing, which can improve efficiency and ensure surface quality.



Four, Conclusion



The selection of abrasive particle size is an important factor affecting the quality and efficiency of polishing. Reasonable particle size can not only improve processing efficiency but also effectively control costs, extend tool life, and enhance product competitiveness. Therefore, in practical applications, it is necessary to comprehensively consider the material characteristics of the workpiece, processing requirements, and equipment conditions, flexibly adjust the abrasive particle size, and thus achieve efficient and high-quality polishing processing.