The rotation speed of the grinding and polishing disc is one of the key factors affecting the grinding and polishing effect. The higher the rotation speed, the stronger the grinding ability, but it also increases the possibility of a deformation layer on the sample surface. For some soft materials, such as aluminum alloys, pure aluminum and titanium alloys, too high a rotation speed may cause organizational changes, such as slip, twinning and other defects. Therefore, when selecting the rotation speed, it is necessary to make appropriate adjustments according to the material and hardness of the sample to ensure the best grinding and polishing effect.
Polishing pressure also has a significant effect on the grinding and polishing effect. Appropriate pressure can ensure that the grinding and polishing material is in full contact with the sample surface, thereby achieving effective grinding and polishing. However, too high pressure may cause scratches or deformation on the sample surface, affecting the final observation results. Therefore, during operation, it is necessary to reasonably set the polishing pressure according to the hardness of the sample and the characteristics of the polishing fabric.
The length of polishing time will also affect the grinding and polishing effect. Too short a polishing time may not completely remove the defects and impurities on the sample surface, while too long a polishing time may cause excessive wear on the sample surface and even produce grinding and polishing corrosion pits.
Therefore, when setting the polishing time, it is necessary to comprehensively consider the material, hardness and required polishing effect of the sample to ensure that the polishing time is neither too long nor too short.
The choice of polishing fabric also has an important influence on the grinding and polishing effect. Polishing fabrics of different materials have different hardness and wear resistance, and are suitable for samples of different materials. When rough polishing, you can choose a polishing fabric with large recovery and long fibers or nap to maintain a high polishing efficiency; while when fine polishing, you should choose a polishing fabric with shorter fibers or nap to obtain a smoother sample surface.
Polishing fluid is an indispensable part of the grinding and polishing process. Choosing a suitable polishing fluid can effectively improve the polishing effect. Commonly used polishing fluids include diamond polishing fluid and oxide polishing fluids such as aluminum oxide and silicon oxide. Diamond polishing fluid has a fast polishing rate and high efficiency, and is suitable for sample preparation of most metal materials; while for some non-ferrous alloys or low hardness materials, aluminum oxide, silicon oxide and other polishing fluids should be used for polishing. In addition, the amount of polishing liquid also needs to be reasonably controlled. Too much or too little will affect the polishing effect.
The wear of the grinding and polishing disc and polishing pad of the metallographic semi-automatic grinding and polishing machine will also affect the grinding and polishing effect. With the increase of use time, the grinding and polishing disc and polishing pad will gradually wear out, resulting in a decrease in the polishing effect. Therefore, it is necessary to regularly check and replace the severely worn grinding and polishing disc and polishing pad to ensure the stability and consistency of the polishing effect.
Although the metallographic semi-automatic grinding and polishing machine has a high degree of automation, the skill level of the operator still has a certain impact on the grinding and polishing effect. The operator needs to be familiar with the operating procedures and precautions of the equipment, and be able to adjust the grinding and polishing parameters according to the actual situation to ensure the best grinding and polishing effect. In addition, the operator also needs to have a certain knowledge of materials science to better understand the sample characteristics and grinding and polishing requirements.
