The use of metallographic sandpaper is believed to be a basic skill for every metallographic engineer, who can share their own set of usage methods and techniques, so that ordinary metallographic sandpaper can also play its due role. However, there is no end to learning, so the pulse detection metallographist will share with friends their experience in using it. When encountering a user's metallographic white, teach them how to use metallographic sandpaper correctly through their hands until they learn it!

Grinding with metallographic sandpaper is a commonly used method for preparing metallographic samples, with the aim of removing damage and deformation layers generated during the cutting process and making sufficient technical preparations for the polishing process of the sample surface. The grinding effect of metallographic sandpaper directly affects the quality of sample preparation. Therefore, the correct use of metallographic sandpaper is the guarantee of sample preparation quality. The following methods are for friends to learn from.


Replace old metallographic sandpaper in a timely manner


In the process of metallographic sample preparation, the amount of metallographic sandpaper used is relatively large, and saving use is an effective way to economically prepare samples. However, if a piece of sandpaper is overused and not replaced in a timely manner, it will cause secondary damage to the sample preparation, but it will be labor-intensive and time-consuming, and even lead to sample failure. How to timing the replacement of metallographic sandpaper? Judgment is the key!

Look at a set of pictures. The above picture shows a cross-sectional comparison between the new and old metallographic sandpaper. The abrasive particles of the new sandpaper are upright, with clear edges and sharp edges; Worn and worn metallographic sandpaper, the abrasive particles are basically ground flat, and the abrasive particles are almost buried in the bonding layer, making them sharp and dull in comparison. The result is that the grinding ability of old metallographic sandpaper significantly deteriorates. Continuing to use it and rubbing it directly onto the paper base will result in good reflectivity on the surface of the sample, creating an illusion of a mirror like effect on the surface, while the actual scratches are deeper. As shown in the following figure:

It is obvious that the new sandpaper has clearer grinding marks and a distinct three-dimensional morphology. On the right side, the sandpaper grinding marks appear relatively smooth, with a blurry surface due to the planarization of the sample surface grinding marks and good reflectivity. However, in reality, the depth of the deformation layer is deeper, which is the result of excessive use of metallographic sandpaper. Therefore, when metallographic sandpaper is used to this extent, it is necessary to replace it with a new one in a timely manner.


Each grade of metallographic sandpaper should be thoroughly rinsed after grinding

Thorough flushing should be done from two aspects: used sandpaper and ground samples should be thoroughly rinsed. To prepare a metallographic sample, 2-3 different grades of metallographic sandpaper are usually used. The key point is to ensure that after grinding with each grade of metallographic sandpaper, the sample is thoroughly and thoroughly rinsed to avoid cross contamination caused by residual abrasive particles in the next grade sandpaper grinding, causing secondary scratches on the sample surface, affecting the quality of sample surface preparation, and avoiding rework. Similarly, the sandpaper that has just been used should also be thoroughly rinsed to remove impurities and loose abrasive particles attached to the surface, and then drained to prepare for the next use.


All the above methods are the Committed step for the correct use of metallographic sandpaper, which can not only ensure the full use of metallographic sandpaper, but also ensure the quality and efficiency of sample preparation. If you haven't explained clearly where, welcome to Kemai Testing Nanjing Laboratory. The metallographist will teach you how to use metallographic sandpaper correctly until you learn it.