Friends who work in metallography know that the preparation of metallographic samples cannot be separated from metallographic sandpaper. In almost every metallographic laboratory's consumables reserve, metallographic sandpaper is probably the most abundant, and its application is really too extensive. But, you know what? Some types of materials should not use metallographic sandpaper for grinding and polishing when preparing metallographic specimens as much as possible. Why? The editor dares to teach and teach, so he can tell his friends that he may be able to help those who are new to the industry.

From the practical experience of metallographic sample preparation, it is not recommended to use metallographic abrasive paper to grind and polish samples for materials such as Thermal spraying coatings, hard alloys and ceramics. This is because metallographic sandpaper mostly uses abrasive particles such as silicon carbide, alumina, and mixed abrasives as grinding media. The quality and process control level of the binder directly affect the grinding ability and wear resistance of the metallographic sandpaper by using the sand planting process to bond the grinding medium particles onto the water resistant paper base. The application of metallographic sandpaper itself is more suitable for grinding and polishing of materials with general hardness. Therefore, it is difficult for metallographic sandpaper to complete the preparation task of materials such as high hardness Thermal spraying coatings, hard alloys and ceramics.

When encountering these high hardness materials, it is better to use diamond grinding discs with strong grinding ability and greater wear resistance. Diamond grinding discs have high-speed removal, excellent edge retention, and surface flatness.
The diamond grinding disc uses diamond as the grinding medium and is bonded to a special material substrate with resin, resulting in a more uniform and dense distribution of medium particles. The diamond grinding disc is specially designed and manufactured for the grinding and polishing of hard materials such as cemented carbide, Thermal spraying coating, ceramics, etc. The harder the material is, the more powerful the diamond grinding disc can be used to give play to its super grinding ability and maintain good edges.
Therefore, when encountering these high hardness materials, it is a good choice to avoid using metallographic sandpaper to grind and prepare samples, and instead use diamond grinding discs with stronger grinding ability and greater wear resistance.