The metallographic polishing machine is a product polishing machine, and it cannot do without the help of polishing powder in its work. Polishing powder is usually composed of cerium oxide, aluminum oxide, silicon oxide, iron oxide, zirconium oxide, chromium oxide and other components. Different materials have different hardnesses and different chemical properties in water, so they are used in different situations.
If we want to find polishing powder suitable for the processing of our own products, we have to understand this thing in depth. Let me give you a brief introduction to facilitate customers to make a decision when choosing polishing powder for metallographic polishing machines.
1. Powder suspension: The polishing powder of a good metallographic polishing machine must have good suspension. The shape and particle size of the powder have a certain impact on the suspension performance. The suspension of polishing powder with flake shape and finer particle size is better. It's relatively better, but it's not absolutely correct. The suspension performance of polishing powder can also be improved by adding suspension (agent).
2. The particle size of the powder: determines the polishing accuracy and speed of the metallographic polishing machine, usually based on the number of meshes and the average particle size of the powder. The mesh size of the sieve can determine the relative particle size of the powder. The average particle size determines the overall level of the polishing powder particle size.
3. Crystal form of powder: The crystal form of powder is single crystal particles agglomerated together, which determines the cutting performance, wear resistance and fluidity of the powder.
4. Powder Mohs hardness: Powder with relatively high hardness has a faster cutting effect. At the same time, adding some grinding aids, etc. can also improve the cutting effect; different application fields will have great differences, including their own processing technology. .
5. Appearance color: The content of Pr in the raw material is related to the burning temperature and other factors. The higher the content of praseodymium, the powder will appear brownish red. Low cerium polishing powder contains a large amount of praseodymium (cerium praseodymium material), which makes it appear brownish red. For the high-cerium polishing powder used in metallographic polishing machines, the higher the burning temperature, the more it will appear white-pink, and the lower the temperature (around 900 degrees), the more it will appear light yellow.The actual hardness of polishing powder is related to the material. For example, the hardness of cerium oxide is about 7 on Mohs hardness, and all kinds of cerium oxide are similar. However, different cerium oxide bodies in metallographic polishing machines give people different hardnesses. This is because cerium oxide polishing powder is usually an agglomerate. The attached picture is an electron microscope photo of a polishing powder agglomerate.
Due to the different firing temperatures of the metallographic polishing machine, the strength of the agglomerates is also different, so the hardness will feel different when used. Of course, if harder materials such as alumina are added to some polishing powders, the grinding rate and wear resistance will be improved.
