Every metallographic laboratory has a metallographic polishing machine. A useful metallographic polishing machine is a good helper for metallographic engineers. It not only saves sample preparation costs, but also improves work efficiency. Similarly, working eight hours a day with good equipment can bring unexpected benefits. But in the actual work of our metallographic engineers, good equipment is only a necessary condition for high-quality analysis of surface preparation, not a sufficient condition. If the polishing solution is chosen incorrectly, it is difficult to prepare an ideal metallographic analysis surface in any case. Therefore, whether a metallographic polishing machine is good or not, it is necessary to choose the right metallographic polishing solution!


Chaineng Metallographic Editor will share with you several solutions recommended by senior metallographic sample preparation engineers for your reference!

    cheme I Selection of alumina final suspension


When using pure mechanical methods to remove materials, alumina is more suitable for steel, stainless steel, cast iron, copper, precious metals, polymers, minerals, and microelectronics than final polishing solution. The characteristic is that it is not easy to aggregate, and the pH value is 8.5

    Option 2: Selection of silica final suspension


When the chemical mechanical polishing method is used, the reaction layer is generated by chemical reaction first, and then the reaction layer is removed by mechanical means. At this time, silicon oxide is more suitable for silicon in Refractory metals, aluminum, ceramics and microelectronics than the final polishing solution. The characteristics are: non crystalline polishing solution, which is easy to obtain excellent scratch free surface effect; The weakly alkaline pH value is 10.5.


Option 3: Selection of Metallographic Polishing Fluids for Different Analysis Purposes


Of course, even for the same material, due to different polishing methods and the purpose of analyzing the material surface, the selection of polishing solution is also different. The key to determining depends on the material and experimental purpose. Below, we will take the copper welding layer as an example to illustrate.

    The above figure shows that using pure mechanical polishing can make the surface of the sample flat, and using aluminum oxide as the final polishing solution, but in reality, it cannot guarantee that the copper will not be damaged. Therefore, it is more suitable for coating measurement and Boundary layer analysis.

    This adopts a chemical mechanical polishing method, using a silicon oxide final polishing solution. It not only causes corrosion on the solder, but also has slight polishing protrusions, but will not damage the sample. Therefore, it is more suitable for microstructure analysis and EBSD of copper.


In summary, we know that a good metallographic polishing machine is only a necessary condition for us to prepare high-quality samples. To prepare samples well and ideally, we must add our professional knowledge, experience, and constantly exploring practice in order to find better methods in work practice.


The above options for metallographic polishing fluids are only for your reference. If you still have any questions or encounter difficulties in your work, please contact the application engineer of Chain Metallography, who may provide you with some better suggestions.