With the rapid development of industrial economy, aluminum alloy is a type of non-ferrous metal structural material widely used in industry. It is widely used in aerospace, aviation, mechanical manufacturing, automotive, shipbuilding, and chemical industries. The demand is increasing day by day, and research on aluminum alloy materials is also becoming more in-depth. Metallographic analysis is one of the essential Committed step in the research process. However, there is a high requirement for the preparation of aluminum alloy metallographic samples. This paper mainly discusses the application of aluminum oxide polishing solution in the preparation of aluminum alloy metallographic samples.
Aluminum metal itself is a relatively soft and malleable metal, which is difficult to solve due to deformation, oxidation film formation on the surface after preparation, and corrosion difficulties. Commercial grade aluminum produces metal compounds with different performance characteristics depending on its composition, known as aluminum alloys. For aluminum alloys, the metal compound particles that make up their composition are more susceptible to corrosion by corrosive agents than the matrix. It would be more appropriate to use energy spectrum analysis for identification.
For the preparation of metallographic samples of aluminum alloys, MgO is the ideal final polishing medium in both the four step and five step preparation processes. However, its disadvantage is that it is not easy to use and cannot be provided with very small particle sizes. For many aluminum alloys, the four step method is more suitable for preparation, generally using silica gel and alumina polishing solution to replace MgO.

For aluminum alloys, alumina polishing solution is a very effective final polishing medium. It is worth noting that standard calcined alumina polishing medium is not suitable for the preparation of aluminum alloy samples.

For many aluminum alloys, the ideal polishing results can be obtained through the following four step preparation method, as shown in the table below: the final polishing method using silica gel combined with lint free polishing cloth or alumina polishing solution combined with short/medium velvet polishing cloth can retain all intermetallic compound particles in the aluminum alloy and control the protrusion to a small extent.

During the medium grinding process using diamond polishing fluid, embedding phenomenon is often encountered. Replacing the diamond polishing fluid with diamond polishing paste will greatly reduce embedding.
The above are the commonly used methods for preparing aluminum alloy metallographic samples and the application of alumina polishing solution in preparation, for your reference.