Why is the metallographic structure of aluminum piston on the shore not good?

1. The metallographic test in the coastal area needs to cut and polish the sample, which will affect the surface of aluminum piston, such as scratches and stretching, and will affect the surface quality and service life of aluminum piston.

2. The oxide layer on the surface of aluminum piston will affect the accuracy of metallographic examination around the coast, because the oxide layer will lead to the illusion in the examination results.

3. The microstructure of aluminum piston changes along the axial direction of aluminum piston, and the metallographic test around the coast can only provide local microstructure information, which can not fully reflect the microstructure characteristics of aluminum piston and is not accurate enough.

4. The metallographic test around the coast requires chemical corrosion treatment of aluminum piston, which will cause corrosion damage to the surface of aluminum piston and further reduce the surface quality and service life of aluminum piston.