After shot blasting passivation, aluminum castings need cutting fluid during processing. The transit time is about ten days! There are white spots after cleaning with a cleaning machine! Causes and measures
1, chemically speaking, aluminum is a very active metal, which is not only easily oxidized in air, but also reacts in acidic and alkaline environments. The main corrosion forms of aluminum alloy are surface discoloration and pitting corrosion. The surface of aluminum changes from brown to black, and pitting will not occur in a large area. Cavitation erosion is a small and deep erosion, but sometimes it connects with each other to form large holes and precipitate white powder, commonly known as white rust.
2. Therefore, in the process of using cutting fluid, because the ph value of cutting fluid is generally around 9, in alkaline environment, if there is no correct corrosion inhibitor for aluminum, the above corrosion situation is very easy to occur. Cutting fluid is recommended for aluminum processing, and neutral cleaning agent or solvent cleaning agent is best used for cleaning.