Chemical conversion film treatment is in the surface treatment for aluminum and aluminum alloy corrosion resistance of the most widely used technology, the development of more than half a century of chemical conversion coating technology becoming mature, and constantly to derive other new processing methods.No doubt, chemical oxidation treatment will play an important role in the future.However, due to the increasingly serious environmental pollution, higher requirements are put forward on the cleanliness and harmlessness of surface treatment process.This can be done in the following directions.
1. Low-temperature development of metal surface pretreatment to develop energy-saving surface treatment technology.
2. Low chromium and chrome-free treatment.
3. No water washing treatment: remove the whole process of water washing process, in addition to solving the pollution problem of wastewater discharge to the environment fundamentally, it can also save water resources.Japan reported: chromate surface treatment agent, is Cr3, +, Cr6, + and a mixture of water soluble organic resin, used in aluminum plate, the coating film forming method is adopted, not washed, even including chromium ion will not pollute the environment;Natural drying, convenient for sealing system processing;Membrane corrosion resistance and film adhesion are the same as the past surface treatment, even better.
4. The pretreatment process and the forming process adopt the mutual closed circulation mode, and all the chemical agents in the system are recycled, without replacing the original liquid, only the consumed drugs are added on a regular basis;Both water washing and non-water treatment can be closed.The closed process can greatly improve the field operation environment, reduce waste residue, waste liquid discharge, save energy and resources, and the economic and social environmental benefits are obvious.
