The introduction of Passivation technology

Trivalent chromium surface passivation treatment is used for aluminum alloy or zinc alloy surface corrosion prevention treatment process, the agent used is trivalent chromium passivation agent, so it is also called trivalent chromium passivation treatment. For aluminum alloy trivalent chromium passivation agent, first concern is its corrosion resistance, which is the length of neutral salt spray test time. It is not wrong to use neutral salt spray test time to measure the trivalent chromium passivation agent, but, for mass production, only use neutral salt spray test to measure aluminum alloy trivalent chromium passivation agent is far from enough.

Also need to use the following indicators to measure: one is the use of aluminum alloy trivalent chromium passivation agent concentration indicator. In general, the concentration will change because of the temperature of the tank, corrosion resistance time requirements, but the basic is between 5%-20%, that requires the use of more than 20% aluminum passivation agent manufacturers, either for the benefit of the use of low active ingredients, or potion performance is not good, Naively trying to increase the concentration, improve the thickness of the film, and then improve the corrosion resistance time.

The second is the sensitivity of the effect of the concentration of the potion on the corrosion resistance, that is, the potion operability index, the bad potion concentration difference, the corrosion resistance difference is very big, resulting in mass production management and control is very troublesome, good potion, the concentration in a certain range, the corrosion resistance difference is not too big. In summary, aluminum alloy trivalent chromium passivation agent is good or bad, a more comprehensive measurement index should be three: one is to measure the corrosion resistance of the neutral salt spray test, one is the use of concentration, the third is the potion operability index.