Treating solution for preparing Al-Mo-Mn-Re quaternary composite passivation film on aluminum profile surface and its application method

Abstract

The invention discloses a treating solution for preparing a corrosion resistant Al-Mo-Mn-Re quaternary composite passivation film on an aluminum alloy surface and its application method. The passivation solution is characterized by being a passivation treatment solution which is used for preparing a passivation film on an aluminum alloy surface by utilizing a molybdate, a rare earth salt and a permanganate oxidant. Per liter of the treating solution consists of: 8g.L<-1>-25g.L<-1> of sodium molybdate (or ammonium molybdate), 5g.L<-1>-10g.L<-1> of potassium permanganate, 0.5g.L<-1>-3g.L<-1> of sodium fluoride (or potassium fluoride), 0.5g.L<-1>-5g.L<-1> of cerium nitrate (or ceric sulfate, lanthanum nitrate), 1g.L<-1>-5g.L<-1> of acetic acid, 0.5g.L<-1>-1g.L<-1> of sodium dodecyl benzene sulfonate (or OP-10) . The application method includes: (1) removing adhered dust and other dirt from the aluminum alloy; (2) then conducting pretreatment on the aluminum alloy surface; (3) using the treating solution for passivation treatment; and (4) carrying out water washing and drying. The treating solution of the invention has the advantages of fast film formation speed, simple process, uniform film, strong corrosion resistance, and less environmental pollution, etc.

Description

technical field

[0001] The invention relates to an aluminum alloy surface treatment method, in particular to preparing an Al-Mo-Mn-Re quaternary composite passivation film with good corrosion resistance on the aluminum alloy surface by using a non-chromium passivation treatment liquid. Background technique

[0002] Aluminum alloy is widely used in many fields such as automobiles, aerospace, architectural decoration, home appliances, instruments, computers, mobile phones, daily hardware, etc. It is the second largest metal structural material after steel. Due to the high chemical activity of aluminum and its alloys, damages such as pitting corrosion, crevice corrosion, stress corrosion and corrosion fatigue are very easy to occur, which cannot meet the use requirements in harsh environments. In order to improve the service life of aluminum alloys and meet the requirements of product appearance and decoration, aluminum alloy products must undergo surface treatment before use. ...