Preparation And Corrosion Resistance Research Of Molecular Sieve Membrane Materials On Aluminum Alloy

2024aluminum alloy has excellent performance and occupies an irreplaceableposition in the ocean development and aerospace industry. However, sea water andair contain a large number of corrosive ions which can corrode the oxide film ofaluminum alloy and cause local corrosion. Therefore, research on aluminum alloycorrosion is extremely important. As a kind of aluminosilicate crystal with theadvantage of adjustable micropore structure, resistance to chemical erosion andbioerosion and high mechanical strength etc, Zeolite molecular sieve is widely usedin membrane separation and catalysis, which is a kind of environmental friendlymaterial. In this paper, preparation and corrosion resistance of zeolite molecularsieve membrane on aluminum alloy were investigated.The main contents of this research are as follows:(1) ZSM-5molecular sieve membrane layers on aluminum alloy carrier wereprepared using the in situ hydrothermal method as the main process. The growthdirection, the thickness and the surface morphology of the obtained molecular sievemembrane layers were controlled by changing the carrier position. The influencesof these factors on the corrosion resistance performance of the molecular sievemembrane layers on aluminum alloy carrier were also researched.(2) Seeding method is a novel method of preparing molecular sieve membranelayer at a lower temperature and shorter time in recent years. Using different seedpre-coating methods and enhancing the binding force between molecular sieve seed crystal and aluminum alloy substrate, a homogeneous molecular sieve membranewith good stability can be produced. In this paper, the electrodeposition seedingmethod and layer by layer self-assembly seeding method were used. The molecularsieve seeds with negative charge migrate to the surface of the anode aluminumcarrier to form the seed layer by the role of the applied electric field directional. It isproved by research that the electrodeposition seeding method has a morehomogeneous dense distribution on the surface of aluminum alloy carrier, and alsohas better corrosion resistance. Layer by layer self-assembly seeding method wasused to sequentially electrostatic adsorb polyelectrolyte of opposite charge on thecarrier and make the carrier surface positively charged. The molecular sieve seed isstrongly adsorbed onto the carrier surface under the action of electrostatic force.The morphology of seed layer of aluminum alloy after adsorbing seeding, themorphology of molecular sieve membrane layer after hydrothermal and thecorrosion resistance performance were investigated.(3) Binding force between aluminum alloy carrier and molecular sieve membranelayer is fragile, the layer often desquamate from the carrier. The influence ofchemical etching to the surface of aluminum alloy on the binding force wasresearched in this paper, and the corrosion resistance of aluminum alloy afterchemical etching was also investigated.