Preparation method of magnesium alloy surface super-hydrophobic fluorine conversion coating

A conversion coating, magnesium alloy technology, applied in the direction of metal material coating process, etc., can solve the problems of unsuitable large-scale production, poor anti-corrosion performance and other problems, and achieve simple and easy-to-control equipment, low cost, and slow ion exchange. effect of time

Inactive Publication Date: 2018-02-27
CHONGQING UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a simple and easy preparation method for superhydrophobic fluorine conversion coatings on the surface of magnesium alloys by using a method combining liquid phase growth and hydrothermal treatment, so as to solve the problems of existing magnesium alloys. The corrosion resistance of bone implant materials is not effective and is not suitable for mass production

Method used

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  • Preparation method of magnesium alloy surface super-hydrophobic fluorine conversion coating
  • Preparation method of magnesium alloy surface super-hydrophobic fluorine conversion coating
  • Preparation method of magnesium alloy surface super-hydrophobic fluorine conversion coating

Examples

Experimental program
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Effect test

Embodiment 1

[0034] 1) Clean and polish

[0035] Cut the magnesium alloy AZ31 into a sample of 15mm×1.5mm×2mm. There is a small hole with a diameter of 1mm at the corner of the sample, which can be tied with a thin wire for hanging in the experiment. Use SiC sandpaper (the roughness of the sandpaper is 200#, 400#, 600#, 800#, 1000#) to polish the sample in turn until the surface is smooth and no scratches can be seen with the naked eye. Clean it in an ultrasonic cleaner, then put it into the polishing solution (the volume ratio is HF:HNO 3 :H 2 O=1:10:89), take it out immediately after soaking for 5-10 seconds, rinse the surface with deionized water, dry it with a hair dryer, and set it aside.

[0036] 2) Preparation of micro / nanostructured fluorinated layer

[0037] Put the polished magnesium alloy sample of step 1) into a solvent bottle with a concentration of 40% hydrofluoric acid solution, seal the plastic wrap and wrap it with scotch tape, and soak for 7 days. After taking out the...

Embodiment 2

[0046] The morphology of the magnesium alloy coating prepared in Example 1 and Comparative Example 2 was observed with a Σ IGMA HDTM field emission scanning electron microscope (SEM) ( figure 1 ).

[0047] From figure 1 It can be seen that under SEM, a single fluorine conversion coating (comparative example 2) forms a sheet-like fluorine conversion crystal layer (such as figure 1 a), but there are many gaps between the crystals. And after further carrying out hydrophobic treatment on the fluorine conversion surface (embodiment 1), a superhydrophobic stearic acid film layer is formed on the fluorine conversion surface (such as figure 1 b), and the stearic acid film penetrates into the micro-nano structure fluorine conversion film layer, filling many gaps between the crystals, effectively preventing the solution from penetrating through the gaps of the film layer structure to cause corrosion of the substrate.

[0048] Use the Drop Meter A-100P surface and interfacial tens...

Embodiment 3

[0052] The electrochemical corrosion performance was tested by E G&G Model l273 electrochemical workstation. The measurement adopts a three-electrode system: the reference electrode is a saturated calomel electrode (SCE), the auxiliary electrode is a platinum electrode, and the working electrode is the sample to be tested. The corrosion medium is Hank's biomimetic solution with a pH of 7.4 (composition: NaCl: 8 g / l, KCl: 0.4 g / l, CaCl 2 : 0.14 g / l, NaHCO 3 :0.35 g / l, C 6 h 6 o 6 : 1.0 g / l, MgCl 2 ·6H 2 O:0.1 g / l, MgSO 4 ·7H 2 O: 0.06 g / l, KH 2 PO4: 0.06 g / l, Na 2 HPO 4 12H 2 O: 0.06 g / l). The result is as image 3 shown.

[0053] From image 3 It can be seen from the figure that compared with the single fluorine conversion coating, the self-corrosion potential of the magnesium alloy sample with the fluorine conversion layer treated with stearic acid in Hank's solution is increased, the self-corrosion current density is reduced, and the damage The blunt potentia...

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Abstract

The invention discloses a preparation method of a magnesium alloy surface super-hydrophobic fluorine conversion coating. The super-hydrophobic fluorine conversion coating of a micro/nano structure isprepared on the surface of a magnesium alloy by the adoption of a liquid-phase growth and hydro-thermal treatment combined method. Through cleaning, polishing, preparation of a fluorine conversion layer and hydrophobization treatment, a porous hydrophobic coating of a micro/nano structure is formed on the film layer. The contact angle of the coating in simulated body fluid reaches 150 degrees, thecontact area between a magnesium alloy sample and the liquid can be reduced, the corrosion current density of the magnesium alloy can be lowered by 3 grades, and the impedance magnitude is increasedfrom 12000 omega.cm<2> to 1400000 Omega.cm<2> and is increased by 100 times. The preparation method of the hydrophobic coating of the nano-structure is simple, equipment is simple and easy to control,cost is low, and the controllability is good.

Description

technical field [0001] The invention belongs to the technical field of magnesium alloy surface modification and anticorrosion, and in particular relates to a preparation method of a superhydrophobic fluorine conversion coating on the surface of a magnesium alloy. Background technique [0002] Magnesium and magnesium alloys have excellent mechanical properties, biocompatibility, and degradability. In the past ten years, they have become a research hotspot among scholars at home and abroad as new degradable bone implant materials. However, in a physiological environment, magnesium alloy implants degrade before the tissue heals, which cannot meet the necessary mechanical and morphological requirements for orthopedic implants during their service life. Excessively high magnesium ion concentrations may not only induce serious damage to local tissues. The inflammatory response can also cause excessive secretion of bone morphogenetic proteins, activate osteoclasts, and lead to oste...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C23C22/34
CPCC23C22/34
Inventor 张春艳张世雨张均
Owner CHONGQING UNIV OF TECH
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