CN113564590A - Method for preparing hydrotalcite coating on surface of magnesium alloy by combining acid pretreatment with steam method - Google Patents
Method for preparing hydrotalcite coating on surface of magnesium alloy by combining acid pretreatment with steam method Download PDFInfo
- Publication number
- CN113564590A CN113564590A CN202110867457.2A CN202110867457A CN113564590A CN 113564590 A CN113564590 A CN 113564590A CN 202110867457 A CN202110867457 A CN 202110867457A CN 113564590 A CN113564590 A CN 113564590A
- Authority
- CN
- China
- Prior art keywords
- magnesium alloy
- hydrotalcite
- acid
- acid pretreatment
- coating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229910000861 Mg alloy Inorganic materials 0.000 title claims abstract description 315
- 238000000576 coating method Methods 0.000 title claims abstract description 214
- 239000011248 coating agent Substances 0.000 title claims abstract description 210
- GDVKFRBCXAPAQJ-UHFFFAOYSA-A dialuminum;hexamagnesium;carbonate;hexadecahydroxide Chemical compound [OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[Mg+2].[Mg+2].[Mg+2].[Mg+2].[Mg+2].[Mg+2].[Al+3].[Al+3].[O-]C([O-])=O GDVKFRBCXAPAQJ-UHFFFAOYSA-A 0.000 title claims abstract description 206
- 229960001545 hydrotalcite Drugs 0.000 title claims abstract description 204
- 229910001701 hydrotalcite Inorganic materials 0.000 title claims abstract description 204
- 239000002253 acid Substances 0.000 title claims abstract description 146
- 238000000034 method Methods 0.000 title claims abstract description 92
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims abstract description 209
- 239000000758 substrate Substances 0.000 claims abstract description 79
- 238000005260 corrosion Methods 0.000 claims abstract description 67
- 230000007797 corrosion Effects 0.000 claims abstract description 50
- 239000011159 matrix material Substances 0.000 claims abstract description 37
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 claims abstract description 27
- 238000011065 in-situ storage Methods 0.000 claims abstract description 26
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims abstract description 15
- 150000007524 organic acids Chemical class 0.000 claims abstract description 14
- 235000006408 oxalic acid Nutrition 0.000 claims abstract description 9
- 239000000956 alloy Substances 0.000 claims description 78
- 238000006243 chemical reaction Methods 0.000 claims description 23
- 238000001035 drying Methods 0.000 claims description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 15
- 238000004140 cleaning Methods 0.000 claims description 14
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 12
- 150000003839 salts Chemical class 0.000 claims description 11
- 238000002791 soaking Methods 0.000 claims description 11
- 238000010438 heat treatment Methods 0.000 claims description 10
- 239000007921 spray Substances 0.000 claims description 10
- -1 polytetrafluoroethylene Polymers 0.000 claims description 8
- 238000001816 cooling Methods 0.000 claims description 7
- 239000003960 organic solvent Substances 0.000 claims description 7
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 7
- 239000004810 polytetrafluoroethylene Substances 0.000 claims description 7
- 239000007788 liquid Substances 0.000 claims description 6
- 238000005498 polishing Methods 0.000 claims description 6
- 239000011780 sodium chloride Substances 0.000 claims description 5
- 229910045601 alloy Inorganic materials 0.000 claims description 4
- 229910003023 Mg-Al Inorganic materials 0.000 claims description 3
- 239000000853 adhesive Substances 0.000 abstract description 3
- 230000001070 adhesive effect Effects 0.000 abstract description 3
- 230000000052 comparative effect Effects 0.000 description 47
- 239000000243 solution Substances 0.000 description 38
- 239000011777 magnesium Substances 0.000 description 29
- 229910018131 Al-Mn Inorganic materials 0.000 description 23
- 229910018461 Al—Mn Inorganic materials 0.000 description 23
- 230000008569 process Effects 0.000 description 18
- 150000007522 mineralic acids Chemical class 0.000 description 17
- 239000010410 layer Substances 0.000 description 15
- 230000000694 effects Effects 0.000 description 11
- 239000000463 material Substances 0.000 description 11
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 10
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 10
- 239000002131 composite material Substances 0.000 description 9
- 239000010408 film Substances 0.000 description 9
- 238000002360 preparation method Methods 0.000 description 9
- 229910052782 aluminium Inorganic materials 0.000 description 8
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 7
- 229910017604 nitric acid Inorganic materials 0.000 description 7
- 238000001878 scanning electron micrograph Methods 0.000 description 7
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 6
- 239000011572 manganese Substances 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- 238000012360 testing method Methods 0.000 description 6
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 5
- 239000011247 coating layer Substances 0.000 description 5
- 230000007774 longterm Effects 0.000 description 5
- 229910052749 magnesium Inorganic materials 0.000 description 5
- 230000007246 mechanism Effects 0.000 description 5
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 4
- 238000001514 detection method Methods 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 230000010287 polarization Effects 0.000 description 4
- 238000000026 X-ray photoelectron spectrum Methods 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 239000012528 membrane Substances 0.000 description 3
- 101001108245 Cavia porcellus Neuronal pentraxin-2 Proteins 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- 238000002441 X-ray diffraction Methods 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000003912 environmental pollution Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 2
- 238000005342 ion exchange Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229910021645 metal ion Inorganic materials 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000006911 nucleation Effects 0.000 description 2
- 238000010899 nucleation Methods 0.000 description 2
- 238000007745 plasma electrolytic oxidation reaction Methods 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 239000004575 stone Substances 0.000 description 2
- TUSDEZXZIZRFGC-UHFFFAOYSA-N 1-O-galloyl-3,6-(R)-HHDP-beta-D-glucose Natural products OC1C(O2)COC(=O)C3=CC(O)=C(O)C(O)=C3C3=C(O)C(O)=C(O)C=C3C(=O)OC1C(O)C2OC(=O)C1=CC(O)=C(O)C(O)=C1 TUSDEZXZIZRFGC-UHFFFAOYSA-N 0.000 description 1
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- 239000001263 FEMA 3042 Substances 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- IMQLKJBTEOYOSI-GPIVLXJGSA-N Inositol-hexakisphosphate Chemical compound OP(O)(=O)O[C@H]1[C@H](OP(O)(O)=O)[C@@H](OP(O)(O)=O)[C@H](OP(O)(O)=O)[C@H](OP(O)(O)=O)[C@@H]1OP(O)(O)=O IMQLKJBTEOYOSI-GPIVLXJGSA-N 0.000 description 1
- LRBQNJMCXXYXIU-PPKXGCFTSA-N Penta-digallate-beta-D-glucose Natural products OC1=C(O)C(O)=CC(C(=O)OC=2C(=C(O)C=C(C=2)C(=O)OC[C@@H]2[C@H]([C@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)[C@@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)[C@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)O2)OC(=O)C=2C=C(OC(=O)C=3C=C(O)C(O)=C(O)C=3)C(O)=C(O)C=2)O)=C1 LRBQNJMCXXYXIU-PPKXGCFTSA-N 0.000 description 1
- IMQLKJBTEOYOSI-UHFFFAOYSA-N Phytic acid Natural products OP(O)(=O)OC1C(OP(O)(O)=O)C(OP(O)(O)=O)C(OP(O)(O)=O)C(OP(O)(O)=O)C1OP(O)(O)=O IMQLKJBTEOYOSI-UHFFFAOYSA-N 0.000 description 1
- 239000003929 acidic solution Substances 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- ILRRQNADMUWWFW-UHFFFAOYSA-K aluminium phosphate Chemical compound O1[Al]2OP1(=O)O2 ILRRQNADMUWWFW-UHFFFAOYSA-K 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 238000000975 co-precipitation Methods 0.000 description 1
- 230000000536 complexating effect Effects 0.000 description 1
- 238000010668 complexation reaction Methods 0.000 description 1
- 238000007739 conversion coating Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 229940079593 drug Drugs 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 238000000840 electrochemical analysis Methods 0.000 description 1
- 230000005518 electrochemistry Effects 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- LRBQNJMCXXYXIU-QWKBTXIPSA-N gallotannic acid Chemical compound OC1=C(O)C(O)=CC(C(=O)OC=2C(=C(O)C=C(C=2)C(=O)OC[C@H]2[C@@H]([C@@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)[C@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)[C@@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)O2)OC(=O)C=2C=C(OC(=O)C=3C=C(O)C(O)=C(O)C=3)C(O)=C(O)C=2)O)=C1 LRBQNJMCXXYXIU-QWKBTXIPSA-N 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000002638 heterogeneous catalyst Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 238000009830 intercalation Methods 0.000 description 1
- 230000002687 intercalation Effects 0.000 description 1
- 239000003562 lightweight material Substances 0.000 description 1
- GVALZJMUIHGIMD-UHFFFAOYSA-H magnesium phosphate Chemical compound [Mg+2].[Mg+2].[Mg+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O GVALZJMUIHGIMD-UHFFFAOYSA-H 0.000 description 1
- 239000004137 magnesium phosphate Substances 0.000 description 1
- 229910000157 magnesium phosphate Inorganic materials 0.000 description 1
- 229960002261 magnesium phosphate Drugs 0.000 description 1
- 235000010994 magnesium phosphates Nutrition 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000003595 mist Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000002808 molecular sieve Substances 0.000 description 1
- 235000005985 organic acids Nutrition 0.000 description 1
- 238000000643 oven drying Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 235000002949 phytic acid Nutrition 0.000 description 1
- 239000000467 phytic acid Substances 0.000 description 1
- 229940068041 phytic acid Drugs 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 235000015523 tannic acid Nutrition 0.000 description 1
- 229940033123 tannic acid Drugs 0.000 description 1
- 229920002258 tannic acid Polymers 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C26/00—Coating not provided for in groups C23C2/00 - C23C24/00
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
- C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
- C23G1/12—Light metals
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Treatment Of Metals (AREA)
Abstract
The invention discloses a method for preparing a hydrotalcite coating on the surface of a magnesium alloy by combining acid pretreatment with a steam method, which mainly solves the technical problem that the corrosion resistance of the hydrotalcite coating in the prior art is not ideal, and comprises the following steps: (1) pretreating the surface of the magnesium alloy substrate; (2) carrying out acid pretreatment on the pretreated magnesium alloy matrix; (3) and preparing the hydrotalcite coating on the surface of the magnesium alloy substrate subjected to acid pretreatment by adopting an in-situ steam method, wherein an acid solution adopted in the acid pretreatment is a weak organic acid solution, and the weak organic acid is at least one of oxalic acid, an acetic acid solution or citric acid. The hydrotalcite coating obtained by the invention has the characteristics of compact structure, strong adhesive force, good corrosion resistance and long service life.
Description
Technical Field
The invention relates to the technical field of preparation of magnesium alloy surface coatings, in particular to a method for preparing a hydrotalcite coating on the surface of a magnesium alloy by combining acid pretreatment and a steam method.
Background
Lightweight materials such as magnesium and magnesium alloys have excellent properties such as high specific strength, specific stiffness and excellent workability, and thus have been widely spotlighted and studied in the fields of aerospace, automobiles and biomedicine. However, its active chemistry and poor corrosion resistance hinder its practical application and development. The preparation of high performance coatings by surface modification techniques, such as chemical conversion coating, micro-arc oxidation (MAO) coating and phase-coating self-assembled coating, is one of the effective methods to solve this problem. However, these coatings are typically prepared using large amounts of chemicals, which tend to contaminate the environment. Therefore, the development of a corrosion-resistant coating with low cost and environmental friendliness on the surface of the magnesium alloy is particularly urgent.
Hydrotalcite (LDH) has been extensively studied for its potential application in heterogeneous catalysts, anion exchangers, thermally stable materials and molecular sieves. Notably, because LDH has a unique ion exchange capacity, it can trap corrosive ions in corrosive media, thereby inhibiting the occurrence of corrosion reactions. Therefore, the LDH coating can effectively improve the corrosion resistance of the sample. In previous work, the literature "Rong-Chang Zeng, Journal of Materials Chemistry A2014, 2: 13049" discloses a process of co-precipitation and hydrothermal combination to prepare MoO on the surface of AZ31 magnesium alloy4 2-The intercalated LDH coating obtained by the method has self-healing performance and ion exchange performance, can provide good corrosion resistance for a matrix, but has the disadvantages of time-consuming reaction, slow film forming rate and low efficiency, so that a method for preparing the hydrotalcite coating, which has a short experimental process and can provide long-term effective protection for the matrix, is needed.
The document "T.Ishizaki, ECS Electrochemistry Letters,2013,2: C15" discloses a method for preparing a hydrotalcite coating on the surface of AZ31 magnesium alloy by using an in-situ steam process, wherein pure water is only used as a steam source in the preparation process, no chemical is required to be added, and the reaction is carried out under the conditions of high temperature and high pressure to obtain LDH/Mg (OH)2And (4) coating. The method for preparing the LDH coating has the advantages of simple operation, short period, no environmental pollution and the like, and has good application prospect. But the hydrotalcite coating prepared only by the in-situ steam method has thinner thickness andloose and cannot provide long-term effective protection for the matrix. In addition, chinese patent CN103320782A discloses a method for preparing a magnesium alloy composite membrane, which discloses using organic acid to perform a conversion membrane treatment (such as phytic acid, tannic acid, etc.) to obtain a conversion membrane sample, then placing the sample in a steam treatment furnace, raising the temperature to 100 ℃ in the air atmosphere, and keeping the temperature for 60 minutes; then introducing water vapor, exhausting air in the furnace, starting treatment timing, closing a switch after 150 minutes of treatment, releasing the steam, taking out a sample and drying when the temperature is lower, and obtaining a compact composite film on the surface of the magnesium alloy2Although the composite film formed by the method uses less chemicals, the composite film is substantially divided into two layers, the bonding force with the substrate is relatively weak, destructive ions in corrosive media can enter the composite film through the layer gaps, and the substrate is further corroded after the inner layer is corroded and damaged. Therefore, the corrosion resistance of the composite film prepared by the preparation method is still not ideal, and the composite film cannot provide long-term protection for the magnesium alloy matrix.
At present, the hydrotalcite coating is prepared by an in-situ steam method, but the thickness of the prepared hydrotalcite coating is guaranteed alternately and is loose, so that the hydrotalcite coating cannot provide long-term effective protection for a matrix. In addition, other methods are available, for example, CN108330472A discloses a method for enhancing the corrosion resistance of an LDH coating on the surface of a magnesium alloy, and CN112680090A discloses a method for preparing a corrosion-resistant self-repairing coating on the surface of a magnesium alloy, and although the prepared composite coating has excellent corrosion resistance, the composite coating has the disadvantages of various used drugs, high cost and easy environmental pollution, so that it is very important to prepare a corrosion-resistant coating on the surface of a magnesium alloy, which has low cost, simple operation and environmental friendliness.
Disclosure of Invention
The invention aims to provide a method for preparing a hydrotalcite coating on the surface of a magnesium alloy by combining acid pretreatment and a steam method, which only needs pure water as a steam source, adopts an acid solution as an oxalic acid solution, an acetic acid solution or a citric acid solution as an organic acid in the acid pretreatment process, is easy to dissolve in water, has certain acidity, is generally present in some plants, is environment-friendly, does not need to add other chemicals, has no pollution to the environment, has short reaction period and simple and easy operation, and the hydrotalcite coating prepared by the method has compact structure, strong adhesive force, good corrosion resistance and longer service life.
The invention specifically adopts the following technical scheme:
a method for preparing a hydrotalcite coating on the surface of a magnesium alloy by combining acid pretreatment and a steam method comprises the following steps:
(1) pretreating the surface of the magnesium alloy substrate;
(2) carrying out acid pretreatment on the magnesium alloy substrate pretreated in the step (1);
(3) and (3) preparing a hydrotalcite coating on the surface of the magnesium alloy substrate subjected to acid pretreatment in the step (2) by adopting an in-situ steam method.
Preferably, the step (1) is specifically: and polishing the magnesium alloy matrix to remove the surface oxide layer, and then cleaning and drying the magnesium alloy matrix by using an organic solvent.
Preferably, the step (2) is specifically: preparing an acid solution, immersing the pretreated magnesium alloy matrix into the acid solution for soaking, then taking out the magnesium alloy matrix, cleaning and drying.
Preferably, the acid solution is a weak organic acid solution.
Preferably, the weak organic acid solution is at least one of an oxalic acid solution, an acetic acid solution or a citric acid solution.
Preferably, the concentration of the weak organic acid solution is 10-50 g/L, and the soaking time is 10-60 s.
Preferably, the step (3) is specifically: suspending the magnesium alloy substrate subjected to acid pretreatment in a 100mL hydrothermal kettle with a polytetrafluoroethylene lining, and then adding 10-30 mL pure water, wherein the distance between the magnesium alloy substrate and the liquid level is kept at 1-4 cm; and (3) starting the hydrothermal kettle for heating at the temperature of 100-220 ℃ for 1-18 h, taking out after the reaction is finished, and naturally cooling to room temperature to obtain the magnesium alloy material with the hydrotalcite coating.
Preferably, the magnesium alloy is a Mg — Al alloy.
The magnesium alloy material with the hydrotalcite coating prepared by the method has salt spray corrosion resistance time of more than 500 hours in a salt spray atmosphere of 5 wt.% of sodium chloride.
In order to better understand the above technical solution, the related mechanism thereof will now be briefly described.
(1) The mechanism of acid pretreatment:
taking AZ31 magnesium alloy (Al-3 wt.%, Zn-1 wt.%), for example, there are two main phases, an α -Mg matrix and an Al-Mn phase. When AZ31 magnesium alloy is immersed in an acidic activation solution, many galvanic corrosions are formed on the surface due to the difference in the microstructure of the alpha-Mg phase and the Al-Mn phase and the standard electrode potential, the alpha-Mg phase acts as the anode, and the Al-Mn phase acts as the cathode.
In the micro-anodic region (α -Mg phase), Mg dissolves:
Mg→Mg2++2e-
hydrogen generation in the micro-cathode region (Al — Mn phase):
2H++2e-→H2↑
therefore, after the acid pretreatment, on one hand, the acid pretreatment can remove an oxide layer and a hydroxide layer on the surface of the magnesium alloy; on the other hand, Mg on the surface of the magnesium alloy is dissolved into Mg2+And the Al-Mn phase on the surface of the magnesium alloy is exposed, so that the phase density, the volume fraction and the activity of the Al-Mn phase on the surface of the magnesium alloy are increased, and more growth sites are provided for preparing the hydrotalcite coating by the in-situ steam method.
For other Mg-Al alloys, the α -Mg phase acts as the anode and the aluminum rich phase acts as the cathode, and the corrosion mechanism in acidic solution is similar to that of AZ31 magnesium alloy. Based on the method, the hydrotalcite coating is further prepared by pretreating other Mg-Al series alloys by acid and combining an in-situ steam method, so that the hydrotalcite coating with excellent corrosion resistance is prepared.
(2) The mechanism of preparing the hydrotalcite coating by the in-situ steam method is as follows:
the magnesium alloy after acid pretreatment is put into a hydrothermal kettle with polytetrafluoroethylene as a lining for closed heating, and the hydrotalcite coating is prepared by adopting an in-situ steam method. Firstly, the surface of the magnesium alloy after acid pretreatment has a large amount of Al-Mn phases, and then steam generated by water under high pressure and high temperature has high kinetic energy and reactivity, so that Mg and Al in the magnesium alloy can be dissolved into Mg2+And Al3+Then Mg2+And Al3+Reacting with water vapor and carbon dioxide in a container to form a hydrotalcite coating on the surface of the magnesium alloy, namely the steam and the carbon dioxide react with Mg on the surface of the magnesium alloy2+、Al3+Reaction to form Mg (OH)2And Mg-Al-CO3 2-LDH, thereby depositing a layer of hydrotalcite (Mg) on the surface of the magnesium alloy6Al2(OH)16CO3·4H2O) a thin film. In the preparation process, only water is needed to be used as a reaction source, elements needed in the growth process of the hydrotalcite are all from the surface of the magnesium alloy substrate, other chemical reagents and the like are not needed to be added, and the production process is environment-friendly, simple and easy to control.
In addition, Al required for the hydrotalcite growth process in the reaction process for forming the hydrotalcite coating layer by the in-situ steam method3+All come from the surface of the magnesium alloy matrix, and the acid pretreatment can expose the aluminum-rich phase on the surface of the magnesium alloy matrix, increase the Al content and activity on the surface of the magnesium alloy matrix and provide more growth sites for the growth of a subsequent hydrotalcite coating. Therefore, the optimal reaction condition can be achieved by combining the in-situ steam method after the surface of the magnesium alloy substrate is pretreated by acid, the surface of the prepared hydrotalcite coating is more compact, the thickness is obviously increased, the adhesion with the substrate is strong, and the corrosion resistance of the magnesium alloy can be effectively improved.
According to the invention, by observing the growth process of the coating with different reaction times, the existence of the Al-Mn phase is proved to provide more growth sites for the growth of the coating and promote the growth of the LDH coating, so that a more compact and thicker hydrotalcite coating is obtained, and the electrochemical test results, the soaking experiment and the salt spray experiment results show that: the prepared hydrotalcite coating can provide long-term effective protection for a matrix.
The invention has the following beneficial effects:
(1) the method prepares the hydrotalcite coating by combining acid pretreatment and an in-situ steam method, puts the magnesium alloy substrate into an acid solution for pretreatment, can remove an oxide layer and a hydroxide layer on the surface of the magnesium alloy by the acid pretreatment, and dissolves Mg on the surface of the magnesium alloy into Mg2+The Al-Mn phase on the surface of the magnesium alloy is exposed, the phase density, the volume fraction and the activity of the Al-Mn phase on the surface of the magnesium alloy are increased, more growth sites are provided for preparing the hydrotalcite coating by an in-situ steam method, the surface of the prepared hydrotalcite coating is more compact, the thickness of the hydrotalcite coating is increased, the hydrotalcite coating can better play a role in blocking corrosive media from entering the internal structure of the hydrotalcite coating, the corrosion rate is slowed down, the in-situ steam method only needs water as a reaction source, elements needed in the growth process of the hydrotalcite are all from the surface of the magnesium alloy substrate, other chemical reagents and the like do not need to be added, and the production process is environment-friendly, simple and easy to control;
(2) the oxalic acid solution, the acetic acid solution or the citric acid solution adopted in the acid pretreatment process is an organic weak acid, is easy to dissolve in water, has certain acidity, commonly exists in some plants and is environment-friendly;
(3) the magnesium alloy material with the hydrotalcite coating prepared after acid pretreatment has the self-corrosion potential increased and the self-corrosion current density reduced, for example, the self-corrosion potential of the AZ31 magnesium alloy material prepared by combining the magnesium alloy material with the hydrotalcite coating pretreated by 30g/L of citric acid solution for 30s can be increased to-1280 mV, and the self-corrosion current density is reduced to 4.46 multiplied by 10-8A/cm2(ii) a The self-corrosion potential of the AZ80 magnesium alloy material prepared by treating 30s with 20g/L citric acid solution can be increased to-1250 mV, and the self-corrosion current density is reduced to 5.08 multiplied by 10-8A/cm2；
(4) In the acid pretreatment process, the concentration of an acid solution and the soaking time of the magnesium alloy matrix in the acid solution need to be controlled, so that the surface of the magnesium alloy matrix is prevented from being excessively corroded by acid;
(5) the hydrotalcite coating has good self-healing behavior, and when the hydrotalcite coating is in a salt mist atmosphere of 5 wt.% of sodium chloride for 576 hours, the small corrosion pits appear at the extreme edge of the sample, which indicates that the hydrotalcite coating has excellent corrosion resistance;
(6) the hydrotalcite coating prepared by the invention has the characteristics of compact structure, strong adhesive force, good corrosion resistance, long service life and the like.
Drawings
The invention will be further described with reference to the accompanying drawings in which:
FIG. 1 is a metallographic photomicrograph (magnification 100) of the magnesium alloy matrix of comparative example 1 which has not been subjected to acid pretreatment, the magnesium alloy matrix of comparative example 2 which has been subjected to inorganic acid pretreatment, and the magnesium alloy matrix of example 1 which has been subjected to citric acid pretreatment, and the change in volume fraction of the aluminum-rich phase;
FIG. 2 is a Scanning Electron Microscope (SEM) photograph (magnification of 2500X) of a magnesium alloy substrate of comparative example 1 which has not been subjected to acid pretreatment and a magnesium alloy substrate of example 1 which has been subjected to citric acid pretreatment;
FIG. 3 is an energy spectrum (EDS) of a magnesium alloy substrate not subjected to acid pretreatment of comparative example 1 and a magnesium alloy substrate subjected to citric acid pretreatment of example 1;
fig. 4 is an energy spectrum (EDS) of the magnesium alloy material with hydrotalcite coating prepared in comparative example 1 without acid pretreatment and the magnesium alloy material with hydrotalcite coating prepared in example 1 with citric acid pretreatment;
fig. 5 is a Scanning Electron Microscope (SEM) photograph (3500 x magnification) of a cross section of the magnesium alloy material with hydrotalcite coating prepared without acid pretreatment of comparative example 1 and the magnesium alloy material with hydrotalcite coating prepared with citric acid pretreatment of example 1;
FIG. 6 is a metallographic photograph of the surface of a AZ80 magnesium alloy substrate after being subjected to pretreatment with citric acid for various periods of time and the volume fraction of Al-Mn phase corresponding to the surface of the magnesium alloy substrate in example 2;
fig. 7 is a scanning electron micrograph (3500 times magnification) of a cross section of an AZ80 magnesium alloy material with a hydrotalcite coating prepared in example 2 at different times of pretreatment with citric acid;
fig. 8 is a Scanning Electron Microscope (SEM) photograph (magnification 20000 times) of the magnesium alloy material with hydrotalcite coating prepared in comparative example 1 without acid pretreatment and the magnesium alloy material with hydrotalcite coating prepared in example 1 with citric acid pretreatment;
fig. 9 is an X-ray diffraction (XRD) pattern of the magnesium alloy material with hydrotalcite coating prepared in comparative example 1 without acid pretreatment and the magnesium alloy material with hydrotalcite coating prepared in example 1 with citric acid pretreatment;
fig. 10 is a comparison of potentiodynamic polarization (tafel) plots for comparative example 1 magnesium alloy material with hydrotalcite coating prepared without acid pretreatment, comparative example 2 magnesium alloy material with hydrotalcite coating prepared with inorganic acid pretreatment, and example 1 magnesium alloy material with hydrotalcite coating prepared with citric acid pretreatment, and magnesium alloy substrate;
fig. 11 is a potentiodynamic polarization (tafel) plot of AZ80 magnesium alloy material with hydrotalcite coating prepared in example 2 at different times of citric acid pretreatment;
fig. 12 is a bode plot comparing the magnesium alloy material with hydrotalcite coating prepared in comparative example 1 without acid pretreatment with the magnesium alloy material with hydrotalcite coating prepared in comparative example 2 with inorganic acid pretreatment and the magnesium alloy material with hydrotalcite coating prepared in example 1 with citric acid pretreatment and the magnesium alloy substrate;
fig. 13 is a nyquist plot of electrochemical energy of the magnesium alloy substrate and the magnesium alloy material with the hydrotalcite coating prepared in comparative example 1 without acid pretreatment, in comparison with the magnesium alloy material with the hydrotalcite coating prepared in comparative example 2 with inorganic acid pretreatment, and the magnesium alloy material with the hydrotalcite coating prepared in example 1 with citric acid pretreatment;
fig. 14 is a scanning electron micrograph (magnification is 1000 times) of a magnesium alloy substrate of AZ31, a magnesium alloy material with a hydrotalcite coating prepared in comparative example 1 without acid pretreatment, and a magnesium alloy material with a hydrotalcite coating prepared in example 1 with citric acid pretreatment after being immersed in a sodium chloride solution with a mass percentage concentration of 3.5% for 10 days, respectively;
fig. 15 is a photograph of a digital camera in which a magnesium alloy substrate of AZ31, a magnesium alloy material with a hydrotalcite coating prepared in comparative example 1 without acid pretreatment, and a magnesium alloy material with a hydrotalcite coating prepared in example 1 with citric acid pretreatment were placed in a sodium chloride salt fog environment with a concentration of 5% by mass for different times, respectively;
FIG. 16 is an X-ray photoelectron spectrum of the peak C1s of magnesium alloy material with a magnesium alloy substrate pretreated by citric acid, a hydrotalcite coating treated for 0.5h after the citric acid pretreatment, and a hydrotalcite coating treated for 1.5h after the citric acid pretreatment;
fig. 17 is a macro-photograph of a micro scratch test of an extruded AZ61 magnesium alloy material with a hydrotalcite coating prepared by pretreatment of example 3 with citric acid.
Detailed Description
The invention provides a method for preparing a hydrotalcite coating on the surface of a magnesium alloy by combining acid pretreatment and a steam method, and in order to make the advantages and technical scheme of the invention clearer and clearer, the invention is described in detail by combining specific embodiments and drawings.
The raw materials required by the invention can be purchased from commercial sources.
Example 1
The matrix material is an extruded magnesium alloy AZ31, and the step of preparing the hydrotalcite coating on the surface of the extruded magnesium alloy AZ31 is as follows:
(1) pretreating the surface of the extruded magnesium alloy AZ 31: polishing an extruded magnesium alloy AZ31 sample to remove a surface oxide layer, cleaning with an organic solvent and drying by blowing after no obvious burrs exist on the surface of a base material, wherein the organic solvent can adopt an ethanol solution;
(2) carrying out acid pretreatment on the magnesium alloy sample pretreated in the step (1): preparing a 30g/L citric acid solution, immersing an AZ31 magnesium alloy sample into the citric acid solution, taking out after soaking for 30s, and then cleaning and drying to obtain an acid-pretreated magnesium alloy sample for later use;
(3) preparing a hydrotalcite coating on the surface of the magnesium alloy sample after acid pretreatment by adopting an in-situ steam method: suspending a magnesium alloy sample pretreated by citric acid in a 100mL hydrothermal kettle with a polytetrafluoroethylene lining, and then adding 20mL pure water, wherein the distance between the magnesium alloy sample and the liquid level is kept at 2.5 cm; and (3) starting the hydrothermal kettle for heating at 160 ℃ for 6h, taking out after the reaction is finished, and naturally cooling to room temperature to obtain the magnesium alloy material with the hydrotalcite coating.
The thickness of the hydrotalcite coating of the prepared magnesium alloy material is detected, and the thickness is 37.65 mu m.
Example 2
The matrix material is an extruded magnesium alloy AZ80, and the step of preparing the hydrotalcite coating on the surface of the extruded magnesium alloy AZ80 is as follows:
(1) pretreating the surface of the extruded magnesium alloy AZ80 matrix: taking 4 magnesium alloy samples from the same magnesium alloy plate, polishing the extruded magnesium alloy AZ80 sample to remove a surface oxide layer until no obvious burr is formed on the surface of the base material, cleaning with an organic solvent and drying;
(2) carrying out acid pretreatment on the magnesium alloy sample pretreated in the step (1): preparing a 20g/L citric acid solution, immersing an extruded AZ80 magnesium alloy sample into the citric acid solution, respectively soaking for 0s (namely not subjected to acid pretreatment), 10s, 20s and 30s, then taking out, cleaning and drying to obtain the magnesium alloy sample subjected to acid pretreatment for later use;
(3) the method comprises the following steps of respectively preparing hydrotalcite coatings on the surfaces of magnesium alloy samples subjected to acid pretreatment by adopting an in-situ steam method: suspending a magnesium alloy sample pretreated by citric acid in a 100mL hydrothermal kettle with a polytetrafluoroethylene lining, and then adding 20mL pure water, wherein the distance between the magnesium alloy sample and the liquid level is kept at 2.5 cm; and (3) starting the hydrothermal kettle for heating at 160 ℃ for 7h, taking out after the reaction is finished, and naturally cooling to room temperature to obtain the magnesium alloy material with the hydrotalcite coating.
The thickness of the hydrotalcite coating of the prepared magnesium alloy material and the volume fraction of the Al-Mn phase on the surface of the magnesium alloy sample are detected, and the detection results are shown in the following Table 1.
Table 1 test results of example 2
Example 3
The matrix material is an extruded magnesium alloy AZ61, and the step of preparing the hydrotalcite coating on the surface of the extruded magnesium alloy AZ61 is as follows:
(1) pretreating the surface of the magnesium alloy substrate: polishing a magnesium alloy sample to remove a surface oxide layer until no obvious burrs exist on the surface of a base material, cleaning with an organic solvent and drying;
(2) carrying out acid pretreatment on the magnesium alloy sample pretreated in the step (1): preparing a 20g/L citric acid solution, immersing an AZ61 magnesium alloy sample into the citric acid solution, taking out after soaking for 40s, and then cleaning and drying to obtain an acid-pretreated magnesium alloy sample for later use;
(3) preparing a hydrotalcite coating on the surface of the magnesium alloy sample after acid pretreatment by adopting an in-situ steam method: suspending a magnesium alloy sample pretreated by citric acid in a 100mL hydrothermal kettle with a polytetrafluoroethylene lining, and then adding 20mL pure water, wherein the distance between the magnesium alloy sample and the liquid level is kept at 2.5 cm; and (3) starting the hydrothermal kettle for heating at 160 ℃ for 6h, taking out after the reaction is finished, and naturally cooling to room temperature to obtain the magnesium alloy material with the hydrotalcite coating.
The thickness of the hydrotalcite coating of the prepared magnesium alloy material is detected, and the thickness is 60.87 mu m.
Example 4
The base material is as-cast AZ31 magnesium alloy, and the step of preparing the hydrotalcite coating on the surface of the as-cast AZ31 magnesium alloy is as follows:
(1) pretreating the surface of the magnesium alloy substrate: taking 2 samples from the same as-cast magnesium alloy, polishing the magnesium alloy sample to remove a surface oxide layer until no obvious burrs exist on the surface of a base material, cleaning with an organic solvent and drying;
(2) carrying out acid pretreatment on the magnesium alloy sample pretreated in the step (1): preparing 10g/L and 20g/L oxalic acid solutions, respectively soaking the as-cast AZ31 magnesium alloy samples into the oxalic acid solutions for 40s, taking out, cleaning and drying to obtain magnesium alloy samples subjected to acid pretreatment for later use;
(3) preparing a hydrotalcite coating on the surface of the magnesium alloy sample after acid pretreatment by adopting an in-situ steam method: suspending a magnesium alloy sample pretreated by oxalic acid in a 100mL hydrothermal kettle with a polytetrafluoroethylene lining, and then adding 20mL pure water, wherein the distance between the magnesium alloy sample and the liquid level is kept at 2.5 cm; and (3) starting the hydrothermal kettle for heating at 160 ℃ for 6h, taking out after the reaction is finished, and naturally cooling to room temperature to obtain the magnesium alloy material with the hydrotalcite coating.
The thickness of the prepared hydrotalcite coating is detected, and the thickness is 41.25 μm and 35.25 μm.
Example 5
The substrate material is as-cast AM50 magnesium alloy, which is different from example 4 in that it is pretreated for 40s only by 10g/L oxalic acid, and the rest is the same as example 4, and the thickness of the hydrotalcite coating on the surface of the as-cast AM50 magnesium alloy prepared is 47.32 μm.
Example 6
The substrate material was as-cast magnesium alloy AZ91, and the rest was the same as in example 1, and the thickness of the hydrotalcite coating on the surface of the prepared magnesium alloy AZ91 was 57.20. mu.m.
Comparative example 1
The base material was magnesium alloy AZ31 in an extruded state and was obtained from the same magnesium alloy sheet as in example 1. This comparative example 1 is different from example 1 in that this comparative example 1 was not subjected to acid pretreatment in the preparation of the hydrotalcite coating layer, and the thickness of the hydrotalcite coating layer on the surface of the magnesium alloy AZ31 prepared in this comparative example 1 was 30.75 μm, as in example 1.
Comparative example 2
The base material was magnesium alloy AZ31 in an extruded state and was obtained from the same magnesium alloy sheet as in example 1. The comparative example 2 is different from the example 1 in that the comparative example 2 uses inorganic acid pretreatment in preparing the hydrotalcite coating, 10ml/L of phosphoric acid, 5ml/L of hydrochloric acid and 30ml/L of nitric acid, respectively, and the rest is the same as the example 1, and the thickness of the hydrotalcite coating on the surface of the magnesium alloy AZ31 prepared in the comparative example 1 is 26.51 μm, 29.91 μm and 34.59 μm, respectively.
Example 1 and example 2 were selected as representative examples, and correlation tests in fig. 1 to fig. 16 were performed on example 1 and example 2 and comparative example 1 and comparative example 2, and the test results and analysis were as follows.
In fig. 1, (a) is a metallographic photograph (magnification 100 times) of a magnesium alloy matrix of AZ31 not subjected to acid pretreatment of comparative example 1, (b) is a metallographic photograph (magnification 100 times) of a magnesium alloy matrix of comparative example 2 subjected to phosphoric acid pretreatment, (c) is a metallographic photograph (magnification 100 times) of a magnesium alloy matrix of comparative example 2 subjected to hydrochloric acid pretreatment, (d) is a metallographic photograph (magnification 100 times) of a magnesium alloy matrix of comparative example 2 subjected to nitric acid pretreatment, (e) is a metallographic photograph (magnification 100 times) of a magnesium alloy matrix of example 1 subjected to citric acid pretreatment, (f) the volume fractions of the Al — Mn phases on the surfaces of the AZ31 magnesium alloy substrate not subjected to acid pretreatment in comparative example 1, the AZ31 magnesium alloy substrate subjected to nitric acid pretreatment in comparative example 2, and the magnesium alloy substrate subjected to acid pretreatment in example 1 were calculated. As shown in FIG. 1(a), the surface of AZ31 magnesium alloy which is not subjected to acid pretreatment has less Al-Mn phase; as shown in (b) and (c) of FIG. 1, the Al-Mn phase on the surface of the AZ31 magnesium alloy cannot be increased through the pretreatment of phosphoric acid and hydrochloric acid, and a large number of pitting pits appear on the surface of the alloy, which causes more serious corrosion defects, especially the most serious corrosion of hydrochloric acid, although the acidity of the phosphoric acid is relatively weak, the surface of the magnesium alloy is corroded first by the phosphoric acid, and then phosphate ions and Mg are corroded2+And Al3+Magnesium phosphate and aluminum phosphate are generated and deposited on the surface of the magnesium alloy substrate, not only Mg is consumed2+And Al3+And a layer of film is formed on the surface to cover the surface, so that the growth of the hydrotalcite coating is influenced; as shown in the diagrams (d) and (e), the Al-Mn phase on the surface of the AZ31 magnesium alloy pretreated by nitric acid and citric acid tends to increase, and the surface of the magnesium alloy pretreated by nitric acid has only a few pitting pits, although nitric acid is a strong acid, it is a strong oxidizing acid unlike hydrochloric acid, and an oxide film is formed on the surface of the substrate, so that a large amount of pitting corrosion is not easy to occur; and citric acidThe organic weak acid can cause slight micro-couple corrosion on the surface of the magnesium alloy, so that Mg on the surface of a substrate is dissolved into Mg2+And at the same time, the Al-Mn phase is exposed. In addition, as can be seen from fig. 1(f), the volume fraction of the aluminum-manganese phase on the surface of the magnesium alloy pretreated by citric acid is increased from 1.98% to 5.40% compared with the magnesium alloy without acid pretreatment, which is approximately increased by three times, and further illustrates that the aluminum-rich phase on the surface of the magnesium alloy substrate pretreated by citric acid is increased, so that more growth sites can be provided for the growth of the subsequent hydrotalcite coating.
Fig. 2(a), (b) are scanning electron micrographs (magnification of 2500 x) of a magnesium alloy substrate of AZ31 without acid pretreatment of comparative example 1 and a magnesium alloy substrate of example 1 with citric acid pretreatment. As shown in fig. 2(a), the exposed Al-Mn phase on the surface of the AZ31 magnesium alloy without acid pretreatment is less, while as can be seen from fig. 2(b), the exposed Al-Mn phase on the surface of the AZ31 magnesium alloy after acid pretreatment is more, which indicates that the acid pretreatment can increase the Al-Mn phase on the surface of the magnesium alloy, and the result is consistent with the result of a metallographic microscope, so that more growth sites are provided for the subsequent hydrotalcite growth.
Fig. 3(a), (b) are EDS graphs of the AZ31 magnesium alloy substrate without acid pretreatment of comparative example 1 and the magnesium alloy substrate with citric acid pretreatment of example 1. As shown in fig. 3(a), the surface of the AZ31 magnesium alloy substrate that has not been subjected to acid pretreatment mainly contains Mg, and from fig. 3(b), it can be seen that the phase compositions exposed on the surface of the AZ31 magnesium alloy substrate that has been subjected to acid pretreatment mainly contain Al, Mn, and Si, which further indicates that the aluminum-rich phase on the surface of the magnesium alloy substrate after acid pretreatment is increased.
Fig. 4(a), (b) are EDS graphs of the magnesium alloy material with hydrotalcite coating prepared without acid pretreatment and the magnesium alloy material with hydrotalcite coating prepared by example 1 through citric acid pretreatment. As shown in fig. 4(a) and (b), it can be seen that the content of Al element and C element on the surface of the hydrotalcite coating prepared on the surface of the AZ31 magnesium alloy subjected to acid pretreatment in example 1 is significantly increased compared with the content of Al element and C element on the surface of the hydrotalcite coating prepared on the surface of the AZ31 magnesium alloy not subjected to acid pretreatment in comparative example 1, which indicates that the magnesium alloy substrate subjected to acid pretreatment has more Al element participating in the reaction, and also indicates that the Al — Mn phase on the surface of the magnesium alloy substrate subjected to acid pretreatment can promote the growth of the hydrotalcite coating.
Fig. 5(a), (b) scanning electron micrographs (3500 x magnification) of cross sections of the magnesium alloy material with hydrotalcite coating prepared without acid pretreatment and the magnesium alloy material with hydrotalcite coating prepared in example 1 with citric acid pretreatment. As shown in fig. 5(a) and (b), it can be seen that the hydrotalcite coating prepared on the surface of the extruded AZ31 magnesium alloy subjected to acid pretreatment of example 1 is denser, the bonding between the coating and the substrate is tighter than the hydrotalcite coating prepared on the surface of the extruded AZ31 magnesium alloy not subjected to acid pretreatment of comparative example 1 (as can be seen from fig. 5(a), the adhesion between the hydrotalcite coating not subjected to acid pretreatment and the substrate is not tight enough, large pores exist between the coating and the substrate), and the coating thickness is increased from 30.85 μm to 37.65 μm, indicating that the acid pretreatment enhances the growth rate of the coating and causes the coating thickness to be increased significantly. The reason is that the acid pretreatment can increase the phase density, content and activity of the aluminum-rich phase on the surface of the magnesium alloy, and provide more growth sites for the growth of the subsequent hydrotalcite coating, thereby promoting the growth of the hydrotalcite coating.
Fig. 6 is a metallographic photograph of the surface of the AZ80 magnesium alloy substrate after the pretreatment with citric acid and the corresponding volume fraction of the Al — Mn phase on the surface of the magnesium alloy substrate of example 2, wherein fig. 6(a) is a metallographic photograph (magnification 100 times) of the surface of the magnesium alloy substrate without the pretreatment with acid; fig. 6(b), (c), and (d) are metallographic photographs (magnification 100 times) of the surface of the magnesium alloy matrix after pretreatment with citric acid for 10s, 20s, and 30s, respectively, and fig. (e) is the volume fraction of the Al — Mn phase on the surface of the corresponding magnesium alloy matrix. Fig. 7 is a scanning electron micrograph (3500 times magnification) of a cross section of the AZ80 magnesium alloy material having a hydrotalcite coating prepared in example 2, in which fig. 7(a) was not subjected to acid pretreatment, and fig. 7(b), (c), and (d) were subjected to citric acid pretreatment for 10s, 20s, and 30s, respectively. As can be seen from fig. 6 and 7, as the pretreatment time with citric acid increases, the volume fraction of the Al-Mn phase on the surface of the magnesium alloy substrate increases, and the thickness of the hydrotalcite coating increases accordingly, further indicating that the acid pretreatment can activate the surface of the magnesium alloy, increase the volume fraction of the Al-Mn phase on the surface of the magnesium alloy, and further indicating that the presence of the Al-Mn phase can provide more growth sites for the growth of the hydrotalcite coating.
Combining the correlation detection and analysis of fig. 1-7, it can be concluded that: the volume fraction and activity of the Al-Mn phase on the surface of the magnesium alloy substrate can be increased by the pretreatment of the organic weak acid, and the existence of the Al-Mn phase can provide more growth sites for preparing the hydrotalcite coating by the in-situ steam method.
Next, the relative physical and chemical properties of the prepared hydrotalcite coating layer were examined.
Fig. 8(a), (b) are scanning electron micrographs (magnification of 20000 times) of the magnesium alloy material with hydrotalcite coating prepared in comparative example 1 without acid pretreatment and the magnesium alloy material with hydrotalcite coating prepared in example 1 with citric acid pretreatment. As shown in fig. 8(a) and (b), the hydrotalcite coating prepared on the surface of the AZ31 magnesium alloy pretreated by citric acid in example 1 is denser than the hydrotalcite coating prepared on the surface of the AZ31 magnesium alloy not pretreated by acid in comparative example 1, and can provide better protection for the substrate.
Fig. 9 is an X-ray diffraction (XRD) pattern of the magnesium alloy material with hydrotalcite coating prepared in comparative example 1 without acid pretreatment and the magnesium alloy material with hydrotalcite coating prepared in example 1 with citric acid pretreatment. As shown in fig. 9, it can be seen that characteristic peaks of the (003) plane and the (006) plane of the hydrotalcite layered structure appear at diffraction angles of 11.27 ° and 23 °, and the hydrotalcite characteristic diffraction peak of the hydrotalcite coating prepared on the surface of the AZ31 magnesium alloy subjected to acid pretreatment of example 1 is stronger, indicating that the hydrotalcite coating prepared after acid pretreatment has a higher hydrotalcite content.
Fig. 10 is a comparison of zeta potential polarization (tafel) plots of the magnesium alloy material with hydrotalcite coating prepared without acid pretreatment in comparative example 1, the magnesium alloy material with hydrotalcite coating prepared with inorganic acid pretreatment in comparative example 2, the magnesium alloy material with hydrotalcite coating prepared with citric acid pretreatment in example 1, and the AZ31 magnesium alloy substrate. As can be seen from FIG. 10, AZ31 Mg alloy pretreated with citric acid was compared with the Mg alloy substrateCompared with the hydrotalcite coating prepared on the surface of AZ31 magnesium alloy without acid pretreatment and the hydrotalcite coating prepared on the surface of AZ31 magnesium alloy by inorganic acid pretreatment, the hydrotalcite coating prepared on the surface of gold has the advantages that the self-corrosion potential is increased, and the self-corrosion current density is obviously reduced, which indicates that the existence of the hydrotalcite coating effectively improves the corrosion resistance of the magnesium alloy matrix; compared with the hydrotalcite coating which is not pretreated by acid and the hydrotalcite coating which is pretreated by inorganic acid, the self-corrosion potential of the hydrotalcite coating prepared on the surface of AZ31 magnesium alloy which is pretreated by citric acid is increased from-1310 mV to-1280 mV, and the self-corrosion current density is increased from 4.22 multiplied by 10-7A/cm2Reduced to 4.46X 10-8A/cm2The corrosion resistance of the magnesium alloy material prepared by the citric acid pretreatment is better.
FIG. 11 is a plot of zeta potential polarization (tafel) of the AZ80 magnesium alloy material with hydrotalcite coating prepared in example 2, and combining the detection results of FIG. 6 and FIG. 7, it can be seen that, when the hydrotalcite coating is thicker, the higher the self-corrosion potential of the magnesium alloy material is, and the lower the self-corrosion current density is, the self-corrosion potential of the AZ80 magnesium alloy material without acid pretreatment is-1420 mV, and the self-corrosion current density is 8.28 × 10-6A/cm2And the magnesium alloy material prepared by treating for 30s with 20g/L citric acid solution has the self-corrosion potential of-1250 mV and the self-corrosion current density of 5.08 multiplied by 10-8A/cm2Two orders of magnitude are achieved under the self-corrosion current density, which shows that the thicker the thickness of the hydrotalcite coating is, the better the corrosion resistance of the magnesium alloy material is, and further shows that the pretreatment of the organic weak acid plays a positive role in the process of preparing the hydrotalcite coating.
Fig. 12 is a bode graph comparing the magnesium alloy material with hydrotalcite coating prepared in comparative example 1 without acid pretreatment with the magnesium alloy material with hydrotalcite coating prepared in comparative example 2 with inorganic acid pretreatment and the magnesium alloy material with hydrotalcite coating prepared in example 1 with citric acid pretreatment and the AZ31 magnesium alloy substrate. As can be seen from fig. 12, compared with the magnesium alloy substrate, the impedances of the hydrotalcite coating prepared on the surface of the AZ31 magnesium alloy pretreated by citric acid and the hydrotalcite coating prepared on the surface of the AZ31 magnesium alloy not pretreated by acid and the hydrotalcite coating pretreated by inorganic acid are obviously increased, which indicates that the corrosion resistance of the magnesium alloy substrate is effectively improved by the presence of the hydrotalcite coating; compared with a hydrotalcite coating which is not subjected to acid pretreatment and a hydrotalcite coating which is prepared by inorganic acid pretreatment, the impedance of the hydrotalcite coated stone prepared on the surface of the AZ31 magnesium alloy subjected to citric acid pretreatment is obviously increased, which shows that organic weak acid pretreatment plays a positive role in the process of preparing the hydrotalcite coating, and the corrosion resistance of the magnesium alloy material prepared by the citric acid pretreatment is better, and is consistent with the tafel curve result in fig. 10.
Fig. 13 is a comparison of the nyquist plot of the electrochemical energy of the magnesium alloy substrate of AZ31 and the magnesium alloy material with hydrotalcite coating prepared in comparative example 1 without acid pretreatment, the magnesium alloy material with hydrotalcite coating prepared in comparative example 2 with inorganic acid pretreatment, and the magnesium alloy material with hydrotalcite coating prepared in example 1 with citric acid pretreatment. As shown in fig. 13, compared with the magnesium alloy substrate, the hydrotalcite coating prepared on the surface of the AZ31 magnesium alloy pretreated by citric acid has a significantly larger capacitive arc than the hydrotalcite prepared on the surface of the AZ31 magnesium alloy not pretreated by acid and the hydrotalcite coating prepared by inorganic acid pretreatment, which indicates that the existence of the hydrotalcite coating effectively improves the corrosion resistance of the magnesium alloy substrate; compared with a hydrotalcite coating which is not subjected to acid pretreatment and a hydrotalcite coating which is prepared by inorganic acid pretreatment, the capacitive arc resistance of the hydrotalcite coated stone prepared on the surface of the AZ31 magnesium alloy subjected to citric acid pretreatment is also remarkably increased, which shows that organic weak acid pretreatment plays a positive role in the process of preparing the hydrotalcite coating, and the corrosion resistance of the magnesium alloy material prepared by the citric acid pretreatment is better, and is consistent with the tafel curve result in fig. 10.
Fig. 14(a), (b) and (c) are scanning electron micrographs (magnification of 1000 times) of a magnesium alloy substrate of AZ31, a magnesium alloy material with a hydrotalcite coating prepared in comparative example 1 without acid pretreatment, and a magnesium alloy material with a hydrotalcite coating prepared in example 1 with citric acid pretreatment, respectively, after being immersed in a sodium chloride solution having a concentration of 3.5% by mass for 10 days. As shown in fig. 14(a), the surface of the magnesium alloy substrate is completely covered by the corrosion product, and severe corrosion occurs, as shown in fig. 14(b), the hydrotalcite morphology of the hydrotalcite coating prepared on the surface of the AZ31 magnesium alloy which is not subjected to acid pretreatment substantially disappears, as shown in fig. 14(c), the hydrotalcite coating prepared on the surface of the AZ31 magnesium alloy which is subjected to acid pretreatment is substantially complete in morphology, and no corrosion crack or corrosion pit occurs, which indicates that the hydrotalcite coating prepared on the surface of the AZ31 magnesium alloy which is subjected to organic weak acid pretreatment has an excellent corrosion protection effect on the magnesium alloy substrate.
FIG. 15 (a)1-a5)、(b1-b5) And (c)1-c5) Digital camera photographs of a magnesium alloy substrate of AZ31, a magnesium alloy material (whose surface is a hydrotalcite coating prepared without acid pretreatment) prepared in comparative example 1, and a magnesium alloy material (whose surface is a hydrotalcite coating prepared by citric acid pretreatment) prepared in example 1 were respectively placed in a sodium chloride salt fog atmosphere with a mass percentage concentration of 5% for different times. As shown in FIG. 15 (a)2) As shown in FIG. 15 (b), the corrosion of the surface of the magnesium alloy substrate was severe after 72 hours of standing in a salt spray atmosphere2) As shown, there were few corrosion pits on the surface of the hydrotalcite coating prepared on the surface of AZ31 magnesium alloy which had not been subjected to acid pretreatment, as shown in FIG. 15 (c)2) The surface of a hydrotalcite coating prepared on the surface of AZ31 magnesium alloy subjected to acid pretreatment has no obvious change; as shown in FIG. 15 (a)4) As shown, the surface of the magnesium alloy substrate was completely corroded after being left for 288 hours in the salt spray atmosphere, as shown in FIG. 15 (b)4) As shown, the hydrotalcite coating prepared on the surface of AZ31 magnesium alloy which has not been subjected to acid pretreatment has a large number of large corrosion pits on the surface, as shown in FIG. 15 (c)4) After 288 hours of salt spray experiments, the hydrotalcite coating prepared on the surface of the AZ31 magnesium alloy subjected to acid pretreatment has no corrosion pits in other areas except for the small corrosion pits at the edge, which is probably caused by the stress concentration caused by cutting the sample; as shown in FIG. 15 (c)5) The surface of AZ31 magnesium alloy which is pretreated by acid is shown to be preparedAfter 576 hours of salt spray experiments, no corrosion pit appears in other areas except the corrosion pit at the edge of the prepared hydrotalcite coating, which is probably caused by stress concentration caused by cutting a sample, and the above results show that the hydrotalcite coating prepared on the surface of the AZ31 magnesium alloy subjected to acid pretreatment has excellent corrosion resistance protection effect on a magnesium alloy substrate. In addition, the corrosion resistance of the hydrotalcite coating prepared on the magnesium alloy surface subjected to nitric acid pretreatment is detected, and a large number of corrosion pits appear after 288 hours in a salt spray test, so that the magnesium alloy surface is pretreated by using weak organic acid, and the effect is better.
Combining the correlation detection and analysis of fig. 9-15, it can be concluded that: the effect of acid pretreatment by organic weak acid is better than that of inorganic acid, so the invention provides a method for acid pretreatment by organic weak acid, and the method is combined with an in-situ steam method to prepare the hydrotalcite coating on the surface of the magnesium alloy substrate, and the prepared hydrotalcite coating has thick coating, compact structure and excellent corrosion resistance.
In addition, in order to further study the effect of the weak organic acid on the growth of the hydrotalcite coating layer better than that of the inorganic acid, the mechanism of the weak organic acid was further studied, and the X-ray photoelectron spectrum of the C1s peak of the following sample was detected.
Sample 1: soaking an AZ31 magnesium alloy sample in a citric acid solution of 30g/L for 30s, taking out, cleaning and drying to obtain a magnesium alloy sample 1 pretreated by citric acid;
sample 2: preparing a hydrotalcite coating on a magnesium alloy sample pretreated by citric acid by adopting an in-situ steam method by adopting the preparation method of example 1, heating the magnesium alloy sample at 160 ℃ for 0.5h, taking out the magnesium alloy sample after the reaction is finished, and naturally cooling the magnesium alloy sample to room temperature to obtain a magnesium alloy sample 2 with the hydrotalcite coating;
sample 3: the preparation method of example 1 is adopted, the magnesium alloy sample pretreated by citric acid is prepared into the hydrotalcite coating by the in-situ steam method, the heating temperature is 160 ℃, the heating time is 1.5h, and after the reaction is finished, the magnesium alloy sample is taken out and naturally cooled to the room temperature, so that the magnesium alloy sample 3 with the hydrotalcite coating is obtained.
As shown in fig. 16(a), (b), and (C), which are X-ray photoelectron spectra of the C1s peak of the above 3 samples, the peak of C1s in fig. 16(a) and (b) is divided into three peaks: C-C, 284.6 eV; C-O, 286.6 eV; c ═ O, 288.4eV, where the bond C ═ O corresponds to C6H8O7Is present. After acid pretreatment and oven drying, C can also be detected6H8O7The presence of (B) indicates that C6H8O7Has certain complexing ability with metal ions, is complexed on the surface of a magnesium alloy substrate, and can continuously complex free Mg in the forming process of the LDH coating2+And Al3+。
To further explore C6H8O7Fig. 16 shows XPS curve fitting of C1s for each sample.
In FIG. 16(a), C6H8O7After acid pretreatment, the existence of C ═ O bonds on the surface of the AZ31 magnesium alloy can be observed, which indicates that the surface of the magnesium alloy substrate has C after acid pretreatment, cleaning and drying6H8O7And (4) remaining. At this stage, C is more easily produced6H8O7With Mg2+Because the dissolution of alpha-Mg occurs mainly at this time, Mg at the matrix/solution interface2+The content is relatively high;
in fig. 16(b), after 0.5h of in situ steam reaction, the presence of C ═ O bonds could still be detected, demonstrating that C was present at this stage6H8O7There is still the presence of Mg first, before LDH formation2+And Al3+And with OH-Reaction to form Mg (OH)2And Al (OH)3Citric acid in this process complexes predominantly free Mg2+And Al3+The complexation mainly plays a role in carboxyl, adsorbs and binds metal ions in solution and is Mg (OH)2And Al (OH)3Provide a continuous supply of Mg2+And Al3+Playing an important role in the nucleation process of the hydrotalcite coating;
in FIG. 16(c), CO was observed after 1.5h of in situ steam reaction3 2-Group, but no C ═ O bond was detected, indicating C6H8O7Does not participate in the subsequent growth of the LDH coating, and at the same time, CO3 2-The presence of the group indicates that the intercalation ion between the layers of the LDH is CO3 2-Thus, C can be inferred6H8O7Only during the initial stages of coating growth.
The carboxyl groups present in the weak organic acids may complex with free Mg2+And Al3+The method plays an important role in the nucleation process of the hydrotalcite coating, so that the method has better effect than inorganic acid by adopting organic weak acid to pretreat the surface of the magnesium alloy, and the generated hydrotalcite coating has large thickness and high density.
Fig. 17 is a macroscopic photograph of a micrometer scratch test of the hydrotalcite vapor coating prepared on the surface of the extruded AZ61 magnesium alloy pretreated by the acid in example 3, and under the constant stress of 20N, a part of the coating in the middle area of the scratch is still not scratched, which indicates that the hydrotalcite coating prepared by the vapor method has good bonding force with the substrate and can provide good protection for the substrate.
In addition, the preparation method of the embodiment 1 is adopted to prepare the hydrotalcite coating on the surfaces of the extruded AZ31 magnesium alloy pipe and section, and macroscopic observation shows that the surfaces of the obtained pipe and section are grey and the surface coating is dense, which shows that the pipe and section can be successfully prepared into the hydrotalcite coating by the in-situ steam method, and shows that the process can be applied to the magnesium alloy member with a complex shape.
The parts not mentioned above can be realized by referring to the prior art.
It is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art may make modifications, alterations, additions or substitutions within the spirit and scope of the present invention.
Claims (9)
1. A method for preparing a hydrotalcite coating on the surface of a magnesium alloy by combining acid pretreatment and a steam method is characterized by comprising the following steps:
(1) pretreating the surface of the magnesium alloy substrate;
(2) carrying out acid pretreatment on the magnesium alloy substrate pretreated in the step (1);
(3) and (3) preparing a hydrotalcite coating on the surface of the magnesium alloy substrate subjected to acid pretreatment in the step (2) by adopting an in-situ steam method.
2. The method for preparing the hydrotalcite coating on the surface of the magnesium alloy by combining the acid pretreatment with the steam method according to claim 1, wherein the step (1) is specifically as follows: and polishing the magnesium alloy matrix to remove the surface oxide layer, and then cleaning and drying the magnesium alloy matrix by using an organic solvent.
3. The method for preparing the hydrotalcite coating on the surface of the magnesium alloy by combining the acid pretreatment with the steam method according to claim 1, wherein the step (2) is specifically as follows: preparing an acid solution, immersing the pretreated magnesium alloy matrix into the acid solution for soaking, then taking out the magnesium alloy matrix, cleaning and drying.
4. The method for preparing hydrotalcite coating on magnesium alloy surface by acid pretreatment combined with steam method as claimed in claim 3, wherein the acid solution is weak organic acid solution.
5. The method for preparing hydrotalcite coating on magnesium alloy surface by acid pretreatment combined with steam method as claimed in claim 4, wherein the weak organic acid solution is at least one of oxalic acid solution, acetic acid solution or citric acid solution.
6. The method for preparing hydrotalcite coating on magnesium alloy surface by combining acid pretreatment and steam method according to claim 3, wherein the concentration of the weak organic acid solution is 10-50 g/L, and the soaking time is 10-60 s.
7. The method for preparing the hydrotalcite coating on the surface of the magnesium alloy by combining the acid pretreatment with the steam method according to claim 1, wherein the step (3) is specifically as follows: suspending the magnesium alloy substrate subjected to acid pretreatment in a 100mL hydrothermal kettle with a polytetrafluoroethylene lining, and then adding 10-30 mL pure water to keep the distance between the magnesium alloy substrate and the liquid level at 1-4 cm; and (3) placing the hydrothermal kettle in a heater for heating at the temperature of 100-220 ℃ for 1-18 h, taking out after the reaction is finished, and naturally cooling to room temperature to obtain the magnesium alloy material with the hydrotalcite coating.
8. The method for preparing hydrotalcite coating on the surface of magnesium alloy by combining acid pretreatment and steam method according to claim 1, wherein the magnesium alloy is Mg-Al series alloy.
9. The hydrotalcite coated magnesium alloy material prepared according to any of claims 1-8, wherein the hydrotalcite coated magnesium alloy material has a salt spray corrosion resistance time of more than 500 hours in a salt spray atmosphere of 5 wt.% sodium chloride.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110867457.2A CN113564590A (en) | 2021-07-30 | 2021-07-30 | Method for preparing hydrotalcite coating on surface of magnesium alloy by combining acid pretreatment with steam method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110867457.2A CN113564590A (en) | 2021-07-30 | 2021-07-30 | Method for preparing hydrotalcite coating on surface of magnesium alloy by combining acid pretreatment with steam method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113564590A true CN113564590A (en) | 2021-10-29 |
Family
ID=78169314
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110867457.2A Pending CN113564590A (en) | 2021-07-30 | 2021-07-30 | Method for preparing hydrotalcite coating on surface of magnesium alloy by combining acid pretreatment with steam method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113564590A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102677038A (en) * | 2011-03-10 | 2012-09-19 | 中国科学院金属研究所 | Film forming solution for growing Mg-Al hydrotalcite film in situ on surface of magnesium alloy and application thereof |
| CN103320782A (en) * | 2013-06-21 | 2013-09-25 | 四川理工学院 | Preparation method of magnesium alloy composite film |
| CN108707889A (en) * | 2018-06-12 | 2018-10-26 | 西安交通大学 | A kind of method of magnesium alloy growth in situ LDH conversion films |
-
2021
- 2021-07-30 CN CN202110867457.2A patent/CN113564590A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102677038A (en) * | 2011-03-10 | 2012-09-19 | 中国科学院金属研究所 | Film forming solution for growing Mg-Al hydrotalcite film in situ on surface of magnesium alloy and application thereof |
| CN103320782A (en) * | 2013-06-21 | 2013-09-25 | 四川理工学院 | Preparation method of magnesium alloy composite film |
| CN108707889A (en) * | 2018-06-12 | 2018-10-26 | 西安交通大学 | A kind of method of magnesium alloy growth in situ LDH conversion films |
Non-Patent Citations (2)
| Title |
|---|
| QIU ZAI-MENG: "Corrosion resistance and hydrophobicity of myristic acid modified Mg-Al LDH/Mg(OH)2 steam coating on magnesium alloy AZ31", 《FRONTIERS OF MATERIALS SCIENCE》 * |
| 仇在孟: "《AZ31镁合金表面水滑石蒸汽涂层和复合涂层的制备及其耐蚀性研究》", 《中国优秀硕士学位论文全文数据库，工程科技Ⅰ辑》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Lingjie et al. | Formation and characterization of cerium conversion coatings on magnesium alloy | |
| JP6115912B2 (en) | High corrosion resistance magnesium-based material, method for producing the same, and surface treatment method for magnesium-based material | |
| Pak et al. | Fabrication of environmentally friendly anti-corrosive composite coatings on AZ31B Mg alloy by plasma electrolytic oxidation and phytic acid/3-aminopropyltrimethoxysilane post treatment | |
| JP5157487B2 (en) | Steel plate for containers and manufacturing method thereof | |
| Nakamura et al. | Formation mechanism of Mg-Al layered double hydroxide-containing magnesium hydroxide films prepared on Ca-added flame-resistant magnesium alloy by steam coating | |
| Nabizadeh et al. | Comparative investigation of Cu ion and adipic acid addition on electrochemical and microstructure characteristics of vanadium conversion coating on AZ31 Mg alloy | |
| JP5186814B2 (en) | Steel plate for containers and manufacturing method thereof | |
| Roshan et al. | Improved performance of Ti-based conversion coating in the presence of Ce/Co ions: Surface characterization, electrochemical and adhesion study | |
| Jian et al. | Characteristic V-Mn conversion coating in reinforcing corrosion resistance of electroless Ni-P coated LZ91 Mg alloy | |
| Pan et al. | Advances in Mg–Al-layered double hydroxide steam coatings on Mg alloys: a review | |
| Al Bacha et al. | Hydrolysis properties, corrosion behavior and microhardness of AZ91 “model” alloys | |
| Fayed et al. | Corrosion inhibition characteristics of multilayer Si-DLC, phosphating and anodizing coatings deposited on 2024 Al alloy: a comparative study | |
| Bai et al. | Surface modifications of aluminum alloy 5052 for bipolar plates using an electroless deposition process | |
| CA2848347C (en) | Zincating aluminum | |
| Park et al. | Ultra-high corrosion resistance of Al-Mg-Si film on steel sheet formed by PVD Mg coating and heat treatment | |
| CN102011115A (en) | Pretreatment liquid and pretreatment method before rare earth conversion | |
| WO2019225674A1 (en) | Aluminum alloy material having excellent corrosion resistance and strength, and method for producing same | |
| Liu et al. | Unraveling the formation mechanism of a hybrid Zr-based chemical conversion coating with organic and copper compounds for corrosion inhibition | |
| Bhat et al. | Surface structure and electrochemical behavior of Zinc-Nickel anti-corrosive coating | |
| Hamdy et al. | Deposition, characterization and electrochemical properties of permanganate-based coating treatments over ZE41 Mg-Zn-rare earth alloy | |
| Feng et al. | Influence of intermetallic Al-Mn particles on in-situ steam Mg-Al-LDH coating on AZ31 magnesium alloy | |
| CN113564590A (en) | Method for preparing hydrotalcite coating on surface of magnesium alloy by combining acid pretreatment with steam method | |
| CA2769198C (en) | Method for manufacturing a thermal barrier | |
| CN113042343B (en) | Preparation method of super-hydrophobic intermetallic compound-based protective layer with high mechanical stability and corrosion resistance | |
| Zhang et al. | Anticorrosion Performance of LDH Coating Prepared by CO 2 Pressurization Method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20211029 |