CN101029387A - Production of magnesium-alloy surface molybdate phosphate composite transferring film - Google Patents
Production of magnesium-alloy surface molybdate phosphate composite transferring film Download PDFInfo
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- CN101029387A CN101029387A CN 200710034700 CN200710034700A CN101029387A CN 101029387 A CN101029387 A CN 101029387A CN 200710034700 CN200710034700 CN 200710034700 CN 200710034700 A CN200710034700 A CN 200710034700A CN 101029387 A CN101029387 A CN 101029387A
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- molybdate
- magnesium
- alloy surface
- phosphate
- alloy
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Abstract
Production of magnesium-alloy surface molybdate phosphate composite conversion film and its treating agent are disclosed. The treating agent consists of molybdate, dihydric phosphate, nitrate of lime, manganese slat, improver and oxidant; it is prepared by adding into molybdate, dissolving, adjusting solution to acidity by phosphoric acid, adding into dihydric phosphate, nitrate of lime and manganese salt, adjusting pH-value to 5-6, and adding into improver and oxidant The process is carried out by sanding for magnesium-alloy sample surface by gold-phase abrasive paper, washing by running water and deionized water, acetone supersonic cleaning, washing by deionized water, putting magnesium-alloy into treating agent, chemical treating at 50degree for 5mins, washing by running water, and drying by cold wind. It has excellent anti-corrosion performance.
Description
Technical field
The present invention relates to chemical field, further be meant the preparation method of magnesium-alloy surface molybdate phosphate composite transferring film.
Background technology
Magnesium alloy has higher strength-weight ratio, is widely used in fields such as automatization, computer, mobile telephone, aviation as the structural metal.Yet the standard potential of magnesium is lower, causes the corrosion resisting property of magnesium alloy very poor, thereby Application of Magnesium is restricted.
The magnesium alloy chemical treatment process is widely used because of it is simple to operate, with low cost, adopt chromating to handle usually to strengthen rete solidity to corrosion and and organic coating film between bonding force, but legislations of environmental protection clearly provides against and contains poisonous chromium (Cr
6+) use of compound, the particularly formal RoHS environmental protection instruction of putting into effect of European Union in 2005, after i.e. 1 day July in 2006, the electric equipment products in input European Union market must not contain Polybrominated biphenyl and the 6 kinds of objectionable impuritiess such as Poly Brominated Diphenyl Ethers, sexavalent chrome in mercury, lead, cadmium, the halogen flame retardant.Therefore it is imperative that Mg alloy surface adopts eco-friendly chromium-free deactivation processing.
Some environmental friendliness chemical treatment methods are obtained certain application at magnesium and alloy surface thereof, mainly comprise phosphoric acid salt permanganate, stannate, cerium and other rare earth metal, fluozirconate system etc.Because existing chromium-free treatment method and traditional chromate treating still have a certain distance on corrosion resistance nature and self-reparing capability, develop new chromium-free treatment agent and treatment process thereof and remain from now on focus.Recently, the phosphate transfection metallization processes is developed in the research of magnesium alloy substrate surface, and still single phosphate conversion layer is not enough to the corrosion protection of magnesium alloy substrate.Molybdate is a kind of local corrosion inhibitor, has low toxicity, harmless, efficient, good stability, with multiple material advantages such as synergistic effect is arranged, and is used widely, has replaced chromic salt, nitrite in many systems gradually.But the molybdate of lower concentration is not enough on matrix to form the rete with provide protection, and the molybdate of higher concentration handles that then cost is too high.
Summary of the invention
The technical problem to be solved in the present invention is, defective at the prior art existence, a kind of preparation method of magnesium-alloy surface molybdate phosphate composite transferring film is proposed, the gained rete has excellent corrosion resisting performance and processing performance, can effectively substitute Mg alloy surface chromic salt technology, have good use prospect.
Technical scheme of the present invention is that the preparation method of described magnesium-alloy surface molybdate phosphate composite transferring film comprises:
(1) treatment solution of magnesium-alloy surface molybdate phosphate composite transferring film preparation:
A. the composition of described treatment solution is, every premium on currency solution contains:
Molybdate 0.1mol～0.2mol,
Dihydrogen phosphate 0.2mol～0.4mol,
Nitrocalcite 0.02mol～0.1mol,
Manganese salt 0.02mol～0.06mol,
Promotor≤0.01mol,
Oxygenant≤0.01mol; Wherein:
Described molybdate is one or more the arbitrary proportion mixture in Sodium orthomolybdate or the ammonium molybdate;
Described dihydrogen phosphate is one or more the arbitrary proportion mixture in SODIUM PHOSPHATE, MONOBASIC or the monocalcium phosphate;
Described manganese salt is one or more the arbitrary proportion mixture in manganese acetate or potassium permanganate, the manganous nitrate;
Described promotor is any in SODIUMNITRATE or nitrocalcite, sodium chlorate, the calcium chlorate;
Described oxygenant is potassium perchlorate or potassium permanganate;
B. the blending process of described treatment solution is: add described molybdate earlier, dissolve the back and with phosphoric acid solution is transferred to acidity; Add calcium salt, to prevent precipitation; Add dihydrogen phosphate and manganese salt then, re-adjustment pH value is 5～6, adds described promotor, oxygenant;
(2) step of preparation process of magnesium-alloy surface molybdate phosphate composite transferring film is:
A. the pre-treatment of Mg alloy surface: extremely carefully polished by thick one by one with abrasive paper for metallograph in the magnesium alloy sample surface, or adopt clean-out system to remove surface contaminants;
B. tap water cleans;
C. washed with de-ionized water;
D. chemical conversion is handled: place described treatment solution to carry out the chemical conversion film forming magnesium alloy sample and handle, treatment time 4-6 minute, the treatment solution temperature was controlled at 20 ℃-55 ℃;
E. the sample after chemical conversion being handled cleans with tap water, and cold wind dries up, promptly.
Below the present invention made further specify.
Among the present invention, the pH value of the used treatment solution of magnesium-alloy surface molybdate phosphate composite transferring film preferably is controlled at 5～6, because development person of the present invention a large number of experiments show that, when pH 〉=6.0, conversion film is not sufficiently complete to the covering of matrix surface, transforms to finish rapidly, and when pH≤4.0, sedimentation velocity is too fast, inhomogeneous, the dust of film layer structure, and Corrosion Protection is poor.
When the present invention transformed the film forming processing, the temperature of treatment solution preferably was controlled at 40～50 ℃, and too high temperature can make the film forming speed of solution accelerate, and can make the crystal grain that forms at Mg alloy surface thick like this, and the solidity to corrosion of alloy is reduced.
Among the present invention, the formation time of magnesium-alloy surface molybdate phosphate composite transferring film was about about 5 minutes, and the long time can generate new crystallization on conversion film, made conversion film loose, the solidity to corrosion variation.
Promotor in the treatment solution of the magnesium-alloy surface molybdate phosphate composite transferring film that the present invention proposes is preferentially used potassium perchlorate, and it can strengthen cathodic depolarization, and film process is more rapid, and the phosphatize phosphate coat crystallization is more fine and closely woven.
In the treatment solution of the present invention, the oxygenant consumption should be accurate, and its concentration preferably is controlled at 0.1mol/L and is advisable.
Molybdate and phosphatic molar ratio are preferably 1: 2 in the treatment solution of the magnesium-alloy surface molybdate phosphate composite transferring film that the present invention proposes, and have best Corrosion Protection this moment.
The magnesium-alloy surface molybdate phosphate composite transferring film performance characterization that the present invention makes is:
Molybdate phosphate conversion film is a corrosion/deposition process in the growth of Mg alloy surface, phosphoric acid salt because the relative metal molybdate of solubility product is lower by preferential deposition, molybdenum in the rete (Mo) element mainly exists with the form of oxide compound, along with growing up rapidly of single crystal grain, matrix surface is capped gradually, stable Me
3(PO
4)
2(Me is metal ion: Mn
2+, Mg
2+, Ca
2+) salt and composite salt thereof, and may form cancellated oxide compound (as MgO, Al
2O
3) fully combination, constituting together more complicated provides better corrosion protection for magnesium alloy substrate.
Table one is the saline soak test result of the magnesium-alloy surface molybdate phosphate composite transferring film prepared of the present invention.
The saline soak test of table one magnesium-alloy surface molybdate phosphate composite transferring film
| The conversion film type | Outward appearance before the test | T b/h | ?S c/S t | Soaking 72h caudacoria outward appearance describes |
| Molybdenum film molybdenum/phosphatize phosphate coat chromaking film | Blue or green brown grey Dark grey | 2 ? 22 ? 24 ? | ?4/5 ? ?2/5 ? ?1/3 ? | The macro-corrosion product is deposited in specimen surface; The plaque area is bigger, and typical uniform corrosion filiform corrosion reduces plaque; A small amount of grey corrosion product is piled up; Color: ash-bluish yellow-reddish brown plaque concentrates on the sample middle part; Slight coming off arranged; Uncorroded local color shoals |
T
b---begin to occur the plaque time
S
cThe sample area that the is corroded behind-72h
S
t---the sample total area
X-ray diffraction spectrum: by U.S. D8 ADVANCE, the x x ray diffractometer x of BRUKER/AXS company is measured;
Scanning electronic microscope: by the XL-30 determination of electron microscopy of Japanese PHILIPS company;
Electro-chemical test: the CHI604B electrochemical workstation by Shanghai occasion China equipment company is measured.
The results of property of the magnesium-alloy surface molybdate phosphate composite transferring film that above Equipment Inspection the present invention makes is as follows:
1. the magnesium-alloy surface molybdate phosphate composite transferring film major ingredient that makes of the present invention comprises metal phosphate, CaMoO
4, MgAl
2O
4, MgO, Al
2O
3And molybdenum oxide, they exist with the formation of composite salt, form mixed phase and provide corrosion protection for matrix.
2. the polarization resistance value of the magnesium-alloy surface molybdate phosphate composite transferring film layer that makes of the present invention reaches 3400k Ω.
3. the solidity to corrosion of the magnesium-alloy surface molybdate phosphate composite transferring film that makes of the present invention is near chromate conversion coating, and plaque is thread, reduced corroded area.
4. the Mg alloy surface molybdate conversion film that makes of the present invention presents the uneven line of chapping of microcosmic, is " withered riverbed " shape; The magnesium-alloy surface molybdate phosphate composite transferring film layer is a crystalline structure, and its microcosmic surface is evenly " honeycomb " shape, has good bonding force with follow-up coating.
As known from the above, the present invention is the preparation method of magnesium-alloy surface molybdate phosphate composite transferring film, it adopts molybdate phosphoric acid salt composite treating agent that the surface treatment of magnesium alloy is handled first, the gained rete has excellent corrosion resisting performance and processing performance, and this molybdate phosphoric acid salt composite treatment process is the substitute technology of the good use prospect of having of Mg alloy surface chromate treating.
Description of drawings
Fig. 1 is the SEM photo (2000 times) of the AZ91D magnesium-alloy surface molybdate phosphate composite transferring film prepared of the present invention;
Fig. 2 is the SEM photo (2000 times) of the AM60 magnesium-alloy surface molybdate phosphate composite transferring film prepared of the present invention.
Embodiment
Embodiment 1: the preparation method of magnesium-alloy surface molybdate phosphate composite transferring film comprises:
(1) treatment solution of magnesium-alloy surface molybdate phosphate composite transferring film preparation:
A. the composition of described treatment solution is, every premium on currency solution contains:
Sodium orthomolybdate or ammonium molybdate 0.1mol,
SODIUM PHOSPHATE, MONOBASIC or monocalcium phosphate 0.2mol,
Nitrocalcite 0.1mol,
Manganese salt 0.06mol,
Promotor 0.01mol,
Oxygenant 0.01mol; Wherein:
Described manganese salt is one or more the arbitrary proportion mixture in manganese acetate or potassium permanganate, the manganous nitrate, preferred manganese acetate;
Described promotor is any in SODIUMNITRATE or nitrocalcite, sodium chlorate, the calcium chlorate, preferred SODIUMNITRATE;
Described oxygenant is potassium perchlorate or potassium permanganate, preferred potassium perchlorate;
B. the blending process of described treatment solution is: add described molybdate earlier, dissolve the back and with phosphoric acid solution is transferred to acidity; Add calcium salt, to prevent precipitation; Add dihydrogen phosphate and manganese salt then, re-adjustment pH value is 5～6; Add described promotor, oxygenant;
(2) step of preparation process of magnesium-alloy surface molybdate phosphate composite transferring film is:
A. the pre-treatment of Mg alloy surface: extremely carefully polished by thick one by one with abrasive paper for metallograph in the magnesium alloy sample surface;
B. tap water cleans;
C. washed with de-ionized water;
D. chemical conversion is handled: place described treatment solution to carry out the chemical conversion film forming magnesium alloy sample and handle, in 5 minutes treatment times, the treatment solution temperature is controlled at 50 ℃;
E. the sample after chemical conversion being handled cleans with tap water, and cold wind dries up, promptly.
The conversion film structure: the result of scanning electron microscope shows: AZ91D Mg alloy surface molybdate conversion film presents the uneven line of chapping of microcosmic, is " withered riverbed " shape (as Fig. 1); AM60 magnesium-alloy surface molybdate phosphate composite transferring film microcosmic surface obviously rises and falls, and light and shade accumulation is clearly arranged, and presents evenly " honeycomb " shape crystalline structure (as Fig. 2);
Erosion resistance: molybdate phosphate composite transferring film filiform corrosion just occurs through saline soak after 22 hours, plaque is less, and a small amount of grey corrosion product is piled up; Corresponding molybdate conversion film then corrodes comparatively serious, and molybdate phosphate composite transferring film has the anticorrosion ability near chromate conversion coating.The electrochemical impedance test result shows in the compound conversion rete of formation stable Me is arranged
3(PO
4)
2Phase, at the cathodic area preferential deposition, the rete of this moment has higher corrosion resistance value, reaches 3400k Ω.
Embodiment 2: the preparation method of magnesium-alloy surface molybdate phosphate composite transferring film, and the composition of described treatment solution is that every premium on currency solution contains:
Sodium orthomolybdate or ammonium molybdate 0.2mol,
SODIUM PHOSPHATE, MONOBASIC or monocalcium phosphate 0.4mol,
Nitrocalcite 0.02mol,
Manganese salt 0.02mol,
Promotor≤0.01mol,
Oxygenant≤0.01mol; Wherein:
Described manganese salt is one or more the arbitrary proportion mixture in manganese acetate or potassium permanganate, the manganous nitrate, preferred manganese acetate;
Described promotor is any in SODIUMNITRATE or nitrocalcite, sodium chlorate, the calcium chlorate, preferred SODIUMNITRATE;
Described oxygenant is potassium perchlorate or potassium permanganate, preferred potassium perchlorate;
All the other are with embodiment 1.
Claims (1)
1, a kind of preparation method of magnesium-alloy surface molybdate phosphate composite transferring film is characterized in that, this method comprises:
(1) treatment solution of magnesium-alloy surface molybdate phosphate composite transferring film preparation:
A. the composition of described treatment solution is, every premium on currency solution contains:
Molybdate 0.1mol-0.2mol,
Dihydrogen phosphate 0.2mol-0.4mol,
Nitrocalcite 0.02mol-0.1mol,
Manganese salt 0.02mol-0.06mol,
Promotor≤0.01mol,
Oxygenant≤0.01mol; Wherein:
Described molybdate is one or more the arbitrary proportion mixture in Sodium orthomolybdate or the ammonium molybdate;
Described dihydrogen phosphate is one or more the arbitrary proportion mixture in SODIUM PHOSPHATE, MONOBASIC or the monocalcium phosphate;
Described manganese salt is one or more the arbitrary proportion mixture in manganese acetate or potassium permanganate, the manganous nitrate;
Described promotor is any in SODIUMNITRATE or nitrocalcite, sodium chlorate, the calcium chlorate;
Described oxygenant is potassium perchlorate or potassium permanganate;
B. the blending process of described treatment solution is: add described molybdate earlier, dissolve the back and with phosphoric acid solution is transferred to acidity; Add calcium salt, to prevent precipitation; Add dihydrogen phosphate and manganese salt then, re-adjustment pH value is 5-6; Add described promotor, oxygenant;
(2) step of preparation process of magnesium-alloy surface molybdate phosphate composite transferring film is:
A. the pre-treatment of Mg alloy surface: extremely carefully polished by thick one by one with abrasive paper for metallograph in the magnesium alloy sample surface, or adopt clean-out system to remove surface contaminants;
B. tap water cleans;
C. washed with de-ionized water;
D. chemical conversion is handled: place described treatment solution to carry out the chemical conversion film forming magnesium alloy sample and handle, treatment time 4-6 minute, the treatment solution temperature was controlled at 20 ℃-55 ℃;
E. the sample after chemical conversion being handled cleans with tap water, and cold wind dries up, promptly.
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|---|---|---|---|
| CNB2007100347002A CN100543182C (en) | 2007-04-09 | 2007-04-09 | The preparation method of magnesium-alloy surface molybdate phosphate composite transferring film |
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|---|---|
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| CN100543182C CN100543182C (en) | 2009-09-23 |
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| CN101805900A (en) * | 2010-04-23 | 2010-08-18 | 哈尔滨工程大学 | Magnesium-lithium alloy molybdate and phosphate conversion solution and method for forming conversion coating |
| CN103451645A (en) * | 2013-05-31 | 2013-12-18 | 惠州市宏亚金属处理有限公司 | Magnesium alloy coating agent |
| CN104005014A (en) * | 2014-06-16 | 2014-08-27 | 重庆研镁科技有限公司 | Oxidation liquid and method for preparing corrosion resistant composite membrane on surface of magnesium alloy |
| EP2876186A1 (en) * | 2013-11-21 | 2015-05-27 | Samsung Electronics Co., Ltd | Composition for forming film of metal object, film formed using the same, and method of forming film |
| CN105331967A (en) * | 2015-10-31 | 2016-02-17 | 山东奇威特太阳能科技有限公司 | Metal preservative and applications thereof |
| CN107245710A (en) * | 2017-05-11 | 2017-10-13 | 安徽省金寨县新诚机械制造有限公司 | A kind of environmentally friendly surface treatment liquid of magnesium alloy |
| CN110592570A (en) * | 2019-09-27 | 2019-12-20 | 山东华盛荣镁业科技有限公司 | Magnesium alloy surface black chemical conversion process |
| CN112695310A (en) * | 2020-12-18 | 2021-04-23 | 东莞理工学院 | Magnesium alloy surface conversion treatment liquid and application |
| CN114606486A (en) * | 2022-03-11 | 2022-06-10 | 重庆大学 | Magnesium alloy CaCO3Conversion film treating agent and treating method thereof |
| CN115161627A (en) * | 2022-06-13 | 2022-10-11 | 东莞理工学院 | Magnesium alloy surface conversion liquid and preparation method of magnesium alloy surface conversion film |
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2007
- 2007-04-09 CN CNB2007100347002A patent/CN100543182C/en not_active Expired - Fee Related
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101805900A (en) * | 2010-04-23 | 2010-08-18 | 哈尔滨工程大学 | Magnesium-lithium alloy molybdate and phosphate conversion solution and method for forming conversion coating |
| CN103451645A (en) * | 2013-05-31 | 2013-12-18 | 惠州市宏亚金属处理有限公司 | Magnesium alloy coating agent |
| CN103451645B (en) * | 2013-05-31 | 2016-06-08 | 惠州市宏亚金属处理有限公司 | A kind of adopt magnesium alloy film agent that magnesium alloy is carried out the method for surface treatment |
| EP2876186A1 (en) * | 2013-11-21 | 2015-05-27 | Samsung Electronics Co., Ltd | Composition for forming film of metal object, film formed using the same, and method of forming film |
| CN104005014A (en) * | 2014-06-16 | 2014-08-27 | 重庆研镁科技有限公司 | Oxidation liquid and method for preparing corrosion resistant composite membrane on surface of magnesium alloy |
| CN105331967A (en) * | 2015-10-31 | 2016-02-17 | 山东奇威特太阳能科技有限公司 | Metal preservative and applications thereof |
| CN107245710A (en) * | 2017-05-11 | 2017-10-13 | 安徽省金寨县新诚机械制造有限公司 | A kind of environmentally friendly surface treatment liquid of magnesium alloy |
| CN110592570A (en) * | 2019-09-27 | 2019-12-20 | 山东华盛荣镁业科技有限公司 | Magnesium alloy surface black chemical conversion process |
| CN112695310A (en) * | 2020-12-18 | 2021-04-23 | 东莞理工学院 | Magnesium alloy surface conversion treatment liquid and application |
| CN114606486A (en) * | 2022-03-11 | 2022-06-10 | 重庆大学 | Magnesium alloy CaCO3Conversion film treating agent and treating method thereof |
| CN115161627A (en) * | 2022-06-13 | 2022-10-11 | 东莞理工学院 | Magnesium alloy surface conversion liquid and preparation method of magnesium alloy surface conversion film |
| CN115161627B (en) * | 2022-06-13 | 2024-04-23 | 东莞理工学院 | Magnesium alloy surface conversion liquid and preparation method of magnesium alloy surface conversion film |
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