CN1256302C - Sintered metal powder coating material and method of preparing metal ceramic anti corrosive coating - Google Patents

Abstract

The present invention relates to sintering type metal powder paint and a method for preparing a metal ceramic anticorrosive coat by using the sintering type metal powder paint, particularly to environmental protection type sintering type metal powder paint and a technology using the metal powder paint to prepare a metal ceramic anticorrosive coat. The paint of the present invention is prepared from the components by the following weight percentage: 32 to 65% of flaky metal powder, 2 to 10% of molding agent, 0.001 to 0.01% of sintering addition agent and balance of dispersion medium. The preparation method of the coat comprises the following steps: step a, metal powder paint is prepared; step b, dispersed metal powder paint is coated on a workpiece surface, the workpiece surface with the metal powder paint is heated at a constant temperature; step c, then, the temperature of the workpiece surface with the metal powder paint is risen, and the molding is carried out; step d, after the temperature is reduced to a normal temperature, step b and step c are repeatedly operated, the activated sintering is carried out, and the anticorrosive coat is obtained. In the method, the metal powder paint can be coated on the workpiece surface for multiple times, heated and molded, and the metal powder paint can be densified through sintering for only one time. The sintering type metal powder paint of the present invention has the advantages of good corrosion resistance, greenness, environmental protection, low energy consumption and high storage stability.

Description

The sintered type metal powder coating reaches and prepares the method for sintering metal corrosion protection coating with it

Technical field:

The present invention relates to a kind of environment-friendly type sintered type metal powder coating and prepare the technology of sintering metal corrosion protection coating with this metal powder coating.

Background technology:

In order to solve the atomospheric corrosion problem of iron and steel, people carry out various processing at steel surface, as plating, coating, phosphatization or the like, but all have such or such shortcoming, can cause hydrogen embrittlement as plating, and coating pollutes the environment, and the erosion resistance of phosphatization is poor.U.S. ocean company succeeded in developing Dacromet technology (domestic being translated into " Dacroment ") in 1970, China formally is defined as zinc-chromium coating with it, though this technology does not adopt resin, but the sexavalent chrome that contains strong carcinogenesis in the component, and bigger ethylene glycol, ethylene glycol monoethyl ether, butyl glycol ether and the Diethylene Glycol of toxicity, so not can be regarded as real environmental protection.Certainly, also there are some to adopt silicate, phosphatic waterborne zinc-rich coating, but because its coating is loose porous, need under the thicker situation of coating, can realize anticorrosionly, be not suitable for fastening piece, and at the protection against corrosion cost height of same anticorrosion time limit condition.In this case, press for a kind of coating that can address the above problem, it is good corrosion resistance under the prerequisite of coating relatively thin (7～12 microns) not only, and have no liberation of hydrogen (the iron and steel ground can not produce hydrogen embrittlement), do not contain the bigger organic solvent of toxicity, do not contain sexavalent chrome or trivalent chromium compound, characteristics such as use is fairly simple, cost is lower.Study if also rest on the basis of Dacroment or various zinc-rich paint, may find a kind of film forming densification more hardly, the tackiness agent that passivation is good replaces chromic anhydride, so need solve this problem with new thinking from a new angle.The common corrosion protection coating of existing sintering metal, minimumly want two to be coated with two moulding, one burning, coat-thickness is 6～8 microns, decide for weighing as required anticorrosion, general three are coated with that three moulding one are burnt or four to be coated with that four moulding one burn be fully enough, and the Dacroment method, the per pass coating all must be heated to 300 ℃, constant temperature solidified in 20 minutes, had wasted energy consumption so greatly.Repeatedly sintering densification does not have too much influence to the density of coating, can detrimentally affect be arranged to other component in the coating such as interfacial agents and passivator on the contrary.

Summary of the invention:

The present invention for solve traditional zinc-chromium coating contain sexavalent chrome and trivalent chromium serious environment pollution, apt to deteriorate under the hot environment in summer, sintering temperature is high, energy consumption is big and problem such as production cost height, provide a kind of and keep that traditional Dyclo paint height is anti-corrosion, hypertonicity, heat resistance is good and do not have the sintered type metal powder coating of performances such as hydrogen embrittlement and prepare the method for sintering metal corrosion protection coating with this coating.Metal powder coating of the present invention comprises flaky metal powder, forming agent, sintering aid and four kinds of compositions of dispersion medium, and wherein the weight percent of each composition is: flaky metal powder 32～65%, forming agent 2～10%, sintering aid 0.001～0.01%, surplus are dispersion medium.The method for preparing the sintering metal corrosion protection coating with the sintered type metal powder coating is carried out according to following step: a, be that flaky metal powder 32～65%, forming agent 2～10%, sintering aid 0.001～0.01%, surplus are the ratio preparing metal powder coating of dispersion medium according to weight percent; B, scattered metal powder coating being coated on workpiece surface, is constant temperature 7～10 minutes under 90～95 ℃ the condition in temperature; C, temperature is risen to 150～210 ℃, constant temperature moulding in 10～15 minutes with 8～12 ℃/minute temperature rise rate then; D, treat that workpiece surface temperature is reduced to normal temperature after, repetitive operation b and c step, up to coat-thickness reach specify to require after, in 300～370 ℃ of following activated sinterings 15～25 minutes, obtain fine and close sintering metal corrosion protection coating.Common anticorrosion, minimumly want two to be coated with two moulding, one burning, coat-thickness is 6～8 microns, for heavy as required anticorrosion and decide, general three are coated with that three moulding one are burnt or four to be coated with that four moulding one burn be complete enough.For the present invention, can repeatedly be coated in the workpiece surface hot briquetting, only need to get final product through once sintered densification; And there is no need as traditional Dacroment method, the per pass coating all must be heated to 300 ℃, constant temperature curing in 20 minutes, energy efficient so greatly.Certainly, the present invention also can the per pass coating carry out sintering densification, but find in the research, once sintered densification and repeatedly sintering densification the density of coating is not had too much influence, can detrimentally affect be arranged to other component in the coating such as interfacial agents and passivator on the contrary.If coating is too thick, just be easy to cause coating outside surface hardened forming, and moisture does not also fully volatilize totally in the bottom, and can residual a large amount of emulsifying dispersant in coating, these all can have a strong impact on the quality of coating, so cannot once directly apply too thick coating, then a hot briquetting sintering.Also find under study for action, in fact coating through 150～210 ℃ of moulding after, certain protective has just been arranged, but protective is poor.We are carrying out (70 ℃ of corrosion resistance coating accelerated tests, 20% ammonium nitrate) time, only 10～15 minutes, a large amount of spot corrosion and bubbling just do not appear in the coating through sintering densification, and this is that ground corrodes because corrosive medium penetrates coating, generating hydrogen causes, this explanation sheet metal is not in conjunction with tight, and coating is fine and close inadequately, otherwise zinc powder and aluminium powder sacrificial corrosion in the coating should occur.Because the electropotential of iron is-0.44 volt, and the electropotential of zinc and aluminium is-0.7628 volt and-1.66 volts, and metal zinc in the coating and aluminium powder and ground form galvanic cell, and they should preferentially corrode; And spot corrosion and bubbling should not appear.Yet behind 300～370 ℃ of sintering densifications, same corrosion resistance coating accelerated test, corrosion situation are exactly that aluminum zinc powder preferentially is corroded, and have improved the protective of coating so greatly.For composition of the present invention, we are general to adopt two component packings, although the present invention also can pass through to regulate prescription, adds corresponding adjuvants and realizes single-component package (it also has the package stability above 6 months), and we do not advise adopting.Because except adding the corresponding adjuvants, not only require good stopping property, and the chlorion in the composition, calcium ion content height or pH value are less than 4 or greater than 9.5 o'clock, be very easy to cause the reaction of zinc powder and aluminium powder and water, generate a large amount of hydrogen, even can cause forming agent because catalysis hydroxy and serious polycondensation in the water, system viscosity sharply rises and causes composition rotten and can't use, and bi-component package just can be avoided above-mentioned situation.We generally with flake metal powder, wetting agent, sintering aid, forming agent as the A component, and other is dissolved in the water as the B component as passivator, interfacial agents, inorganic dispersant etc.Even after we found also that under study for action this composition AB component is mixed simultaneously, sealing was at normal temperatures preserved, and through abundant dispersed with stirring, still can normally use after 7 days, can the protective of metal-ceramic coating not had much impact.For having applied metal-ceramic coating of the present invention, its surface still can apply other various organic or inorganic coatings again, and we also find, the sticking power of organic coating on this coating is higher than its sticking power on ground, this is that the roughness of this coating is the Sa2.5 level much larger than the desired ground roughness of general anticorrosive construction because this coatingsurface is compared with the normal processing ground; And this coating is generally the mixing of zinc powder and aluminium powder, and the hydroxyl on their surfaces is more much more than general steel surface, and these all very help coating adhering on this coating.Metallic paint of the present invention is good corrosion resistance under the prerequisite of coating relatively thin (7～12 microns) not only, and have no liberation of hydrogen (the iron and steel ground can not produce hydrogen embrittlement), do not contain the bigger organic solvent of toxicity, do not contain sexavalent chrome or trivalent chromium compound, characteristics such as use is fairly simple, cost is lower.It is mainly as follows that the present invention and present various technology are compared the advantage that is had: (1), good corrosion resistance: under the same thickness, far be better than the anticorrosion of widely used zinc-plated mode at present, near zinc-chromium coating (Dacroment); (2), environmental protection: water dispersion medium, do not contain deleterious organic solvent, do not contain trivalent chromium and sexavalent chrome, can not pollute environment; (3), energy consumption is lower: with respect to zinc-chromium coating, approximately can save 20% energy; (4), excellent storage stability: two-pack still has 7 days work-ing life after mixing.

Embodiment:

Embodiment one: the metal powder coating of present embodiment comprises flaky metal powder, forming agent, sintering aid and four kinds of compositions of dispersion medium, and wherein the weight percent of each composition is: flaky metal powder 32～65%, forming agent 2～10%, sintering aid 0.001～0.01%, surplus are dispersion medium.Described dispersion medium is a water.The length of described flake metal powder is less than 80 microns, and length-to-diameter ratio is greater than 50, wherein flake metal powder be in zinc powder, aluminium powder, glass putty, titanium valve and their the alloyed metal powder one or more.Described forming agent is one or more in polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, modified silicasol, tetraethyl silicate and the silane coupling agent.Described sintering aid is one or more in glass putty, nanometer aluminium powder, nano titanium powder, nanometer iron powder and the nano-nickel powder.

Embodiment two: the metal powder coating of present embodiment is become to be grouped into for four kinds by flaky metal powder, forming agent, sintering aid and dispersion medium, and wherein the weight percent of each composition is: flaky metal powder 42～48%, forming agent 3～5%, sintering aid 0.002～0.005%, surplus are dispersion medium.Described flake metal powder length is preferably 30～45 microns, length-to-diameter ratio is 60～80, wherein flake metal powder is the mixture of zinc powder and aluminium powder or zinc powder and titanium valve, and wherein the weight ratio of zinc powder and aluminium powder or zinc powder and titanium valve is (1～8): 1, and the weight ratio of preferred zinc powder and aluminium powder is 4: 1; The weight ratio of zinc powder and titanium valve is 5: 1.Described forming agent is preferably one or more in polyvinyl alcohol, modified silicasol and the silane coupling agent.Described sintering aid is preferably particle diameter less than the aluminium powder of 10 microns glass putty, 30～50 nanometers and in the titanium valve one or more.

Because the density of coating has determined the barrier propterty of this coating to a great extent, with the zinc powder is example, the fusing point of zinc is 419 ℃, sintering forms 0.8～0.9 times the temperature that sintering metal needs fusing point at least, promptly 335.2 ℃～377.1 ℃, the metallic zinc atom just can diffuse to form fine and close ceramic structure, and temperature is high more, and structure is fine and close more.Along with the development of nanotechnology, we know that metal particle size is more little, and fusing point is low more, and concrete formula is: $T_m=T_{\∞}[1-\frac{{2v}_s^{1/3}}{{\mathrm{\λ}}_{m}r}({\mathrm{\σ}}_s{v}_s^{2/3}-{\mathrm{\σ}}_L{v}_L^{2/3})].$ For length is that 30 microns, length-to-diameter ratio are 60 zinc flake, and its thickness is 0.5 micron; For zinc flake edge, we can think that a diameter is 0.5 micron a spheroid, be updated to like this in the above-mentioned formula, we obtain, the fusing point of edge is 373.1 ℃, corresponding densified sintering product turns to 298.5 ℃～339.4 ℃, so adopt zinc flake can form dense sintering metal under lower sintering temperature.Certainly, if do not add sintering aid fully, suitable raising temperature or the littler metal powder of employing particle diameter also are can realize sintering densification fully.For example: the employing particle diameter is that 0.5 micron spherical metal zinc carries out sintering at 340 ℃, obtains fine and close metal-ceramic coating equally.But particle diameter is more little, and price is high more, should not adopt.

Want sintering to form metal-ceramic coating, forming agent is absolutely necessary naturally, because not before the sintering, must have certain forming agent that metal-powder is sticked to substrate surface in coating.The material that can be used as forming agent is very many, we find in practical study, the thermoset forming agent is best, because the heat curing-type forming agent has not only guaranteed composition period of storage at normal temperatures, and also can be with more firm bonding of metal-powder in heat-processed, wherein silane coupling agent is reasonable selection, because on the one hand it can hydrolysis, is relatively good forming agent, on the other hand, it also is reasonable interfacial agents, and multi-functional auxiliary agent can reduce production process; Modified silicasol also is a well selection, particularly by the teos hydrolysis polycondensation, use epoxychloropropane modified resulting epoxide modified silicon sol simultaneously, this kind material has been declared patent at present, has been extensive use of (publication number: US1410476) at present.

As previously mentioned, because the zinc flake marginal dimension is less, can be at lower temperature sintering densification, but the edge diffusion densification of depending merely on zinc powder is not enough, needs to add corresponding sintering aid, improves the density of coating.Find under study for action, the metal that fusing point is lower is very effective sintering aid, because in ceramic-metallic sintering process, temperature raises, the sintering aid fusing point is low, can liquefy, and this liquid can the dissolution of metals powder, improve the diffusibility of metal-powder surface atom so greatly, more helped forming fine and close sintering metal.As: glass putty (fusing point is 232 ℃) or its alloy, they all are reasonable sintering aids.For Nano metal powder, we think, may be to descend significantly owing to size relationship causes fusing point, and have the activated sintering effect; Also might be that Nano metal powder is very easy to be oxidized and very exothermic causes local temperature acutely to raise (being higher than the sheet metal fusing point), the flaky metal powder fusing, and then obtain the densification coating.As particle diameter is metal powders such as 30～50 nano titanium powders and aluminium powder, and theoretical fusing point is all about 300 ℃; And we are when studying them, 300 ℃ of vigorous oxidations of observing them, so they also all are more effective sintering aids.What is interesting is that more a spot of Nano metal powder can be good at improving the protective of coating.

Embodiment three: what present embodiment and embodiment one, two were different is that it also comprises the wetting agent that accounts for composition total weight 2～5%.Other compositions are identical with embodiment one, two with content.Described wetting agent is one or both in ethanol and the acetone.

Find under study for action, the deployment conditions of metal-powder is directly connected to coating agglomerating density, and the compatibility of metal zinc and aluminium powder is not very good, so suitable emulsifying dispersant and wetting agent have bigger influence for the performance of last metal-ceramic coating.Consider the environmental protection characteristic of this composition, for wetting agent, we adopt in ethanol and the acetone one or both, because not only toxicity is very low for they, can in human body, not produce and accumulate, and surface tension is also very low, only is about 1/3 of water, they can abundant wetting metal-powder, can also realize regulating the rate of volatilization of moisture content by the consumption of regulating wetting agent.We just find that in experiment the appropriateness volatilization of moisture content has a significant impact next step hot briquetting.

Embodiment four: what present embodiment and embodiment one, two, three were different is that it also comprises the emulsifying dispersant that accounts for composition total weight 0.1～5%.Other compositions are identical with embodiment one, two, three with content.Described emulsifying dispersant is one or more in OP series (as: polyoxyethylene glycol, polyacrylic acid, tween), tripoly phosphate sodium STPP, sodium polyacrylate and the Sodium hexametaphosphate 99.

Emulsifying dispersant mainly is in order to solve dispersiveness and zinc powder and aluminium powder composite of metal-powder in water.OP series emulsifying agent is relatively good, because they are nonionic surface active agent, contained vinyl ether can be adsorbed on the metal-powder surface in their molecular structures, forms stable sterically hindered effect, prevent the reunion once more of metal-powder, they also have certain antioxygenation simultaneously; And their Calcium ion stability is also very good, do not worry in the composition that a spot of hydrated zinc ion can produce detrimentally affect to the emulsification dispersion effect, but consumption must not be too many, otherwise it can remain in the coating, seriously reduces the solidity to corrosion of coating; General consumption is a total composition 2～4%.And inorganic dispersant as Sodium hexametaphosphate 99, tripoly phosphate sodium STPP, sodium polyacrylate etc., all possesses very strong electric charge dissemination, they can be adsorbed on the metallics surface and form electrostatic double layer, help disperseing, its consumption more needs strict control, is generally total composition 0.15～0.3%; Because it is a water soluble inorganic salt, in a single day consumption too high, will reduce the solidity to corrosion of coating, and many inorganic dispersant polycondensations that meeting takes place in water, and the result causes the viscosity of composition sharply to rise, and influence is constructed.

Embodiment five: the metal powder coating of present embodiment is made up of flaky metal powder, forming agent, sintering aid, dispersion medium, wetting agent, emulsifying dispersant, wherein the weight percent of each composition is: flaky metal powder 42～48%, forming agent 3～5%, sintering aid 0.002～0.005%, wetting agent 3～5%, emulsifying dispersant 0.1～0.5%, surplus are dispersion medium.Described emulsifying dispersant is preferably the composite of OP series and Sodium hexametaphosphate 99.

Embodiment six: what present embodiment and embodiment one, two, three, four, five were different is that it also comprises the interfacial agents that accounts for composition total weight 0.1～1%.Other compositions are identical with embodiment one, two, three, four, five with content.

Adhesive force of coatings is a unalterable quota of coating performance quality, the good corrosion resistance of coating, and do not mean that its protective is all right.The erosion resistance of tetrafluoroethylene is just very good, but because it is very poor to the sticking power of ground, has had a strong impact on its protective to workpiece.So it is very necessary improving adhesive force of coatings.Along with development in science and technology, increasing interfacial agents is widely used, as in Sulphanilic Acid, benzaminic acid, aluminate coupling agent, aluminium titanium composite coupler and the silane coupling agent etc. one or more.So-called interfacial agents is meant at different surfaces, the tackiness agent that can couple together the object at two different interfaces by chemical reaction.In order to improve the sticking power of metal-ceramic coating on workpiece, suitable interfacial agents is necessary.Interfacial agents can directly join in the composition as the case may be, also can be mixed with the aqueous solution and construct in workpiece surface; Latter's effect is slightly more better than the former, but can increase labor cost.

Embodiment seven: what present embodiment and embodiment one, two, three, four, five, six were different is that it also comprises the passivator that accounts for composition total weight 0.1～6%.Other compositions are identical with embodiment one, two, three, four, five, six with content.

Zinc and aluminium all are very easy to passivation, if there is a spot of passivator in corrosive medium, zinc and aluminium just can slow down the corrosion of corrosive medium to it greatly because be passivated, thereby have prolonged the work-ing life of coating.Passivator is generally the organic or inorganic material that can generate water-fast precipitation with zinc or reactive aluminum or zinc or aluminium surface oxidation can be formed dense oxidation film; As in boron compound, molybdate, tungstate and the permanganate etc. one or more.Boric acid for example, it can generate zinc borate and aluminum borate with zinc and reactive aluminum, they all are the precipitations that are insoluble in water, rareer valuable be that it also has certain forming agent effect; Its consumption is 1.7～2.6% of a total composition.Composite more a spot of oxygenant better effects if of while, as ammonium molybdate, it can be with zinc powder and aluminium powder passivation, and its consumption is 0.1～0.5% of a total composition; Its consumption is too high can to influence the sintering densification process, and the price comparison height of molybdate.

Embodiment eight: present embodiment is mixed by the proportioning of following composition according to weight percent: flaky metal powder 42～48%, forming agent 3～5%, sintering aid 0.002～0.005%, wetting agent 3～5%, emulsifying dispersant 0.1～0.5%, interfacial agents 0.2～0.5%, passivator 0.5～3%, oxygenant 0.1～0.5%, surplus are dispersion medium.Described passivator is preferably boric acid, ammonium molybdate and potassium permanganate composite; Described interfacial agents is preferably aluminium titanium composite coupler, contains amino silane coupling agent, and they can directly mix with composition, also can be made into 1～3% hydrolyzed solution spraying or brush substrate surface.

Embodiment nine: the method for preparing the sintering metal corrosion protection coating with the sintered type metal powder coating of present embodiment is carried out according to following step: a, be that flaky metal powder 32～65%, forming agent 2～10%, sintering aid 0.001～0.01%, surplus are the ratio preparing metal powder coating of dispersion medium according to weight percent; B, scattered metal powder coating being coated on workpiece surface, is constant temperature 7～10 minutes under 90～95 ℃ the condition in temperature, treats that moisture fully volatilizees; C, temperature is risen to 150～210 ℃, constant temperature moulding in 10～15 minutes with 8～12 ℃/minute temperature rise rate then; D, treat that workpiece surface temperature is reduced to normal temperature after, repetitive operation b and c step, up to coat-thickness reach specify to require after, in 300～370 ℃ of following activated sinterings 15～25 minutes, finally obtain fine and close sintering metal corrosion protection coating.

Embodiment ten: present embodiment is made up of A and two kinds of components of B, wherein the A component is: weighing 210 gram zinc flakes and 48 gram flake aluminums, this aluminium powder contains about 1% 200# industrial naptha, add emulsifying dispersant OP-7 and OP-10 12 grams and 17 grams respectively, add nano titanium powder 1.0 grams, add dehydrated alcohol 90 grams again, after stirring, add silane coupling agent 22 grams again, disperseed 30 minutes, amount to 400 grams at high speed dispersor; The B component is: respectively 18.3 gram boric acid, 2 gram ammonium molybdates and 0.7 gram Sodium hexametaphosphate 99 are dissolved in 379 gram deionized waters, amount to 400 grams.

A, with the mixed of AB two components by weight=1: 1, disperse 2 hours (800 rev/mins) or homogeneous emulsifying machine to disperse 40 minutes (3000 rev/mins) at high speed dispersor; B, brush through 120# sand papering cross on the cast iron print, in 90～95 ℃ baking oven constant temperature 8 minutes; C, temperature is risen to 200 ℃, constant temperature moulding in 15 minutes with 12 ℃/minute temperature rise rate then; D, then treat that workpiece surface temperature is reduced to normal temperature after, the following one coat of coating heats moisture evaporation and hot briquetting once more again, after the hot briquetting, directly, be warmed up to 350 ℃ for the third time with 11 ℃/minute temperature rise rate, activated sintering in 15～25 minutes finally obtains dense coating.Detecting its adhesion amount as follows is 317mg/dm ², 10.6 microns of coat-thicknesses, sticking power 〉=4,600 hours no red rusts of salt spray resistance.

One, adhesion amount is measured by weighting method: (JDIS K 5311)

So-called weighting method is exactly with sodium hydroxide solution dissolving Dacroment coating, divided by surface-area, just can obtain the adhesion amount of unit surface with the weight difference before and after the dissolving.Its detailed main points are as follows:

Get test piece (50～100 gram) with the chemical balance that the is accurate to 1mg W that weighs ₁(mg), 20% sodium hydroxide solution of putting into heating (70～80 ℃) in advance then soaked 10 minutes, allowed coating all dissolve, and then test piece was fully washed and rapid drying, measured W ₂(mg):

(W ₁-W ₂)/S=adhesion amount (mg/dm ²)

Surface-area (the dm of S-test piece ²)

Remarks (1): the part of discontented 50 grams of weight also can put together test together.

Remarks (2): after the Dacroment coating immerses sodium hydroxide solution, begin dissolving immediately.When the dipping time that reaches regulation, when all dissolving not yet, till then can being dipped into coating and dissolving fully always.

Two, adhesion test: (JDIS K 5311)

The cellophane adhesive tape of subsides JIS Z 1522 regulations is pinned adhesive tape with the thumb belly and is firmly slided in test piece, to get rid of bubble, peels off rapidly from an end of adhesive tape then, checks whether to have metal-ceramic coating on adhesive tape.(when peeling off, the angle between an end of adhesive tape and the Dacroment coat side of test piece is generally about 45 °)

Three, salt-fog test: (ASTM B 117-2)

During test, print is placed in the constant temperature salt fog cabinet, makes it to be exposed in the common salt aqueous solution of 5% (wt), keep and stablize for some time, use water rinse then, weigh extent of corrosion with the per-cent of red rust area.

Embodiment 11: present embodiment is made up of A and two kinds of components of B, wherein the A component is: weighing 210 gram zinc flakes and 48 gram flake aluminums, this aluminium powder contains about 3% 200# industrial naptha, add emulsifying dispersant OP-7 and OP-10 12 grams and 17 grams respectively, add glass putty 2 grams, add ethanol 90 grams again, disperseed 30 minutes, amount to 379 grams at high speed dispersor; The B component is: after respectively 18.3 gram boric acid, 2 gram ammonium molybdates and 0.7 gram Sodium hexametaphosphate 99 being dissolved in 304 grams deionized waters fully dissolving, add the epoxide modified silicon sol of 54 grams again, amount to 379 grams.

A, with the mixed of AB two components by weight=1: 1, disperse 2 hours (800 rev/mins) or homogeneous emulsifying machine to disperse 40 minutes (3000 rev/mins) at high speed dispersor; B, brush on cast iron print, in 80 ℃～85 ℃ baking oven constant temperature 12 minutes through the 120# sand papering; C, temperature is risen to 150 ℃, constant temperature moulding in 20 minutes with 12 ℃/minute temperature rise rate then; D, then treat that workpiece surface temperature is reduced to normal temperature after, the following one coat of coating heats moisture evaporation and hot briquetting once more again, directly with 11 ℃/minute temperature rise rate, is warmed up to 310 ℃, activated sintering in 15～25 minutes finally obtains dense coating.Detecting its adhesion amount as stated above is 228mg/dm ², 7.3 microns of coat-thicknesses, sticking power 〉=4,400 hours no red rusts of salt spray resistance.

Embodiment 12: present embodiment is made up of A and two kinds of components of B, wherein the A component is: weighing 210 gram zinc flakes and 48 gram flake aluminums, this aluminium powder contains about 1% 200# industrial naptha, add emulsifying dispersant OP-7 and OP-10 10 grams and 15 grams respectively, add glass putty 2.0 grams, add ethanol 90 grams again, after stirring, add silane coupling agent (kh-550) 25 grams again, disperseed 30 minutes, amount to 400 grams at high speed dispersor; The B component is: respectively 18.3 gram boric acid, 2 gram ammonium molybdates, 0.7 gram Sodium hexametaphosphate 99 and 1.5 gram urotropines are dissolved in 377.5 gram deionized waters, amount to 400 grams.

A, with the mixed of AB two components by weight=1: 1, disperse 2 hours (800 rev/mins) or homogeneous emulsifying machine to disperse 40 minutes (3000 rev/mins) at high speed dispersor, sealing is stored in the Glass Containers, Kaifeng, dispersion of process brushing high speed dispersor or homogeneous emulsifying machine dispersion once more again after 7 days; B, brush on cast iron print equally, in 90 ℃～95 ℃ baking oven constant temperature 8 minutes through the 120# sand papering; C, temperature is risen to 200 ℃, constant temperature moulding in 15 minutes with 12 ℃/minute temperature rise rate then; D, then treat that workpiece surface temperature is reduced to normal temperature after, the following one coat of coating heats moisture evaporation and hot briquetting once more again, directly with 11 ℃/minute temperature rise rate, is warmed up to 350 ℃ then, activated sintering in 15～25 minutes finally obtains dense coating.Detecting its adhesion amount as stated above is 297mg/dm ², 10.3 microns of coat-thicknesses, sticking power 〉=4,600 hours no red rusts of salt spray resistance.

Claims (10)

1, sintered type metal powder coating, it is characterized in that it comprises flaky metal powder, forming agent, sintering aid and four kinds of compositions of dispersion medium, wherein the weight percent of each composition is: flaky metal powder 32～65%, forming agent 2～10%, sintering aid 0.001～0.01%, surplus are dispersion medium.

2, sintered type metal powder coating according to claim 1 is characterized in that described dispersion medium is a water.

3, sintered type metal powder coating according to claim 1, it is characterized in that described flake metal powder be in zinc powder, aluminium powder, glass putty, titanium valve and their the alloyed metal powder one or more.

4, sintered type metal powder coating according to claim 1 is characterized in that described forming agent is one or more in polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, remodeling silicon sol, tetraethyl silicate and the silane coupling agent.

5, sintered type metal powder coating according to claim 1 is characterized in that described sintering aid is one or more in glass putty, nanometer aluminium powder, nano titanium powder, nanometer iron powder and the nano-nickel powder.

6, sintered type metal powder coating according to claim 1 is characterized in that it also comprises the wetting agent that accounts for composition total weight 2～5%, and described wetting agent is one or both in ethanol and the acetone.

7, according to claim 1 or 6 described sintered type metal powder coatings, it is characterized in that it also comprises the emulsifying dispersant that accounts for composition total weight 0.1～0.5%, described emulsifying dispersant is one or more in polyoxyethylene glycol, polyacrylic acid, Ye Wen, tripoly phosphate sodium STPP, sodium polyacrylate and the Sodium hexametaphosphate 99.

8, sintered type metal powder coating according to claim 7, it is characterized in that it also comprises the interfacial agents that accounts for composition total weight 0.1～1%, described interfacial agents is one or more in Sulphanilic Acid, benzaminic acid, aluminate coupling agent, aluminium titanium composite coupler and the silane coupling agent.

9, according to claim 1,6 or 8 described sintered type metal powder coatings, it is characterized in that it also comprises the passivator that accounts for composition total weight 0.1～6%, described passivator is one or more in boric acid, molybdate, tungstate and the permanganate.

10, the method for preparing the sintering metal corrosion protection coating with the sintered type metal powder coating is characterized in that it carries out according to following step: a, be that flaky metal powder 32～65%, forming agent 2～10%, sintering aid 0.001～0.01%, surplus are the ratio preparing metal powder coating of dispersion medium according to weight percent; B, scattered metal powder coating being coated on workpiece surface, is constant temperature 7～10 minutes under 90～95 ℃ the condition in temperature; C, temperature is risen to 150～210 ℃, constant temperature moulding in 10～15 minutes with 8～12 ℃/minute temperature rise rate then; D, treat that workpiece surface temperature is reduced to normal temperature after, repetitive operation b and c step, up to coat-thickness reach specify to require after, in 300～370 ℃ of following activated sinterings 15～25 minutes, obtain fine and close sintering metal corrosion protection coating.