JPH01501071A - Mechanical plating of metals that are easily oxidized - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Mechanical plating of metals susceptible to oxidation [Background of the invention] Granular metals, metal mixtures and alloys are deposited on a metal substrate along with metal particles for plating. plating by applying sufficient mechanical force to cause adhesion between the body surface and the body surface. It is known that The mechanical force required to cause such adhesion is Metal particles, solid impact media (e.g. glass or steel beads), such as plating The materials and metal substrates that promote l) Obtained by placing it in In this way, the rotation of the ball mill or the The rotation of the vessel imparts kinetic energy to the impact medium, and the force is applied to the metal particles for plating. and the particles are deposited as a coating onto the surface of the substrate.

Early work in this field of mechanical plating was published in U.S. Patent No. 2,640,001, No. 2,640,002, Reissue No. 23,861, No. 2.689,808, and No. 2,723,204 [all by Clayton et al. ]. Typically, these mechanical plating methods reduce the effectiveness of the plating. of plating fluids containing additives that improve the rate and/or quality of the deposited metal. It is done in the presence of These additives include surfactants, film-forming materials , foam inhibitors, dispersants, and corrosion inhibitors. Some of these materials are For example, gallbladder is often added to the plating liquid as an accelerator chemical. U.S. Pat. No. 3,460,977 to Golben describes mechanical plating. Special 6 surfactant and organic acid substances along with accelerator chemicals are listed. Ru. U.S. Pat. No. 3,328°197 to Simon describes mechanical Accelerator formulation in the form of a solid cake or bar containing a combination of accelerator chemicals for plating As the mechanical plating process progresses, it is taught to use chemical substances. The rod or cake melts at a rate that provides the optimum amount of accelerator chemicals to the chemical plating process. Understand. U.S. Patent No. 3,268,356 to Simon (the "'356 Patent") ), the accelerator chemicals and/or plating metal particles are placed in a plating container. The density and density of the metal coating for plating are increased over the entire surface of the substrate. Optimizing uniformity is described.

U.S. Pat. No. 3,400,012 to Golben describes the advantages of electroplating as follows: It is intended to be achieved by mechanical plating methods. So. electromechanical (ga) l　vano*eeha’ii’;al　plating Dynamic “Driving” J, i.e. the design of the metal for inducing plating and the metal to be plated The "driving" metal selected is made by adding an ionizable salt. , a metal for plating or a metal that is baser than the metal on the surface of the metal to be plated. When mechanically plating tin on steel washers, the plating metal is in the form of tin chloride. The driving metal is aluminum powder.

No. 3,531.315 (hereinafter referred to as the “'315 Patent”) to Goleben. ) describes that mechanical plating is carried out in the presence of a strong acid. ’ Prior to the '315 patent, agitation of plating metals, impact media, and substrates was achieved by using plating metals, impact media, and substrates such as citric acid. It is carried out in the presence of weak organic acids. This is done using a citric acid-based plating method. Remove all strong acids used to clean or copper-coat the parts before It is necessary to rinse the plating container to ensure that the plating is removed. '315 patent method , the mechanical plating method can be performed without an intermediate rinsing step; Making the method very economical.

German patent DE 2854159 by Tolkmit states: Intermediate coatings such as copper flash coatings typically applied before mechanical plating The coating is applied in a one-step process from a slurry containing an intermediate coating metal and a final metal. Ru.

One form of mechanical plating produces a lightweight, relatively thin coating of 0.1 to 1.0 mils thick. 0 Mechanical galvanizing Other forms of mechanical plating are thicker (i.e., approximately 1.0 to 5.3 mils) and heavier. i.e., approximately 0.7 to 2.5 oz/ft”) of mechanically applied metal coating. During the development of such mechanical galvanizing methods, mechanical galvanizing The stronger adhesion of the Ising coating mechanically builds up further layers of plated metal. It has been discovered that what can be achieved by

U.S. Pat. No. 4,389,431 (hereinafter referred to as Erisman) , referred to as the “'431 Patent”) is a step-by-step method of mechanical galvanizing. The method of the '315 patent is applied to the addition of the genus powder. This is two chemical accelerators This has been achieved using a system. The first is that before adding the plating metal to the system, The base is coated with a thin flash coat of nobler metal than the plating metal. 6, which is a flash accelerator that coats the body, followed by a second continuous accelerator (contin uingpromoter)) adds v & grain mechanical plating metal little by little are added little by little at some or all of the stages, and the layers accumulate Perform mechanical galvanizing.

Mechanical plating methods are compatible with any malleable metal, metal mixture, or alloy Although some metals such as aluminum are disclosed as having this It is more difficult than others to plate in this way, aluminum has an oxide surface layer , which is difficult to remove before using aluminum powder in mechanical plating methods. Not only is it beautiful, but it is also easily reformed during the process. This oxide coating is prevents efficient coverage of the film. For example, machine metal mixtures containing aluminum powder When compared to other metal powders in the mixture, aluminum is It has been found that only a small amount adheres to A similar problem exists with titanium, mag It also occurs when mechanically plating mixtures containing nesium and powders of these metals. coming.

As a result of the difficulty of mechanically plating aluminum, If necessary, other plating techniques had to be used.

For example, at the same time to the United States by Levinstein et al. Iron and nickel are bonded using the pack-cementation method. Coated with cobalt superalloy. US special by Austin No. 3,503,775 discloses that the aluminum coating is applied by electrostatic deposition, rolling, It is applied to ferrous metal substrates by heating and heating. Whitfield U.S. Pat. No. 3,577.268 to ieM) et al. Using a binder/slurry method, aluminum/magnesium alloys can be made of iron, nickel, Coated with cobalt superalloy.

Some attempts have been made to coat substrates with aluminum by mechanical plating. came. U.S. Patent No. 3,443,98 to Cutcliffe No. 5 uses a powdered aluminum consisting of 50% aluminum, 45% tin and 5% zinc. A microscopically smooth, non-metallic material used as an impact medium to coat nails with minium alloys. Uses balls that do not ionize.

In U.S. Pat. No. 3,754,976 by B. Abecki et al. The mixture of aluminum and small solid striking particles is applied to various surfaces at high speeds. It's spraying. German Published Patent No. 3.011,662 by Torkmitz , the oxide problem caused by aluminum is caused by aluminum, hydrazine derivatives, Mechanical treatment in liquids containing polymeric products of lopyrene and ethylene oxide and corrosion inhibitors. It is stated that this can be prevented by plating. Apparently hydrazine is water liberates oxygen, which combines with oxygen residues in the liquid. The activity of aluminum is maintained by the coalescing product and, if necessary, alkali fluoride or fluorofluoride. It is maintained by further addition of silicate. These discoveries are based on aluminum. However, these conventional techniques are not suitable for corrosion-resistant aluminum resulting in a Ni-coated substrate. Because of this problem, lightweight mechanically plated aluminum The use of aluminum coatings is restricted. Therefore, aluminum yields a corrosion-resistant product. There is a need for a mechanical plating method.

[Summary of the invention]

The present invention is suitable for use with oxidation-prone materials such as aluminum. Mainly metals (i.e. metals that usually have or are susceptible to oxide coatings) This invention relates to a method for mechanically plating metal substrates. This method has a large plating efficiency. It not only provides a strong bonding coating with improved resistance to corrosive environments. produce a cover.

These improvements include the ability to combine metal substrates with individual metal layers and/or multiple dispersed metal layers. Mechanical plating with different metals in granular form applied in various sequences to cover layers This is achieved by These metals plated onto metal substrates are susceptible to oxidation. Includes hard metals, protective metals and immersion metals.

Oxidizable metals usually (i.e. under typical conditions) have an oxide layer on their surface. It is a fine powder useful in target plating methods, and is used to remove the oxide layer that was already present. Also, it is easy to form an oxide surface layer again.

Immersion metal is mechanical plating onto a metal substrate. During the plating process, metals and substrates that are easily oxidized are coated with a metal that is easily oxidized during the plating process. Minimize the formation of oxide layers on metals.

Protective metal is a protective metal that prevents the plated metal substrate from oxidizing when exposed to the environment. Although it is not necessary to use it, it is preferable to use it because of its anti-corrosion effect. .

The engraving agent in the aqueous mixture removes all surface oxide layers from fine-grained oxidizable metals. It is effective for Another, less preferred embodiment is a mechanical plating process. Separately, fine-grained easily oxidized metals are pretreated with etching agents and immersion metals, and then Pre-treated metals that are easily oxidized are subjected to a fiM plating process without using an etching agent. be able to.

According to the present invention, due to the pre-existing oxide coating, and during the plating process, the oxide coating is removed. Aluminum is difficult to mechanically plate using other methods due to its tendency to Metals such as aluminum can be efficiently mechanically plated onto metal substrates. the The coating obtained from mechanical plating such as % consists of metals that are easily oxidized, and the rest is immersion metal (one or more types), and a small amount impurities, and optionally a protective metal.

[Detailed description of the invention]

The methods of the invention generally include operating methods and operating factors, impact media, surfactants, dispersions, The additives and corrosion inhibitors are the same as in conventional mechanical plating methods. similar The apparatus in which the plating process is carried out is a known mechanical plating container (barrel). ) or mill.

As taught by the '315 and '431 patents, the substrate to be plated The body is placed in a rotatable plating container containing glass peas impact media. Waterfall Add a strong acid surface conditioner such as sulfuric acid and sulfuric acid into the container and then rotate the plating container. For example, as shown in the examples of the '431 patent, The method according to the '315 patent uses water and strong i! ! Clean before adding conditioner. , rinsing can optionally be included. Cleaning in advance like that , degrease with an alkaline cleaning agent, remove rust with an acid cleaner, or degrease and remove rust. in a plating vessel or some other tank by carrying out both Can be done. After pre-cleaning, rinse the substrate.

According to the '315 patent, there is no subsequent draining or rinsing after adding the surface conditioner. Between the rinsing and the addition of water and strong acid surface conditioners, some oxide scale may be present. However, the sulfuric acid surface conditioner removes such scales from being placed in a rotating container. This will be removed during dispersion.

Disperse the sulfuric acid surface conditioner and water in a rotating plating container containing the substrate and impact medium. After plating, the copper can be removed without draining the acid from the plating container or rinsing the substrate with water. Coating agent (e.g. copper sulfate pentahydrate) Add to the container. This deposits copper on the surface of the substrate, which in turn Serves as a basis for attaching the next coating to the substrate.

Accelerator chemicals are then added to the plating vessel to provide the proper conditions for mechanical plating. I can do it. In addition, accelerator chemicals act to clean the plating metal powder that is added later. A suitable accelerator may be used to adjust the size of the metal agglomerates for plating. Chemicals include strong acids or acid-forming salts, and later added plating and/or corrosive Contains metal salts that are more harmful than inhibitors. For soluble salts of metals that are more dangerous than metals for plating. contains cadmium, lead, and preferably tin (e.g. stannous chloride, stannous sulfate). For example, strong acids or acid-producing salts include sulfuric acid, potassium or ammonium hydrogen sulfate. Dispersants and corrosion inhibitors that can be sodium chloride, sulfamic acid or sodium hydrogen sulfate may be any of those listed in columns 3-4 of the '315 patent. The agent may contain up to 400 grams of strong acids or acid-forming salts per 100 ft. of plating surface; It contains from about 10 to about 80 grams of a soluble salt of a metal more important than the plating metal. Furthermore, minutes Addition of effective amounts of dust and/or corrosion inhibitors as necessary for the purpose. can do.

After the accelerator is placed in the rotating container, the plating metal powder is added. Metal powder for plating The addition of is a flash coating of some or all of the accelerator metal in the metal container. Then, by rotating the container, the glass is removed. The speed impact medium hits the substrate, and the metal powder for the metal plate is struck so that it adheres to the substrate. It starts to fall.

Alternatively, the accelerator system described in the '431 patent may be used, as described above. Kuko's system uses two types of accelerators: flash accelerators and continuous accelerators. . Franche accelerators contain the same ingredients in the same amounts as those used in the accelerators mentioned above. Contains. Continuous accelerators range from about 20 to about 150 mm per pound of metal to be plated. The solubility of metals is greater than that of strong acids or acid-forming salts, about 1 to 20 sr of plating metals. salt, and optionally an effective amount of a dispersant and/or dispersant capable of dispersing the plating metal. a) contain an effective amount of corrosion inhibitor capable of preventing corrosion of the substrate and plating metal; Flash accelerators, including flash accelerators, are added to the plating metal powder after the copper coating is complete. Add to rotating container before washing. Continuous accelerators are added to rotating vessels for plating Each time the metal powder is added little by little, it is added at the same time. Described in the '431 patent The dual accelerator system eliminates the inhibitor present in the container before mechanical plating is complete. or when the amount of dispersant is insufficient. can be determined by a person skilled in the art When such a deficiency occurs, a continuous accelerator can be added. continuous Such addition of accelerators will depend on the degree of corrosion and dispersion in the metal container. , may or may not be required for each addition of granular coating metal. .

In the case of the present invention, the oxidizable metal, the immersion metal, and optionally the protective metal are , are all applied to the surface of metal substrates during mechanical plating, and are therefore generally used for plating. It functions as a genus.

As mentioned earlier, metals that are easily oxidized usually have an oxide layer on their surface, which can be removed. It is easy to re-form even after

Such metals are more likely to have oxide layers on their surfaces than protective metals; Examples of susceptible metals include aluminum, titanium, magnesium and mixtures thereof. The preferred oxidizable metal is aluminum.

The etching agent removes the oxide surface coating from the fine-grained oxidizable metals used in this method. Any compound or mixture of compounds effective to Particularly effective are alkali metal fluorides, ammoniated fluorides, K2Z Fluoridation such as intermetallic fluoride compounds such as rF* and mixtures thereof The 0-etching agent, which is a compound, is smaller than the fluoride of immersion metal, but it is easily etched into oxidation. 1nstability constants larger than that of metal fluoride tant). Fluoride is used to remove oxides from easily oxidized metals. In methods where metals that are easily oxidized are included as a component in the coating liquid (for example, metals that are easily oxidized (If etched without dipping metal) The concentration of fluoride is generally lower than the easily oxidized gold present. It ranges from about 1% to about 30% based on the weight of the genus. Plating metal powder that easily oxidizes These methods, in which the etchant is treated separately from the process itself, generally An appropriate concentration of etchant may be used.

The immersion metal of the present invention is designed to minimize the formation of oxide coatings during mechanical plating processes. , coated on or otherwise associated with fine-grained oxidizable metals. be.

Immersion of metal (one or more types) onto oxidizable metals, such as when used with etching agents. ) coating may be done as part of the mechanical plating process, or may be performed as part of the actual plating process. Examples of dipped metals, which may be done separately from or before the process, include tin, copper, and dipping. Includes copper, cadmium, zinc, lead and mixtures thereof. These metals , oxides, salts, WXH salts, etc. (for example, 5nO1Cu　O, and NiS○, ) in any non-metallic soluble form, such as In this form, The immersed metal is reduced to its metallic state at the surface of the easily oxidized metal (i.e. its oxidation number is 0), then mechanically applied to the substrate surface. Typically plating metal or The concentration of immersion metal used in the pre-treatment step is such that the mechanically plated coating is susceptible to oxidation. at least about 50% by weight of immersion metal, with the remainder being immersion metal(s) and time More preferably, the concentration will consist of small amounts of impurities (e.g. iron) present in the Alternatively, the mechanically plated coating comprises at least 65% oxidizable metal; The concentration of immersed metal(s) is preferably at least about 80%. adjustments will be made to obtain such results.

According to one aspect of the invention, the metal substrate is cleaned, if desired, according to known methods. If not, a copper flash can be applied using mechanical plating equipment. oxide surface The fine-grained, easily oxidized metal is pre-treated in a separate operation with an etching agent to remove the layer. , further pre-treated separately in the presence of one or more immersion metals to further remove the oxidizable metals. Protects it from oxidation, and finally the ratio of oxidizable metal to immersion metal (one 0-order that can provide mechanically plated adhesion with a species or A metal substrate, an impact medium, and a known method Other additives (e.g. surfactants, dispersants, p Mechanical plating containing H modifiers, corrosion inhibitors, drive metals, additional liquid media, etc.) After adding the metal to the device, the agitation or rotation of the device is used to remove metals that are likely to oxidize the surface of the substrate. for a sufficient period of time to plate.

Such agitation can be continuous during the mechanical plating process or It can be done intermittently after addition to.

In another embodiment, the oxidizable metal powder, optionally pre-treated with an etching agent, can be prepared using an immersion metal powder. Added to the device without pretreatment with genus. Immersion of metal and even etching agents into easily oxidized gold The metal may be pre-dissolved in the plating liquid before addition, or it may be easily oxidized. It may be added at the same time as the metal, or both may be pre-dissolved and the easily oxidized metal and They may be added at the same time.

In a preferred embodiment of the invention, the protective metal in the metallic state is exposed to the environment as previously discussed. Used to prevent oxidation of plated metal substrates during exposure. A suitable protective metal is It is more positive in the electrical series than iron. Examples of such protective metals include Contains lead, cadmium and mixtures thereof. The weight of protective metals vs. oxidizable metals Particularly when zinc and aluminum are used, the quantitative ratio is 1:99 to 99:9, respectively. 1, preferably 1:4 to 4:1.

When carrying out the process of the invention according to the preferred embodiments mentioned in the previous paragraph, the acid using frangible metals, protective metals, immersion metals, and etching agents in any of various sequences In this case, the order of adding the easily oxidized metal and the protective metal is Determines the order in which the genera coat the substrate.

That is, the first metal added to the plating liquid forms the first coating layer on the substrate; The metal added to the substrate forms a second coating layer on the substrate, etc. It is preferable to use pickled metals to pre-treat metals that are otherwise susceptible to oxidation. The etching agent preferably added to the plating liquid in the plating container is independent of the plating order. may be added at any point during the mechanical plating process (i.e., to remove oxidizable metals). (before, during, or after addition), the carving agent is susceptible to oxidation. Preferably, it is added to the plating liquid and dispersed therein before the metal is added.

Metals that are easily oxidized should be added to the plating liquid with or after the addition of the protective metal. can be added to. If metals that easily oxidize and protective metals are added to the plating liquid at the same time, If added to the plating layer, the coating layer containing the dispersed oxidizable metal and the protective metal After stirring the liquid, it is formed on the metal substrate. If the protective metal is easy to oxidize after The metal is added to the plating liquid with a plating liquid agitation step after each addition. If the coating on the metal substrate is a layer of oxidizable metal surrounding the protective metal layer, It will be like there is.

It is particularly preferred to coat the substrate with a layer of an oxidizable metal on top of a layer of protective metal. In desirable 0 mechanically plated substrates, the mechanically plated coating usually contains The created pores are sealed by zinc corrosion products. However, aluminum When mechanically plated onto a substrate, aluminum does not fill the pores of the coating. There is a layer of 6 protective metal to be passivated or a co-deposited layer of protective metal and aluminum. Unless there is a corrosive environment, a corrosive environment can reach the metal substrate.

in either of the two previously mentioned plating sequences for oxidizable metals and protective metals. , immersion metal is used so that easily oxidized metals can be plated onto metal substrates. plating solution before, after, or during the addition of protective metals and metals that are easily oxidized. In any of these orders of adding immersed metals, the The metal is coated with easily oxidized metal particles dispersed in the plating liquid, and the resulting It is possible to perform fruit plating. Furthermore, immersed metal particles also preserve aluminum. Plating on top of any already plated layer containing aluminum to protect be able to. Some of the particles used as immersion metal are If added before the oxidizable metal, along with a reducing agent, the This plated gold 2 functions as an immersion metal. The purpose of immersed metal is to provide a barrier coating over oxidizable metal. This is because the purpose of this is to minimize the formation of oxides.

For example, a mixture of metals, protective metals, and immersion metals that easily oxidize the substrate. Coat by adding plating liquid at the same time and stirring this liquid. Can be done. Additionally, dispersed immersion metal, protective metal, and oxidizable metal particles or Another layer of dipped metal can be applied to the substrate surrounding the precipitate & 0 order order The following is one method of forming such a coating = (1) Protective metal, which is easily oxidized. the metal, the etching agent and the immersion metal together in the plating liquid containing the substrate and the impact medium. (2) Stir the plating liquid; (3) Additionally, add easily oxidized metals, Adding the protective metal and the immersion metal together to the plating liquid; (4) adding the plating liquid to the plating liquid; Stir; (5) Add more immersion metal to the plating liquid; and (6) Plate Stir the liquid for use.

The dispersed oxidizable metal, protective metal and immersion metal layers are separated by placing the immersion metal in a plating solution. Add to the body, stir the plating liquid, and plate the easily oxidized metal and protective metal at the same time. It can also be formed by adding plating liquid to the plating liquid and stirring the plating liquid. Ru. In this order, the immersed metal in the plating liquid will remove the easily oxidized metal that will be added later. Coating, oxidizable metals, protective metals and immersion metals are plated together on a metal substrate. It will be.

Alternatively, the substrate is immersed with a dispersed oxidizable metal surrounding a layer of protective metal. It can be coated with a layer of metal by the following process sequence = (1) Adding a protective metal to the plating liquid containing the metal substrate and impact medium: (2) Plating (3) Stir the oxidizable metal, etching agent and immersion metal together. (4) Stir the plating liquid; (5) Add the immersion metal to the plating liquid; and (4) stir the plating liquid; (6) agitating the plating liquid;

The dispersed oxidizable metal, protective metal and immersion metal layers are separated by placing the immersion metal in a plating solution. Add to the body, stir the plating liquid, and plate the easily oxidized metal and protective metal at the same time. It can also be formed by adding it to the plating liquid and stirring the plating liquid. Wear. In this order, the immersed metal in the plating liquid is the metal that is easily oxidized and is added later. coating, oxidizable metals, protective metals and immersion metals are plated together on a metal substrate will be done.

Alternatively, the substrate is immersed with a dispersed oxidizable metal surrounding a layer of protective metal. The layer with metal can be coated by the following process sequence: (1) metal Adding a protective metal to a plating liquid containing a substrate and an impact medium: (2) its plating; (3) Stir the oxidizable metal, etching agent and immersion metal together. and (4) stir the plating liquid. Alternatively, this Coating is achieved by adding a protective metal and a metal that is easily oxidized to the plating liquid at the same time. Stir the plating liquid, add the immersion metal to the plating liquid, and stir the plating liquid. It can be applied by In the latter process sequence, the size of metals that are easily oxidized is The protective metal is mechanically applied to the metal substrate while the part remains in the plating liquid. .

If the immersion metal is later added to the plating liquid, the metal that is susceptible to oxidation is protected metal. Zero-dispersion immersion metal plated mechanically onto an already coated substrate and oxidizable The oxidizable metal and the immersion metal are successively added to accumulate an outer layer of hard metal. It's okay.

Immersion is applied onto a layer of dispersed oxidizable metal and immersion metal surrounding a layer of protective metal. Adding immersion metal to a plating liquid and stirring the plating liquid It can be applied by By such addition of immersion metal alone, Can surround dispersed immersed metal and oxidizable metal particles or aggregates . Further addition and stirring results in the accumulation of immersed metal.

Instead of applying immersion metal around a layer of dispersed oxidizable metal and immersion metal , the layer of dispersed oxidizable metal and immersion metal further comprises immersion metal and oxidizable gold. can be accumulated by adding metals to the plating liquid.

In all of these various cases of coating, oxidizable metals, protective metals, and ) By theory, adjacent layers of immersed metal will have a tendency to diffuse into each other. Although we do not want to be constrained by the For plating with residual metal powder, metal powder for the next layer is added. It is thought that this is caused by the fact that the ki continues even at 1 o'clock when it started.

Example 1 In a plating container with a capacity of 1/3 ft', a 5 ft2 carbon steel needle, 4,000 ．． Glass impact taste (ranging from 0.01 to 0.2 inches in diameter), and those nails and impact Enough water was added to cover the medium.

The nails were cleaned, degreased, and copper flashed according to the method described in the '315 patent. coated. 0.64g sodium sulfate, 6.4g tin oxide, 5.0. N of )(, F - HF, g A solution of major adjuvant and dispersant was added to the container. The container was filled with approx. Rotate for a minute to dissolve all ingredients. After that, 25. of aluminum powder is added to the container. Then, 3 g of copper sulfate was added and rotation continued for 25 minutes. I got it.

The nails were removed from the container and rinsed with water, a flaky metal coating was observed on the nails. . A cross-section of the nail was taken and analysis using energy dispersive X-ray method revealed that the coating was 80%. It was shown to consist of aluminum, 3% copper, 12% tin and 5% iron. Message The efficiency was 60%.

Coated nails are subjected to salt spray testing (ASTM B117) to ensure that no problematic corrosion is observed. It was found to withstand salt spray for 72 to 86 hours until the temperature was exceeded. Chrome-plated (chromatecl) nails were heated at 1,000° C. until significant corrosion was observed. Withstood 0 hours of salt spray.

Example 2 Using 10g of 2ZrF6 instead of ammoniated fluoride as an etching agent, Example 1 was repeated. Similar results were obtained.

Example 3 Example 1 was repeated using 0.5 g of sodium fluoride as the etching agent. salt r Corrosion resistance was observed for 300 hours in fog.

Examples 4-7 Using the fluoride etchant of Example 3 and the method of Example 1, various amounts of aluminum were Ni, tin, and copper are placed in a mechanical plating liquid and the resulting coated needle is placed in a coating containing The material was analyzed. The results are shown in Table 1 below.

meat AI Cu5O, SnOAt Cu Sn4 25 10 2.3 80 10 105 25 3 9.3 55 540 6 25 3 2.3 83 9 8 7 25 10 9.3 65 15 20 Example 8 2500 g of 1 inch Phillips screws were cleaned and copper coated according to the '315 patent. , and tin-coated zero-order, two portions of cadmium powder (10.5 g each) > was added to the vessel at 5 minute intervals. 5 minutes after the last addition, add 3.5 g of heavy fluorine. 10 g each of ammonium chloride and 2.5 g of stannous oxide. Two portions of the powder were added to the container.

During the aluminum addition, the pH was adjusted to 2 by adding 20% sulfuric acid at 5 minute intervals. kept lower. 5 minutes after the last addition, add 3 g of ViL acid cupric acid and add to the container. was rotated for an additional 10 minutes. The screws were removed from the container and rinsed with water.

The coated screws were subjected to a salt spray corrosion test (ASTM B117) to detect problematic corrosion. It was found to withstand salt spray for 96 hours until observed. Chrome plated The screws withstood 3,816 hours of salt spray before red rust was observed.

Example 9 Example 8 was added with a powder mixture of zinc and cadmium (weight ratio 1:1.9.7 g each). It was repeated using

The screws were subjected to a 5% neutral salt spray test (ASTM B117) to ensure that no corrosion was present. It was found to withstand 96 hours of spraying until observed. chrome plated The screws withstood 4,536 hours of salt spray before red rust was observed.

Example 10 Hexagonal head hexagonal screw 1172 bond, hexagonal head bolt 172bond and 6d ordinary The nail 2 bond mixture was cleaned, copper coated and tin coated according to Example 8. Overturned.

Zinc (in three portions of 8 g each) was then added at 3 minute intervals. Last 3 minutes after adding zinc, aluminum powder (Log), ammonium bifluoride Add a mixture of After rotating the container for 5 minutes, aluminum <10g> and stannous oxide (3, 5g) was added and the vessel was rotated for 5 minutes.

Finally, cupric sulfate (2.0 g) was added and the vessel was rotated for a further 10 minutes. soot After drying, the coated screws were subjected to a neutral salt spray corrosion test (ASTM B117). I put it on. Initially, the non-chrome-plated samples showed red rust after 168 hours of spraying. However, the chrome plated sample first showed red rust after 3,816 hours.

Example 11 A steel plate (2.5 kg) was cleaned and copper coated according to the -315 patent. Then it was coated with tin. Dull powder (8g), aluminum powder (10.0g), heavy fume A mixture of ammonium fluoride (3.6 g), 2 and M oxide (2.4 g) was placed in a container. and then rotated the container for 5 minutes. Furthermore, zinc (3g), aluminum (12 g) and -fi oxide (2.4 g) were added and plating continued for 5 minutes. . During these additions, keep the pH below 2 by adding 20% P acid. did. Finally, VT acid copper (2.4 g) was added and the vessel was rotated for another 10 minutes. After removing the 6 parts and rinsing them with water and drying them, the parts were subjected to 5% neutral salt spray corrosion. The non-chromium-plated specimens tested (ASTM B117) were 16 Does not show any significant rust (i.e. more than 10% rust) until after 8 hours of spraying Ta. When the sample was plated with chrome, the red rust was first removed after 504 hours, but after 2,50 hours Even after the 0:00 leap exposure, only 5% of the red rust appeared.

Example 12 Steel Phillips screws, zinc, aluminum over zinc, aluminum over cadmium , ram, or aluminum co-deposited with zinc to the thicknesses shown in Table 1 below. coated with. The coated screws were subjected to a 5% neutral salt spray test and the M of interest (i.e. 1 The time taken for rust to occur (greater than 0% rust) was determined. As shown in Table 1 below , zinc coating applied according to the invention, aluminum on zinc, cadmium on of aluminum, inferior to coatings with aluminum deposited simultaneously with zinc. there was.

meat Zinc 0.3 384 Zinc 0.6 504 Zinc 0.9 624 On zinc A I 0.6 >2000 AI on cadmium 0.6 > 2000AI: Zn simultaneous deposition 0.5 > 20 00A I: A n simultaneous adhesion 0.6 > 2000 However, aluminum on zinc coated with aluminum, aluminum on cadmium, or aluminum co-deposited with zinc. This superior salt spray corrosion resistance of coated substrates is due to the fact that coated substrates are repeatedly exposed to sulfur dioxide. Environment used in the Kestnernich test It does not apply to .

As shown in Table 2, screws coated with zinc or cadmium are made of aluminum over cadmium. coated with aluminum, aluminum on zinc, or co-deposited aluminum and zinc; withstand the same or more cycles against sulfur dioxide than chrome-plated screws. You can get it.

Zinc〉20 Cadmium 14 Cd top A I 0.6 11 Zn top A I 0.6 15 AI: Zn simultaneous adhesion 0.6 14 Example 13 2-inch bolt/nut combination with zinc, zinc top A/L miniram, or zinc The coating was coated with aluminum simultaneously deposited to the thickness shown in Table 3 below. Next These combinations were fixed on an aluminum plate and sprayed with 5% neutral salt. until the composite has problematic rust (i.e. more than 10% rust), and aluminum Determine how many hours it took until the first small pit was noticed in the board. did. As shown in Table 3 below, the zinc coated combination corroded severely and the zinc The aluminum plate to which the sheathing combination is attached may develop small holes as a result of galvanic corrosion. It was terribly open. In contrast, co-deposited aluminum and zinc or on zinc Aluminum plated combinations exhibit virtually no corrosion; There were almost no holes in the aluminum plate to which the fixture was attached.

"Shadow Coating Time until up to 10% red rust appears on the aluminum plate in the combination First hole Time until damage is recognized Zinc (chrome plated) 0.35 264 144 0.6 384 288 AI: Zn simultaneous deposition 0.35 > 1104 1008 The present invention is described in detail for illustrative purposes. Although described in detail, such detail is for that purpose only and is not limited to the scope of the claims. Various modifications can be made by those skilled in the art without departing from the scope of the invention as defined. You will understand that.

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Claims (40)

[Claims] 1. metal substrate, and Metals that easily oxidize and coatings that easily oxidize to minimize corrosion of easily oxidized metals. a coating on said metal substrate consisting of a coating immersed in metal; Mechanically plated articles consisting of 2. Claims wherein the coating further includes a protective metal to prevent oxidation of the metal substrate. A mechanically plated article according to Box 1. 3. Metals that are easily oxidized are more easily oxidized than protective metals, such as aluminum, titanium, and Claim 2 selected from the group consisting of gnesium and mixtures thereof. Mechanically plated articles. 4. the protective metal is selected from the group consisting of zinc, cadmium and mixtures thereof; 4. A mechanically plated article according to claim 3. 5. Immersion metals include tin, copper, nickel, cadmium, zinc, lead and mixtures thereof. The machine according to claim 4, which is a salt or oxide of a metal selected from the group consisting of Target-plated items. 6. The mechanical plating according to claim 4, wherein the easily oxidized metal is aluminum. Items that have been damaged. 7. 7. A mechanically plated article according to claim 6, wherein the protective metal is zinc. 8. Claim 7, wherein the weight ratio of zinc to aluminum is 1:99 to 99:1. mechanically plated articles. 9. Claim 8, wherein the weight ratio of zinc to aluminum is from 1:4 to 4:1. Mechanically plated articles. 10. the protective metal is selected from the group consisting of zinc, cadmium and mixtures thereof; 3. A mechanically plated article according to claim 2. 11. Immersion metals include tin, copper, nickel, cadmium, zinc, lead and mixtures thereof. According to claim 10, which is a salt or oxide of a metal selected from the group consisting of Mechanically plated articles. 12. The mechanical mesh of claim 2, wherein the coating is between 0.1 and 5.3 mils thick. Items that have been damaged. 13. Claims in which the coating consists of dispersions of oxidizable metals, protective metals and immersion metals Mechanically plated articles according to scope 2. 14. The coating is a layer of dispersed oxidizable metal and immersed metal surrounding the protective metal. 3. A mechanically plated article according to claim 2, comprising: 15. The coating further contains dispersed oxidizable metal and immersed metal particles or aggregates. 15. A mechanically plated article according to claim 14 having a surrounding layer of dipped metal. . 16. The coating contains dispersed protective metal, oxidizable metal, and immersion metal particles or aggregates. A mechanically plated plate according to claim 2 comprising a layer of dipped metal surrounding the agglomerate. Goods. 17. The metal that easily oxidizes is aluminum, and the protective metal is zinc, and the difference between zinc and aluminum is The mechanical plating according to claim 5, wherein the weight ratio of Ni is 1:99 to 99:1. goods that have been 18. The metal that easily oxidizes is aluminum, and the protective metal is zinc, and the difference between zinc and aluminum is The mechanical plating according to claim 17, wherein the weight ratio of aluminum is 1:4 to 4:1. Items that have been damaged. 19. 2. A mechanical device according to claim 2, wherein the protective metal is more electrically positive than iron. plated articles. 20. In a method of mechanically plating a metal substrate, the metal substrate and an impact medium are applying a plating liquid containing etched or unetched grains to said plating liquid; Protects easily oxidizable metals from oxidizing. dipped metal, and optionally, if the particulate oxidizable metal is not etched, or If granular oxidizable metal is etched without immersion metal, add an etching agent, and The plating liquid is stirred so that the impact medium hits the metal substrate and forms particulate particles. steps of applying oxidizable metals and immersion metals as coatings to said metal substrate; A method of mechanically plating a metal substrate consisting of: 21. It is recommended to add protective metals to the plating liquid to prevent oxidation of the metal substrate. 21. The method according to claim 20. 22. 22. The method of claim 21, wherein the stirring is continuous. 23. 22. The method according to claim 21, wherein the stirring is intermittent. 24. Metals that are easily oxidized are more easily oxidized than protective metals, such as aluminum, titanium, Claim 21 selected from the group consisting of magnesium and mixtures thereof. How to put it on. 25. the protective metal is selected from the group consisting of zinc, cadmium and mixtures thereof; 25. The method according to claim 24. 26. The metal that easily oxidizes is aluminum, and the protective metal is zinc, and the difference between zinc and aluminum is 26. The method according to claim 25, wherein the weight ratio of Ni is between 1:99 and 99:1. 27. Claim 26, wherein the weight ratio of zinc to aluminum is from 1:4 to 4:1. How to put it on. 28. 22. The method of claim 21, further comprising adding an etching agent to the plating liquid. Method. 29. 29. The method of claim 28, wherein the etching agent is a fluoride compound. 30. The concentration of fluoride compounds in the plating fluid is based on the weight of the oxidizable metal. 30. The method according to claim 29, wherein the amount is 1.0 to 30% by weight. 31. Fluoride compound etchants are smaller than fluoride in immersion metals, but are more susceptible to oxidation 31. The method of claim 30 having a greater instability constant than metal fluorides. 32. Fluoride compounds include alkali metal fluorides, ammoniated fluorides, metal Claim 31 selected from the group consisting of interfluorides and mixtures thereof. the method of. 33. Addition of etching agents to easily oxidize metals, protective metals and/or immersion metals The method according to claim 28, carried out before, after and/or during the addition. . 34. Covering oxidizable metals, protective metals, and immersion metals with a coating of at least 65% by weight Claim 21 added to the plating liquid so as to contain % of the easily oxidizable metal. Method described. 35. Addition and stirring Adding a protective metal to a plating liquid containing a metal substrate and an impact medium; Stirring the plating liquid, Combining oxidizable metals, etching agents, and immersion metals together with protective metals already added. plating liquid, and stirring the plating liquid; 22. The method of claim 21, comprising the steps of: 36. Addition and stirring Plating solutions with oxidizable metals, etching agents, and immersion metals already added together Add more immersion metal to the body, and stirring the plating liquid; 36. The method of claim 35, further comprising the step. 37. Addition and stirring Add the oxidizable metal, etching agent, and immersion metal together, then add to the plating liquid. together with the oxidizable metal and the immersion metal, and stirring the plating liquid; 36. The method of claim 35, further comprising the step. 38. Addition and stirring Metal substrates and plating liquids containing impact media, protective metals, metals that are easily oxidized, and etching agents. , and immersion metal are added together and the plating liquid is stirred; The above-mentioned method has already added protective metals, oxidizable metals, etching agents, and immersion metals. Further, a protective metal, an easily oxidized metal, and an immersion metal are added to the coating liquid, Stirring the plating liquid, Plating solution with protective metal, oxidizable metal and immersion metal already added together Adding more immersion metal to the body, and stirring the plating liquid; 22. The method of claim 21, comprising the steps of: 39. 22. The method of claim 21, wherein the protective metal is more electrically positive than iron. . 40. In a method of mechanically plating a metal substrate, (a) the metal substrate is plated in an acidic solution. contact with a liquid to clean the surface of the metal substrate and remove rust; (b) rinsing the metal substrate with water; (c) containing a strong acid in an agitated plating vessel containing an impact medium and said metal substrate; A surface conditioner is added to keep the surface of the metal substrate clean and free of oxides. Hold, (d) adding said metal to said stirred plating container without performing an intermediate rinse; Addition of copper coating agent that forms a thin copper coating on the clean, oxide-free surface of the substrate and (e) adding the final solution to the agitated plating vessel without intermediate rinsing. The substrate is coated by adding a salt of a metal nobler than the target plating metal and a small amount of granular coating metal. (f) flash-coating a copper-coated surface with said more noble metal; Add the etched or unetched material to the stirred plating container without performing any Particulate oxidizable metal, immersion metal coating oxidizable metal, optionally said metal base. Protective metal to prevent body oxidation, and optionally granular oxidizable metal etched If not, or if the immersed metal is not etched, add an etching agent to it. Therefore, the impact medium may damage the protective metal, the immersed metal, and the oxidizable metal. The metal is applied as a plating layer to the copper and nobler metal coatings on the surface of the metal substrate. to put on, A method of mechanically plating metal substrates, which consists of various steps.