CN204589340U - A kind of super anti-corrosion nickel plating-chromium parts - Google Patents

Abstract

The utility model relates to a super-corrosion-resistant nickel-chromium plated part, which belongs to the technical field of electroplating. It includes a substrate; a pretreatment coating deposited over the entire substrate, on which a copper plating layer is formed; and a semi-bright nickel layer, which is formed on the copper plating layer; and a full-gloss nickel layer or satin A nickel layer formed on the semi-bright nickel layer; and a functional layer formed on the full-gloss nickel layer or satin nickel layer, wherein the functional layer includes a low-potential nickel layer and a microporous nickel layer formed on the low-potential nickel layer and a decorative layer formed on the microporous nickel layer. The potential difference between the low-potential nickel layer and the microporous nickel layer is 10-120mv; the low-potential nickel layer includes a high-sulfur nickel layer and a composite between one or two layers of the micro-cracked nickel layer. When using micro-cracks and In the case of high-sulfur nickel composite coating, the potential difference between microcracks and high-sulfur nickel is 10-80mv. It not only ensures the bright appearance of the microporous nickel layer of the component, but also makes it have super high corrosion resistance, hardness and wear resistance.

Description

A Super Corrosion Resistant Nickel-Chromium Plated Component

technical field

The utility model relates to a workpiece with a surface electroplating layer structure, in particular to a super-corrosion-resistant nickel-chrome plated part.

In this application, the potential difference is the difference between the standard potentials measured by taking each of the two adjacent layers as a whole.

Background technique

The European market has increasingly stringent environmental protection requirements, and automobile factories have higher and higher requirements for electroplating corrosion resistance. At present, chromium electroplating cannot meet the corrosion requirements of specific environments (at the same time, it can meet the salt spray resistance test of 80h and the Russian mud resistance test. 336h).

In the electroplating industry, the method of firstly plating double-layer nickel or triple-layer nickel and then chromium plating is generally used to improve the anti-corrosion ability of the workpiece. The layer nickel process includes: semi-bright nickel + light nickel + microporous nickel + crack-free chromium, or semi-bright nickel + light nickel + micro-crack nickel + crack-free chromium, but due to the high stress of the chromium layer itself, it is difficult to obtain in industry A chromium electroplating layer (including hexavalent chromium and trivalent chromium plating) without cracks or pores at all. After the chromium electroplating layer exposed to the air is passivated, its potential is more positive than that of nickel. When it encounters a corrosive medium, it will It forms a corrosion battery with the nickel layer, causing corrosion of the nickel layer. In extreme environments, excessive corrosion will occur, resulting in large-scale peeling off of the surface chromium layer, which will affect the quality of the product. In order to further improve the anti-corrosion ability of the coating, microporous nickel and microcracked nickel are applied to the light nickel coating. Its function is to promote a large number of microcracks or micropores on the surface of the product through different plating processes, forming a large number of tiny Corrosion channels, so as to separate the corrosion points into points that cannot be recognized by the naked eye, reduce the shedding of the chrome layer, and improve the appearance quality during use. Due to the use of microporous nickel or microcracked nickel alone, the improvement of corrosion resistance is limited; and the combination of microcracks and trivalent chromium has problems such as poor appearance, resulting in inapplicability for products with high corrosion resistance requirements. At the same time, in some existing technologies, it is disclosed to change the microporous nickel process to achieve noble potential characteristics, so as to meet the corrosion resistance requirements of trivalent chromium, but this process technology cannot achieve collinear production with hexavalent chromium and trivalent chromium. All components meet high-quality corrosion-resistant requirements.

In the prior art, for example, the Chinese patent application (publication number: CN 101988211A) relates to a multi-layer nickel plating process on metal surfaces with excellent anti-corrosion properties. The electroplating process flow is: A. metallization of the surface of plastic parts, B. bright copper, C. semi-bright nickel, D. high-sulfur nickel E. bright nickel, F. microporous nickel, G. washing, H. bright chrome, I. washing, J. drying; although the four-layer nickel nickel is used in this technical scheme Electroplating the plastic surface with electroplating solution improves the corrosion resistance of plastic parts to a certain extent, but the corrosion resistance of this process still cannot meet the requirements of the corrosive environment containing deicing salt (CaCl ₂ ). And about the technique of introducing micro-crack nickel, as Chinese patent application (publication number: CN101705508A) relates to a kind of electroplating solution and application thereof for micro-crack nickel electroplating, the main composition of this micro-crack nickel electroplating solution is as follows: nickel chloride: 180-260 g/l, acetic acid: 20-60 ml/l, ELPELYT MR: 80-20 ml/l, 62A: 1-5 ml/l, the evaluation of the examples described in the patent literature is practically limited to hexavalent chromium plating , did not talk about trivalent chromium plating, and at the same time, it was verified that there were phenomena such as poor corrosion resistance and inconsistent appearance.

Contents of the invention

The technical problem to be solved by the utility model is to provide a super-corrosion-resistant nickel-chromium plated part in view of the current situation of the prior art. It ensures the bright appearance of the microporous nickel layer, and has the multiple corrosion resistance of the functional layer containing microporous nickel, microcracked nickel and/or high-sulfur nickel layer, which can make the product achieve ultra-high corrosion resistance and structural stability , hardness, wear resistance, even after the low-potential nickel layer is corroded, the microporous nickel layer, semi-bright nickel layer, full-bright nickel layer or satin nickel layer can also support and delay corrosion.

The technical solution adopted by the utility model to solve the above-mentioned technical problems is: a super corrosion-resistant nickel-chrome plated part, the super corrosion-resistant nickel-chrome plated part comprises:

Substrate; here the utility model substrate can adopt metal, plastics and other parts that can be applicable to electroplating;

Pretreatment coating (pretreatment coating can include any one or two layers of chemical nickel layer or primer nickel layer, and there is no such layer on the substrate. The specific choice depends on the material of the substrate. When the chemical nickel layer When existing simultaneously with the bottoming nickel layer, then the chemical nickel layer is formed on the substrate, and the bottoming nickel layer is formed on the chemical nickel layer), which is deposited on the entire substrate, and a copper plating layer is formed on the pretreatment coating; and

a semi-gloss nickel layer formed on the copper plating layer; and

a full-bright nickel layer or a satin nickel layer formed over a semi-bright nickel layer; and

A functional layer formed on the full-bright nickel layer or satin nickel layer, wherein the functional layer includes a low-potential nickel layer and a microporous nickel layer formed on the low-potential nickel layer; and

Decorative layer, which is formed on the microporous nickel layer, said decorative layer is any one of trivalent chromium plating or hexavalent chromium plating, wherein the trivalent chromium plating can be trivalent white chromium plating or trivalent black chromium plating or other Types of trivalent chromium coating, the surface of the trivalent chromium coating can also contain a passivation film.

Measures taken to optimize the above-mentioned scheme include:

In the aforementioned super-corrosion-resistant nickel-chrome plated part, the potential difference between the microporous nickel layer and the low-potential nickel layer is in the range of 10-120mv.

In the above-mentioned super-corrosion-resistant nickel-chrome plated part, the low-potential nickel layer includes a high-sulfur nickel layer and a layer of micro-cracked nickel layer or a composite coating between the two layers.

In the above-mentioned super corrosion-resistant nickel-chrome plated part, the potential difference between the microporous nickel layer and the low potential nickel layer is in the range of 20-100mv.

In above-mentioned a kind of super-corrosion-resistant nickel-chromium plating parts, when the low-potential nickel layer adopts the composite coating of micro-crack nickel layer and high-sulfur nickel layer, the potential difference between the micro-crack nickel layer and the high-sulfur nickel layer is 10 Within -80mv. Here, when the corrosion reaches the low-potential nickel layer, since the potential of the micro-cracked nickel layer is higher than that of the high-sulfur nickel layer, the high-sulfur nickel layer is preferentially corroded as an anodic coating, prolonging the corrosion of the micro-cracked nickel layer, thereby Further improved corrosion resistance.

In the aforementioned super-corrosion-resistant nickel-chrome plated part, the potential difference between the all-gloss nickel layer or satin nickel layer and the low-potential nickel layer is in the range of 0-100mv.

In the aforementioned super-corrosion-resistant nickel-chrome plated part, the potential difference between the semi-bright nickel layer and the full-gloss nickel layer or satin nickel layer is within the range of 100-200mv.

The manufacturing method of the super-corrosion-resistant nickel-chrome plated part disclosed by the utility model comprises the following steps:

Pretreating the surface of the substrate;

depositing a pretreatment coating over the entire substrate, and forming a copper plating layer on the pretreatment coating; and

forming a semi-gloss nickel layer on the copper plating layer; and

forming a full-bright nickel layer or a satin nickel layer on the semi-bright nickel layer; and

forming the low-potential layer in the functional layer on the all-bright nickel layer or the satin nickel layer; and

The microporous nickel layer in the functional layer is formed on the low-potential nickel layer; the potential difference between the microporous nickel layer and the low-potential nickel layer is 10-120mv, and the potential difference is controlled within this range. Bubbling is not easy to occur during the process, and the coating structure is more stable and firm, and it is not easy to separate and peel off;

A decorative layer is formed on the microporous nickel layer.

In the above-mentioned manufacturing method of a super-corrosion-resistant nickel-chrome plated part, the low-potential nickel layer includes a high-sulfur nickel layer, a layer of micro-cracked nickel layer or a composite between the two layers.

In the above-mentioned manufacturing method of a super corrosion-resistant nickel-chrome plated part, the microporous nickel layer is formed by electroplating with a microporous nickel plating solution, and the microporous nickel plating solution includes a composition and a concentration of: Hydrous nickel sulfate 300-350g/L, hydrous nickel chloride 50-60g/L, boric acid 40-50g/L, nickel seal brightener 6-12ml/L , MacDermid Technology (Suzhou) Co., Ltd. hereinafter referred to as MacDermid, such as Lesi’s 63 and MacDermid’s NIMAC 14INDEX), nickel sealing master light agent 4-7.5ml/L (such as Lesi’s 610CFC and MacDermid’s NIMAC 33), nickel-sealed particles 0.2-1.5g/L (such as ENHANCER from Schleich and MacDermid’s NiMac Hypore XL dispersant), nickel-sealed particle dispersant 0.5-3ml/L, wetting agent 1-5ml/L. The microporous nickel layer is plated at an operating temperature of 50-60°C, a pH value of 3.8-4.6, a current density of 2-5ASD, and an operating time of 2-8 minutes, through direct current electrolysis The nickel is deposited on the electroplated parts, and the thickness of the microporous nickel layer is not less than 1.5 microns. Microporous nickel plating refers to plating a layer of uniform coating containing countless non-conductive particles on the surface of the substrate to further disperse the corrosion current, reduce the corrosion current density, and comprehensively improve the corrosion resistance of the coating.

In the above-mentioned manufacturing method of a super-corrosion-resistant nickel-chrome plated part, the microcracked nickel layer is formed by electroplating with a microcracked nickel plating solution, and the microcracked nickel plating solution includes a composition and a concentration of: Nickel chloride: 180-260g/L, acetic acid: 20-60ml/L, PN-1A: 40-90g/L, PN-2A: 1-5ml/L, wetting agent: 1-5ml/L. The operating temperature is controlled between 25-35°C, the pH value is controlled between 3.6-4.6, the current density is 5-9ASD, and the operating time is controlled between 2-5min. The nickel is deposited on the nickel-plated- On the surface of the all-bright nickel layer of chromium parts, the thickness of the micro-cracked nickel layer is required to be not less than 1.5 microns. Nickel plating with microcracks refers to plating a layer of uniform coating containing numerous cracks on the surface of the substrate to disperse the corrosion current and reduce the corrosion current density.

In the above-mentioned manufacturing method of a super-corrosion-resistant nickel-chrome plated part, the high-sulfur nickel layer is formed by electroplating with a high-sulfur nickel plating solution, and the high-sulfur nickel plating solution includes a composition and a concentration of: Nickel sulfate 250-350g/L, hydrous nickel chloride 35-60g/L, boric acid 35-65g/L, high sulfur additive 3-10ml/L, wetting agent 0.5-3ml/L. Wetting agents such as Lesi's 62A and MacDermid's NIMAC 32C WETTER. The operating temperature is controlled between 55-65°C, the pH is controlled between 2.0-3.5, the current density is 2-6ASD, the operating time is controlled between 2-8min, and nickel is deposited on the parts through direct current electrolysis On the surface of the nickel layer or satin nickel layer, the thickness of the high-sulfur nickel plating layer is not less than 1.0 micron.

In the above-mentioned manufacturing method of a super corrosion-resistant nickel-chrome plated part, the semi-gloss nickel layer is formed by electroplating with a semi-gloss nickel plating solution, and the semi-gloss nickel plating solution includes a composition and a concentration of: Nickel sulfate 200-300g/L, hydrated nickel chloride 35-50g/L, boric acid 35-50g/L, semi-gloss nickel primary brightener 3.0-7.0ml/L (such as BTL MU from Lesi and NIMAC SF from MacDermid DUCT), semi-gloss nickel secondary brightener 0.3-1.0ml/L (such as TL-2 of Lesi and NIMAC SF LEVELER of Mai Demei), potential difference regulator 0.1-0.6ml/L (such as B supplement of Lesi and NIMAC SF MAINTENANCE), wetting agent 1.0-3.0ml/L (such as Lesi's 62A and NIMAC 32C WETTER). The operating temperature is controlled between 50-60°C, the pH value is controlled between 3.6-4.6, the current density is 2-5ASD, and the operating time is controlled between 12-24min. The nickel is deposited on the nickel-plated- On the surface of the copper plating layer of the chromium component, the thickness of the semi-gloss nickel layer is not less than 8 microns.

In the manufacturing method of above-mentioned a kind of super-corrosion-resistant nickel-chrome plating parts, the all-gloss nickel layer is formed by electroplating with all-gloss nickel plating solution, and the all-gloss nickel plating solution includes composition and concentration: aqueous nickel sulfate 240- 360g/L, hydrated nickel chloride 35-65g/L, boric acid 35-65g/L, bright nickel softener 8-15ml/L (such as Lesi’s 63 and MacDermid’s NIMAC 14INDEX), bright nickel brightener A 5 -10ml/L (such as Schleich's 610CFC and MacDermid's NIMAC 33), bright nickel main light agent 0.5-0.9ml/L (such as Schleich's 66E and MacDermid's NiMac Challenger Plus), wetting agent 1.0-3.0 ml/L (such as Lesi's 62A and MacDermid's NIMAC 32C WETTER). The operating temperature is controlled between 50-60°C, the pH value is controlled between 3.6-4.6, the current density is 2-5ASD, and the operating time is controlled between 9-20min. The nickel is deposited on the nickel-plated- On the surface of the semi-bright nickel layer of the chromium component, the thickness of the full-bright nickel layer is not less than 5 microns.

In the manufacturing method of the above-mentioned super corrosion-resistant nickel-chromium parts, the satin nickel layer is formed by electroplating with a satin nickel plating solution, and the satin nickel plating solution includes composition and concentration: hydrated nickel sulfate 250-350g/ L, aqueous nickel chloride 35-60g/L, boric acid 35-65g/L, auxiliary additives 5-20ml/L (such as Elpelyt pearlbrite carrier K4 and Elpelyt carrier brightener H of Lesi), sardine nickel former 0.1-0.6 ml/L (such as Elpelyt pearlbrite additive K6AL of Lesi).

When the base layer is a semi-bright nickel layer or a full-bright nickel layer, the composition of the plating solution in the semi-bright nickel and full-gloss nickel plating is the same, but the additives are different, so that the formed coating structure is different, and each step has a different effect. Function, the semi-bright nickel layer can improve the corrosion resistance of the coating, and the full-gloss nickel layer can improve the brightness of the coating. Semi-bright nickel plating refers to plating a layer of semi-bright nickel layer on the surface of nickel-chromium-plated parts. Semi-bright nickel The layer has a columnar structure, which can improve the corrosion resistance of the coating. All-bright nickel plating refers to plating a layer of all-bright nickel layer on the surface of nickel-chrome-plated parts. The full-bright nickel layer has a layered structure, which can improve the brightness of the coating.

In the manufacturing method of the above-mentioned super-corrosion-resistant nickel-chromium parts, it also includes the pretreatment process of the base material, wherein the pretreatment process of the non-metallic base material including ABS resin at least includes a surface grease treatment process, a surface affinity Water, surface roughening treatment process, surface neutralization treatment process, surface pre-dipping, surface activation treatment process and surface debonding treatment process; while metal substrates can be subsequently plated after degreasing in the surface grease treatment process The work also applies to the corresponding procedures in the pre-treatment procedures of non-metallic foundations stated below.

In the manufacturing method of the above-mentioned super-corrosion-resistant nickel-chrome plated parts, the pretreatment process of the non-metallic substrate is specifically to clean the substrate blank in a mixed solution of sodium hydroxide, sodium carbonate and sodium silicate to remove grease, remove The grease is then immersed in a mixture of chromic anhydride and sulfuric acid for surface roughening, then put into hydrochloric acid solution for surface neutralization, after neutralization, use colloidal palladium solution for surface activation treatment, and then perform surface degelling treatment in sulfuric acid solution.

As preferably, composition and concentration are included in the mixed solution of surface grease treatment step: the concentration of sodium hydroxide is 20-50g/L, the concentration of sodium carbonate is 10-40g/L, the concentration of sodium silicate is 10-40g/L L, surfactant 1-3g/L.

Here, the surface degreasing step can remove oil and other impurities on the surface of the substrate, promote uniform surface roughening, and improve the bonding force of the coating.

Preferably, the concentration of the sulfuric acid solution in the surface hydrophilic step is 20-100g/L, and the finishing agent is 0.5-2ml/L.

Preferably, the components and concentrations included in the mixed liquid in the surface roughening treatment step are: the concentration of chromic anhydride is 330-480 g/L, and the concentration of sulfuric acid is 330-480 g/L.

Here, chromic anhydride is the main salt in the plating solution. Metal chromium is deposited on the surface of the substrate through the mechanism of oxidation-reduction reaction and electron gain and loss, and chromium trioxide hydrate is produced, which makes the coating black, and chromic anhydride has an effect on the plating solution The deep-plating ability has a great influence. If the content of chromic anhydride is high, the deep-plating ability will be strong and the crystallization will be fine. The surface of the substrate is to form a microscopic rough surface on the surface of the substrate to ensure the "locking effect" required for electroless plating, thereby improving the bonding force between the surface of the substrate and the coating. However, sulfate radicals will reduce the color properties of the coating and make the coating yellow. In order to corrode the surface of the substrate and reduce harmful effects at the same time, it is necessary to precisely configure the content of sulfuric acid.

Preferably, the concentration of the hydrochloric acid solution in the surface neutralization process is 30-100ml/L, and the concentration of hydrazine hydrate is 15-60ml/L.

Preferably, the concentration of the hydrochloric acid solution in the surface pre-soaking process is 40-120ml/L.

Preferably, the colloidal palladium solution for surface activation treatment includes components and concentrations: the concentration of palladium chloride is 20-60ppm, the concentration of stannous chloride is 1-6g/L, and hydrochloric acid is 180-280ml/L.

Here, in the colloidal palladium solution, palladium chloride covers the surface of the substrate to provide a catalytic center for the subsequent chemical nickel, while the tin ions of stannous chloride can be deposited around the palladium ion as a compound group to prevent the palladium ion from Oxidation and shedding in water or air can increase the service life of the colloidal palladium solution.

Preferably, the concentration of the sulfuric acid solution in the surface degumming treatment process is 40-100 g/L.

Surface degelling treatment refers to the use of sulfuric acid to remove the stannous chloride coated around the palladium oxide in the colloidal palladium solution, exposing the metal palladium particles, making the subsequent chemical nickel deposition process smoother.

As preferably, include composition and concentration in the electroless nickel layer plating solution of chemical nickel layer process: the concentration of nickel sulfate is 15-40g/L, and the concentration of sodium hypophosphite is 20-50g/L, and the concentration of sodium citrate is 10 -4g/L, ammonium chloride 10-50g/L, ammonia water, for pH adjustment, PH=8.6-9.2.

As preferably, include composition and concentration in the bottoming nickel plating solution of laying nickel plating step: the concentration of aqueous nickel sulfate is 180-280g/L, the concentration of aqueous nickel chloride is 35-60g/L, the concentration of boric acid is 35-60g/L, wetting agent 1-3ml/L.

When the chemical nickel layer and the bottoming nickel layer exist on the substrate at the same time, the substrate has been covered with a thin conductive nickel layer through the oxidation-reduction reaction in the chemical nickel deposition; In nickel, a layer of nickel is plated on the chemical nickel by electrochemical method to further enhance the conductivity of the coating. In this step, the hydrated nickel sulfate and hydrated nickel chloride provide the nickel ions required for the electrochemical reaction.

As preferably, each component and concentration are in the copper plating layer bath of copper plating layer process: the concentration of copper sulfate is 160-260g/L, the concentration of sulfuric acid is 50-100g/L, and chloride ion is 40-100ppm, the whole Leveling agent 0.2-1ml/L, moving agent 0.2-1ml/L, cylinder opening agent 2-10ml/L.

The purpose of the copper plating layer here is to use the characteristics of copper sulfate to improve the brightness and smoothness of the substrate surface, and also to improve the overall toughness of the plating layer. This is because copper plating has better ductility than nickel plating and other metal plating, so after the acid copper layer is plated, the toughness and leveling of the overall plating are improved.

Wherein, in the nickel-chromium plated part of the present utility model, when the low-potential nickel layer adopts a single micro-crack nickel layer or a composite nickel layer composed of a high-sulfur nickel layer and a micro-crack nickel layer, the utility model can be made to achieve the best Corrosion resistance effect, the reason why the micro-cracked nickel layer, microporous nickel layer or the combination of the two in the functional layer can prevent corrosion and protect the substrate is that the coating metal/base metal on the workpiece is extremely easy to form a corrosion cell, and the negative and positive When the electrode potential is determined, the corrosion rate is controlled by the ratio of the exposed area of the base metal (anode) on the surface of the coating metal (cathode). When there is only one corrosion point, the cathode/anode ratio is the largest at this time, the corrosion current is concentrated at this point, the corrosion rate becomes very large, and it is easy to form pitting corrosion inward, but when there are more potential corrosion points on the surface of the metal coating At the corrosion point, the cathode/anode ratio is small, the corrosion current is distributed everywhere, the current on the original corrosion point is significantly reduced, and the corrosion rate is also greatly reduced. At the same time, due to the division between micropores or cracks, the cathode of the coating is discontinuous, and the divided coating changes from a large area to a small area, which further limits the cathode/anode ratio. However, as time goes by, when the surface of the coating is affected by external factors and large cracks begin to appear, the potential corrosion cells of micro-cracks and micro-porous structures will be triggered, thereby protecting the corrosion points, so that it can be It plays the role of dual core to reduce the corrosion current density, thus greatly improving the corrosion resistance.

Anticorrosion Mechanism of Low Potential Nickel

Step 1: When removing the corrosive medium on the surface of the part, due to the presence of a highly corrosion-resistant passivation layer on the decorative layer (such as the chromium layer), micropores on the surface of the chromium layer exist, which guide the corrosion of the nickel layer at the micropores to expand. The discontinuity of the pores leads to the fact that the corrosion is divided into many areas when the total amount of corrosion remains unchanged, so the corrosion proceeds without affecting the appearance. .

Step 2: When the corrosion reaches the low-potential nickel layer, since the potential of the microporous nickel is higher than that of the low-potential nickel, the low-potential nickel is preferentially corroded as an anodic coating (that is, the low-potential nickel layer is preferentially used as a sacrificial layer), and the micro Corrosion in the porous nickel is stopped. Under the action of a large number of discontinuous micro-cracks, the corrosion is guided to develop simultaneously in the depth and lateral direction of the cracks, and the area of the corroded nickel layer will be greatly increased and discontinuous. Under the condition of a certain corrosion current, these "micro-pores" are greatly dispersed. The corrosion current reduces the single point corrosion rate again, delays the corrosion rate, and protects the chromium layer on the appearance surface and the microporous nickel layer attached to it, further improving the corrosion resistance of the product surface.

Step 3: When the corrosion extends further downward in the low-potential nickel layer, since the potential of the plating layer (such as copper plating layer) under the low-potential nickel layer is also higher than that of low-potential nickel, the low-potential nickel is also regarded as an anodic coating. At this time, the corrosion extending downward is terminated, and the corrosion direction is carried out horizontally in the low-potential nickel, which further delays the time for corrosion to the substrate and greatly reduces the corrosion speed.

Compared with the prior art, the utility model has the advantages of:

1. The dual-core method multi-layer nickel on the surface of the substrate of the present invention is a semi-gloss nickel layer, a full-gloss nickel layer or a satin nickel layer, a high-sulfur nickel layer in a low-potential nickel layer and/or a micro-crack nickel layer, and micropores The nickel layer has the advantages of high anti-corrosion performance, high hardness, high wear resistance, good coating adhesion, and high brightness. The microporous nickel layer and low-potential nickel layer obtained by electroplating the substrate surface of the utility model have high anti-corrosion properties. High performance, high hardness, high wear resistance, good bonding force of the coating, high brightness, etc.; at the same time, the microporous nickel layer with high potential characteristics and the multilayer nickel with low potential characteristics—low potential nickel layer are used as functional layers. The low-potential nickel layer is used as a sacrificial layer, and the microporous nickel layer with a microporous structure can disperse the microcurrent of electrochemical corrosion, delay the occurrence of corrosion, and at the same time form an oxide through the microporous structure after oxidation. The support can form a support for the low-potential nickel layer as a sacrificial layer after it is corroded more severely, reducing the damage speed of the plating layer of the part. The low-potential nickel layer set as a sacrificial layer has a lower potential. When electrochemical corrosion occurs on the surface coating of the part, the low-potential nickel layer corrodes preferentially, and when there is a microporous nickel layer or a microcracked nickel layer, its micropores Or the micro-crack structure can also disperse the corrosion micro-current, and at the same time, when there is an outer layer structure outside the low-potential nickel layer (such as a decorative layer or a protective layer), the outer structure can also be supported by the micro-pore or micro-crack structure. Enhance the stability of the material structure. In addition, the utility model scheme utilizes the pore structure of microporous nickel and microcracked nickel, which can reduce the quality of the coating and reduce the consumption of raw materials while enhancing the structural support performance of the material. At the same time, its microporous structure can also form a large-area oxide film structure when oxidation and corrosion occur, thereby greatly delaying the occurrence of corrosion.

Description of drawings

Fig. 1 is a schematic diagram of the coating structure of an embodiment of the nickel-chrome plated part of the present invention.

Metallographic diagram after 72 hours of nickel-chromium plating parts CASS of Fig. 2 prior art, among Fig. 2 (a) is the front metallographic diagram of sample after experiment, among Fig. 2 (b) is the side (section) of sample after experiment Metallographic chart.

Fig. 3 metallographic diagram after 72 hours of nickel-chromium plating part CASS of the utility model, among Fig. 3 (a) is the front metallographic diagram of sample after experiment, among Fig. 3 (a) is the side metallographic diagram of sample after experiment.

Fig. 4. Pictures of prior art nickel-chrome plated parts after fluorogypsum experiments were carried out for 168 and 336 hours.

Fig. 5 is the pictures after 168 hours and 336 hours of the fluorogypsum experiment of the nickel-chromium plated part of the utility model.

Fig. 6 potential difference picture of composite low-potential nickel layer of the utility model (low-potential nickel layer is a composite layer of high-sulfur nickel layer and micro-crack nickel layer).

Figure 7 is a picture of the potential difference of the single low-potential nickel layer of the utility model (the low-potential nickel layer is either a high-sulfur nickel layer or a micro-cracked nickel layer).

Figure 8 is a schematic diagram of multilayer nickel corrosion of the utility model (using ABS as the part base material).

List of reference signs:

1. Substrate; 2. Pretreatment coating; 21. Corrosion vacancies; 3. Copper plating layer; 31. Surface micropores; 32. Corrosion holes; 4. Functional layer; 141. Low potential nickel layer; 142. Microporous nickel layer; 62, semi-bright nickel layer; 61, full-gloss nickel layer or satin nickel layer; 801, corrosion medium; 802, decorative layer; 805, corrosion surface; 808, primer nickel layer; 809, chemical nickel layer; 810 , ABS substrate.

Detailed ways

The utility model will be further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the utility model and are not intended to limit the scope of the utility model.

The solvent of the solution in the embodiment of the utility model is water (including but not limited to distilled water, deionized water, low hardness water, etc.) unless otherwise specified.

As shown in FIG. 1 , the coating structure of the nickel-plated part of the present invention will be described below.

Structural Example 1

Substrate 1 (ABS material); Pretreatment coating 2 comprises chemical nickel layer 809, making a bottom nickel layer 808, and chemical nickel layer 809 is deposited on the whole substrate 1, and making bottom nickel layer 808 is deposited on the chemical nickel layer 809, in A copper-plated layer 3 is formed on the bottom nickel layer 808; a semi-gloss nickel layer 62, which is formed on the copper-plate layer 3; and a full-gloss nickel layer 61, which is formed on the semi-gloss nickel layer 62; and a functional layer 4, It is formed on the all-optical nickel layer 61, wherein the functional layer 4 includes a low-potential nickel layer 141 and a microporous nickel layer 142 formed on the low-potential nickel layer, wherein the low-potential nickel layer 141 is a high-sulfur nickel layer, which is formed on On the full light nickel layer 61; And decoration layer 802, it is formed on the microporous nickel layer 142, and decoration layer 802 is trivalent white chromium plating.

Structural Example 2

Substrate 1 (ABS material); Pretreatment coating 2 comprises chemical nickel layer 809, making a bottom nickel layer 808, and chemical nickel layer 809 is deposited on the whole substrate 1, and making bottom nickel layer 808 is deposited on the chemical nickel layer 809, in A copper-plated layer 3 is formed on the bottom nickel layer 808; a semi-gloss nickel layer 62, which is formed on the copper-plate layer 3; and a full-gloss nickel layer 61, which is formed on the semi-gloss nickel layer 62; and a functional layer 4, It is formed on the all-optical nickel layer 61, wherein the functional layer 4 includes a low-potential nickel layer 141 and a microporous nickel layer 142 formed on the low-potential nickel layer, wherein the low-potential nickel layer 141 is a micro-crack nickel layer, which is formed on on the full-gloss nickel layer 61; and a decoration layer 802, which is formed on the microporous nickel layer 142, and the decoration layer 802 is a trivalent black chromium plating layer.

Structural Example 3

Substrate 1 (ABS material); Pretreatment coating 2 comprises chemical nickel layer 809, making a bottom nickel layer 808, and chemical nickel layer 809 is deposited on the whole substrate 1, and making bottom nickel layer 808 is deposited on the chemical nickel layer 809, in A copper-plated layer 3 is formed on the bottom nickel layer 808; a semi-gloss nickel layer 62, which is formed on the copper-plate layer 3; and a full-gloss nickel layer 61, which is formed on the semi-gloss nickel layer 62; and a functional layer 4, It is formed on the all-optical nickel layer 61, wherein the functional layer 4 includes a low-potential nickel layer 141 and a microporous nickel layer 142 formed on the low-potential nickel layer, wherein the low-potential nickel layer 141 is a micro-crack nickel layer, which is formed on All-light nickel layer 61 is a high-sulfur nickel layer and microcrack nickel layer (can be that high-sulfur nickel layer is formed on all-light nickel layer or satin nickel layer 5, and micro-crack nickel layer is formed on high-sulfur nickel layer; It is that the micro-crack nickel layer is formed on the full light nickel layer or the satin nickel layer 5, and the high-sulfur nickel layer is formed on the micro-crack nickel layer); and the decoration layer 802, which is formed on the microporous nickel layer 142, the decoration layer 802 Trivalent black chrome plating.

Structural Example 4

Substrate 1 (ABS material); Pretreatment coating 2 comprises chemical nickel layer 809, and chemical nickel layer 809 is deposited on the whole substrate 1, is formed with copper plating layer 3 on chemical nickel layer 809; Semi-light nickel layer 62, its Formed on the copper-plated layer 3; and the full light nickel layer 61, which is formed on the semi-light nickel layer 62; and the functional layer 4, which is formed on the full light nickel layer 61, wherein the functional layer 4 includes a low-potential nickel layer 141 And the microporous nickel layer 142 formed on the low-potential nickel layer, wherein the low-potential nickel layer 141 is a high-sulfur nickel layer, which is formed on the full-gloss nickel layer 61; and the decoration layer 802, which is formed on the microporous nickel layer 142 Above, the decorative layer 802 is a trivalent white chrome plating.

Structural Example 5

Substrate 1 (ABS material); Pretreatment coating 2 comprises chemical nickel layer 809, and chemical nickel layer 809 is deposited on the whole substrate 1, is formed with copper plating layer 3 on chemical nickel layer 809; Semi-light nickel layer 62, its Formed on the copper-plated layer 3; and the full light nickel layer 61, which is formed on the semi-light nickel layer 62; and the functional layer 4, which is formed on the full light nickel layer 61, wherein the functional layer 4 includes a low-potential nickel layer 141 And the microporous nickel layer 142 formed on the low-potential nickel layer, wherein the low-potential nickel layer 141 is a microcrack nickel layer, which is formed on the full-gloss nickel layer 61; and the decoration layer 802, which is formed on the microporous nickel layer 142 Above, the decorative layer 802 is a hexavalent chromium plating layer.

Structural Example 6

Substrate 1 (ABS material); Pretreatment coating 2 comprises chemical nickel layer 809, and chemical nickel layer 809 is deposited on the whole substrate 1, is formed with copper plating layer 3 on chemical nickel layer 809; Semi-light nickel layer 62, its Formed on the copper-plated layer 3; and the full light nickel layer 61, which is formed on the semi-light nickel layer 62; and the functional layer 4, which is formed on the full light nickel layer 61, wherein the functional layer 4 includes a low-potential nickel layer 141 And the microporous nickel layer 142 formed on the low-potential nickel layer, wherein the low-potential nickel layer 141 is a micro-crack nickel layer, which is formed on the full-light nickel layer 61 as a high-sulfur nickel layer and a micro-crack nickel layer (which can be a high-sulfur nickel layer) The nickel layer is formed on the full-bright nickel layer or the satin nickel layer 5, and the micro-crack nickel layer is formed on the high-sulfur nickel layer; it can also be that the micro-crack nickel layer is formed on the full-bright nickel layer or the satin nickel layer 5, and the high sulfur nickel layer formed on the microcracked nickel layer); and a decorative layer 802 formed on the microporous nickel layer 142, the decorative layer 802 is a hexavalent chromium plating layer.

Structural Example 7

Substrate 1 (ABS material); Pretreatment coating 2 comprises nickel layer 808, and chemical nickel layer 808 is deposited on the whole substrate 1, and is formed with copper-plated layer 3 on nickel layer 808; Semi-light nickel layer 62 , which is formed on the copper-plated layer 3; and a full-bright nickel layer 61, which is formed on the semi-bright nickel layer 62; and a functional layer 4, which is formed on the full-bright nickel layer 61, wherein the functional layer 4 includes low-potential nickel Layer 141 and the microporous nickel layer 142 formed on the low-potential nickel layer, wherein the low-potential nickel layer 141 is a high-sulfur nickel layer, which is formed on the full-bright nickel layer 61; and the decorative layer 802, which is formed on the microporous nickel On the layer 142, the decorative layer 802 is a trivalent black chromium plating layer.

Structural Example 8

Substrate 1 (ABS material); Pretreatment coating 2 comprises a nickel layer 808, and the chemical nickel layer 808 is deposited on the entire substrate 1, and a copper-plated layer 3 is formed on the nickel layer 808; Semi-gloss nickel layer 62 , which is formed on the copper-plated layer 3; and a full-bright nickel layer 61, which is formed on the semi-bright nickel layer 62; and a functional layer 4, which is formed on the full-bright nickel layer 61, wherein the functional layer 4 includes low-potential nickel Layer 141 and the microporous nickel layer 142 formed on the low-potential nickel layer, wherein the low-potential nickel layer 141 is a micro-cracked nickel layer, which is formed on the full-gloss nickel layer 61; and the decorative layer 802, which is formed on the microporous nickel layer On the layer 142, the decoration layer 802 is a trivalent black chromium plating layer, and the surface of the trivalent black chromium plating layer contains a passivation film.

Structural Example 9

Substrate 1 (ABS material); Pretreatment coating 2 comprises a nickel layer 808, and the chemical nickel layer 808 is deposited on the entire substrate 1, and a copper-plated layer 3 is formed on the nickel layer 808; Semi-gloss nickel layer 62 , which is formed on the copper-plated layer 3; and a full-bright nickel layer 61, which is formed on the semi-bright nickel layer 62; and a functional layer 4, which is formed on the full-bright nickel layer 61, wherein the functional layer 4 includes low-potential nickel Layer 141 and the microporous nickel layer 142 formed on the low-potential nickel layer, wherein the low-potential nickel layer 141 is a micro-cracked nickel layer, which is formed on the full-light nickel layer 61 as a high-sulfur nickel layer and a micro-cracked nickel layer (which can be The high-sulfur nickel layer is formed on the full-bright nickel layer 5, and the micro-crack nickel layer is formed on the high-sulfur nickel layer; it may also be that the micro-crack nickel layer is formed on the full-bright nickel layer 5, and the high-sulfur nickel layer is formed on the micro-crack nickel layer); and a decorative layer 802, which is formed on the microporous nickel layer 142, the decorative layer 802 is a trivalent white chromium coating, and the surface of the trivalent white chromium coating contains a passivation film.

The only difference between Structural Examples 10-18 and Structural Examples 1-9 is that: the all-bright nickel layer 5 is a satin nickel layer 5 .

The only difference between structural examples 19-36 and structural examples 1-18 is that the base material 1 is made of nylon.

The only difference between structural examples 37-54 and structural examples 1-18 is that the base material 1 is made of PVC.

The only difference between structural examples 55-72 and structural examples 1-18 is that the base material 1 is made of pc.

The only difference between structural examples 73-90 and structural examples 1-18 is that the base material 1 is made of pet material.

The only difference between the structural examples 91-108 and the structural examples 1-18 is that the base material 1 is bakelite.

The only difference between structural examples 109-126 and structural examples 1-18 is that the base material 1 is cast iron (including but not limited to gray cast iron, white cast iron, nodular cast iron, vermicular cast iron, malleable cast iron and alloy cast iron, etc.) material.

The only difference between structural examples 127-144 and structural examples 1-18 is that the base material 1 is made of steel (including various common steels, stainless steel, etc.), aluminum alloy, and magnesium alloy.

The material of the base material 1 adopted in the technical solution of the utility model can also be other materials that can be used for plating copper, nickel, and chrome coatings on its surface.

The solvent of the solution in the embodiment of the utility model is water (including but not limited to distilled water, deionized water, low hardness water, etc.) unless otherwise specified, and the concentration is measured by the solution per unit volume or mass.

The base material of the parts in the following examples is preferably made of ABS.

Preparation Examples 1-5

The manufacturing method of the nickel-plated part of an embodiment of the present invention is as follows, the surface of the substrate is pretreated (the pretreatment includes the following steps in turn: surface degreasing, surface hydrophilic treatment, surface roughening treatment, surface neutralization treatment , pre-dipping, surface activation treatment, surface debonding treatment); the pre-treatment coating (including electroless nickel and primer nickel, in addition to whether the pre-treatment coating is retained and the selection of the composition of the pre-treatment coating depends on the material of the substrate and the process Flexible selection according to product requirements) deposited on the entire substrate, the chemical nickel layer and the bottom nickel layer formed from the surface of the substrate in sequence, and the copper plating layer is formed on the pretreatment coating (outside the bottom nickel layer) and the semi-light nickel layer is formed on the copper-plated layer; and the full-light nickel layer is formed on the semi-light nickel layer; and the low-potential layer in the functional layer is formed on the copper-plated layer, where the low-potential nickel layer is high a sulfur nickel layer; and forming the microporous nickel layer in the functional layer on the high sulfur nickel layer; forming a decoration layer on the microporous nickel layer.

Wherein, the potential difference between the microporous nickel layer and the low potential nickel layer is any of 20, 30, 40, 50, 60, 10, 80, 90, 100mv or any other value within the range of 20-100mv (Embodiments 1-5 can select (as 20, 40, 60, 80, 100mv) different numerical values in 20-100mv respectively to be the potential difference between the microporous nickel layer and the low-potential nickel layer in the corresponding embodiment, each embodiment The potential difference between the microporous nickel layer and the low potential nickel layer can also be the same).

The potential difference between the all-optical nickel layer and the low-potential nickel layer is any of 0, 10, 20, 30, 40, 50, 60, 10, 80, 90, 100mv or other within the range of 0-100mv Arbitrary value (embodiment 1-5 can select respectively in 0-100mv (as 0,30,60,80,100mv) different numerical value is the potential difference between all light nickel layer and low potential nickel layer in the corresponding embodiment, each In the embodiment, the potential difference between the all-optical nickel layer and the low-potential nickel layer can also be the same).

The potential difference between the semi-bright nickel layer and the full-bright nickel layer is any of 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200mv or other within the range of 100-200mv Any value (embodiment 1-5 can select (as 100, 120, 150, 180, 200mv) different numerical values in 100-200mv respectively is the potential difference between semi-bright nickel layer and full-bright nickel layer in the corresponding embodiment, each In the embodiment, the potential difference between the semi-bright nickel layer and the full-bright nickel layer can also be the same).

The method for electroplating nickel on the above-mentioned nickel-chromium plated parts may further comprise the steps:

(1) Surface degreasing: cleaning treatment in a mixed solution of sodium hydroxide NaOH, sodium carbonate Na ₂ CO ₃ and sodium silicate Na ₂ SiO ₃ . In this step, the concentration ratio of each component in the mixed solution in different embodiments is shown in Table 1:

Table I:

(2) Surface hydrophilic process: carried out in sulfuric acid H ₂ SO ₄ and finishing agent. In this step, the concentration ratio of the surface conditioner and sulfuric acid _H2SO4 in different embodiments is shown in Table ₂ :

Table II:

(3) Surface roughening treatment: carried out in a mixed solution of chromic anhydride CrO ₃ and sulfuric acid H ₂ SO ₄ . In this step, the concentration ratios of chromic anhydride CrO3 and sulfuric _{acid H2SO4} in different embodiments are shown in Table ₃ :

Table three:

(4) Surface neutralization treatment: put the parts after surface roughening treatment into hydrochloric acid solution. In this step, the concentration ratio of the hydrochloric acid solution in different embodiments is shown in Table 4:

Table four:

(5) Surface pre-soaking process: put the parts after surface neutralization treatment into hydrochloric acid solution. In this step, the concentration ratio of the hydrochloric acid solution in different embodiments is shown in Table 5:

Table five:

(6) surface activation treatment: surface activation treatment adopts colloidal palladium solution, palladium chloride PdCl in the colloidal palladium solution ₂ and stannous chloride SnCl ₂ concentration ratios in different embodiments are shown in Table 6:

Table six:

(7) Surface degumming treatment: carried out in sulfuric acid H ₂ SO ₄ solution. In this step, the concentration ratio of sulfuric acid solution in different embodiments is shown in Table 7:

Table seven:

(8) Electroless nickel precipitation: carried out in a mixed solution containing nickel sulfate Ni ₂ SO ₄ -6H ₂ O, sodium hypophosphite NaH ₂ PO ₃ -H ₂ O and sodium citrate C ₆ H ₅ Na ₃ O ₇ . In this step, the concentration ratio of each component in the mixed solution in different embodiments is shown in Table 8:

Table Eight:

(9) Primer nickel plating: carried out in a mixed solution containing aqueous nickel sulfate Ni ₂ SO ₄ -6H ₂ O, aqueous nickel chloride NiCl ₂ -6H ₂ O, and boric acid H ₃ BO ₃ . In this step, the concentration ratio of each component in the mixed solution in different embodiments is shown in Table 9:

Table nine:

(10) Copper plating: carried out in a mixed solution of copper sulfate CuSO ₄ and sulfuric acid H ₂ SO ₄ . The concentration ratio of copper sulfate CuSO ₄ and sulfuric acid H ₂ SO ₄ in different embodiments is shown in Table 10:

Table ten:

(11) Semi-gloss nickel layer: carried out in a mixed solution containing nickel sulfate Ni ₂ SO ₄ -6H ₂ O, nickel chloride NiCl ₂ -6H ₂ O, and boric acid H ₃ BO ₃ . In this step, the concentration ratio of each component in the mixed solution in different embodiments is shown in Table 11; other parameters in the semi-gloss nickel plating process are shown in Table 12:

Table Eleven:

Table twelve:

(12) Full-bright nickel plating: carried out in a mixed solution containing nickel sulfate Ni ₂ SO ₄ -6H ₂ O, aqueous nickel chloride NiCl ₂ -6H ₂ O, and boric acid H ₃ BO ₃ . In this step, the concentration ratio of each component in the mixed solution in different embodiments is shown in Table 13; other parameters in the all-bright nickel plating process are shown in Table 14:

Table 13:

Table Fourteen:

(13) A high-sulfur nickel layer (low-potential nickel layer) and a microporous nickel layer are plated in sequence. Among them, in the process steps of microporous nickel plating and high-sulfur nickel plating, the main components of the plating solution are the same, which are aqueous nickel sulfate Ni ₂ SO ₄ -6H ₂ O, aqueous nickel chloride NiCl ₂ -6H ₂ O and boric acid H ₃ BO ₃ Mix the solution. The concentration ratios of high-sulfur nickel plating and microporous nickel plating in different examples are shown in Table 15 and Table 17 respectively. Here, the nickel sealing brightener is Schleich 63; The encapsulation particle carrier is ENHANCER from Schleich; among them, other parameters in the processes of high-sulfur nickel plating and microporous nickel plating are shown in Table 16 and Table 18 respectively:

Table 15:

Table sixteen:

Table 17:

Table eighteen:

(14) Decorative plating: carried out in a mixed solution containing chromium chloride and potassium formate. In this step, the concentration ratio of each component in the mixed solution in different embodiments is shown in Table 19:

Table nineteen:

The only difference between Preparation Examples 6-10 and Preparation Examples 1-5 is that the low-potential nickel layer is a microcrack layer, and the corresponding microcrack nickel layer plating solution uses the plating solution shown in Table 20 below to plate microcracks Other parameters in the nickel process are shown in Table 21:

Table 20:

Table 21:

The only difference between Preparation Examples 11-15 and Preparation Examples 1-5 is that the low-potential nickel layer includes a high-sulfur nickel layer (each embodiment plating solution is shown in Table 15 in sequence), micro-cracked nickel layer (each embodiment plating solution is correspondingly shown in Table 20 sequentially) Composite between two layers. Wherein, the potential difference between the microcracked nickel layer and the high-sulfur nickel layer is respectively any of 10, 20, 30, 40, 50, 60, 10, 80mv or any other value within the range of 10-80mv (implementation Example 11-15 can select (as 10, 20, 40, 60, 80mv) different numerical values in 10-80mv respectively to be the potential difference between the micro-crack nickel layer and the high-sulfur nickel layer in the corresponding embodiments, and the micro-crack nickel layer in each embodiment The potential difference between the cracked nickel layer and the high-sulfur nickel layer can also be the same).

The only difference between Preparation Examples 16-30 and Preparation Examples 1-15 is that the all-bright nickel layer is replaced by a satin nickel layer, and the corresponding plating solution for the satin nickel layer is as shown in Table 22. (Any numbered embodiment corresponds to the value).

Table 22:

The only difference between Preparation Examples 31-60 and Preparation Examples 1-30 is that the trivalent white chromium layer in the decorative layer is replaced by a trivalent black chromium layer, and the corresponding trivalent black chromium layer plating solution uses the following table Plating solution shown in twenty-three (corresponding value of any numbering embodiment).

Table 23:

The only difference between Preparation Examples 61-90 and Preparation Examples 1-30 is that the trivalent white chromium layer in the decorative layer is replaced by a hexavalent chromium layer, and the corresponding hexavalent chromium layer plating solution uses the following table 20 Plating solution shown in four (corresponding value of any numbering embodiment).

Table twenty-four:

In the above preparation examples, PN-1A and PN-2A are commercially available products from Atotech (China) Chemical Co., Ltd.

Based on all the above embodiments, it can be seen that all the embodiments of the technical solution of the present invention reach 96-120h and above through the CASS experiment (the prior art then proposes to be 40-48h), and the fluorogypsum experiment then reaches a stability of more than 336h (the existing The product obtained by the technology is unstable and cannot be quantified).

In the technical solution of the utility model, the base material can also be made of materials including but not limited to PC, PP, PVC, PET, bakelite and metal materials. When selecting other substrates except ABS, the pretreatment coating can be selected according to the actual material performance and process requirements with pretreatment coating or without pretreatment coating.

Fig. 3 is the corrosion state diagram obtained after the nickel-plated part sample obtained by an embodiment of the utility model through the 72h CASS experiment, and Fig. 2 is after the nickel-plated part sample of the prior art through the 72h CASS experiment (under the same experimental conditions ) obtained by comparing the corrosion state diagram, it can be seen intuitively that the existing samples have a large number of coating peelings after the experiment and corrosion vacancies 21 after corrosion, which seriously affects the quality of the product coating. It can be seen from Fig. 3 that the nickel-plated sample obtained by the utility model only has a certain number of surface micropores 31 on the surface, while the cross-section shows that there are only small corrosion holes 32, no matter the surface micropores and the sacrificial layer. The resulting corrosion holes are not able to damage the coating structure of the components, and do not affect the use and appearance of the product.

Fig. 4 and Fig. 5 are respectively the sample surface corrosion state diagram (in the figure) of the nickel-plated part sample of the prior art and the nickel-plated part sample gained by an embodiment of the utility model through the fluorogypsum experiment (336h, 336h, 168h) The inside of the circle is divided into experimental areas), as can be seen from the figure, the surface of the nickel-plated parts sample of the prior art is corroded to varying degrees, while the sample obtained by the utility model is corroded very slightly and does not change color substantially. It can be seen that there is no doubt that the nickel-plated part obtained by the technical solution of the utility model has better plating stability and corrosion resistance, making the nickel-plated part more durable and beautiful.

It can be seen from the coating potential diagrams of Fig. 6 and Fig. 7 that in the utility model scheme, no matter whether the low-potential layer is a single layer or a composite layer structure, the low-potential nickel layer is used as the sacrificial layer when being corroded, and the low-potential nickel layer is used as the sacrificial layer. When the layer is a composite layer of high-sulfur nickel layer and micro-cracked nickel layer, the potential of the high-sulfur nickel layer and micro-cracked nickel layer is adjusted according to the actual production process, and the potential of the high-sulfur nickel layer can be slightly higher or slightly higher. The potential of the cracked nickel layer is slightly higher.

As shown in Figure 8, the mechanism when the nickel-plated parts obtained by the utility model scheme is corroded is: in the figure, an chemical nickel layer 809, a nickel layer 808, and a copper-plated layer 3 are formed layer by layer on the ABS substrate 1 , semi-bright nickel layer 62, full-gloss nickel or satin nickel layer 61, low-potential nickel layer 141 and microporous nickel layer 142, decorative layer 802, corrosion medium 801 disperses corrosion current in the microporous structure of microporous nickel layer 142 and Enter the low-potential nickel layer 141 (reduce the area actually involved in corrosion, have a smaller corrosion area, form a plurality of independent corrosion points, thereby disperse the corrosion current, and delay the corrosion speed), after corrosion forms the corrosion surface 805, when the corrosion After the surface 805 penetrates the low-potential nickel layer 141, it encounters the high-potential copper plating layer 3, and then stops the longitudinal corrosion and turns it into horizontal corrosion until the entire low-potential nickel layer 141 is corroded, and then the next step of corrosion will be carried out until the coating structure is completely destroy.

The embodiment here does not exhaust the mid-point value of the technical scope claimed by the utility model, and all of them are also within the scope of the utility model.

The technical means disclosed in the solution of the utility model are not limited to the technical means disclosed in the above technical means, but also include technical solutions composed of any combination of the above technical features. The above are the specific embodiments of the present utility model, and it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present utility model, some improvements and modifications can also be made, and these improvements and modifications are also considered It is the protection scope of the utility model.

Claims (8)

1. A super-corrosion-resistant nickel-chromium plated part, the super-corrosion-resistant nickel-chromium plated part comprises: Substrate; a pretreatment coating deposited over the entire substrate with a copper plating layer formed on the pretreatment coating; and a semi-gloss nickel layer formed on the copper plating layer; and a full-bright nickel layer or a satin nickel layer formed over a semi-bright nickel layer; and A functional layer formed on the full-bright nickel layer or satin nickel layer, wherein the functional layer includes a low-potential nickel layer and a microporous nickel layer formed on the low-potential nickel layer; and The decorative layer is formed on the microporous nickel layer, and the decorative layer is any one of a trivalent chromium plating layer or a hexavalent chromium plating layer. 2. A super corrosion-resistant nickel-chromium plated part according to claim 1, characterized in that the potential difference between the microporous nickel layer and the low potential nickel layer is within the range of 10-120mv. 3. A kind of super corrosion-resistant nickel-chromium plating part according to claim 1 or 2, is characterized in that, described low-potential nickel layer comprises one or two layers in high-sulfur nickel layer, microcrack nickel layer Composite coating between. 4. A super corrosion resistant nickel-chromium plated part according to claim 1 or 2, characterized in that the potential difference between the microporous nickel layer and the low potential nickel layer is within the range of 20-100mv. 5. A super-corrosion-resistant nickel-chromium plated part according to claim 3, characterized in that the potential difference between the microporous nickel layer and the low potential nickel layer is within the range of 20-100mv. 6. a kind of super corrosion-resistant nickel-chromium plating part according to claim 3, is characterized in that, when low-potential nickel layer adopts the composite coating of microcrack nickel layer and high-sulfur nickel layer, microcrack nickel layer and high-sulfur nickel layer The potential difference between the sulfur nickel layers is within 10-80mv. 7. A kind of super-corrosion-resistant nickel-chromium plated part according to claim 1, characterized in that, the potential difference between the all-gloss nickel layer or the satin nickel layer and the low-potential nickel layer is in the range of 0-100mv Inside. 8. A kind of super-corrosion-resistant nickel-chromium plated part according to claim 1, characterized in that, the potential difference between the semi-gloss nickel layer and the full-gloss nickel layer or the satin nickel layer is in the range of 100-200mv Inside.