A coated neodymium iron boron magnet product, its electroplating method, and electronic products thereof.

Abstract

This invention provides a coated NdFeB magnet product, its electroplating method, and an electronic product thereof. The electroplating method includes the following steps: a NdFeB substrate undergoes pretreatment to obtain a pretreated NdFeB substrate, the pretreatment including pickling; the pretreated NdFeB substrate is subjected to a first electroplating of zinc in a first electroplating solution to obtain a first NdFeB magnet with a zinc plating layer; the first NdFeB magnet is subjected to a second electroplating of zinc and nickel in a second electroplating solution to obtain a second NdFeB magnet with a zinc and nickel plating layer; wherein the surface roughness Ra of the pretreated NdFeB substrate is 0.2–0.35 μm; and the surface roughness Ra of the first NdFeB magnet is 0.3–0.45 μm. The electroplating method of this invention can obtain electroplated products with thinner coatings and better adhesion, and has broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of neodymium iron boron (NdFeB) technology, and more particularly to a coated NdFeB magnet product, its electroplating method, and electronic products thereof. Background Technology

[0002] Common surface treatment methods for neodymium iron boron include: electroplating zinc, electroplating nickel-copper-nickel, electrophoresis, and phosphating.

[0003] Products used in 3C electronic devices such as mobile phones, speakers, smartwatches, tablets, and headphones require the magnet surface to have an electroplated zinc layer (which has high requirements for magnet demagnetization and adhesive properties). In recent years, with the increasing use of end products, especially small acoustic products, the requirements for corrosion resistance and adhesion testing have increased. The original zinc plating layer on the magnet surface can no longer meet the more stringent corrosion resistance requirements, and new research is needed on magnet surface treatment.

[0004] Furthermore, as more applications tend to be miniaturized, higher requirements are being placed on the thickness of the coating to be thinner and more uniform.

[0005] Therefore, the requirements for thinner, more uniform, and stronger adhesion of these coatings pose new challenges to the surface treatment methods of NdFeB. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a coated NdFeB magnet product, its electroplating method, and an electronic product thereof. This method achieves better adhesion between the coating and the NdFeB substrate while obtaining a thinner coating, and has broad application prospects.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a method for electroplating neodymium iron boron, the electroplating method comprising the following steps:

[0009] The neodymium iron boron (NdFeB) substrate undergoes a pretreatment process to obtain a pretreated NdFeB substrate, the pretreatment including pickling; the pretreated NdFeB substrate is then subjected to a first electroplating solution for zinc plating to obtain a first NdFeB magnet with a zinc plating layer; the first NdFeB magnet is then subjected to a second electroplating solution for zinc-nickel plating to obtain a second NdFeB magnet with a zinc-nickel plating layer; wherein the surface roughness Ra of the pretreated NdFeB substrate is 0.2–0.35 μm; and the surface roughness Ra of the first NdFeB magnet is 0.3–0.45 μm.

[0010] It is worth noting that conventional technical thinking in this field holds that a higher surface roughness in the pretreatment of the NdFeB substrate is more conducive to improving the adhesion between the substrate and the coating. However, the researchers in this application found that if the surface roughness of the NdFeB substrate is too high during pretreatment such as pickling with an acidic solution, it will affect the state of the near-surface region of the NdFeB substrate. As a result, cracks are prone to appear in the near-surface region of the NdFeB substrate after subsequent electroplating, which will reduce the adhesion between the substrate and the coating (especially detrimental to drop tests). Therefore, after pretreatment, the surface roughness of the NdFeB substrate needs to be controlled within a reasonable range to improve the adhesion of the coating and at the same time suppress the occurrence of cracks in the near-surface region of the substrate. However, after comprehensively studying multiple factors such as coating adhesion, substrate roughness, and the state of the near-surface region of the substrate, this application adjusts the surface roughness of the NdFeB substrate after pretreatment to the range of Ra = 0.2 to 0.35 μm, in order to maximize the protection of the near-surface region of the substrate, reduce the occurrence of NdFeB substrate after electroplating, and make the final drop test show better results.

[0011] Furthermore, based on adjusting the surface roughness of the NdFeB substrate to Ra = 0.2–0.35 μm, in order to improve the adhesion of the zinc-nickel plating layer, after the first electroplating, the surface roughness of the zinc plating layer is adjusted to the range of Ra = 0.3–0.45 μm. The roughness of the zinc plating layer is improved compared to the existing technology. When the substrate roughness is low, the roughness is significantly increased by the zinc plating layer, which can improve the electroplating foundation of the final coating, that is, make the anti-corrosion effect of the electroplated zinc-nickel layer better.

[0012] Specifically, the surface roughness Ra of the NdFeB matrix after pretreatment is 0.2–0.35 μm, for example, it can be 0.2 μm, 0.22 μm, 0.24 μm, 0.25 μm, 0.27 μm, 0.29 μm, 0.3 μm, 0.32 μm, 0.34 μm or 0.35 μm, etc.; the surface roughness Ra of the first NdFeB is 0.3–0.45 μm, for example, it can be 0.3 μm, 0.32 μm, 0.34 μm, 0.35 μm, 0.37 μm, 0.39 μm, 0.4 μm, 0.42 μm, 0.44 μm or 0.45 μm, etc.

[0013] Preferably, the first electroplating solution contains 150-240 g / L of zinc sulfate, for example, it can be 150 g / L, 160 g / L, 170 g / L, 180 g / L, 190 g / L, 200 g / L, 210 g / L, 220 g / L, 230 g / L or 240 g / L, etc., preferably 150-230 g / L.

[0014] It is worth noting that, since the surface roughness of the NdFeB substrate is adjusted to Ra = 0.2–0.35 μm, it is difficult to achieve the required coating adhesion using conventional first electroplating solutions (i.e., zinc plating solutions). Therefore, this application has refined the control of the zinc plating solution, specifically including: 1) The zinc plating solution includes a low concentration of 150–240 g / L zinc sulfate. The reduction in zinc sulfate concentration can maximize the protection of the substrate's surface condition during the electroplating process, making it less prone to crack propagation. 2) The zinc plating solution does not include brighteners. Brighteners decompose during the electroplating process, and the resulting organic matter is difficult to remove. During the electroplating process, the decomposed organic matter gradually accumulates, and the increased concentration increases the brittleness of the zinc plating layer, thereby weakening the adhesion of the zinc layer.

[0015] Optionally, the first electroplating solution contains sodium sulfate, and the concentration of sodium sulfate in the first electroplating solution is 100-200 g / L, for example, it can be 100 g / L, 112 g / L, 123 g / L, 134 g / L, 145 g / L, 156 g / L, 167 g / L, 178 g / L, 189 g / L or 200 g / L, etc.

[0016] Furthermore, after controlling the surface state of the NdFeB substrate, the low surface roughness of the NdFeB substrate affects the plating rate of the zinc layer to some extent. In order to control the roughness value of the zinc layer within the above range and to prevent the near-surface area of ​​the substrate from being further affected during the electroplating process, the present invention also adds 100-200 g / L of sodium sulfate to the first electroplating solution. When the sodium sulfate is within the above range, it is possible to achieve a roughness of Ra = 0.3-0.45 μm with a relatively thin zinc layer thickness of less than 7 μm. The roughness of this zinc layer is improved compared with the prior art. When the roughness of the NdFeB substrate is low, the roughness is significantly increased by the first electroplating, which can improve the electroplating basis of the final zinc-nickel layer and make the anti-corrosion effect of the zinc-nickel layer better.

[0017] In this invention, sodium sulfate acts as a conductive salt, which can improve the conductivity and current efficiency of the first electroplating solution.

[0018] Optionally, the first electroplating solution contains boric acid, and the concentration of boric acid in the first electroplating solution is 10 to 40 g / L, for example, it can be 10 g / L, 14 g / L, 17 g / L, 20 g / L, 24 g / L, 27 g / L, 30 g / L, 34 g / L, 37 g / L or 40 g / L, etc.

[0019] Optionally, the pH of the first electroplating solution is 3.0 to 5.0, for example, it can be 3.0, 3.3, 3.5, 3.7, 3.9, 4.2, 4.4, 4.6, 4.8 or 5.0.

[0020] Preferably, the temperature of the first electroplating solution during the first zinc electroplating process is 20-35°C, for example, it can be 20°C, 22°C, 24°C, 25°C, 27°C, 29°C, 30°C, 32°C, 34°C or 35°C, etc.

[0021] Optionally, the current density during the first electroplating zinc process is 0.1–2 A / dm³. 2 For example, it could be 0.1A / dm 2 0.4A / dm 2 0.6A / dm 2 0.8A / dm 2 1A / dm 2 1.2A / dm 2 1.4A / dm 2 1.6A / dm 2 1.8A / dm 2 or 2A / dm 2 wait.

[0022] Optionally, the thickness of the zinc plating layer is 0.1 to 7 μm, for example, it can be 0.1 μm, 0.2 μm, 0.5 μm, 1.2 μm, 1.9 μm, 2.5 μm, 3.2 μm, 3.9 μm, 4.5 μm, 5.2 μm, 5.9 μm, 6.5 μm, 6.8 μm or 7.0 μm.

[0023] Optionally, the first electroplating of zinc includes at least one sub-plating process. In this invention, the number of sub-plating processes can be greater than one, as long as the total thickness meets the requirement that the zinc coating thickness is 0.1 to 7.0 μm and the roughness is Ra = 0.3 to 0.45 μm.

[0024] Preferably, between the first electroplating of zinc and the second electroplating of zinc and nickel, the electroplating method further includes: activating the first neodymium iron boron.

[0025] Optionally, the activation includes: washing the first neodymium iron boron in an activation solution.

[0026] Optionally, the activation solution used for activation is a hydrochloric acid solution.

[0027] Optionally, the volume concentration of the hydrochloric acid solution in the activation process is 0.2% to 0.6%, for example, it can be 0.2%, 0.25%, 0.29%, 0.34%, 0.38%, 0.43%, 0.47%, 0.52%, 0.56%, or 0.6%.

[0028] Optionally, the activation cleaning time is 5 to 15 seconds, for example, it can be 5 seconds, 7 seconds, 8 seconds, 9 seconds, 10 seconds, 11 seconds, 12 seconds, 13 seconds, 14 seconds or 15 seconds.

[0029] Preferably, the second electroplating solution contains 10-30 g / L of zinc chloride, for example, it can be 10 g / L, 13 g / L, 15 g / L, 17 g / L, 19 g / L, 22 g / L, 24 g / L, 26 g / L, 28 g / L or 30 g / L.

[0030] Optionally, the second electroplating solution contains 200-260 g / L of potassium chloride, for example, 200 g / L, 207 g / L, 214 g / L, 220 g / L, 227 g / L, 234 g / L, 240 g / L, 247 g / L, 254 g / L or 260 g / L, preferably 230-260 g / L.

[0031] Optionally, the second electroplating solution contains 10 to 40 g / L of nickel chloride, for example, 10 g / L, 14 g / L, 17 g / L, 20 g / L, 24 g / L, 27 g / L, 30 g / L, 34 g / L, 37 g / L or 40 g / L.

[0032] Optionally, the mass ratio of zinc chloride to nickel chloride in the second electroplating solution is (2-4):1, for example, it can be 2:1, 2.3:1, 2.5:1, 2.7:1, 2.9:1, 3.2:1, 3.4:1, 3.6:1, 3.8:1 or 4:1, etc.

[0033] It is worth noting that in this invention, the zinc plating layer is in close contact with the NdFeB substrate, and the bonding state between the zinc plating layer and the NdFeB substrate has a significant impact on the drop test results. The zinc-nickel plating layer is crucial for corrosion protection. In the second electroplating zinc-nickel process, to ensure the zinc-nickel plating layer is stably and uniformly applied on top of the zinc plating layer, ultimately improving the corrosion resistance of the zinc-nickel plating layer, enhancing the consistency of the plating layer, and increasing the stability control during the electroplating process, two aspects can be controlled. Firstly, the solution composition: in the second electroplating solution, the concentration of potassium chloride is controlled at 200–260 g / L. By increasing the amount of potassium chloride added, it better complexes the zinc ions in the solution. In addition, a complexing agent of 1–10 ml / L is added simultaneously to better complex the nickel ions in the solution. Finally, the mass ratio of zinc chloride to nickel chloride is controlled at 2:1–4:1 to improve the brightness in the low current density area and make the nickel content more uniform in both high and low current density areas. The nickel content in the plating layer is controlled at 0.1–20 wt% to achieve a uniform plating effect.

[0034] Furthermore, from the perspective of solution stability control, it is preferable to add complexing agent and buffer to the electroplating solution at least once during the zinc-nickel electroplating process. The volume ratio of complexing agent and buffer to pure water each time is 1:(2-5), for example, it can be 1:2, 1:2.5, 1:2.8, 1:3.0, 1:3.2, 1:3.3, 1:3.5, 1:3.8, 1:4.0, 1:4.5 or 1:5, etc. The complexing agent and buffer are added to the electroplating solution in proportion every 1000 ampere-hours.

[0035] Optionally, the second electroplating solution does not contain boric acid.

[0036] Optionally, the second electroplating solution also contains a complexing agent of 1 to 10 ml / L, for example, 1 ml / L, 2 ml / L, 3 ml / L, 4 ml / L, 5 ml / L, 6 ml / L, 7 ml / L, 8 ml / L, 9 ml / L, or 10 ml / L.

[0037] Optionally, the complexing agent comprises, by weight percentage, 15-25% diethylenetriamine, 10-30% sodium benzoate, and 2-6% p-toluenesulfonic acid.

[0038] Specifically, 15-25% diethylenetriamine, for example, can be 15%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, or 25%; 10-30% sodium benzoate, for example, can be 10%, 13%, 15%, 17%, 19%, 22%, 24%, 26%, 28%, or 30%; and 2-6% p-toluenesulfonic acid, for example, can be 2%, 2.5%, 2.9%, 3.4%, 3.8%, 4.3%, 4.7%, 5.2%, 5.6%, or 6%.

[0039] The present invention uses a complexing agent, which can improve the brightness of the low current density region and make the nickel content more uniform in the high and low current density regions, thereby reducing scorching in the high-density region.

[0040] Optionally, the second electroplating solution further contains a buffer at a concentration of 70–110 ml / L, such as 70 ml / L, 75 ml / L, 79 ml / L, 84 ml / L, 88 ml / L, 93 ml / L, 97 ml / L, 102 ml / L, 106 ml / L, or 110 ml / L. The addition of the buffer in this invention prevents scorching in high current density areas.

[0041] Optionally, the buffer comprises potassium acetate at a concentration of 40-60 wt%, for example, 40 wt%, 43 wt%, 45 wt%, 47 wt%, 49 wt%, 52 wt%, 54 wt%, 56 wt%, 58 wt%, or 60 wt%.

[0042] In the second zinc-nickel electroplating solution, the present invention adds an ultra-high content of buffer 226 (70-110 ml / L). The buffer includes potassium acetate with a concentration of 40-60 wt%. By adding the buffer, the electroplating process in the high current density area (at the top corner of the magnet) can be precisely controlled, making the overall electroplating process of the coating more balanced, reducing the range between the edges and center of the coating, and finally controlling the roughness to achieve the technical effect of Ra = 0.2-0.35 μm. If the buffer content is low, the edges of the product will appear black after electroplating, and the anti-corrosion performance will be greatly reduced.

[0043] Optionally, the second electroplating solution also contains a brightener, the concentration of which is 0.1 to 10 ml / L, for example, 0.1 ml / L, 1.2 ml / L, 2.3 ml / L, 3.4 ml / L, 4.5 ml / L, 5.6 ml / L, 6.7 ml / L, 7.8 ml / L, 8.9 ml / L, or 10 ml / L.

[0044] Optionally, the second electroplating solution also contains a wetting agent with a concentration of 1 to 20 ml / L, such as 1 ml / L, 4 ml / L, 6 ml / L, 8 ml / L, 10 ml / L, 12 ml / L, 14 ml / L, 16 ml / L, 18 ml / L, or 20 ml / L.

[0045] The present invention does not impose any special restrictions on the wetting agent in the above process. Any wetting agent known to those skilled in the art that can be used in electroplating solutions can be used, and adjustments can also be made according to the actual process.

[0046] Optionally, the second electroplating solution further contains a low-position reinforcing agent, the concentration of which is 0.1 to 10 ml / L, for example, 0.1 ml / L, 1.2 ml / L, 2.3 ml / L, 3.4 ml / L, 4.5 ml / L, 5.6 ml / L, 6.7 ml / L, 7.8 ml / L, 8.9 ml / L, or 10 ml / L.

[0047] The present invention does not impose any special restrictions on the low-position strengthening agent in the above process. Any low-position strengthening agent known to those skilled in the art that can be used in electroplating solutions can be used, and adjustments can also be made according to the actual process.

[0048] Preferably, the temperature of the second electroplating of zinc and nickel is 25°C to 36°C, for example, it can be 25°C, 27°C, 28°C, 29°C, 30°C, 32°C, 33°C, 34°C, 35°C or 36°C.

[0049] Optionally, the pH value of the second electroplated zinc-nickel is 5.0 to 5.7, for example, it can be 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6 or 5.7.

[0050] Optionally, the current density of the second zinc-nickel electroplating is 0.1–5 A / dm². 2 For example, it could be 0.1A / dm 2 0.7A / dm 2 1.2A / dm 2 1.8A / dm 2 2.3A / dm 2 2.9A / dm 2 3.4A / dm 2 4A / dm 2 4.5A / dm 2 Or 5A / dm 2 wait.

[0051] Optionally, the thickness of the zinc-nickel plating layer is 0.1 to 6 μm, for example, it can be 0.1 μm, 0.8 μm, 1.5 μm, 2.1 μm, 2.8 μm, 3.4 μm, 4.1 μm, 4.7 μm, 5.4 μm or 6 μm.

[0052] Optionally, the nickel content in the zinc-nickel plating layer is 0.1 to 20 wt%, for example, it can be 0.1 wt%, 2.4 wt%, 4.6 wt%, 6.8 wt%, 9 wt%, 11.2 wt%, 13.4 wt%, 15.6 wt%, 17.8 wt%, or 20 wt%.

[0053] Optionally, the surface roughness Ra of the zinc-nickel plating layer is 0.2 to 0.35 μm, for example, it can be 0.2 μm, 0.22 μm, 0.24 μm, 0.25 μm, 0.27 μm, 0.29 μm, 0.3 μm, 0.32 μm, 0.34 μm or 0.35 μm.

[0054] Preferably, the pretreatment includes: the NdFeB substrate being successively ground and chamfered, acid-washed, and ultrasonically cleaned.

[0055] Optionally, the grinding and chamfering includes: using a vibratory grinding and chamfering machine and / or a centrifugal grinding and chamfering machine, using abrasives, removing burrs from the surface of the NdFeB substrate, and grinding the right angles at the edges and corners into R-angles.

[0056] Optionally, the electroplating method further includes an oil removal process disposed between grinding and chamfering and pickling.

[0057] Optionally, the degreasing process includes: using a metal cleaning agent to remove oil stains from the surface of the chamfered NdFeB substrate.

[0058] Optionally, the concentration of the cleaning agent in the metal cleaning agent is 2 to 6 wt%, for example, it can be 2 wt%, 2.5 wt%, 2.9 wt%, 3.4 wt%, 3.8 wt%, 4.3 wt%, 4.7 wt%, 5.2 wt%, 5.6 wt%, or 6 wt%.

[0059] Optionally, the temperature of the degreasing process is 40 to 60°C, for example, 40°C, 43°C, 45°C, 47°C, 49°C, 52°C, 54°C, 56°C, 58°C, or 60°C.

[0060] Optionally, the processing time of the degreasing process is 90 to 150 seconds, for example, it can be 90 seconds, 95 seconds, 105 seconds, 110 seconds, 115 seconds, 125 seconds, 130 seconds, 135 seconds, 140 seconds or 150 seconds.

[0061] Optionally, the pickling includes: removing the oxide layer on the surface of the NdFeB substrate using acid. Removing the surface oxide layer yields an NdFeB substrate free of oxide layer and corrosion.

[0062] Optionally, the pickling includes at least one sub-pickling, which can be divided into two pickling processes.

[0063] Optionally, the acid solution used for pickling is 1 to 4 wt% nitric acid, for example, it can be 1 wt%, 1.4 wt%, 1.7 wt%, 2 wt%, 2.4 wt%, 2.7 wt%, 3 wt%, 3.4 wt%, 3.7 wt%, or 4 wt%.

[0064] Optionally, the pretreatment further includes a pre-activation step after ultrasonic cleaning; the pre-activation step includes cleaning the ultrasonically cleaned NdFeB matrix with a pre-activation solution.

[0065] This invention uses an ultrasonic cleaner to thoroughly clean the surface of the acid-washed NdFeB substrate, preventing poor adhesion and the introduction of impurities into the electroplating solution.

[0066] Optionally, the pre-activation solution includes an activator with a volume concentration of 5-12%, such as 5%, 6%, 7%, 8%, 9%, 10%, 11%, or 12%.

[0067] Optionally, the cleaning time of the pre-activation step is 5 to 15 seconds, for example, it can be 5 seconds, 7 seconds, 8 seconds, 9 seconds, 10 seconds, 11 seconds, 12 seconds, 13 seconds, 14 seconds or 15 seconds.

[0068] Optionally, after the second zinc-nickel electroplating, the electroplating method further includes: the second NdFeB magnet is sequentially subjected to brightening, passivation and drying to obtain a NdFeB magnet product with a coating.

[0069] Optionally, the light extraction includes treating the second neodymium iron boron with an HCl solution of volume concentration of 0.1% to 0.6% to extract light, for example, the concentration can be 0.1%, 0.2%, 0.3%, 0.3%, 0.4%, 0.4%, 0.5%, 0.5%, 0.6%, or 0.6%.

[0070] Optionally, the light emission time is 5 to 45 seconds, for example, it can be 5 seconds, 10 seconds, 14 seconds, 19 seconds, 23 seconds, 28 seconds, 32 seconds, 37 seconds, 41 seconds or 45 seconds.

[0071] Optionally, the passivating agent includes a trivalent chromium passivating solution.

[0072] Optionally, the pH value of the trivalent chromium passivation solution is 4.0 to 4.5, for example, it can be 4.0, 4.1, 4.2, 4.3, 4.4 or 4.5.

[0073] Optionally, the concentration of chromium in the trivalent chromium passivation solution is 1.5 to 2.5 g / L, for example, it can be 1.5 g / L, 1.6 g / L, 1.7 g / L, 1.8 g / L, 1.9 g / L, 2.0 g / L, 2.1 g / L, 2.2 g / L, 2.3 g / L, 2.4 g / L, or 2.5 g / L.

[0074] Optionally, the passivation temperature is 20 to 30°C, for example, it can be 20°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C or 30°C.

[0075] Optionally, the passivation time is 40 to 90 seconds, for example, 40 seconds, 46 seconds, 52 seconds, 57 seconds, 63 seconds, 68 seconds, 74 seconds, 79 seconds, 85 seconds, or 90 seconds.

[0076] As a preferred technical solution of the present invention, the electroplating method includes the following steps:

[0077] (1) Use a vibratory grinding chamfering machine and / or a centrifugal grinding chamfering machine to use abrasive to remove burrs from the surface of the NdFeB substrate and grind the right angles at the corners into R angles; then use 2-6wt% metal cleaning agent to remove oil stains from the surface of the chamfered NdFeB substrate at 40-60℃ for 90-150s.

[0078] Then, 1-4 wt% nitric acid is used to remove the oxide layer on the surface of the NdFeB substrate to obtain an NdFeB substrate without oxide layer and corrosion. The surface of the acid-washed NdFeB substrate is then cleaned with an ultrasonic cleaner. The ultrasonically cleaned NdFeB substrate is then cleaned with an activator with a volume concentration of 5-12% for 5-15 seconds to obtain the pretreated NdFeB substrate.

[0079] (2) The pretreated NdFeB substrate is subjected to a first electroplating solution with a current density of 0.1–2 A / dm². 2 A first electroplating of zinc is performed, with the pH of the first electroplating solution being 3.0–5.0 and the temperature being 20–35°C, to obtain a first neodymium iron boron magnet containing a zinc plating layer.

[0080] The first electroplating solution comprises 150–240 g / L zinc sulfate, 100–200 g / L sodium sulfate, and 10–40 g / L boric acid.

[0081] (3) The first neodymium iron boron magnet was washed in a 0.2-0.6% hydrochloric acid solution for 5-15 seconds to obtain the activated first neodymium iron boron magnet.

[0082] (4) The zinc-containing NdFeB layer is electroplated in a second electroplating solution with a current density of 0.1–5 A / dm². 2 A second zinc-nickel electroplating process is performed at a temperature of 25℃ to 36℃ and a pH value of 5.0 to 5.7 to obtain a second neodymium iron boron magnet containing a zinc-nickel plating layer.

[0083] The second electroplating solution comprises 10–30 g / L zinc chloride, 200–260 g / L potassium chloride, 10–40 g / L nickel chloride, 1–10 ml / L complexing agent (by mass percentage, the complexing agent includes 15–25% diethylenetriamine, 10–30% sodium benzoate, and 2–6% p-toluenesulfonic acid), 70–110 ml / L buffer (40–60 wt% potassium acetate), 0.1–10 ml / L brightener, 1–20 ml / L wetting agent, and 0.1–10 ml / L low-position strengthening agent.

[0084] (5) The second NdFeB magnet is treated with HCl solution with a volume concentration of 0.1-0.6% for 5-45 seconds for brightening. Then, the second NdFeB magnet is passivated with trivalent chromium passivation solution with pH value of 4.0-4.5 and chromium concentration of 1.5-2.5 g / L at 20-30℃ for 40-90 seconds. Finally, it is dried to obtain the NdFeB magnet product with coating.

[0085] The method for preparing the NdFeB matrix in this invention includes:

[0086] 1) Alloy quick-setting sheets are made using a quick-setting process.

[0087] 2) The quick-setting sheet was hydrogen-crushed and then subjected to air jet milling with the addition of additives to obtain alloy powder. The average particle size D50 of the alloy powder was 2-5 μm.

[0088] 3) Press the alloy powder obtained in step 2) into a compact under magnetic field orientation with a magnetic field strength of 1.8-2.5T to obtain a compact.

[0089] 4) Place the pressed blank obtained in step 3) into a sintering furnace and sinter and age it in a vacuum or inert atmosphere to obtain a blank.

[0090] The sintering process is as follows: the sintering temperature is 1030~1120℃, and the time is 1~10h, preferably 6~10h.

[0091] The aging process is as follows: the first stage aging temperature is 870-1000℃, and the holding time is 0.5-6h; the second stage aging temperature is 450-700℃, and the holding time is 1-10h.

[0092] 5) The blank is machined to obtain a neodymium iron boron matrix of the corresponding size.

[0093] In a second aspect, the present invention provides a coated neodymium iron boron magnet product, wherein the neodymium iron boron magnet product is prepared by the electroplating method of neodymium iron boron described in the first aspect.

[0094] Preferably, the neodymium iron boron magnet product includes a neodymium iron boron substrate and a zinc plating layer and a zinc-nickel plating layer sequentially disposed on the surface of the neodymium iron boron substrate.

[0095] Optionally, the thickness of the zinc plating layer is 0.5 to 6.5 μm, for example, it can be 0.5 μm, 1.2 μm, 1.9 μm, 2.5 μm, 3.2 μm, 3.9 μm, 4.5 μm, 5.2 μm, 5.9 μm or 6.5 μm.

[0096] Optionally, the thickness of the zinc-nickel plating layer is 0.1 to 6 μm, for example, it can be 0.1 μm, 0.8 μm, 1.5 μm, 2.1 μm, 2.8 μm, 3.4 μm, 4.1 μm, 4.7 μm, 5.4 μm or 6 μm.

[0097] Optionally, the nickel content in the zinc-nickel plating layer is 0.1 to 20 wt%, for example, it can be 0.1 wt%, 2.4 wt%, 4.6 wt%, 6.8 wt%, 9 wt%, 11.2 wt%, 13.4 wt%, 15.6 wt%, 17.8 wt%, or 20 wt%.

[0098] Optionally, the total length of the cracks in the near-surface region of the NdFeB matrix is ​​less than or equal to 130 μm, for example, it can be 10 μm, 12 μm, 13 μm, 15 μm, 20 μm, 22 μm, 25 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm or 130 μm, etc.

[0099] The near-surface region mentioned in this invention refers to a region extending 20 μm from the surface of the NdFeB substrate into the interior of the NdFeB substrate.

[0100] Optionally, the NdFeB matrix comprises 28–32 wt% R, 0.85–1.05 wt% B, 0–3 wt% M, excluding O, with the balance being T; wherein R represents a rare earth element selected from Nd and at least one of the following rare earth elements: Pr, La, Ce, Gd, Dy, Tb, and Ho; M is selected from any one or a combination of at least two of Cu, Ga, Zr, Ti, Nb, Al, Zn, Ag, or W. T includes Fe and / or Co and other impurity elements, wherein Fe accounts for more than 97 wt% of the total T.

[0101] Specifically, the R element is 28–32 wt%, for example, it can be 28 wt%, 28.5 wt%, 28.9 wt%, 29.4 wt%, 29.8 wt%, 30.3 wt%, 30.7 wt%, 31.2 wt%, 31.6 wt%, or 32 wt%, etc.; the B element is 0.85–1.05 wt%, for example, it can be 0.85 wt%, 0.88 wt%, 0.9 wt%, 0.92 wt%, 0.94 wt%, 0.97 wt%, 0.99 wt%, 1.01 wt%, 1.03 wt%, or 1.05 wt%, etc.; and the M element is 0–3 wt%, for example, it can be 0.1 wt%, 0.4 wt%, 0.7 wt%, 1 wt%, 1.4 wt%, 1.7 wt%, 2 wt%, 2.4 wt%, 2.7 wt%, or 3 wt%, etc.

[0102] The present invention does not impose any special restrictions on the activator in the above process. Any activator known to those skilled in the art that can be used to activate the NdFeB matrix can be used. The activator can also be adjusted according to the actual process, for example, it can be dilute sulfuric acid, dilute hydrochloric acid, etc.

[0103] Thirdly, the present invention provides an electronic product, the electronic product comprising the coated neodymium iron boron magnet product described in the second aspect.

[0104] The electronic product provided in the third aspect of the present invention includes the coated neodymium iron boron magnet product provided in the second aspect, and thus has better corrosion resistance and drop resistance.

[0105] Compared with the prior art, the present invention has at least the following beneficial effects:

[0106] (1) The electroplating method for neodymium iron boron provided by the present invention can obtain neodymium iron boron magnet products with excellent corrosion resistance on the basis of thinner coating. Specifically, the load-bearing drop resistance test of the neodymium iron boron magnet products with coating prepared by the present invention can reach more than 50 times, preferably more than 60 times; and the salt spray resistance test can reach more than 100 hours, preferably more than 120 hours; and the high temperature and high humidity resistance test can reach more than 450 hours, preferably more than 504 hours.

[0107] (2) The zinc plating layer and zinc-nickel plating layer of the neodymium iron boron magnet products prepared by the electroplating method of the present invention are significantly reduced, which is in line with the trend of miniaturization of application scenarios. Attached Figure Description

[0108] Figure 1 This is an electron microscope image of the coated neodymium iron boron magnet product provided in Embodiment 1 of the present invention.

[0109] Figure 2 This is an electron microscope image of the coated neodymium iron boron magnet product provided in Comparative Example 3 of the present invention. Detailed Implementation

[0110] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0111] It should be understood that in the description of this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0112] For ease of comparison, the methods for preparing the NdFeB matrix provided in the following examples and comparative examples include the following steps:

[0113] 1) Alloy quick-setting sheets are made using a quick-setting process.

[0114] 2) The quick-setting sheet was hydrogen-crushed and then subjected to air jet milling with the addition of additives to obtain alloy powder. The average particle size D50 of the alloy powder was 3.5 μm.

[0115] 3) Press the alloy powder obtained in step 2) into a compact under magnetic field orientation with a magnetic field strength of 2.0T to obtain a compact.

[0116] 4) Place the pressed blank obtained in step 3) into a sintering furnace and sinter and age it in a vacuum or inert atmosphere to obtain a blank.

[0117] The sintering process is as follows: the sintering temperature is 1100℃ and the time is 5h, preferably 6 to 10h.

[0118] The aging process is as follows: the first aging temperature is 900℃ and the holding time is 6h; the second aging temperature is 500℃ and the holding time is 8h.

[0119] 5) The blank is machined to obtain a neodymium iron boron matrix of the corresponding size.

[0120] Example 1

[0121] This embodiment provides an electroplating method for neodymium iron boron, the electroplating method comprising the following steps:

[0122] The neodymium iron boron matrix used in this embodiment has a composition of (PrNd). 29.5 Co1B 0.9 Cu 0.1 Ga 0.3 Al 0.1 Fe 余 The subscript indicates the percentage content by mass.

[0123] (1) A vibratory grinding and chamfering machine was used to remove burrs from the surface of the NdFeB substrate and grind the right angles at the edges and corners into R-angles; then, 3.5wt% metal cleaning agent (specifically 3M) was used. TM Citrus-BasedCleaner / Degreaser7100 was used to remove oil stains from the chamfered NdFeB substrate surface for 120 seconds at 50°C.

[0124] Then, the oxide layer on the surface of the NdFeB substrate was removed twice using 2.5wt% nitric acid to remove the oxide layer and obtain an NdFeB substrate without oxide layer and corrosion. The surface of the acid-washed NdFeB substrate was then cleaned with an ultrasonic cleaner. The ultrasonically cleaned NdFeB substrate was then cleaned with an activator (Tween 20) with a volume concentration of 8% for 10 seconds to obtain the pretreated NdFeB substrate. The surface roughness Ra of the pretreated NdFeB substrate was 0.2μm.

[0125] (2) The pretreated NdFeB substrate is subjected to a first electroplating solution with a current density of 1.0 A / dm². 2 The first electroplating of zinc was carried out, with the pH of the first electroplating solution being 4.0 and the temperature being 30°C, to obtain the first neodymium iron boron magnet containing a zinc plating layer.

[0126] The first electroplating solution consists of 200 g / L zinc sulfate, 150 g / L sodium sulfate, and 20 g / L boric acid.

[0127] (3) The first neodymium iron boron magnet was washed in a 0.5% hydrochloric acid solution for 10 seconds to obtain the activated first neodymium iron boron magnet.

[0128] (4) The first neodymium iron boron magnet is subjected to a second electroplating solution at a current density of 3.5 A / dm². 2A second zinc-nickel electroplating process is performed at a temperature of 30°C and a pH value of 5.2, resulting in a second NdFeB magnet with a zinc-nickel plating layer. To ensure the stability of the second electroplating solution, a complexing agent and a buffer are added to the plating solution at least once during the second zinc-nickel electroplating process. The volume ratio of the complexing agent to the buffer to the pure water is 1:2.5 each time, and the complexing agent and buffer are added to the plating solution proportionally every 1000 ampere-hours.

[0129] The second electroplating solution comprises 25 g / L zinc chloride, 250 g / L potassium chloride, 30 g / L nickel chloride, 5 ml / L complexing agent (by mass percentage, the complexing agent includes 20% diethylenetriamine, 25% sodium benzoate and 3.5% p-toluenesulfonic acid), and 100 ml / L buffer (potassium acetate at a concentration of 50 wt%).

[0130] (5) The second NdFeB magnet was treated with HCl solution with a volume concentration of 0.5% for 35s to produce light, and then the second NdFeB magnet was passivated for 50s at 25℃ with trivalent chromium passivation solution with a pH of 4.2 and a chromium concentration of 2g / L. Finally, it was dried to obtain the NdFeB magnet product with coating.

[0131] Example 2

[0132] This embodiment provides an electroplating method for neodymium iron boron, the electroplating method comprising the following steps:

[0133] The composition of the neodymium iron boron matrix in this embodiment is the same as in Embodiment 1.

[0134] (1) A centrifugal grinding and chamfering machine was used with abrasive to remove burrs from the surface of the NdFeB substrate and to grind the right angles at the edges into R-angles; then a 2wt% metal cleaning agent (specifically 3M) was used. TM Citrus-BasedCleaner / Degreaser7100 was used to remove oil stains from the chamfered NdFeB substrate surface for 150 seconds at 40°C.

[0135] Then, the oxide layer on the surface of the NdFeB substrate was removed twice with 3wt% nitric acid to remove the oxide layer on the surface of the NdFeB substrate, so as to obtain an NdFeB substrate without oxide layer and corrosion. Then, the surface of the acid-washed NdFeB substrate was cleaned with an ultrasonic cleaner. Then, the ultrasonically cleaned NdFeB substrate was cleaned with an activator (Tween 80) with a volume concentration of 12% for 10s to obtain the pretreated NdFeB substrate. The surface roughness Ra of the pretreated NdFeB substrate was 0.35μm. (2) The pretreated NdFeB substrate was subjected to the first electroplating solution with a current density of 2.0A / dm 2A first electroplating of zinc was performed, with the pH of the first electroplating solution being 3.0 and the temperature being 35°C, to obtain a first neodymium iron boron magnet containing a zinc plating layer.

[0136] The first electroplating solution consists of 240 g / L zinc sulfate, 100 g / L sodium sulfate, and 10 g / L boric acid.

[0137] (3) The first neodymium iron boron magnet was washed in a 0.6% hydrochloric acid solution for 15 seconds to obtain the activated first neodymium iron boron magnet.

[0138] (4) The first neodymium iron boron magnet is subjected to a second electroplating solution with a current density of 0.1 A / dm². 2 A second zinc-nickel electroplating process is performed at a temperature of 25°C and a pH of 5.7 to obtain a second NdFeB magnet with a zinc-nickel plating layer. To ensure the stability of the second electroplating solution, a complexing agent and a buffer are added to the plating solution at least once during the second zinc-nickel electroplating process. The volume ratio of the complexing agent to the buffer to the pure water is 1:5 each time, and the complexing agent and buffer are added to the plating solution proportionally every 1000 ampere-hours.

[0139] The second electroplating solution comprises 10 g / L zinc chloride, 260 g / L potassium chloride, 10 g / L nickel chloride, 10 ml / L complexing agent (by mass percentage, the complexing agent includes 15% diethylenetriamine, 30% sodium benzoate and 6% p-toluenesulfonic acid), and 110 ml / L buffer (40 wt% potassium acetate).

[0140] (5) The second NdFeB magnet was treated with HCl solution with a volume concentration of 0.1% for 45s to produce light, and then the second NdFeB magnet was passivated for 40s at 30℃ with trivalent chromium passivation solution with a pH of 4.5 and a chromium concentration of 2g / L. Finally, it was dried to obtain the NdFeB magnet product with coating.

[0141] Example 3

[0142] This embodiment provides an electroplating method for neodymium iron boron. Except for the presence of 260 g / L zinc sulfate in the first electroplating solution, the electroplating method is the same as in Example 1, and will not be described again here.

[0143] Example 4

[0144] This embodiment provides an electroplating method for neodymium iron boron. Except that the first electroplating solution contains 5 ml / L of brightener (specifically Parker Ionics 7-36), the electroplating method is the same as in Example 1, and will not be repeated here.

[0145] Example 5

[0146] This embodiment provides an electroplating method for neodymium iron boron. Except for the presence of 150 g / L potassium chloride in the second electroplating solution, the electroplating method is the same as in Example 1, and will not be described again here.

[0147] Example 6

[0148] This embodiment provides an electroplating method for neodymium iron boron. The electroplating method is the same as in Example 1 except that no buffer is added to the second electroplating solution, and will not be described again here.

[0149] Comparative Example 1

[0150] This comparative example provides an electroplating method for NdFeB substrates. Except for the surface roughness Ra of the NdFeB substrate after pretreatment being 0.5 μm, the electroplating method is the same as in Example 1 and will not be repeated here.

[0151] Comparative Example 2

[0152] This comparative example provides an electroplating method for neodymium iron boron magnets. Except for the surface roughness Ra of the first neodymium iron boron magnet being 0.25 μm, the electroplating method is the same as that in Example 1, and will not be repeated here.

[0153] Test methods

[0154] Drop Test: The coated NdFeB magnet product was glued to a fixture, and the glued sample was left to air dry for 2 hours. The fixture was loaded with a weight of 1.2 kg, and the NdFeB magnet glued to the fixture was dropped freely from a height of 1.6 meters to examine whether the coating on the surface of the NdFeB magnet product was intact. The zinc coating on the surface of the NdFeB magnet products prepared in each embodiment was tested and observed to see if it separated from the substrate (the magnet was allowed to separate from the fixture, and the coating did not peel off or flake). If it did not peel off or flake, it indicated that the coating adhesion was qualified, and the number of drops that could withstand the load was calculated.

[0155] Salt spray test: Neutral salt spray test. The test chamber is filled with salt water containing 5% sodium chloride and with a pH value of 6.5 to 7.2. The test specimen is placed in the test chamber and the temperature of the test chamber is 35℃.

[0156] High temperature and high humidity test: The test piece is placed in a condition of 60℃ and 90% relative humidity for high temperature and high humidity test.

[0157] Taking Example 1 and Comparative Example 1 as examples, the electron microscope images of the final NdFeB magnet products with coatings are as follows: Figure 1 and Figure 2 As shown, from Figures 1-2 It can be seen that in the NdFeB magnet product with coating obtained in Comparative Example 1, a large number of long cracks were generated in the near-surface region of the substrate, while Figure 1 The number of cracks in the middle section was significantly reduced and their length shortened.

[0158] The test results of the above embodiments and comparative examples are shown in Table 1.

[0159] Table 1

[0160]

[0161] As can be seen from Table 1:

[0162] (1) As can be seen from the comprehensive examples 1 to 2, the electroplating method of neodymium iron boron provided by the present invention has the advantages of thin coating, good bonding force with neodymium iron boron substrate and excellent corrosion resistance. Among them, the neodymium iron boron magnet products with coating can withstand more than 90 drops, withstand salt spray for more than 120 hours, withstand high temperature and high humidity for more than 504 hours, and the total length of cracks in the near-surface area is less than or equal to 30 μm, which can adapt to the trend of application scenarios towards miniaturization.

[0163] (2) As can be seen from the combined examples 1 and 3, the first electroplating solution in example 1 contains 200 g / L zinc sulfate, compared with 260 g / L zinc sulfate in example 3. The final coated NdFeB magnet product in example 1 has a salt spray resistance of 120 h and a high temperature and humidity resistance of 504 h, while the final coated NdFeB magnet product in example 3 has a salt spray resistance of only 100 h and a high temperature and humidity resistance of 450 h, and can only withstand 60 drops. This shows that by using a suitable concentration of zinc sulfate in the first electroplating solution, the present invention can further improve the adhesion and corrosion resistance of the zinc-nickel plating layer.

[0164] (3) It can be seen from the combined examples 1 and 4 that, in Example 1, no brightener was added. Compared with Example 4, which added a brightener, the surface roughness of the zinc plating layer of the first NdFeB magnet in Example 1 was 0.32 μm, and the salt spray resistance of the final coated NdFeB magnet product was 120 h, and the high temperature and humidity resistance was 504 h. In contrast, the surface roughness of the zinc plating layer of the first NdFeB magnet in Example 4 was 0.30 μm, and the salt spray resistance of the final coated NdFeB magnet product was only 100 h, and the number of times it could withstand heavy drops was only 50. This shows that by preferably not adding a brightener to the first electroplating solution, the present invention can further improve the roughness of the zinc plating layer in the first NdFeB magnet, thereby improving the adhesion and corrosion resistance of the zinc-nickel plating layer.

[0165] (4) It can be seen from the combined examples 1 and 5 that the second electroplating solution in example 1 contains 250 g / L potassium chloride, which is lower than the 150 g / L potassium chloride used in example 5. The potassium chloride content in example 5 is too low, making it difficult to complex zinc ions, resulting in uneven plating. The number of times it can withstand heavy drops is only 50. This shows that the present invention can improve corrosion resistance and drop resistance by using an appropriate concentration of potassium chloride in the second electroplating solution.

[0166] (5) No buffer was added in Example 6, which resulted in uncontrollable roughness, reduced corrosion resistance, and reduced load-bearing drop count to 50 times.

[0167] (6) In Comparative Example 1, the surface roughness Ra of the NdFeB substrate after pretreatment is 0.5 μm, which is too rough. The total length of cracks in the near-surface area is as high as 224 μm, and the number of times it can withstand heavy-duty drops is only 20. In Comparative Example 2, the surface roughness Ra of the first NdFeB magnet is 0.25 μm, which leads to a significant decrease in the adhesion of the coating. The salt spray resistance time is only 48 h, the high temperature and humidity resistance time is only 72 h, and the corrosion resistance is not as good as that of Example 1. This shows that by selecting a NdFeB substrate with a specific roughness and using a specific electroplating method, the present invention can obtain NdFeB magnet products with thin coating, excellent adhesion, and good corrosion resistance, which has broad application prospects.

[0168] The present invention has been illustrated with the above embodiments to illustrate its detailed features, but the present invention is not limited to the above detailed features, that is, it does not mean that the present invention must rely on the above detailed features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the selected technical features, additions of auxiliary technical features, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An electroplating method for neodymium iron boron magnets, characterized in that, The electroplating method includes the following steps: The burrs on the surface of the NdFeB substrate are removed using a vibratory grinding and / or centrifugal grinding and chamfering machine, and the right angles at the edges are ground into R-angles. The oil on the surface of the chamfered NdFeB substrate is removed for 90-150 seconds using a 2-6 wt% metal cleaning agent at 40-60℃. The oxide layer on the surface of the NdFeB substrate is removed by pickling with 1-4 wt% nitric acid. The surface of the acid-washed NdFeB substrate was cleaned using an ultrasonic cleaner, and then cleaned with an activator with a volume concentration of 5-12% for 5-15 seconds to obtain a pretreated NdFeB substrate with a surface roughness Ra of 0.2-0.35 μm. The pretreated NdFeB substrate is subjected to a first electroplating zinc solution to obtain a first NdFeB magnet with a zinc plating layer surface roughness Ra of 0.3~0.45μm. The first electroplating solution includes 150~240g / L zinc sulfate, 100~200g / L sodium sulfate and 10~40g / L boric acid, and the thickness of the zinc plating layer is 0.1~7μm. The first neodymium iron boron magnet is subjected to a second electroplating solution to a second zinc-nickel plating process, resulting in a second neodymium iron boron magnet with a zinc-nickel plating layer having a surface roughness Ra of 0.2~0.35μm. The second electroplating solution comprises 10~30g / L zinc chloride, 200~260g / L potassium chloride, and 10~40g / L nickel chloride, and the mass ratio of zinc chloride to nickel chloride in the second electroplating solution is (2~4):

1.

2. The electroplating method according to claim 1, characterized in that, The pH of the first electroplating solution is 3.0~5.

0.

3. The electroplating method according to claim 1 or 2, characterized in that, During the first zinc electroplating process, the temperature of the first electroplating solution is 20~35℃; And / or, the current density during the first electroplating zinc process is 0.1~2A / dm³. 2 .

4. The electroplating method according to claim 1, characterized in that, The second electroplating solution does not contain boric acid.

5. The electroplating method according to claim 1, characterized in that, The second electroplating solution also contains 1~10 ml / L of complexing agent; According to the mass percentage, the complexing agent includes 15-25% diethylenetriamine, 10-30% sodium benzoate and 2-6% p-toluenesulfonic acid; And / or, the second electroplating solution further contains 70-110 ml / L of buffer; the buffer includes potassium acetate at a concentration of 40-60 wt%.

6. The electroplating method according to claim 1, characterized in that, During the second zinc-nickel electroplating process, the temperature of the second electroplating solution is 25℃~36℃; And / or, the pH value of the second electroplated zinc-nickel is 5.0~5.7; And / or, the current density of the second electroplated zinc-nickel is 0.1~5 A / dm². 2 ; And / or, the thickness of the zinc-nickel plating layer is 0.1~6μm; And / or, the nickel content in the zinc-nickel plating layer is 0.1~20wt%.

7. The electroplating method according to claim 1, characterized in that, After the second zinc-nickel electroplating, the electroplating method further includes: the second NdFeB magnet is sequentially subjected to brightening, passivation and drying to obtain a NdFeB magnet product with a coating.

8. A neodymium iron boron magnet product with a coating, characterized in that, The neodymium iron boron magnet product is manufactured using the electroplating method for neodymium iron boron magnets as described in any one of claims 1 to 7.

9. The neodymium iron boron magnet product according to claim 8, characterized in that, The neodymium iron boron magnet product includes a neodymium iron boron substrate and a zinc plating layer and a zinc-nickel plating layer sequentially disposed on the surface of the neodymium iron boron substrate; And / or, the thickness of the zinc plating layer is 0.5~6.5μm; And / or, the thickness of the zinc-nickel plating layer is 0.1~6μm; And / or, the nickel content in the zinc-nickel plating layer is 0.1~20wt%; And / or, the total length of cracks in the near-surface region of the NdFeB matrix is ​​less than or equal to 130 μm.

10. An electronic product, characterized in that, The electronic product includes the coated neodymium iron boron magnet product as described in claim 8 or 9.

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