阅读说明：本技术 一种应用于钕铁硼表面处理的超薄镀层电镀方法 (Ultrathin plating electroplating method applied to neodymium iron boron surface treatment ) 是由 唐金华 周小雄 于 2021-08-27 设计创作，主要内容包括：本发明公开了一种应用于钕铁硼表面处理的超薄镀层电镀方法,它在钕铁硼基材表面进行镀层,从里到外分别为电镀冲击铜层、电镀脉冲铜层、电镀镍钨合金层、低速化学镍镀层和高磷化学镍镀层；其中,钕铁硼基材表面镀层的总厚为4～4.5μm,电镀冲击铜层的厚度为0.5～0.6μm,电镀脉冲铜层的厚度为0.8～1.0μm,电镀镍钨合金层的厚度为0.3～0.5μm,低速化学镍镀层的厚度为0.4～0.5μm。现有常规化学镀镍只有一层常规高磷化学镍,本发明采用双层化学镀镍,即再正常镀高磷化学镍前,先采用低镀速低孔隙率的特殊化学镍先镀至约0.4～0.5微米,然后转入常规高磷化学镍镀至所需厚度。与现有技术相比,本发明主在要提升镀层质量及性能方面,优势明显,耐腐蚀性更好,磁屏蔽更低。(The invention discloses an ultrathin plating layer electroplating method applied to neodymium iron boron surface treatment, which is characterized in that a plating layer is formed on the surface of a neodymium iron boron substrate, and the plating layer comprises an electroplating impact copper layer, an electroplating pulse copper layer, an electroplating nickel-tungsten alloy layer, a low-speed chemical nickel plating layer and a high-phosphorus chemical nickel plating layer from inside to outside; wherein, the total thickness of the surface coating of the neodymium iron boron substrate is 4-4.5 μm, the thickness of the electroplating impact copper layer is 0.5-0.6 μm, the thickness of the electroplating pulse copper layer is 0.8-1.0 μm, the thickness of the electroplating nickel-tungsten alloy layer is 0.3-0.5 μm, and the thickness of the low-speed chemical nickel coating is 0.4-0.5 μm. The conventional chemical nickel plating only has one layer of conventional high-phosphorus chemical nickel, and the method adopts double-layer chemical nickel plating, namely, before the high-phosphorus chemical nickel is normally plated, special chemical nickel with low plating speed and low porosity is firstly plated to about 0.4-0.5 micrometer, and then the conventional high-phosphorus chemical nickel plating is transferred to the required thickness. Compared with the prior art, the invention has the advantages of obvious advantages, better corrosion resistance and lower magnetic shielding in the aspects of improving the quality and performance of the plating layer.)

1. An ultra-thin plating layer electroplating method applied to neodymium iron boron surface treatment is characterized in that a plating layer is formed on the surface of a neodymium iron boron substrate, wherein the plating layer comprises an electroplating impact copper layer, an electroplating pulse copper layer, an electroplating nickel-tungsten alloy layer, a low-speed chemical nickel plating layer and a high-phosphorus chemical nickel plating layer from inside to outside; wherein, the total thickness of the surface coating of the neodymium iron boron substrate is 4-4.5 μm, the thickness of the electroplating impact copper layer is 0.5-0.6 μm, the thickness of the electroplating pulse copper layer is 0.8-1.0 μm, the thickness of the electroplating nickel-tungsten alloy layer is 0.3-0.5 μm, and the thickness of the low-speed chemical nickel coating is 0.4-0.5 μm.

2. The method for electroplating the ultrathin coating applied to the surface treatment of the neodymium-iron-boron according to claim 1, wherein an impact copper plating solution is adopted in the process of electroplating the impact copper layer, and the plating solution comprises 3-5 g/L, HEDP 110-110 g/L of copper carbonate, 60-80 g/L of potassium carbonate, 0.02-0.04 g/L of bismuth nitrate and 0.003-0.007 g/L of polycation quaternary ammonium salt; the electroplating process comprises the following steps: the temperature is 18-25 ℃, the pH = 9.3-9.8, the current density is 0.3-0.5 ASD, and the electroplating time is 40-60 min.

3. The method for electroplating the ultrathin coating applied to the surface treatment of the neodymium-iron-boron according to claim 1, wherein a pulse copper plating solution is adopted in the process of electroplating the pulse copper layer, and the plating solution comprises 13-15 g/L, HEDP 140-160 g/L of copper carbonate, 60-80 g/L of potassium carbonate, 0.02-0.04 g/L of bismuth nitrate and 0.003-0.007 g/L of polycation quaternary ammonium salt; the electroplating process comprises the following steps: the temperature is 50-60 ℃, the pH = 9.3-9.8, the current density is 0.2-0.4 ASD, and the electroplating time is 70-80 min.

4. The electroplating method of the ultrathin coating applied to the surface treatment of the neodymium-iron-boron according to claim 1, characterized in that the process of electroplating the nickel-tungsten alloy layer adopts a nickel-tungsten mixed plating solution, and the plating solution comprises 14-18 g/L of nickel sulfate, 25-35 g/L of sodium tungstate and 35-45 g/L of citric acid; the electroplating process comprises the following steps: the temperature is 60-70 ℃, the pH = 6.3-6.8, the current density is 0.4-0.6 ASD, and the electroplating time is 10-20 min.

5. The method for electroplating an ultrathin coating applied to neodymium-iron-boron surface treatment according to claim 1, wherein a low-speed chemical nickel plating solution is adopted in the low-speed chemical nickel coating process, and the plating solution comprises 18-22 g/L of nickel sulfate, 18-22 g/L of sodium hypophosphite, 10-15 g/L of citric acid, 8-12 g/L of malic acid, 18-22 g/L of sodium hydroxide, 0.008-0.012 g/L of PPS-OH, and 0.003-0.007 g/L of allyl iodide; the process for plating the low-speed chemical nickel treatment comprises the following steps: the temperature is 80-85 ℃, the pH is = 4.3-4.6, and the treatment time is 30-35 min.

6. The electroplating method of the ultra-thin coating applied to the surface treatment of neodymium iron boron as claimed in claim 1, wherein the process of the high phosphorus chemical nickel coating adopts a high phosphorus chemical nickel plating solution, the plating solution comprises 24-26 g/L nickel sulfate, 28-32 g/L sodium hypophosphite, 10-15 g/L citric acid, 8-12 g/L malic acid, 18-22 g/L sodium hydroxide, 0.008-0.012 g/L PPS-OH, 0.003-0.007 g/L allyl iodide; the process for plating high-phosphorus chemical nickel comprises the following steps: the temperature is 87-90 ℃, the pH is = 4.7-4.9, and the treatment time is 15-25 min.

7. The electroplating method of the ultra-thin coating applied to the surface treatment of the neodymium iron boron according to claim 1, characterized by comprising the following steps:

1) performing pretreatment before the coating of the neodymium iron boron substrate, namely washing and deoiling the neodymium iron boron substrate for 5-20 min at the temperature of 45-55 ℃ by using a deoiling powder solution, then performing duplex washing, then performing acid washing for 2-3 min by using a dilute nitric acid solution with the concentration of 2-4%, and then performing ultrasonic washing and duplex washing in sequence, namely completing the pretreatment;

2) placing the pretreated neodymium iron boron in an impact copper plating solution for electroplating, wherein the direct current impact current intensity in the electroplating process is 0.3-0.5 ASD, the electroplating temperature is 18-25 ℃, and the electroplating time is 40-60 min;

3) then, placing the neodymium iron boron in a pulse copper plating solution for electroplating, wherein the pulse current intensity in the electroplating process is 0.2-0.4 ASD, the electroplating temperature is 50-60 ℃, and the electroplating time is 50-70 min; carrying out activation treatment after pulse electroplating is finished;

4) placing the neodymium iron boron treated in the step 3) in a nickel-tungsten mixed plating solution for electroplating, wherein the current intensity in the electroplating process is 0.4-0.6 ASD, the electroplating temperature is 60-70 ℃, the electroplating time is 10-20 min, and after the electroplating is finished, performing activation treatment;

5) and (3) placing the neodymium iron boron treated in the step 4) in a low-speed chemical nickel plating solution for low-speed chemical nickel plating treatment to form a low-speed chemical nickel plating layer, and then placing the low-speed chemical nickel plating layer in a high-phosphorus chemical nickel plating solution for high-phosphorus chemical nickel plating treatment to form a high-phosphorus chemical nickel plating layer, namely completing the treatment.

8. The electroplating method of the ultra-thin plating layer applied to the surface treatment of the neodymium iron boron according to claim 7, characterized in that the specific process of the low-speed chemical nickel plating treatment in the step 5) is as follows: and (3) placing the workpiece after the nickel-tungsten alloy electroplating and activation treatment in a low-speed chemical nickel plating solution for chemical plating treatment, and carrying out spontaneous reaction for 30-35 min at the pH = 4.3-4.6 and the temperature of 80-85 ℃.

9. The electroplating method of the ultra-thin plating layer applied to the surface treatment of the neodymium iron boron according to claim 7, characterized in that the specific process of the high-phosphorus chemical nickel plating treatment in the step 5) is as follows: and (3) washing the workpiece plated with the low-speed chemical nickel, transferring the workpiece into a high-phosphorus chemical nickel plating solution for chemical plating treatment, and carrying out spontaneous reaction for 15-25 min at the pH = 4.7-4.9 and the temperature of 87-90 ℃.

10. The electroplating method of the ultra-thin coating applied to the surface treatment of the neodymium iron boron according to claim 7, wherein in the step 3) or the step 4), the step of activating treatment is as follows: and (3) placing the neodymium iron boron workpiece in a sulfuric acid solution with the mass concentration of 1-3% for activating for 40-120 seconds, and then washing for 2-3 times by using clear water, namely completing the activation treatment.

Technical Field

The invention relates to an ultrathin plating electroplating method applied to neodymium iron boron surface treatment.

Background

At present, the neodymium iron boron permanent magnet material is used as a magnetic material with high magnetic performance and high cost performance, and is widely applied to a plurality of fields such as electronic machinery, medical equipment and the like. However, because of some characteristics of the ndfeb substrate, such as easy oxidation of the substrate, porous and loose substrate, etc., the surface treatment of the ndfeb substrate has been a difficulty. The novel neodymium iron boron magnet is a third-generation rare earth material, is a magnetic functional material, has poor corrosion resistance and is easy to be affected by temperature. By adopting the composite plating process, a plating layer with excellent corrosion resistance and small thermal demagnetization scene response on the magnet can be formed on the surface of the neodymium iron boron magnet.

In the prior art, in the surface treatment process of the neodymium iron boron, copper plating treatment and chemical nickel plating treatment are generally carried out on the surface of a neodymium iron boron substrate. At present, NiCuNi plating (the thickness is usually 5-15 μm) and CuEN plating (the thickness is usually 6-8 μm) are relatively stable plating layers on the surface of a neodymium iron boron substrate, but with the increasing requirements of electronic consumer products on the lightness and thinness of products, the low porosity is required to be met by a common copper layer and a chemical nickel layer, the single-layer electroplating needs 4-5 micrometers, the traditional plating scheme is not satisfactory, the high corrosion resistance and the low magnetic shielding are difficult to be met under the trend of light weight of the products, and a thin non-magnetic shielding and compact plating layer is urgently needed.

Disclosure of Invention

Aiming at the technical problems in the prior art, the application aims to provide an ultrathin plating electroplating method applied to neodymium iron boron surface treatment.

The electroplating method of the ultrathin coating applied to the surface treatment of the neodymium iron boron is characterized in that the surface of a neodymium iron boron substrate is coated, and the surface of the neodymium iron boron substrate is respectively provided with an electroplating impact copper layer, an electroplating pulse copper layer, an electroplating nickel-tungsten alloy layer, a low-speed chemical nickel coating and a high-phosphorus chemical nickel coating from inside to outside; wherein, the total thickness of the surface coating of the neodymium iron boron substrate is 4-4.5 μm, the thickness of the electroplating impact copper layer is 0.5-0.6 μm, the thickness of the electroplating pulse copper layer is 0.8-1.0 μm, the thickness of the electroplating nickel-tungsten alloy layer is 0.3-0.5 μm, and the thickness of the low-speed chemical nickel coating is 0.4-0.5 μm.

The ultrathin plating layer electroplating method applied to neodymium iron boron surface treatment is characterized in that an impact copper plating solution is adopted in the process of electroplating an impact copper layer, and the plating solution comprises 3-5 g/L, HEDP 110-130 g/L of copper carbonate, 60-80 g/L of potassium carbonate, 0.02-0.04 g/L of bismuth nitrate and 0.003-0.007 g/L of polycation quaternary ammonium salt; the electroplating process comprises the following steps: the temperature is 18-25 ℃, the pH value is 9.3-9.8, the current density is 0.3-0.5 ASD, and the electroplating time is 40-60 min.

The ultrathin plating layer electroplating method applied to neodymium iron boron surface treatment is characterized in that a pulse copper plating solution is adopted in the process of electroplating a pulse copper layer, and the plating solution comprises 13-15 g/L, HEDP 140-160 g/L of copper carbonate, 60-80 g/L of potassium carbonate, 0.02-0.04 g/L of bismuth nitrate and 0.003-0.007 g/L of polycation quaternary ammonium salt; the electroplating process comprises the following steps: the temperature is 50-60 ℃, the pH is 9.3-9.8, the current density is 0.2-0.4 ASD, and the electroplating time is 70-80 min.

The ultrathin plating layer electroplating method applied to neodymium iron boron surface treatment is characterized in that a nickel-tungsten mixed plating solution is adopted in the process of electroplating a nickel-tungsten alloy layer, and the plating solution comprises 14-18 g/L of nickel sulfate, 25-35 g/L of sodium tungstate and 35-45 g/L of citric acid; the electroplating process comprises the following steps: the temperature is 60-70 ℃, the pH value is 6.3-6.8, the current density is 0.4-0.6 ASD, and the electroplating time is 10-20 min.

The ultrathin plating layer electroplating method applied to neodymium iron boron surface treatment is characterized in that a low-speed chemical nickel plating solution is adopted in the process of a low-speed chemical nickel plating layer, and the plating solution comprises 18-22 g/L of nickel sulfate, 18-22 g/L of sodium hypophosphite, 10-15 g/L of citric acid, 8-12 g/L of malic acid, 18-22 g/L of sodium hydroxide, 0.008-0.012 g/L of PPS-OH and 0.003-0.007 g/L of allyl iodine; the process for plating the low-speed chemical nickel treatment comprises the following steps: the temperature is 80-85 ℃, the pH value is 4.3-4.6, and the treatment time is 30-35 min.

The ultrathin plating layer electroplating method applied to neodymium iron boron surface treatment is characterized in that a high-phosphorus chemical nickel plating solution is adopted in the process of the high-phosphorus chemical nickel plating layer, and the plating solution comprises 24-26 g/L of nickel sulfate, 28-32 g/L of sodium hypophosphite, 10-15 g/L of citric acid, 8-12 g/L of malic acid, 18-22 g/L of sodium hydroxide, 0.008-0.012 g/L of PPS-OH and 0.003-0.007 g/L of allyl iodine; the process for plating high-phosphorus chemical nickel comprises the following steps: the temperature is 87-90 ℃, the pH value is 4.7-4.9, and the treatment time is 15-25 min.

The ultrathin plating electroplating method applied to the neodymium iron boron surface treatment is characterized by comprising the following steps of:

1) performing pretreatment before the coating of the neodymium iron boron substrate, namely washing and deoiling the neodymium iron boron substrate for 5-20 min at the temperature of 45-55 ℃ by using a deoiling powder solution, then performing duplex washing, then performing acid washing for 2-3 min by using a dilute nitric acid solution with the concentration of 2-4%, and then performing ultrasonic washing and duplex washing in sequence, namely completing the pretreatment;

2) placing the pretreated neodymium iron boron in an impact copper plating solution for electroplating, wherein the direct current impact current intensity in the electroplating process is 0.3-0.5 ASD, the electroplating temperature is 18-25 ℃, and the electroplating time is 40-60 min;

3) then, placing the neodymium iron boron in a pulse copper plating solution for electroplating, wherein the pulse current intensity in the electroplating process is 0.2-0.4 ASD, the electroplating temperature is 50-60 ℃, and the electroplating time is 50-70 min; carrying out activation treatment after pulse electroplating is finished;

4) placing the neodymium iron boron treated in the step 3) in a nickel-tungsten mixed plating solution for electroplating, wherein the current intensity in the electroplating process is 0.4-0.6 ASD, the electroplating temperature is 60-70 ℃, the electroplating time is 10-20 min, and after the electroplating is finished, performing activation treatment;

5) and (3) placing the neodymium iron boron treated in the step 4) in a low-speed chemical nickel plating solution for low-speed chemical nickel plating treatment to form a low-speed chemical nickel plating layer, and then placing the low-speed chemical nickel plating layer in a high-phosphorus chemical nickel plating solution for high-phosphorus chemical nickel plating treatment to form a high-phosphorus chemical nickel plating layer, namely completing the treatment.

The electroplating method of the ultrathin coating applied to the surface treatment of the neodymium iron boron is characterized in that the specific process of carrying out low-speed chemical nickel plating treatment in the step 5) comprises the following steps: and (3) placing the workpiece which is electroplated with the nickel-tungsten alloy and subjected to activation treatment in a low-speed chemical nickel plating solution, and carrying out chemical plating treatment, wherein the workpiece is subjected to spontaneous reaction for 30-35 min at the pH value of 4.3-4.6 and the temperature of 80-85 ℃.

The electroplating method of the ultrathin coating applied to the surface treatment of the neodymium iron boron is characterized in that the specific process of carrying out high-phosphorus chemical nickel plating treatment in the step 5) comprises the following steps: and (3) washing the workpiece plated with the low-speed chemical nickel, transferring the workpiece into a high-phosphorus chemical nickel plating solution for chemical plating treatment, and carrying out spontaneous reaction for 15-25 min at the pH value of 4.7-4.9 and the temperature of 87-90 ℃.

The ultrathin plating electroplating method applied to the neodymium iron boron surface treatment is characterized in that in the step 3) or the step 4), the activation treatment step is as follows: and (3) placing the neodymium iron boron workpiece in a sulfuric acid solution with the mass concentration of 1-3% for activating for 40-120 seconds, and then washing for 2-3 times by using clear water, namely completing the activation treatment.

In the surface treatment process of the neodymium iron boron, the process of plating treatment is impact copper electroplating layer → pulse copper electroplating layer → activation → nickel tungsten alloy electroplating → activation → low-speed chemical nickel treatment → high-phosphorus chemical nickel treatment. Compared with the prior art, the technical effect that this application gained is:

1. compared with the conventional copper plating layer, the plating layer of the two-step copper plating layer has better bonding force, more compact plating layer, higher glossiness and uniform thickness of the plating layer in high and low regions;

2. compared with the conventional plated watt nickel, the nickel-tungsten alloy plated by the invention has better corrosion resistance.

3. The conventional chemical nickel plating only has one layer of conventional high-phosphorus chemical nickel, the invention adopts double-layer chemical nickel plating, namely before the high-phosphorus chemical nickel is normally plated, special chemical nickel with low plating speed and low porosity is firstly plated to about 0.5 micron (the low-speed chemical nickel treatment is that the plating speed is slower than that of the conventional chemical nickel, the hydrogen evolution reaction is relatively weaker, pores are not easily formed on the plating layer, the porosity is low), the plating layer of the low-speed compact chemical nickel has low porosity, can effectively prevent salt water and the like in the external environment from permeating into the plating layer to corrode a copper layer and a base material, has better corrosion resistance, and is then transferred to the conventional high-phosphorus chemical nickel plating to the required thickness. Compared with the prior art, the invention has the advantages of obvious advantages, better corrosion resistance and lower magnetic shielding in the aspects of improving the quality and performance of the plating layer.

Detailed Description

The present invention is further illustrated by the following examples, which should not be construed as limiting the scope of the invention.

Example 1:

the utility model provides an ultra-thin cladding material electroplating method for neodymium iron boron surface treatment carries out the cladding material on neodymium iron boron substrate surface, from inside to outside respectively for strikeing the copper plate, pulse copper plate, nickel tungsten alloy layer, low-speed chemical nickel cladding material and high phosphorus chemical nickel cladding material, and process flow is: pretreatment → impact plating → pulse plating → activation → nickel tungsten alloy plating → activation → low speed chemical nickel treatment → high phosphorus chemical nickel treatment.

The specific procedure of example 1 is as follows:

1. pretreatment:

the neodymium iron boron workpiece with the performance mark of N48SH and the black piece magnetic moment range of 1.16 +/-0.085 mu Wb cm is selected for surface treatment, and the process is as follows: the neodymium iron boron substrate is pretreated before plating, namely, an oil removing powder aqueous solution with the concentration of 20g/L (oil removing powder is purchased from Jiangxi Pridelai new material Co., Ltd.) is used for washing and oil removing for 10min at the temperature of 50 ℃, then the neodymium iron boron substrate is subjected to duplex washing, then the neodymium iron boron substrate is subjected to acid washing for 2min by a dilute nitric acid solution with the concentration of 3%, and then ultrasonic washing and duplex washing are sequentially carried out, namely the pretreatment is finished;

2. impact plating

Placing the pretreated neodymium iron boron in an impact copper plating solution for electroplating until the thickness of a plating layer is 0.5 micron, wherein the direct current impact current strength in the electroplating process is 0.4ASD, the electroplating temperature is 20 ℃, and the electroplating time is 50 min; the composition of the impact copper plating solution comprises 4g/L, HEDP 120g/L of copper carbonate, 70g/L of potassium carbonate, 0.03g/L of bismuth nitrate, 0.005g/L of polycation quaternary ammonium salt and 9.5 of pH;

the polycation quaternary ammonium salt adopts polyquaternium-7.

3. Pulse plating

Then, placing neodymium iron boron in a pulse copper plating solution for electroplating until the thickness of a plating layer reaches 1.5 microns, wherein the current intensity in the electroplating process is 0.3ASD, the electroplating temperature is 55 ℃, and the electroplating time is 75 min; the composition of the pulse copper plating solution comprises: 14g/L, HEDP 150g/L of copper carbonate, 70g/L of potassium carbonate, 0.03g/L of bismuth nitrate and 0.005g/L of polycation quaternary ammonium salt, wherein the pH value is 9.5;

the polycation quaternary ammonium salt adopts polyquaternium-7.

After the pulse electroplating is finished, carrying out activation treatment, wherein the activation treatment comprises the following steps: and (3) placing the neodymium iron boron workpiece in a sulfuric acid solution with the mass concentration of 2% for activating for 60 seconds, and then washing the neodymium iron boron workpiece for 2-3 times by using clean water, thus completing the activation treatment.

4. Electroplating of nickel-tungsten alloy

Electroplating the neodymium iron boron treated in the step 3 in a nickel-tungsten mixed plating solution until the thickness of a plating layer reaches 1.9 micrometers (namely the thickness of a nickel-tungsten alloy plating layer is 0.4 micrometers), wherein the current intensity in the electroplating process is 0.5ASD, the electroplating temperature is 65 ℃, and the electroplating time is 15 min; the nickel-tungsten mixed plating solution comprises the following components: 16g/L of nickel sulfate, 30g/L of sodium tungstate, 40g/L of citric acid and 6.5 of pH;

after the nickel-tungsten alloy is electroplated, carrying out activation treatment, wherein the activation treatment comprises the following steps: and (3) placing the neodymium iron boron workpiece in a sulfuric acid solution with the mass concentration of 2% for activating for 60 seconds, and then washing the neodymium iron boron workpiece for 2-3 times by using clean water, thus completing the activation treatment.

5. And (3) low-speed chemical nickel plating treatment, namely forming a compact chemical nickel plating layer with the thickness of 0.5 micrometer at a low-speed plating speed, and then adding conventional high-phosphorus chemical nickel until the total plating layer thickness is 4 micrometers, wherein the specific steps are as follows:

placing the workpiece after being electroplated with the nickel-tungsten alloy and activated into low-speed chemical nickel plating solution, wherein the low-speed chemical nickel plating solution comprises 20g/L of nickel sulfate, 20g/L of sodium hypophosphite, 13g/L of citric acid, 10g/L of malic acid, 20g/L, PPS-OH 0.01g/L of sodium hydroxide and 0.005g/L of allyl iodine, and the pH value is 4.5; the chemical plating treatment is carried out, the reaction can be carried out spontaneously without current, the treatment temperature is 83 ℃, and the treatment time is 30 min.

Then washing the workpiece subjected to the low-speed chemical nickel plating treatment with water, and transferring the workpiece into a high-phosphorus chemical nickel plating solution for chemical plating treatment, wherein the high-phosphorus chemical nickel plating solution comprises 25g/L of nickel sulfate, 30g/L of sodium hypophosphite, 13g/L of citric acid, 10g/L of malic acid, 20g/L, PPS-OH, 0.01g/L of sodium hydroxide and 0.005g/L, pH-4.8 of allyl iodine; and (3) carrying out chemical plating treatment, wherein the chemical plating treatment can be carried out spontaneously without current reaction, the treatment temperature is 88 ℃, the treatment time is 20min, the treatment is finished, and finally the neodymium iron boron product subjected to surface treatment is obtained.

In the embodiment 1, all the plating layers on the surface of the neodymium iron boron are not magnetic, and have no magnetic shielding effect on the workpiece.

Comparative example 1:

an ultrathin plating layer electroplating method applied to neodymium iron boron surface treatment is characterized in that a plating layer is formed on the surface of a neodymium iron boron substrate, and the plating layer comprises an impact copper electroplating layer, an electroplating nickel-tungsten alloy layer, a low-speed chemical nickel plating layer and a high-phosphorus chemical nickel plating layer from inside to outside, and the process flow comprises the following steps: pretreatment → impact copper electroplating → activation → electroplating nickel tungsten → activation → low speed chemical nickel treatment → high phosphorus chemical nickel treatment.

The specific treatment process of the comparative example 1 is repeated in the example 1, except that the pulse plating process of the step 3 is omitted, the activation treatment process of the step 3 is directly performed after the impact plating treatment of the step 2, and the rest of the operation conditions are the same as those of the example 1, so that the surface-treated neodymium-iron-boron product is finally obtained.

Comparative example 2:

an ultrathin plating layer electroplating method applied to neodymium iron boron surface treatment is characterized in that a plating layer is formed on the surface of a neodymium iron boron substrate, and the plating layer comprises an impact copper electroplating layer, a pulse copper electroplating layer, an electroplating nickel-tungsten alloy layer and a high-phosphorus chemical nickel plating layer from inside to outside, and the process flow comprises the following steps: pretreatment → impact copper electroplating → pulse copper electroplating → activation → nickel tungsten alloy electroplating → activation → high phosphorus chemical nickel treatment.

The specific treatment process of the comparative example 2 is repeated with the difference that the process of low-speed chemical nickel plating treatment in the step 5 is omitted, the process of high-phosphorus chemical nickel treatment in the step 5 is directly performed after the nickel-tungsten alloy electroplating and activating treatment in the step 4 is finished, and the surface-treated neodymium iron boron product is finally obtained under the same operation conditions as the example 1.

Comparative example 3:

the utility model provides an ultra-thin cladding material electroplating method for neodymium iron boron surface treatment carries out the cladding material on neodymium iron boron substrate surface, from inside to outside respectively for strikeing the copper plate plating, pulse copper plate plating, electroplate half bright nickel layer, low-speed chemical nickel coating and high phosphorus chemical nickel coating, and the process flow is: pretreatment → impact copper electroplating → pulse copper electroplating → activation → electroplating of semi-bright nickel → activation → low speed chemical nickel → high phosphorus chemical nickel.

The specific treatment process of the comparative example 3 is repeated with the embodiment 1, except that the treatment step of the step 4 is different, namely the step 4 of electroplating the nickel-tungsten alloy is replaced by the step of electroplating semi-bright nickel, and the rest of the operation conditions are the same as those of the embodiment 1, so that the surface-treated neodymium-iron-boron product is finally obtained.

Comparative example 3 step 4 the process of electroplating nickel tungsten alloy was as follows:

placing the neodymium iron boron subjected to pulse copper electroplating and activation treatment in a semi-bright nickel plating solution for electroplating until the thickness of a plating layer reaches 1.9 micrometers (namely the thickness of the semi-bright nickel plating layer is 0.4 micrometers), wherein the semi-bright nickel plating solution comprises 320g/L of nickel sulfate, 45g/L of nickel chloride and 45g/L of boric acid, and the pH value is 4.0-4.2; the pH value of the flash plating nickel electroplating treatment is 4.0-4.2, the temperature is 55 ℃, the current density is 0.5ASD, and the electroplating time is 15 min; after the semi-bright nickel is electroplated, carrying out activation treatment, wherein the activation treatment comprises the following steps: and (3) placing the neodymium iron boron workpiece in a sulfuric acid solution with the mass concentration of 2% for activating for 60 seconds, and then washing the neodymium iron boron workpiece for 2-3 times by using clean water, thus completing the activation treatment.

The products prepared in example 1 and comparative examples 1 to 3 were respectively subjected to performance tests, the test items are the corrosion prevention effect of neutral salt spray for more than 24 hours, the test method is carried out according to GB6458-86, the test temperature is about 35 +/-1 ℃, the solution of the salt spray test is a sodium chloride solution with the concentration of 5%, and the pH value is 6.5-7.2. The other test item is the magnetic decay performance of neodymium iron boron before and after surface treatment, after the surface-treated product is magnetized by a Helmholtz coil, the magnetic moment of the product is measured by an flux meter (the test method is shown in GB/T3217: 2013), the magnetic moment data changes of the workpiece before electroplating and after electroplating are compared, and the test results are respectively shown in tables 1 and 2.

Table 1 neutral salt spray test comparison

Referring to table 1, test results were checked every 12h while the neutral salt spray test was in progress. "T" in table 1 indicates the total number of workpieces tested, and all 32 workpieces were subjected to the neutral salt spray test. "F" in Table 1 indicates the number of failed workpieces with corrosion spots on the workpiece surface, and it can be seen that the corrosion resistance of the workpiece of comparative example 1 is the worst, and 1 workpiece has corrosion failure at 48h of neutral salt spray test.

TABLE 2 magnetic moment test comparison

Referring to table 2, the total number of the electroplated workpieces tested in example 1 and comparative examples 1 to 3 is 10, and the average value of 10 groups of data is the average result of the magnetic moment performance of the neodymium iron boron product.

The test results of tables 1 and 2 are combined to show that: the magnetic moment performance of the neodymium iron boron products after the final surface treatment of the comparative examples 1 and 2 is similar to that of the neodymium iron boron products in the example 1, but the corrosion resistance of the comparative examples 1 and 2 is obviously reduced. Compared with the embodiment 1, the comparison example 3 replaces the nickel-tungsten alloy layer with the semigloss nickel layer, and finally the magnetic moment performance of the product after the surface treatment of the nickel-tungsten alloy layer and the semigloss nickel layer is greatly different, because the pure electroplated nickel layer is a magnetic conduction coating and can have a certain magnetic shielding effect on the workpiece, and the nickel-tungsten alloy is non-magnetic and does not have magnetic shielding. Comparative example 3 the corrosion resistance of the surface-treated product was slightly decreased.

The statements in this specification merely set forth a list of implementations of the inventive concept and the scope of the present invention should not be construed as limited to the particular forms set forth in the examples.