CN218710934U - Coating structure for plating zinc alloy die casting trivalent chromium with pearl chromium - Google Patents
Coating structure for plating zinc alloy die casting trivalent chromium with pearl chromium Download PDFInfo
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- CN218710934U CN218710934U CN202221383358.3U CN202221383358U CN218710934U CN 218710934 U CN218710934 U CN 218710934U CN 202221383358 U CN202221383358 U CN 202221383358U CN 218710934 U CN218710934 U CN 218710934U
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Abstract
The utility model discloses a zinc alloy die casting trivalent chromium plating pearl chromium's cladding material structure, including the zinc alloy base member and with the citrate that prepares in proper order from inside to outside on the zinc alloy base member nickel coating in advance, pyrophosphate copper coating, bright nickel coating, pearl nickel cladding material, pearl chromium cladding material, tombarthite electrolysis protection film. The utility model discloses a zinc alloy die casting trivalent chromium plates cladding material structure of pearl chromium, preparation technology environmental protection carries out neutral salt fog test 120 hours according to GB/T10125-2012 "artificial atmosphere corrosion test salt fog test", plates a surperficial no corrosive substance and generates, and the cladding material structure of preparing has good corrosion resistance.
Description
Technical Field
The utility model belongs to the metal plating field, concretely relates to zinc alloy die casting trivalent chromium plates coating structure of pearl chromium.
Background
The trivalent chromium pearl chromium plating has soft and beautiful appearance, and the application in the hardware electroplating is to be developed. The trivalent chromium plating layer has low corrosion resistance and easily darkens in color in natural environment, and how to improve the corrosion resistance is a hot spot of current research in the industry.
The traditional technology for electroplating zinc alloy die castings uses cyanide copper plating as a pre-plating layer, and then pyrophosphate copper plating, bright copper plating and the like are carried out. The use of cyanide copper plating processes is becoming more and more severely limited as cyanide is a highly toxic compound.
Under the background that cyanide is prohibited, how to adopt environment-friendly electroplating technology to replace cyanide copper plating is an urgent problem to be solved in the industry.
Disclosure of Invention
In order to solve the high pollution problem that zinc alloy die casting adopted cyanide copper facing to reach the range of application of further expanding trivalent chromium plating, the utility model provides a zinc alloy die casting trivalent chromium plating pearl chromium's cladding material structure. In order to achieve the purpose, the utility model adopts the following technical scheme:
a plating layer structure for plating pearl chromium on trivalent chromium of a zinc alloy die casting comprises a zinc alloy matrix, and a citrate pre-nickel plating layer, a pyrophosphate copper plating layer, a bright nickel plating layer, a pearl chromium plating layer and a rare earth electrolytic protection film which are sequentially prepared from inside to outside on the zinc alloy matrix.
In some of these embodiments, the citrate pre-nickel plating layer has a thickness of 2 to 7 μm.
In some of these embodiments, the pyrophosphate copper plating layer has a thickness of 7 to 12 μm.
In some of these embodiments, the bright copper plating layer has a thickness of 8 to 15 μm.
In some of these embodiments, the bright nickel plating layer has a thickness of 3 to 10 μm.
In some embodiments, the thickness of the pearl nickel coating is 1-5 μm.
In some embodiments, the pearl chromium coating has a thickness of 0.05-0.35 μm.
The citrate nickel plating solution has high dispersing capacity and deep plating capacity, the pre-plated nickel layer prepared on the zinc alloy die casting by the process has high hole sealing capacity, and then pyrophosphate copper plating is carried out to finally seal the pores on the surface of the zinc alloy die casting. The protective film is prepared on the chromium-plated layer of trivalent chromium by adopting a rare earth electrolytic protection process, so that the corrosion resistance and the discoloration resistance of the plating layer can be effectively improved.
Compared with the prior art, the utility model discloses following beneficial effect has:
1. the utility model discloses a plating layer structure for plating pearl chromium on trivalent chromium of a zinc alloy die casting, which adopts citrate nickel plating to replace cyanide copper plating, thus eliminating pollution and potential safety hazard caused by using virulent cyanide in the prior art;
2. rare earth electrolytic protection is implemented on the pearl chromium plating layer, so that the corrosion resistance and the tarnish resistance of the plating layer can be effectively improved.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, do not constitute a limitation of the invention, and in which:
FIG. 1 is a schematic diagram of the structure of the plating layer in examples 1 and 2 of the present invention.
Detailed Description
The invention will be described in detail with reference to the drawings and specific embodiments, which are used to explain the invention, but not as a limitation thereof.
A plating layer structure for plating pearl chromium on trivalent chromium of a zinc alloy die casting comprises a zinc alloy matrix, and a citrate pre-nickel plating layer, a pyrophosphate copper plating layer, a bright nickel plating layer, a pearl chromium plating layer and a rare earth electrolytic protective film which are sequentially prepared from inside to outside on the zinc alloy matrix.
The zinc alloy die casting is subjected to wax removal, oil removal, polishing and activation by adopting the conventional pretreatment process.
Preferably, a ZDP-92 zinc alloy die casting chemical polishing agent of ultra-Pont chemical Co is adopted in the polishing process, and the polishing process comprises the following steps: ZDP-92 polishing agent 400-650 mL/L, wetting agent 2-3 mL/L, temperature 60-75 deg.C, time 10-60 s.
After the pretreatment of the workpiece, a pre-plated nickel layer is prepared by adopting a citrate nickel plating process, and the thickness of the plating layer is 2-7 mu m.
Preferably, the citrate nickel plating process comprises the following steps: 180-250 g/L of nickel sulfate hexahydrate, 10-12 g/L of sodium chloride, 30-35 g/L of boric acid, 30-40 g/L of magnesium sulfate, 7.0-7.2 of pH range, 50-60 ℃, 1-1.5A/dm < 2 > of cathode current density and 4-6 m/min of cathode movement.
And (3) carrying out pyrophosphate copper plating after pre-plating nickel on the workpiece, wherein the thickness of the pyrophosphate copper plating layer is 7-12 mu m.
Preferably, the pyrophosphate copper plating adopts a PC-1289 pyrophosphate copper process of ultra-nation chemical industry: 60-90 g/L of copper pyrophosphate, 230-280 g/L of potassium pyrophosphate, 2-5 mL/L of ammonia water, 1-3 mL/L of PC-1289 pyrocopper additive, 8.6-9 of pH value, 50-58 ℃ of plating bath temperature, 1-6A/dm < 2 > of cathode current density and air stirring.
After the pyrophosphate copper plating of the workpiece, bright copper is plated, the thickness of the bright copper plating layer is 8-15 μm, and the bright copper plating layer is prepared by adopting the existing acid copper plating process.
The bright nickel plating is carried out on the workpiece after bright copper plating, the thickness of the bright nickel plating layer is 3-10 mu m, and the bright nickel plating is prepared by adopting the existing bright nickel plating process.
The workpiece is plated with pearl nickel after being plated with bright nickel, the thickness of a pearl nickel plating layer is 2-5 mu m, and the pearl nickel plating layer is prepared by adopting the existing pearl nickel plating process.
The pearl nickel plated and pearl chromium plated workpiece is prepared by adopting the existing trivalent chromium plating process, and the thickness of the trivalent chromium plating chromium layer is 0.05-0.35 mu m.
Preferably, the trivalent chromium plating process adopts a superchon chemical Trich-6561 chloride trivalent chromium plating process: 400-450 g/L of Trich-6561 jar-opening salt, 65-85 mL/L of Trich-6563 complexing agent, 1-2 mL/L of Trich-6564 stabilizer, 1-3 mL/L of Trich-6565 wetting agent, wherein the mass concentration of trivalent chromium is 23-25 g/L, the mass concentration of boric acid is 55-60 g/L, the pH range is 2.5-3.0, the operating temperature is 25-36 ℃, the cathode current density is 8-16A/dm < 2 >, and the electroplating time is 1-4 min by stirring in medium air.
Preferably, the trivalent chromium plating process adopts a superconchemical Trich-9551 sulfate trivalent chromium plating process: 8-12 mL/L of Trich-9551M jar-opening salt, 260-300 mL/L of Trich-9551B replenisher and 260-300 g/L of Trich-9551 CS conductive salt, wherein the mass concentration of trivalent chromium is 12-18 g/L, the mass concentration of boric acid is 65-75 g/L, the pH range is 3.4-3.8, the operating temperature is 50-55 ℃, the cathode current density is 8-15A/dm < 2 >, and the electroplating time is 1-6 min under the condition of slight air stirring or cathode movement.
And performing rare earth electrolytic protection after pearl chromium is plated on the trivalent chromium of the workpiece to prepare the rare earth electrolytic protection film.
Preferably, the rare earth electrolytic protection film is prepared by adopting a rare earth electrolytic protection process developed by the ultra-high chemical industry: 1-10 g/L lanthanum acetate, 5-50 g/L HEDP complexing agent, 80-150 g/L anhydrous sodium carbonate, 11.5-12.5 pH (pH is adjusted by sodium hydroxide solution), 0.5-1.5A/dm < 2 > cathode current density, operating at room temperature, using trivalent chromium plated pearl chromium workpiece as cathode, stainless steel plate as anode, and electrolyzing for 10-30 s.
Example 1:
as shown in figure 1, the coating structure for plating the pearl chromium on the trivalent chromium of the zinc alloy die casting comprises a zinc alloy substrate 1, and a citrate pre-nickel plating layer 2, a pyrophosphate copper plating layer 3, a bright copper plating layer 4, a bright nickel plating layer 5, a pearl nickel plating layer 6, a pearl chromium plating layer 7 and a rare earth electrolytic protection film 8 which are sequentially prepared on the zinc alloy substrate 1 from inside to outside.
The zinc alloy die casting is subjected to wax removal, oil removal, polishing and activation by adopting the conventional pretreatment process.
In the polishing process, a ZDP-92 zinc alloy die casting chemical polishing agent of ultra-Pont chemical Co., ltd is adopted, and the polishing process comprises the following steps: ZDP-92 polishing agent 480mL/L, wetting agent 2mL/L, temperature 68 ℃, time 30s.
After the pretreatment of the workpiece, a pre-plated nickel layer is prepared by adopting a citrate nickel plating process, and the thickness of the plating layer is 4 mu m.
The citrate nickel plating process comprises the following steps: 200g/L of nickel sulfate hexahydrate, 10g/L of sodium chloride, 30g/L of boric acid, 30g/L of magnesium sulfate, pH =7.0, temperature 55 ℃, cathode current density 1.2A/dm < 2 >, and cathode movement 5m/min.
After the workpiece is pre-plated with nickel, pyrophosphate copper plating is carried out, and the thickness of the plating layer is 11 microns.
The pyrophosphate copper plating adopts a PC-1289 pyrophosphate copper process of ultra-nation chemical industry: 70g/L of copper pyrophosphate, 240g/L of potassium pyrophosphate, 3mL/L of ammonia water, 2mL/L of PC-1289 copper pyroxide additive, pH =8.8, plating bath temperature of 54 ℃, cathode current density of 4A/dm < 2 >, and air stirring.
After the pyrophosphate copper plating of the workpiece, bright copper is plated, the thickness of the bright copper plating layer is 10 mu m, and the bright copper plating layer is prepared by adopting the existing acid copper plating process.
The bright nickel plating layer is 8 μm thick and is prepared by the existing bright nickel plating process.
The workpiece is plated with pearl nickel after being plated with bright nickel, the thickness of a pearl nickel plating layer is 2 mu m, and the workpiece is prepared by adopting the existing pearl nickel plating process.
The pearl nickel plated and the pearl chromium plated on the workpiece are prepared by adopting the existing trivalent chromium plating process, and the thickness of the trivalent chromium plating chromium layer is 0.2 mu m.
The trivalent chromium plating process adopts a chromium plating process of Trich-6561 chloride of super-bonding chemical industry: 420g/L of cylinder-opening salt of the Trich-6561, 70mL/L of complexing agent of the Trich-6563, 1.5mL/L of stabilizer of the Trich-6564, 2mL/L of wetting agent of the Trich-6565, pH =2.8, the operating temperature is 30 ℃, the cathode current density is 12A/dm < 2 >, and the electroplating time is 1.5min by stirring in medium air.
And performing rare earth electrolytic protection after pearl chromium is plated on the trivalent chromium of the workpiece to prepare the rare earth electrolytic protection film.
The rare earth electrolytic protection film is prepared by adopting a rare earth electrolytic protection process developed by the ultra-high chemical industry: 5g/L lanthanum acetate, 30g/L HEDP complexing agent, 100g/L anhydrous sodium carbonate, pH =12 (pH is adjusted by sodium hydroxide solution), cathode current density is 1A/dm2, operation is carried out at room temperature, a pearl chromium plated workpiece is used as a cathode, a stainless steel plate is used as an anode, and electrolysis is carried out for 20s.
The operation of the embodiment is divided into the following steps:
1. pretreatment: the zinc alloy workpiece 1 is subjected to the steps of "chemical wax removal → water washing → ultrasonic wax removal → water washing → chemical degreasing → water washing → polishing → water washing → acid salt activation → water washing".
2. Pre-plating nickel: a citrate pre-plated nickel layer 2 is prepared on the pre-treated zinc alloy workpiece 1.
3. Pyrophosphate copper plating: a pyrophosphate copper plating layer 3 was prepared on the citrate pre-nickel plating layer 2.
4. Bright copper plating: a bright copper plating layer 4 is prepared on the pyrophosphate copper plating layer 3.
5. Plating bright nickel: a bright nickel plating layer 5 is prepared on the bright copper plating layer 4.
6. Plating pearl nickel: preparing a pearl nickel plating layer 6 on the bright nickel plating layer 5.
7. Plating pearl chromium: preparing trivalent chromium pearl chromium coating 7 on pearl nickel coating 6
8. Electrolytic protection: preparing a rare earth electrolytic protective film 8 on the trivalent chromium pearl chromium plating layer 7, washing and drying.
Example 2:
as shown in figure 1, the coating structure for plating the pearl chromium on the trivalent chromium of the zinc alloy die casting comprises a zinc alloy substrate 1, and a citrate pre-nickel plating layer 2, a pyrophosphate copper plating layer 3, a bright copper plating layer 4, a bright nickel plating layer 5, a pearl nickel plating layer 6, a pearl chromium plating layer 7 and a rare earth electrolytic protection film 8 which are sequentially prepared on the zinc alloy substrate 1 from inside to outside.
The zinc alloy die casting is subjected to wax removal, oil removal, polishing and activation by adopting the conventional pretreatment process.
In the polishing procedure, a chemical polishing agent of ZDP-92 zinc alloy die casting is adopted, and the polishing process comprises the following steps: ZDP-92 polishing agent 520mL/L, wetting agent 2mL/L, temperature 68 ℃, time 30s.
After the pretreatment of the workpiece, a pre-plated nickel layer is prepared by adopting a citrate nickel plating process, and the thickness of the plating layer is 6 mu m.
The citrate nickel plating process comprises the following steps: 220g/L of nickel sulfate hexahydrate, 12g/L of sodium chloride, 35g/L of boric acid, 38g/L of magnesium sulfate, pH =7.2, temperature 55 ℃, cathode current density 1.2A/dm < 2 >, and cathode movement 5m/min.
After the workpiece is pre-plated with nickel, pyrophosphate copper plating is carried out, and the thickness of a plating layer is 8 mu m.
The pyrophosphate copper plating adopts a PC-1289 copper pyrophosphate process: 80g/L of copper pyrophosphate, 260g/L of potassium pyrophosphate, 3mL/L of ammonia water, 2mL/L of PC-1289 copper pyrophosphate additive, pH =8.8, plating bath temperature of 54 ℃, cathode current density of 4A/dm < 2 >, and stirring with air.
After the pyrophosphate copper plating of the workpiece, bright copper is plated, the thickness of the bright copper plating layer is 14 mu m, and the bright copper plating layer is prepared by adopting the existing acid copper plating process.
The bright nickel plating layer is 6 μm thick and is prepared by the existing bright nickel plating process.
The workpiece is plated with pearl nickel after being plated with bright nickel, the thickness of a pearl nickel plating layer is 3 mu m, and the workpiece is prepared by adopting the existing pearl nickel plating process.
The pearl nickel plated and pearl chromium plated workpiece is prepared by adopting the existing trivalent chromium plating process, and the thickness of the trivalent chromium plating chromium layer is 0.1 mu m.
The trivalent chromium plating process adopts a chromium plating process of Trich-9551 sulfate trivalent chromium of super-nation chemical industry: 10mL/L of cylinder opening salt of the Trich-9551M, 280mL/L of Trich-9551B supplement and 280g/L of conductive salt of the Trich-9551 CS, wherein the mass concentration of trivalent chromium is 15g/L, the mass concentration of boric acid is 70g/L, the pH is =3.6, the operation temperature is 52 ℃, the cathode current density is 10A/dm2, and the electroplating time is 2min under the condition of slight air stirring or cathode movement.
And after the pearl chromium is plated on the trivalent chromium of the workpiece, rare earth electrolytic protection is carried out to prepare the rare earth electrolytic protection film.
The rare earth electrolytic protective film is prepared by adopting a rare earth electrolytic protective process developed by ultra-high chemical engineering: lanthanum acetate 6g/L, HEDP complexing agent 35g/L, anhydrous sodium carbonate 110g/L, pH =12 (pH adjusted by sodium hydroxide solution), cathode current density 1A/dm2, room temperature operation, using chromium plating workpiece as cathode, stainless steel plate as anode, electrolysis for 20s.
The operation of the embodiment is divided into the following steps:
1. pretreatment: the zinc alloy workpiece 1 is subjected to the steps of "chemical wax removal → water washing → ultrasonic wax removal → water washing → chemical degreasing → water washing → polishing → water washing → acid salt activation → water washing".
2. Pre-nickel plating: a citrate pre-plated nickel layer 2 is prepared on the pre-treated zinc alloy workpiece 1.
3. Pyrophosphate copper plating: a pyrophosphate copper plating layer 3 was prepared on the citrate pre-nickel plating layer 2.
4. Bright copper plating: a bright copper plating layer 4 is prepared on the pyrophosphate copper plating layer 3.
5. Plating bright nickel: a bright nickel plating layer 5 is prepared on the bright copper plating layer 4.
6. Plating pearl nickel: preparing a pearl nickel plating layer 6 on the bright nickel plating layer 5.
7. Plating pearl chromium: preparing trivalent chromium pearl chromium coating 7 on pearl nickel coating 6
8. Electrolytic protection: preparing a rare earth electrolytic protective layer 8 on the trivalent chromium pearl chromium plating layer 7, washing with water, and drying.
Test example 1:
the plated articles prepared in examples 1 and 2 were subjected to thermal shock test to determine the plating adhesion in accordance with JB 2111-1977 "method for testing adhesion of Metal coating". And (3) heating the plated part in a heating furnace to 190 ℃, taking out the plated part after 30min, placing the plated part in water at room temperature, and cooling the plated part suddenly, wherein the plated layer does not generate bubbles or fall off, and the plated layer has good bonding force.
Test example 2:
the electroplated parts prepared in the embodiment 1 and the embodiment 2 are subjected to a neutral salt spray test for 120h according to GB/T10125-2012 salt spray test for artificial atmosphere corrosion test, and no corrosive substances are generated on the surfaces of the electroplated parts.
The above is to the technical scheme that the embodiment of the utility model provides introduces in detail, and it is right to have used specific individual example herein the utility model discloses the principle and the implementation of embodiment have been explained, and the description of above embodiment only is applicable to help understanding the utility model discloses the principle of embodiment. Variations in the detailed description and the scope of the application will be apparent to those skilled in the art from the following description. In summary, the content of the present specification should not be construed as a limitation of the present invention.
Claims (7)
1. The utility model provides a zinc alloy die casting trivalent chromium plating pearl chromium's cladding material structure which characterized in that: the zinc alloy coating comprises a zinc alloy matrix, and a citrate pre-nickel plating layer, a pyrophosphate copper plating layer, a bright nickel plating layer, a pearl chromium plating layer and a rare earth electrolytic protection film which are sequentially prepared on the zinc alloy matrix from inside to outside.
2. The coating structure for plating pearl chromium with trivalent chromium for zinc alloy die castings according to claim 1, characterized in that: the thickness of the citrate pre-plated nickel layer is 2-7 mu m.
3. The plating structure of zinc alloy die casting trivalent chromium pearl chromium plating of claim 1, characterized in that: the pyrophosphate copper plating layer has a thickness of 7 to 12 μm.
4. The plating structure for plating the zinc alloy die casting with the trivalent chromium and the pearl chromium according to claim 1, wherein: the thickness of the bright copper plating layer is 8-15 mu m.
5. The plating structure of zinc alloy die casting trivalent chromium pearl chromium plating of claim 1, characterized in that: the thickness of the bright nickel plating layer is 3-10 mu m.
6. The plating structure of zinc alloy die casting trivalent chromium pearl chromium plating of claim 1, characterized in that: the thickness of the pearl nickel plating layer is 1-5 mu m.
7. The plating structure of zinc alloy die casting trivalent chromium pearl chromium plating of claim 1, characterized in that: the thickness of the pearl chromium plating layer is 0.05-0.35 mu m.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202221383358.3U CN218710934U (en) | 2022-06-06 | 2022-06-06 | Coating structure for plating zinc alloy die casting trivalent chromium with pearl chromium |
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| CN202221383358.3U CN218710934U (en) | 2022-06-06 | 2022-06-06 | Coating structure for plating zinc alloy die casting trivalent chromium with pearl chromium |
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