Metal component surface coating method

Abstract

The invention discloses a surface coating method for a metal component, belongs to the surface treatment technology of the metal component, and aims to solve the problem that a protective film formed on the surface of the metal component through electroplating in the prior art is low in hardness, not wear-resistant and easy to fall off. The electroplated layer is used as a base layer (bottom layer) of the metal surface protection layer, the sputter coating is used as a surface layer of the metal surface protection layer, the binding force of the base layer and the surface layer on the metal surface is increased, the hardness of the sputter coating is higher than that of the electroplated layer, and the wear resistance is good; and the whole metal surface protection layer is not easy to fall off from the surface of the metal component.

Description

Technical Field

[0001] The invention belongs to the surface treatment technology of metal components, and in particular relates to a metal component surface coating method. Background Art

[0002] In order to prevent the surface of metal components from being corroded, metal components are usually treated on the surface. A common metal surface treatment method is coating, that is, electroplating a protective film on the surface of the metal component. However, the protective film formed by electroplating has a low coating hardness, is not wear-resistant, and is easy to fall off. Summary of the invention

[0003] The technical problem to be solved and the technical task proposed by the present invention is to overcome the defects of the protective film formed on the surface of metal components by electroplating in the prior art, such as low hardness, poor wear resistance and easy falling off, and to provide a method for coating the surface of metal components.

[0004] To achieve the above-mentioned purpose, the surface coating method of a metal component of the present invention is: firstly electroplating the workpiece, and then performing plasma magnetron sputtering coating to form a coating on the basis of electroplating.

[0005] The present invention forms an electroplating layer on the surface of a metal workpiece by electroplating first, and then performs plasma magnetron sputtering coating on the basis of the electroplating layer to form a coating, so that the electroplating layer serves as the base layer (bottom layer) of the metal surface protective layer, and the sputtering coating serves as the surface layer of the metal surface protective layer, thereby increasing the bonding force between the base layer and the surface layer on the metal surface. In addition, since the hardness of the sputtering coating is higher than that of the electroplating layer, it has good wear resistance, so that the entire metal surface protective layer is not easy to fall off from the surface of the metal component.

[0006] Preferably, the target material is one of a titanium target, an aluminum target, a tungsten carbon target and a zirconium target, and the target material presents a thin film structure composed of oxides and nitrides arranged in an amorphous state;

[0007] Input gas: The pressure of the sputtering coating chamber is less than 4×10 -4 After the pressure reaches 2 Pa, the protective gas argon and the reactive gas carbon monoxide or / and nitrogen are simultaneously input into the coating chamber at a pressure range of 2 to 5 Pa; wherein:

[0008] Furnace temperature: 180℃;

[0009] Input gas deposition time: 2h;

[0010] Arc current: 10-300A;

[0011] The thickness of the deposited film is 1 to 3 μm.

[0012] Preferably, the method comprises sequentially performing the following steps on the workpiece: (1) degreasing, (2) cleaning, (3) rust removal, (4) cleaning, (5) activation, (6) water washing, (7) electroplating, (8) cleaning, (9) drying, (10) plasma magnetron sputtering, (11) cooling, and (12) packaging.

[0013] Preferably, the degreasing in step (1) is performed by simultaneously performing electrolytic degreasing and ultrasonic degreasing, that is, an ultrasonic generator is provided in the electrolyte, and the workpiece is placed in the electrolyte for electrolytic degreasing and simultaneously the ultrasonic generator is activated for ultrasonic degreasing. This degreasing method performs both electrolytic degreasing and ultrasonic degreasing at the same time, and the hydrogen and oxygen generated during the degreasing process can tear apart bubbles, better remove oil stains, and can completely degrease.

[0014] Preferably, the electrolyte formula is a mixed aqueous solution of 100±3 g / L sodium hydroxide, 45±1 g / L carbonate, 18±0.3 g / L phosphate and 5±0.02 ml / L active agent; the degreasing duration of step (1) is 15S-50S.

[0015] Preferably, the cleaning in step (2) and step (4) is to clean the workpiece twice with salt water at 70° C., with each cleaning lasting 10S-30S.

[0016] Preferably, the rust removal in step (3) is performed by immersing the workpiece in a 25% hydrochloric acid aqueous solution for 10S-30S.

[0017] Preferably, the activation in step (5) is performed by immersing the workpiece in a 15% sulfuric acid aqueous solution for 15S-50S.

[0018] Preferably, the water washing in step (6) is to rinse the workpiece twice with water.

[0019] Preferably, the electroplating conditions of step (7) are:

[0020] The plating solution formula is a mixed aqueous solution of 280±3g / L nickel sulfate, 65±1g / L nickel chloride, 35±0.5g / L boric acid and 250±3ml / L additives;

[0021] The temperature of the plating solution is 55-65°C;

[0022] Current density is 1.5-3A / dm 2 .

[0023] The present invention forms an electroplating layer on the surface of a metal workpiece by electroplating first, and then performs plasma magnetron sputtering coating on the basis of the electroplating layer to form a coating, so that the electroplating layer serves as the base layer (bottom layer) of the metal surface protective layer, and the sputtering coating serves as the surface layer of the metal surface protective layer, thereby increasing the bonding force between the base layer and the surface layer on the metal surface. In addition, since the hardness of the sputtering coating is higher than that of the electroplating layer, it has good wear resistance, so that the entire metal surface protective layer is not easy to fall off from the surface of the metal component. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the plasma magnetron sputtering coating device of the present invention;

[0025] Explanation of the numbers in the figure: 10 coating chamber, 20 cathode, 30 anode, 40 target, 50 substrate. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The present invention is described in detail below in conjunction with specific embodiments and accompanying drawings.

[0028] like Figure 1 The plasma magnetron sputtering coating device shown comprises a furnace, a coating chamber 10 is arranged in the furnace, a cathode 20 and an anode 30 are arranged opposite to each other in the coating chamber 10, a target 40 is arranged in the cathode 20, and a substrate 50 (workpiece) is arranged in the anode 30; a magnetic field is also arranged in the coating chamber. The coating chamber is connected to an exhaust pump, and the exhaust pump is used to exhaust air to keep the coating chamber at a required low pressure.

[0029] Figure 1 When the plasma magnetron sputtering coating device shown is working, the cathode target is made of coating material, the substrate serves as the anode, argon gas or other inert gas is introduced into the coating chamber, and glow discharge is generated under the action of the negative DC high voltage or radio frequency voltage of the cathode target. The ionized argon ions bombard the surface of the cathode target, causing the cathode target atoms to sputter and deposit on the substrate to form a thin film.

[0030] The metal component surface coating method of the present invention comprises sequentially performing the following steps on the workpiece: (1) degreasing, (2) cleaning, (3) rust removal, (4) cleaning, (5) activation, (6) water washing, (7) electroplating, (8) cleaning, (9) drying, (10) plasma magnetron sputtering, (11) cooling, and (12) packaging. That is, the workpiece is first electroplated, and then plasma magnetron sputtering is performed on the basis of electroplating to deposit a coating on the surface of the workpiece.

[0031] In the above method, the implementation conditions of plasma magnetron sputtering coating are:

[0032] Target material: one of titanium target, aluminum target, tungsten carbon target and zirconium target, the target material presents a thin film structure composed of oxides and nitrides arranged in an amorphous state;

[0033] Input gas: The pressure of the sputtering coating chamber is less than 4×10 -4 After the gas flow rate reaches 1.5 Pa, the gas flow rate is controlled by a mass flow meter, and the protective gas argon and the reactive gas carbon monoxide or / and nitrogen are simultaneously input into the coating chamber at a pressure range of 2 to 5 Pa; wherein:

[0034] Furnace temperature: 180℃;

[0035] Input gas deposition time: 2h;

[0036] Arc current: 10-300A;

[0037] The thickness of the deposited film is 1 to 3 μm.

[0038] In the above method, the degreasing in step (1) is performed by simultaneously performing electrolytic degreasing and ultrasonic degreasing, that is, an ultrasonic generator is provided in the electrolyte, and the workpiece is placed in the electrolyte for electrolytic degreasing and simultaneously the ultrasonic generator is activated for ultrasonic degreasing. This degreasing method performs both electrolytic degreasing and ultrasonic degreasing at the same time, and the hydrogen and oxygen generated during the degreasing process can tear apart bubbles, better remove oil stains, and can completely degrease.

[0039] In the above method, the electrolyte formula is a mixed aqueous solution of 100±3g / L sodium hydroxide, 45±1g / L carbonate, 18±0.3g / L phosphate and 5±0.02ml / L active agent, that is, 100±3g sodium hydroxide, 45±1g carbonate, 18±0.3g phosphate and 5±0.02ml active agent are dissolved in 1L of water; the degreasing duration of step (1) is 15S-50S.

[0040] In the above method, the cleaning in step (2) and step (4) is to clean the workpiece twice with salt water at 70°C, with each cleaning lasting 10S-30S.

[0041] In the above method, the rust removal in step (3) is to immerse the workpiece in a 25% hydrochloric acid aqueous solution for 10S-30S.

[0042] In the above method, the activation in step (5) is to immerse the workpiece in a 15% sulfuric acid aqueous solution for 15S-50S.

[0043] In the above method, the water washing in step (6) is to rinse the workpiece twice with water.

[0044] In the above method, the electroplating conditions of step (7) are:

[0045] The plating solution formula is a mixed aqueous solution of 280±3g / L nickel sulfate, 65±1g / L nickel chloride, 35±0.5g / L boric acid and 250±3ml / L additives, that is, 280±3g nickel sulfate, 65±1g nickel chloride, 35±0.5g boric acid and 250±3ml additives are dissolved in 1L water;

[0046] The temperature of the plating solution is 55-65°C;

[0047] Current density is 1.5-3A / dm 2 .

[0048] Example 1

[0049] The following steps are followed to apply a coating to the surface of the worm wheel of the adjustable wrench: (1) degreasing, (2) cleaning for 20 seconds, (3) rust removal for 20 seconds, (4) cleaning for 20 seconds, (5) activation for 30 seconds, (6) water washing, (7) electroplating, (8) cleaning, (9) drying, (10) plasma magnetron sputtering, (11) cooling, and (12) packaging. That is, the surface of the worm wheel of the adjustable wrench is firstly electroplated, and then plasma magnetron sputtering coating is applied on the basis of electroplating to form a coating.

[0050] The electrolyte formula in step (1) is a mixed aqueous solution of 100 g / L sodium hydroxide, 45 g / L carbonate, 18 g / L phosphate and 5 ml / L active agent; the degreasing duration of step (1) is 30 seconds.

[0051] The electroplating conditions in step (7) are:

[0052] The plating solution formula is a mixed aqueous solution of 280g / L nickel sulfate, 65g / L nickel chloride, 35g / L boric acid and 250ml / L additives;

[0053] The temperature of the plating solution is 60°C;

[0054] The current density is 2.2A / dm 2 .

[0055] The reaction gas is carbon monoxide.

[0056] Example 2

[0057] The following steps are followed to apply surface coating to the worm wheel of the adjustable wrench: (1) degreasing, (2) cleaning for 10 seconds, (3) rust removal for 10 seconds, (4) cleaning for 10 seconds, (5) activation for 15 seconds, (6) water washing, (7) electroplating, (8) cleaning, (9) drying, (10) plasma magnetron sputtering, (11) cooling, and (12) packaging. That is, electroplating is first applied to the surface of the worm wheel of the adjustable wrench, and then plasma magnetron sputtering coating is applied on the basis of electroplating to form a coating.

[0058] The electrolyte formula in step (1) is a mixed aqueous solution of 97 g / L sodium hydroxide, 44.5 g / L carbonate, 17.8 g / L phosphate and 5 ml / L active agent; the degreasing duration of step (1) is 15 seconds.

[0059] The electroplating conditions in step (7) are:

[0060] The plating solution formula is a mixed aqueous solution of 278g / L nickel sulfate, 64.5g / L nickel chloride, 34.5g / L boric acid and 248ml / L additives;

[0061] The temperature of the plating solution is 55°C;

[0062] The current density is 1.5A / dm 2 .

[0063] The reaction gases are carbon monoxide and nitrogen.

[0064] Example 3

[0065] The following steps are followed to apply surface coating to the worm wheel of the adjustable wrench: (1) degreasing, (2) cleaning for 30 seconds, (3) rust removal for 30 seconds, (4) cleaning for 30 seconds, (5) activation for 50 seconds, (6) water washing, (7) electroplating, (8) cleaning, (9) drying, (10) plasma magnetron sputtering, (11) cooling, and (12) packaging. That is, electroplating is first applied to the surface of the worm wheel of the adjustable wrench, and then plasma magnetron sputtering coating is applied on the basis of electroplating to form a coating.

[0066] The electrolyte formula in step (1) is a mixed aqueous solution of 103 g / L sodium hydroxide, 46 g / L carbonate, 18.3 g / L phosphate and 5.0 ml / L active agent; the degreasing duration of step (1) is 50 seconds.

[0067] The electroplating conditions in step (7) are:

[0068] The plating solution formula is a mixed aqueous solution of 283 g / L nickel sulfate, 66.0 g / L nickel chloride, 35.5 g / L boric acid and 252 ml / L additives;

[0069] The temperature of the plating solution is 65°C;

[0070] The current density is 3A / dm 2 .

[0071] Wherein, the reaction gas is nitrogen.

[0072] The coatings obtained from the above-mentioned embodiments and comparative examples were subjected to salt spray tests and hardness tests, and the test results are listed in Table 1. From the hardness and salt spray test rating data of the coatings of the products listed in Table 1, it can be seen that the present invention has better hardness, wear resistance and peeling resistance by first electroplating the workpiece and then performing plasma magnetron sputtering deposition on the basis of electroplating. Among them, the comparative sample is a sample that has only been electroplated (existing sample), the coating hardness test standard is HRC, and the salt spray test test standard is the rust level of salt spray at 5% concentration for 48 hours.

[0073] Table 1:

[0074] Test Data Coating hardness Salt spray test Example 1 44 Level 7 Example 2 46 Level 7 Example 3 45 Level 7 Comparison sample 40 Level 6

Claims

1. A method for coating the surface of a metal component, characterized in that: The workpiece is electroplated first, and then plasma magnetron sputtering coating is performed on the basis of electroplating to form a coating.

2. The method for coating the surface of a metal component according to claim 1, characterized in that: The implementation conditions of plasma magnetron sputtering coating are: Target material: one of titanium target, aluminum target, tungsten carbon target and zirconium target, the target material presents a thin film structure composed of oxides and nitrides arranged in an amorphous state; Input gas: The pressure of the sputtering coating chamber is less than 4×10 -4 After the pressure reaches 2 Pa, the protective gas argon and the reactive gas carbon monoxide or / and nitrogen are simultaneously input into the coating chamber at a pressure range of 2 to 5 Pa; wherein: Furnace temperature: 180℃; Input gas deposition time: 2h; Arc current: 10-300A; The thickness of the deposited film is 1 to 3 μm.

3. The metal component surface coating method according to claim 1 or 2, characterized in that The method comprises sequentially performing the following steps on the workpiece: (1) degreasing, (2) cleaning, (3) rust removal, (4) cleaning, (5) activation, (6) water washing, (7) electroplating, (8) cleaning, (9) drying, (10) plasma magnetron sputtering, (11) cooling, and (12) packaging.

4. The method for coating the surface of a metal component according to claim 3, characterized in that: The degreasing in step (1) is performed by simultaneously performing electrolytic degreasing and ultrasonic degreasing, that is, an ultrasonic generator is arranged in the electrolyte, and the workpiece is placed in the electrolyte to perform electrolytic degreasing and simultaneously the ultrasonic generator is started to perform ultrasonic degreasing.

5. The method for coating the surface of a metal component according to claim 4, characterized in that: The electrolyte formula is a mixed aqueous solution of sodium hydroxide 100±3g / L, carbonate 45±1g / L, phosphate 18±0.3g / L and active agent 5±0.02ml / L; the degreasing duration of step (1) is 15S-50S.

6. The method for coating the surface of a metal component according to claim 3, characterized in that: The cleaning in step (2) and step (4) is to clean the workpiece twice with salt water at 70°C, each cleaning lasting 10S-30S.

7. The method for coating the surface of a metal component according to claim 3, characterized in that: The rust removal in step (3) is to immerse the workpiece in a 25% hydrochloric acid aqueous solution for 10S-30S.

8. The method for coating the surface of a metal component according to claim 3, characterized in that: The activation in step (5) is to immerse the workpiece in a 15% sulfuric acid aqueous solution for 15S-50S.

9. The method for coating the surface of a metal component according to claim 3, characterized in that: The water washing in step (6) is to rinse the workpiece twice with water.

10. The method for coating the surface of a metal component according to claim 3, characterized in that: The electroplating conditions of step (7) are: The plating solution formula is a mixed aqueous solution of 280±3g / L nickel sulfate, 65±1g / L nickel chloride, 35±0.5g / L boric acid and 250±3ml / L additives; The temperature of the plating solution is 55-65°C; Current density is 1.5-3A / dm 2 .

Images