CN107779833A - A kind of composite film coating technique - Google Patents

Abstract

The invention provides a composite coating process, comprising: depositing a Ti/Cu bonding layer on the surface of a substrate by vacuum plating; the vacuum degree of the vacuum chamber is less than 5× ^10-4 Pa, and the temperature is 400-420°C; The functional layer is prepared by electrolytic nickel plating and/or electroless nickel plating on the combination layer to obtain a composite coating film. The composite coating process provided by the present invention adopts an electroplating process with specific parameters combined with a vacuum plating process with a specific process, and the composite film finally prepared has excellent bonding between the coating and the substrate, no stripping, and high bonding force.

Description

A composite coating process

technical field

The invention relates to the field of alloy film preparation, in particular to a composite coating process.

Background technique

Surface engineering technology refers to changing the chemical composition, structure, and stress state of the substrate surface through various physical, chemical, mechanical or composite methods, so that the substrate surface can obtain certain special properties, such as wear resistance, corrosion resistance, and corrosion resistance. A technology with high temperature and excellent optical, magnetic, electrical, thermal and other properties. Electroplating and vacuum plating are two main technologies in the field of surface engineering technology. Electroplating technology is mainly divided into electrolytic plating and chemical plating. Electrolytic plating refers to the method of reducing the chemical substances in the plating solution and depositing them on the surface of the workpiece to form a coating under the condition of external current. In order for the electroplating process to proceed smoothly, the workpiece must be electrically conductive. Electroless plating does not require electricity and has no special requirements on the conductivity of the workpiece. The pre-treatment process of electroplating is relatively complicated, and only weak van der Waals force acts between the coating and the substrate during the coating process, so the bonding force between the coating and the substrate is weak. The common thickness range of electroplating coatings is between 2 and 1000 μm. The electroplating process has a leveling effect, which can improve the surface finish of the substrate, and the coating has excellent corrosion resistance. Vacuum plating, also known as physical vapor deposition, refers to the evaporation or sputtering of solid materials by heating evaporation sources in a vacuum container, so that these evaporated and sputtered materials are deposited on the surface of the substrate to form a coating. Such as evaporation plating, ion plating and sputtering. The vacuum coating process has the advantages of green and environmental protection, no waste water and waste gas discharge, and the product is non-toxic and harmless. It can be easily coated on metal and non-metal surfaces. The coating prepared by vacuum plating has good bonding force with the substrate, the film structure is dense, the hardness is high, and it has excellent wear resistance. The common thickness range of the vacuum plating coating is between 0.1 and 10 μm. The coating is close to the surface of the substrate, and the leveling effect is poor. The vacuum plating coating cannot improve the surface finish of the substrate.

Although electroplating technology has complex problems such as wastewater treatment, electroplating technology has a leveling effect and can prepare thick films, and the cost of electroplating technology to treat workpieces is relatively low. In the short term, it is difficult for vacuum plating to completely replace electroplating. The composite coating process disclosed in the prior art cannot meet the application requirements in the field of surface treatment to a certain extent due to lower requirements on the bonding force, wear resistance and anti-corrosion performance of the film during the coating process.

Contents of the invention

In view of this, the technical problem to be solved by the present invention is to provide a composite coating process. The composite film prepared by the composite coating process provided by the present invention has excellent bonding between the coating and the substrate, no stripping, and high bonding force.

The invention provides a composite coating process, comprising:

A Ti/Cu bonding layer is deposited on the surface of the substrate by vacuum plating; the vacuum degree of the vacuum chamber is less than 5×10 ^{- 4} Pa, and the temperature is 400-420°C;

The functional layer is prepared by electrolytic nickel plating and/or electroless nickel plating on the combination layer to obtain a composite coating film.

Preferably, the substrate is titanium, tungsten, molybdenum, tantalum, ceramics, glass or ferrite.

Preferably, the electrolytic nickel plating is specifically:

One or more pretreatments of acid and alkali are used to electroplate nickel and dry; the electroplating is flash plating; the film thickness of the flash plating is 0.3 μm; the temperature of the flash plating is 45-55°C; The current density of the flash plating is 3-5A; the drying temperature is 80-100°C, and the drying time is 800-1000s.

Preferably, the electroless nickel plating is specifically:

Adopt one or more pretreatments of acid and alkali, carry out electroless nickel plating at 85-90°C, pH value of 8.5-9, and dry; the plating solution of the electroless nickel plating is nickel sulfate or Teflon added nickel sulfate.

Preferably, the vacuum plating is magnetron sputtering, the vacuum degree of the magnetron sputtering is 0.1～1Pa, the gas of the magnetron sputtering is argon; the bias value of the magnetron sputtering is - 20-200V; the power density of the sputtering target of the magnetron sputtering is less than 8W/cm ² ; the thickness of the bonding layer is 0.02-1 μm.

Preferably, the thickness of the metal Ti layer in the bonding layer is 0.02˜0.3 μm, and the thickness of the metal Cu layer is >0.3 μm.

Preferably, the surface treatment specifically includes: degreasing the base material with lye, rinsing with pure water, dehydrating, and drying with hot air at 80-120°C.

The invention provides a composite coating process, comprising:

The bottom layer is prepared by nickel sulfate electrolytic plating on the surface of the substrate; the temperature of the electrolytic plating is 25-35°C; the current density is 0.5-1.2A/dm ² ;

The functional layer is prepared by vacuum plating on the bottom layer; the vacuum plating specifically includes: depositing a metal bonding layer Ti layer in a vacuum chamber with a vacuum degree of less than 5×10 ^{- 4} Pa and a temperature of 130 to 140°C, and then depositing a Ti layer on the bonding layer A titanium carbide functional layer is deposited on the layer; wherein, the vacuum degree of the deposition process is 0.1-1Pa.

Preferably, the base material is aluminum, stainless steel, brass.

Preferably, the thickness of the bottom layer is >5 μm, and the thickness of the functional layer is 0.5-2 μm.

Compared with the prior art, the present invention provides a composite coating process, comprising: adopting vacuum plating to deposit a Ti/Cu bonding layer on the surface of the substrate; the vacuum degree of the vacuum chamber is lower than 5×10 ^-4 Pa , the temperature is 400-420° C.; the functional layer is prepared by electrolytic nickel plating and/or electroless nickel plating on the bonding layer to obtain a composite coating. The composite coating process provided by the present invention adopts an electroplating process with specific parameters combined with a vacuum plating process with a specific process, and the composite film finally prepared has excellent bonding between the coating and the substrate, no stripping, and high bonding force.

Description of drawings

Fig. 1 Optical microscope observation diagram of titanium matrix workpiece after surface treatment by different processes.

Detailed ways

The present invention provides a composite coating process, which can be implemented by those skilled in the art by referring to the content of this article and appropriately improving the process parameters. In particular, it should be pointed out that all similar substitutions and modifications are obvious to those skilled in the art, and they all belong to the protection scope of the present invention. The method and application of the present invention have been described through preferred embodiments, and relevant personnel can obviously make changes or appropriate changes and combinations to the method and application herein without departing from the content, spirit and scope of the present invention to realize and apply the present invention Invent technology.

The invention provides a composite coating process, comprising:

A Ti/Cu bonding layer is deposited on the surface of the substrate by vacuum plating; the vacuum degree of the vacuum chamber is less than 5×10 ^-4 Pa, and the temperature is 400-420°C;

The functional layer is prepared by electrolytic nickel plating and/or electroless nickel plating on the combination layer to obtain a composite coating film.

In the composite coating process provided by the invention, a Ti/Cu bonding layer is deposited on the surface of the substrate by vacuum plating.

The substrate of the present invention is preferably titanium, tungsten, molybdenum, tantalum, ceramics, glass or ferrite.

The present invention first carries out pretreatment to above-mentioned base material surface; Preferably be specifically:

The substrate is degreased with lye, rinsed with pure water, dehydrated, and dried with hot air at 80-120°C.

The lye of the present invention is preferably sodium hydroxide. The concentration of the base is preferably 10 wt.%. The temperature of the alkali treatment is room temperature (25° C.). The time is 30-40s.

The pure water rinsing is preferably 2-3 times; the present invention does not limit the rinsing and dehydration, as long as those skilled in the art are familiar with it.

The hot air drying at 80-120°C in the present invention is preferably hot-air drying at 90-110°C.

After the above surface treatment, the rust, oil stains and other stains on the workpiece can be removed.

On the above-mentioned treated substrate, the present invention first adopts the method of vacuum plating to deposit a Ti/Cu bonding layer.

The vacuum plating of the present invention is preferably carried out in a vacuum coating machine; preferably, the workpiece to be plated is placed in a metal mesh cover of a drum-type vacuum coating machine, and the metal mesh cover is placed in a vacuum chamber.

The vacuum plating is preferably specifically:

a) The vacuum chamber is evacuated, and the vacuum chamber is heated at the same time.

Keep the heating temperature at 420-450°C. When the vacuum degree of the vacuum chamber is less than 5×10 ^-4 Pa, adjust the temperature of the vacuum chamber and stabilize it at 400-420°C;

b) The vacuum chamber is fed with argon gas, and the ion source of the anode layer is operated in the high-voltage and low-current discharge mode to generate argon ions; at the same time, turn on the bias power supply and set the bias value between -1200 ~ -3000V, to be plated The workpiece is cleaned by plasma glow for 30-60 minutes, and the bias power supply can be a DC power supply or a pulse power supply.

c) The bonding layer is prepared by vacuum plating technology.

The vacuum plating is preferably magnetron sputtering, the vacuum degree of the magnetron sputtering is preferably 0.1～1Pa, and the gas of the magnetron sputtering is argon; the bias value of the magnetron sputtering is preferably- 20-200V; the power density of the sputtering target of the magnetron sputtering is less than 8W/cm ² ; preferably 6-8W/cm ² ; the thickness of the bonding layer is 0.02-1 μm. Specifically, the thickness of the metal Ti layer in the bonding layer is preferably 0.02-0.3 μm, and the thickness of the metal Cu layer is preferably greater than 0.3 μm.

The bonding layer of the present invention is usually a composite layer structure, including a layer of metal titanium and a layer of metal copper. The metal bonding layer thickness is controlled by adjusting the deposition time. The bias power supply can be a DC power supply or a pulse power supply.

After the preparation of the bonding layer by vacuum plating technology, stop the drive of the drum-type workpiece holder, and the temperature of the substrate workpiece will drop below 100°C; the vacuum chamber will be filled with dry air; the furnace door will be opened, and the titanium-plated substrate workpiece will be released from the furnace.

A functional layer is prepared by electrolytic nickel plating and/or electroless nickel plating on the bonding layer to obtain a composite film layer.

That is, the functional layer can be prepared by combining electrolytic nickel plating and electroless nickel plating on the bonding layer to obtain a composite film layer.

It is also possible to prepare a functional layer by electroless nickel plating on the bonding layer to obtain a composite film layer.

Wherein, the electrolytic nickel plating is specifically:

Use one or more pretreatments of acid and alkali, electroplate nickel, and dry.

Preferably, it is specifically: alkaline cleaning, pickling, flash nickel plating, electroless nickel (EN), Teflon chemical nickel (Ni-PTFE), and drying.

The alkali is preferably sodium hydroxide; the acid can be sulfuric acid or hydrochloric acid; the concentration of the alkali or acid is preferably 10wt.% to 25wt.%; the electroplating is flash plating; the film thickness of the flash plating is 0.3 μm; the temperature of the flash plating is 45-55° C.; the current density of the flash plating is 3-5A. The drying temperature is 80-100°C, and the drying time is 800-1000s.

Wherein, the electroless nickel plating is specifically:

Use one or more pretreatments of acid and alkali, carry out electroless nickel plating at 85-90°C, pH value 8.5-9, and dry; the plating solution of the electroless nickel plating includes nickel sulfate or Teflon added Nickel sulfate; more preferably nickel sulfate, sodium dihydrogen phosphate, Na ₃ C ₆ H ₅ O ₇ , ammonium chloride.

It is preferably obtained by: pickling, water rinsing, pickling, water rinsing, palladium activation, water rinsing, electroless nickel plating, water rinsing, and drying.

Wherein, the acid can be sulfuric acid or hydrochloric acid; the concentration of the alkali or acid is preferably 10wt.% to 25wt.%; the acid treatment time is preferably 15 to 20s; the water rinsing is preferably deionized water rinsing; The number of times of rinsing is preferably 2-3 times; the rinsing time is preferably 20-40s; the palladium activation time is preferably 15-20s; the drying temperature is 80-100°C, and the drying time is 800-1000s.

The ceramic matrix workpiece treated with the above-mentioned "vacuum plating + electroplating" composite coating process, observed by an optical microscope, has no defects such as cracks, stains, chipping, water lines and other defects on the surface, and there are no fusion lines, sand holes, shrinkage marks, and clamping lines. and other defects. The thickness of the electroless plating functional layer is uniform, and no external current is required. The surface coating of the sample has no bulging or peeling off, and the performance is good. No discoloration on the surface, no corrosion particles.

The present invention also provides the composite coating film prepared by the above composite coating film process.

The invention provides a composite coating process, comprising:

The bottom layer is prepared by nickel sulfate electrolytic plating on the surface of the substrate; the temperature of the electrolytic plating is 25-35°C; the current density is 0.5-1.2A/dm ² ;

The functional layer is prepared by vacuum plating on the bottom layer; the vacuum plating specifically includes: depositing a metal bonding layer Ti layer in a vacuum chamber with a vacuum degree of less than 5×10 ^{- 4} Pa and a temperature of 130 to 140°C, and then depositing a Ti layer on the bonding layer A titanium carbide functional layer is deposited on the layer; wherein, the vacuum degree of the deposition process is 0.1-1Pa.

The base material of the present invention is preferably aluminum, stainless steel, brass.

In the present invention, the bottom layer is prepared by nickel sulfate electrolytic plating on the surface of the substrate.

The electrolytic plating includes: pretreatment, nickel electroplating and baking.

Wherein, firstly, pretreatment is performed on the above-mentioned substrate, and the pretreatment specifically includes: mechanical polishing, chemical degreasing, and acid etching.

Specifically, the chemical degreasing uses sodium carbonate with a mass concentration of 20 g/L and sodium phosphate with a mass concentration of 30 g/L, and degreasing is carried out at a temperature of 30-60° C. for 10 minutes. The acid etching to remove the oxide layer is preferably carried out with a volume ratio of hydrofluoric acid to water of 1:1 at room temperature for 30-120s.

The plating solution of described nickel electroplating preferably comprises the nickel sulfate that mass concentration is 280g/L, the boric acid that mass concentration is 30～40g/L, the sodium chloride that mass concentration is 2～10g/L, the temperature of described electroplating 25～ 35°C, current density 0.5-1.2A/dm ² . The baking temperature is 80°C-100°C, and the baking time is 800-900s.

The bottom layer is obtained by electroplating, wherein the thickness of the bottom layer is greater than 5 μm, and the thickness of the functional layer is 0.5-2 μm.

A functional layer is prepared on the bottom layer by vacuum plating.

The vacuum plating specifically includes: depositing a metal bonding layer Ti layer in a vacuum chamber with a vacuum degree of less than 5×10 ^-4 Pa and a temperature of 130-140° C., and then depositing a titanium carbide functional layer on the bonding layer; wherein, The degree of vacuum in the deposition process is 0.1-1Pa.

The vacuum plating is preferably specifically:

a) The vacuum chamber is evacuated, and the vacuum chamber is heated at the same time.

Keep the heating temperature at 140-150°C. When the vacuum degree of the vacuum chamber is better than 5×10 ^-4 Pa, adjust the temperature of the vacuum chamber and stabilize it at 130-140°C;

b) The vacuum chamber is fed with argon gas, and the ion source of the anode layer is operated in the high-voltage and low-current discharge mode to generate argon ions; at the same time, turn on the bias power supply and set the bias value between -1200 ~ -3000V, to be plated The workpiece is cleaned by plasma glow for 30-60 minutes, and the bias power supply can be a DC power supply or a pulse power supply.

c) The bonding layer is prepared by vacuum plating technology. The thickness of the bonding layer is 0.02-1 μm. Specifically, the thickness of the metal Ti layer in the bonding layer is preferably 0.01-0.3 μm, and the thickness of the metal Cu layer is preferably greater than 0.3 μm.

Preferably, the magnetron sputtering method of the vacuum plating technique is used to deposit the functional layer, and for the black functional layer, titanium carbide is preferably used. Acetylene gas is fed in as the reaction gas, argon gas is fed in as the working gas, and the vacuum degree during the coating process is preferably 0.1-1Pa. The vacuum plating is preferably magnetron sputtering, and the power density of the sputtering titanium target is less than 8W/cm ² ; more preferably 6-8W/cm ² . During the deposition process, the bias power supply is set between -20 and -200V. The bias power supply can be a DC power supply or a pulse power supply, and the pulse bias power supply is preferred; the temperature of the vacuum chamber is adjusted and stabilized at 130-140°C; the thickness of the film layer is passed Control deposition time control.

After the preparation of the functional layer by vacuum plating technology, the drive of the workpiece frame is stopped, and the temperature of the aluminum substrate workpiece is lowered to below 90°C; the vacuum chamber is filled with dry air; the furnace door is opened, and the aluminum substrate workpiece is released from the furnace.

The aluminum matrix workpiece treated by the above-mentioned "electroplating + vacuum plating" composite coating process, observed by an optical microscope, has no defects such as cracks, stains, chipping, water lines and other defects on the surface, and there are no fusion lines, sand holes, shrinkage marks, and clamping lines. and other defects. The hardness of the aluminum matrix workpiece is 135Hv, the thickness of the electroplated nickel layer is 9-10μm, the hardness of the nickel layer is between 740Hv, the thickness of the vacuum-plated functional layer is 1-1.5μm, and the hardness of the vacuum-plated functional layer is 1050Hv. The surface color of the plated parts is black, and the L value (representing the blackness, the smaller the value, the darker) is between 35 and 38. The results of the Baige test show that the coating has an excellent bond with the substrate, no stripping, and the bonding force is over 95%.

The invention provides a composite coating process, comprising: depositing a Ti/Cu bonding layer on the surface of a substrate by vacuum plating; the vacuum degree of the vacuum chamber is less than 5×10 ^-4 Pa, and the temperature is 400-420°C; The functional layer is prepared by electrolytic nickel plating and/or electroless nickel plating on the combination layer to obtain a composite coating film. The composite coating process provided by the present invention adopts an electroplating process with specific parameters combined with a vacuum plating process with a specific process, and the composite film finally prepared has excellent bonding between the coating and the substrate, no stripping, and high bonding force.

In order to further illustrate the present invention, the composite coating process provided by the present invention will be described in detail below in conjunction with the examples.

Example 1

(1) Pretreatment

(a) Degreasing NaOH (10wt.%) with alkaline solution for the workpiece to be plated with titanium base, the temperature is room temperature (25°C), and the time is 30-40s. Rinse with pure water, dehydrate and dry with hot air (80-120°C) to remove rust, oil stains and other stains on the workpiece (see Figure 1a for the appearance of the workpiece);

(b) Put the workpiece to be plated through the process (a) into the metal mesh cover of the drum type vacuum coating machine, and place the metal mesh cover in the vacuum chamber;

(c) The vacuum chamber is evacuated, and the vacuum chamber is heated at the same time. Keep the heating temperature at 420-450°C. When the vacuum degree of the vacuum chamber is less than 5×10 ^-4 Pa, adjust the temperature of the vacuum chamber and stabilize it at 400-420°C;

(d) The vacuum chamber is fed with argon gas, and the ion source of the anode layer is operated in the high-voltage and low-current discharge mode to generate argon ions; at the same time, the bias power is turned on, and the bias value is set between -1200 and -3000V. Titanium-plated matrix workpieces are cleaned by plasma glow for 30-60 minutes, and the bias power supply can be DC power supply or pulse power supply;

(2) The bonding layer is prepared by vacuum plating technology

Preferably, the magnetron sputtering method of vacuum plating technology is used to deposit the metal bonding layer, and the thickness of the bonding layer is 0.02-1 μm; copper layer. The metal bonding layer thickness is controlled by adjusting the deposition time. During the deposition process, the bias power supply is set between -20 and -200V, and the bias power supply can be DC power supply or pulse power supply; the power density of the sputtering target is less than 8W/cm ² ; the vacuum degree during the coating process is 0.1-1Pa, adjust the vacuum The chamber temperature is stable at 400-420°C;

(3) After the preparation of the bonding layer by vacuum plating technology, stop the drive of the roller workpiece rack, and the temperature of the titanium matrix workpiece will drop below 100°C; the vacuum chamber will be filled with dry air; the furnace door will be opened, and the titanium substrate workpiece will be released from the furnace; vacuum plating technology The appearance of the processed titanium matrix workpiece is shown in Figure 1b, and the surface is a metal copper layer;

(4) Preparation of functional layer by electroplating technology

The workpiece processed by vacuum plating technology is then processed by electroplating technology. Using electrolytic plating combined with chemical plating, the electroplating process flow: alkaline washing → sulfuric acid (10wt.%) washing → nickel flash plating (0.3μm) → electroless nickel (EN) → Teflon chemical nickel (Ni-PTFE) → drying ( 90°C, 900s). The appearance of the titanium matrix workpiece treated by electroplating technology is shown in Figure 1c, and the surface is a Teflon chemical nickel layer.

(5) The titanium matrix workpiece treated by the "vacuum plating + electroplating" composite coating process, observed by an optical microscope, has no defects such as cracks, stains, chipping, running water lines and other defects on the surface, and there are no fusion lines, sand holes, shrinkage marks, clips Defects such as molding lines. The use of electroless nickel plating does not require electricity, and the thickness of the plating layer is uniform. The thickness of the functional layer EN+Ni-PTFE is 7-11 μm, wherein the thickness of Ni-PTFE is 1-2 μm. The hardness of the coating after heat treatment is between 500 and 550Hv. The binding force test adopts the 100-grid test method, and the binding force reaches more than 95%. Sweat resistance test, placed at 40°C for 24h and 48h respectively, the titanium matrix workpiece treated by the "vacuum plating + electroplating" composite coating process has no discoloration on the surface and no corrosion particles.

Example 2

(1) Pretreatment

(a) The ceramic matrix workpiece to be plated is degreased with NaOH (10wt.%) in alkaline solution, the temperature is room temperature (25°C), and the time is 30-40s. , Pure water rinsing, dehydration and hot air (80 ~ 120 ℃) drying to remove rust, oil stains and other stains on the workpiece;

(b) putting the ceramic matrix workpiece to be plated into the vacuum chamber through the process (a);

(c) The vacuum chamber is evacuated, and the vacuum chamber is heated at the same time. Keep the heating temperature at 420-450°C. When the vacuum degree of the vacuum chamber is less than 5×10 ^-4 Pa, adjust the temperature of the vacuum chamber and stabilize it at 400-420°C;

(d) The vacuum chamber is fed with argon gas, and the ion source of the anode layer is operated in the high-voltage and low-current discharge mode to generate argon ions; at the same time, the bias power is turned on, and the bias value is set between -1200 and -3000V. Plasma glow cleaning is performed for 30-60 minutes on the workpiece plated with ceramic substrate, and the bias power supply is a bipolar pulse bias power supply or a radio frequency bias power supply;

(2) The bonding layer is prepared by vacuum plating technology

Preferably, the magnetron sputtering method of vacuum plating technology is used to deposit the metal bonding layer, and the thickness of the bonding layer is 0.01-1 μm; the bonding layer is usually a composite layer structure, including a metal titanium layer with a thickness of 0.01-0.1 A copper layer with a thickness greater than 0.3 μm. The metal bonding layer thickness is controlled by adjusting the deposition time. During the deposition process, the bias power supply is set between -20 and -200V, and the bias power supply is preferably a bipolar pulse bias power supply or a radio frequency power supply; the power density of the sputtering target is less than 8W/cm ² ; the vacuum degree during the coating process is 0.1 ～1Pa, adjust the temperature of the vacuum chamber and stabilize it at 400～420℃;

(3) After the preparation of the bonding layer by vacuum plating technology, stop the drive of the workpiece frame, and the temperature of the ceramic substrate workpiece is lowered to below 100°C; the vacuum chamber is filled with dry air; the furnace door is opened, and the ceramic substrate workpiece to be plated is released from the furnace;

(4) Preparation of functional layer by electroplating technology

The workpiece processed by vacuum plating technology is then processed by electroplating technology, using chemical electroplating method, electroplating process flow: pickling (15s) → deionized water rinse (three times, respectively 20s, 20s, 40s) → pickling (5wt .% sulfuric acid, 20s) → deionized water rinse (three times, respectively 20s, 20s, 40 seconds) → palladium activation (15s) → deionized water rinse (three times, 20s, 20s, 40s) → electroless nickel plating (EN, 88°C, 400s) → rinse with deionized water (three times, 30s, 30s, 40s) → dry (90°C, 900s).

(5) The ceramic matrix workpiece processed by the "vacuum plating + electroplating" composite coating process, observed by an optical microscope, has no defects such as cracks, stains, chipping, running water lines, etc. on the surface, and there are no fusion lines, sand holes, shrinkage marks, clips, etc. Defects such as molding lines. The thickness of the electroless plating functional layer is uniform, and no external current is required. The thickness of the EN layer of the functional layer is 3±0.3 μm. The hardness of the coating after heat treatment is between 500 and 550Hv. The results of the Baige test show that the coating has an excellent bond with the substrate, no stripping, and the bonding force is over 95%. The results of the lead-free reflow soldering test (260°C, 15s) show that the surface coating of the sample has no bulging or peeling off, and the performance is good.

Example 3

(1) The bottom layer is prepared by electroplating technology, and the electrolytic plating method is used. Mechanical polishing→chemical degreasing→acid etching→direct nickel plating→baking. Among them, sodium carbonate (20g/L) and sodium phosphate (30g/L) are used for chemical degreasing at a temperature of 30-60°C for 10 minutes. Hydrofluoric acid (1:1) is used for acid etching to remove the oxide layer at room temperature for 30-120s. Nickel sulfate (280g/L), boric acid (30-40g/L) and sodium chloride (2-10g/L) are used for direct nickel plating. The temperature is 25-35°C and the current density is 0.5-1.2A/dm ² . The baking temperature is 90°C, and the baking time is 900s.

(2) The functional layer is prepared by vacuum plating.

The workpiece processed by electroplating technology is then processed by vacuum plating technology. The procedure is as follows:

(a) placing the aluminum-plated substrate workpiece processed through the process (1) into the vacuum chamber;

(b) The vacuum chamber is evacuated while heating the vacuum chamber. Keep the heating temperature at 140-150°C. When the vacuum degree of the vacuum chamber is less than 5×10 ^-4 Pa, adjust the temperature of the vacuum chamber and stabilize it at 130-140°C;

(c) The vacuum chamber is fed with argon gas, and the ion source of the anode layer is operated in the high-voltage and low-current discharge mode to generate argon ions; at the same time, the bias power is turned on, and the bias value is set between -1200 and -3000V. The plated workpiece is cleaned by plasma glow for 30-60 minutes, wherein the bias power supply is a DC bias power supply or a pulse bias power supply, preferably a pulse bias power supply;

(d) Preferably, the magnetron sputtering method of the vacuum plating technique is used to deposit the metal bonding layer, which is usually a metal titanium layer with a thickness of 0.01-0.3 μm. During the deposition process, the bias power supply is set between -20 and -200V. The bias power supply can be a DC power supply or a pulse power supply, and the pulse bias power supply is preferred; the power density of the sputtering target is less than 8W/cm ² ; the vacuum degree during the coating process is 0.1～1Pa, adjust the vacuum chamber temperature and stabilize it at 130～140℃;

(e) The magnetron sputtering method of the vacuum plating technology is preferred to deposit the functional layer. For the black functional layer, titanium carbide is considered. The acetylene gas is fed in as the reaction gas, the argon gas is fed in as the working gas, and the vacuum degree is set at 0.1-1Pa during the coating process. The power density of the sputtering titanium target is less than 8W/cm ² ; the bias power is set between -20 and -200V during the deposition process, and the bias power can be a DC power supply or a pulse power supply, preferably a pulse bias power supply; adjust the temperature of the vacuum chamber And it is stable at 130-140°C; the thickness of the film layer is controlled by controlling the deposition time.

(3) After the preparation of the functional layer by vacuum plating technology, stop the drive of the workpiece frame, and the temperature of the aluminum substrate workpiece is lowered to below 90°C; the vacuum chamber is filled with dry air; the furnace door is opened, and the aluminum substrate workpiece is released from the furnace;

(4) The aluminum matrix workpiece processed by the "electroplating + vacuum plating" composite coating process, observed by an optical microscope, has no defects such as cracks, stains, chipping, water lines and other defects on the surface, and there are no fusion lines, sand holes, shrinkage marks, clips, etc. Defects such as molding lines. The hardness of the aluminum matrix workpiece is 135Hv, the thickness of the electroplated nickel layer is 9-10μm, the hardness of the nickel layer is between 740Hv, the thickness of the vacuum-plated functional layer is 1-1.5μm, and the hardness of the vacuum-plated functional layer is 1050Hv. The surface color of the plated parts is black, and the L value (representing the blackness, the smaller the value, the darker) is between 35 and 38. The results of the Baige test show that the coating has an excellent bond with the substrate, no stripping, and the bonding force is over 95%.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (10)

1. A kind of 1. composite film coating technique, it is characterised in that including：

   Vacuum Deposition depositing Ti/Cu binder courses are used in substrate surface；The vacuum of the vacuum chamber is less than 5 × 10^-4Pa, temperature Spend for 400~420 DEG C；

   Functional layer is prepared using electrolysis electronickelling and/or chemical-electrical nickel plating on the binder course, obtains composite film coating.
2. 2. technique according to claim 1, it is characterised in that the base material is titanium, tungsten, molybdenum, tantalum, ceramics, glass or iron Oxysome.
3. 3. technique according to claim 1, it is characterised in that it is described electrolysis electronickelling be specially：

   Pre-processed, electronickelling, dried using the one or more in bronsted lowry acids and bases bronsted lowry；The plating is flash；The thickness of the flash Spend for 0.3 μm；The temperature of the flash is 45~55 DEG C；The current density of the flash is 3~5A；The temperature of the drying is 80~100 DEG C, the dry time is 800~1000s.
4. 4. technique according to claim 1, it is characterised in that the chemical nickel plating is specially：

   Pre-processed using the one or more in bronsted lowry acids and bases bronsted lowry, be 8.5~9 progress chemical nickel platings in 85~90 DEG C, pH value, dry； The plating solution of the chemical nickel plating includes nickel sulfate or adds the nickel sulfate of Teflon.
5. 5. technique according to claim 1, it is characterised in that the Vacuum Deposition is magnetron sputtering, the magnetron sputtering Vacuum is 0.1~1Pa, and the gas of the magnetron sputtering is argon gas；The bias value of the magnetron sputtering is -20~-200V；Institute The sputtering target power density for stating magnetron sputtering is less than 8W/cm²；The joint thickness is 0.02~1 μm.
6. 6. technique according to claim 1, it is characterised in that metal Ti thickness degree is 0.02~0.3 μ in the binder course M, Ni metal thickness degree are more than 0.3 μm.
7. 7. technique according to claim 1, it is characterised in that the surface treatment is specially：

   Base material is by alkalilye degreasing, pure water rinsing, dehydration, 80~120 DEG C of hot-air seasonings.
8. A kind of 8. composite film coating technique, it is characterised in that including：

   Bottom is prepared using sulfuric acid nickel electrowinning plating in substrate surface；The temperature of the electrolysis plating is 25~35 DEG C；The electricity Current density is 0.5~1.2A/dm²；

   Functional layer is prepared using Vacuum Deposition on the bottom；The Vacuum Deposition is specially：It is less than 5 × 10 in vacuum^-4Pa, temperature Spend deposited metal binder course Ti layers in the vacuum chamber for 130~140 DEG C, then on binder course titanium deposition carbide function Layer；Wherein, deposition process vacuum is 0.1~1Pa.
9. 9. technique according to claim 8, it is characterised in that the base material is aluminium, stainless steel, brass.
10. 10. technique according to claim 8, it is characterised in that the underlayer thickness is more than 5 μm, and functional layer thickness is 0.5 ~2 μm.