CN105908228A - Nickel alloy composition modulated multilayer alloy (CMMA) coating and preparation method thereof - Google Patents

Abstract

The invention provides a nickel alloy CMMA coating and a preparation method thereof. The nickel alloy CMMA coating has a multi-layer structure, and the number of layers is 50-1000; the coating structure contains nano particle phase and amorphous embedded nano crystal composite structure phase. The preparation method controls the liquid-phase mass transfer process of the electrolyte in the cathode by periodically changing the current density during electrodeposition, thereby obtaining a nickel alloy CMMA coating with periodic changes in composition and structure. The nickel alloy CMMA coating of the present invention can perform performance design and microstructure control, has good bonding force with the base material, excellent corrosion resistance and wear resistance, and can be widely used in surface protection of marine engineering machinery, hydraulic metal structures, and mechanical parts deal with.

Description

a nickel alloy CMMA Plating layer and its preparation method

technical field

The invention belongs to the technical field of metal protection, and in particular relates to a nickel alloy CMMA coating and a preparation method thereof.

Background technique

Ni-based W, Mo, and B alloys are widely used in the fields of aerospace, electronic devices, automotive hubs, and marine machinery protection due to their good hardness, corrosion resistance, and mechanical strength. In recent years, the preparation of nano-composite cermet coatings by compounding nano-ceramic particles in alloys has become a research focus in recent years, such as adding TiO ₂ , α-Al ₂ O ₃ , SiO ₂ , SiC, TiN, etc. to Ni-based alloys, It can not only improve the hardness and wear resistance of the alloy, but also enhance its corrosion resistance. However, due to the cathodic hydrogen evolution and residual stress in the preparation process of electrochemical deposition, there will be capillary pores, through holes or micro-cracks in the coating. These defects are difficult to effectively control, which fundamentally limits the improvement of its protective performance. problems that need to be solved urgently.

As the main way to further improve the marine protection performance of coatings, microstructure regulation and performance design have become an important development trend in the field of marine engineering materials. Studies in recent years have shown that CMMA alloy (Composition modulated multilayer alloy) has superior performance than alloys with the same composition thickness, and its corrosion resistance can reach 45 times that of monolayer alloys (Monolayer, Monolithic alloy) with the same thickness. performance advantage. The CMMA multi-layer multi-interface structure makes the defects of each layer terminate at the adjacent interface, without the formation of through holes, which delays the time for the corrosion medium to reach the substrate, due to the surface micro-defects, the filled corrosion medium (electrolyte) and the adjacent layer interface The electric double layer capacitance is formed, and the process is controlled by the charge transfer step, so that the corrosion tends to proceed layer by layer, which has a better protective effect. In prior art CN101462819, CN101445946, CN102747389A, etc., nickel-based alloys have been studied, and their performance has been improved, but because the key factor affecting the corrosion resistance of the coating-the formation of through holes has not been fundamentally suppressed, its performance has not been improved by leaps and bounds. For the complex and harsh marine environment, through performance design and microstructure regulation, solving the problem of through-holes, and developing advanced high-performance marine long-term protective coating technology play an important role in promoting the marine development strategy.

Contents of the invention

The technical problem to be solved: the present invention overcomes the technical problem of low corrosion resistance of the nickel-based alloy coating due to the formation of through holes in the prior art, and provides a nickel alloy CMMA coating and a preparation method thereof.

Technical solution: a nickel alloy CMMA coating, the coating is a multi-layer structure, the number of layers is 50-1000; the coating structure contains a nano particle phase and an amorphous inlaid nano crystal composite structure phase.

Further, the nickel alloy is one of Ni-W, Ni-B or Ni-Zn alloy.

The preparation method of the nickel alloy CMMA coating is to periodically change the current density during electrodeposition to control the liquid phase mass transfer process of the electrolyte in the cathode, thereby obtaining the nickel alloy CMMA coating with periodic changes in composition and structure.

Further, the periodic current density is specifically: the current changes cyclically between i ₁ - i ₂ , the low value i ₁ of the current density is 0.10-2.00A/dm ² , and the high value i ₂ of the current density is 2.50-10A /dm ² , each deposition cycle T is 0.2-10s, and the total number of cycles N is 50-1000.

Further, the electrolyte includes, in terms of mass concentration: nickel salt 150-350 g/L, second main salt 1-6 g/L, nanoparticles 0.01-20 g/L, buffering agent 20-50 g/L, dispersant 0~1g/L, wetting agent 0~1g/L, auxiliary agent 0.1~2g/L, solvent is water.

Further, the nickel salt is selected from at least one of nickel sulfate, nickel chloride or basic nickel carbonate, and must contain nickel sulfate.

Further, the second main salt is one of sodium tungstate, potassium tungstate, ammonium tungstate, trimethylamine borane, sodium hydroborate, zinc sulfate, zinc chloride, and zinc nitrate.

Further, the nanoparticles are one of TiO ₂ , α-Al ₂ O ₃ , SiO ₂ , SiC or TiN, with a particle size of 0.005-2 μm.

Further, the buffer is boric acid.

Further, the dispersant is one of sodium citrate, citric acid, sodium tartrate, tartaric acid, boric acid, sodium borate or sulfamic acid.

Further, the wetting agent is sodium lauryl sulfate, sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate (AES), sodium polyoxyethylene alkylphenol ether sulfate (DRO), One of fatty alcohol ethoxylates (JFC), nonylphenol ethoxylates (NP-10) or octylphenol ethoxylates (OP-10).

Further, the auxiliary agent can be saccharin, brightener and leveling agent.

Further, the pH value of the electrolyte solution is 3-9.

Further, the temperature of the electrolyte solution during electrodeposition is 35-75°C.

Beneficial effect:

1. A nickel alloy CMMA coating CMMA structure design and performance control method disclosed in the present invention, the prepared Ni-based alloy has a CMMA multilayer structure (50-1000 layers), compared with the traditional multilayer structure (generally less than five layers) , greatly inhibited the formation of plating through-holes, and significantly improved corrosion resistance. At the same time, due to the addition of nano-ceramic particles, the wear resistance and hardness of the coating have also been significantly improved, and its protection life in the complex multi-factor coupling environment of the ocean has been improved.

2. The preparation method of the Ni-based alloy CMMA protective layer provided by the present invention can be designed according to the actual needs, the number of layers of the coating, the layer structure, the layer thickness, the layer composition, and the content distribution of the nano-ceramic particle phase and the nano-crystalline phase, The operability of coating microstructure regulation is improved, and it has reference value for the performance design research of advanced coatings in the future.

Description of drawings

Fig. 1 is the schematic diagram that current density changes linearly with time in embodiment 1;

Fig. 2 is the schematic diagram that current density changes nonlinearly with time in embodiment 2;

FIG. 3 is a schematic structural view of the Ni-B/SiC _1.0/4.0/500 coating in Example 1.

detailed description

The following examples further illustrate the content of the present invention, but should not be construed as limiting the present invention. Without departing from the spirit and essence of the present invention, the modifications and substitutions made to the methods, steps or conditions of the present invention all belong to the scope of the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

The nickel alloy CMMA coating of the present invention is a CMMA multi-layer structure, and the number of layers is 50 to 1000; the coating structure has multi-phase and multi-scale characteristics: including nano-scale nanoparticle phase, nano-crystalline phase and micro-scale amorphous phase, micron Scale amorphous mosaic nanocrystalline composite structure phase, as well as micron-scale layered structure.

CMMA alloy (Composition modulated multilayer alloy) has superior performance than alloys with the same composition thickness, and its corrosion resistance can reach the same thickness as monolayer alloys (Monolayer, Monolithic alloy), which has a huge performance advantage. In the present invention, the CMMA multi-layer and multi-interface structure of the nickel alloy CMMA coating makes the defects of each layer terminate at the adjacent interface, without forming through holes, and delays the time for the corrosive medium to reach the base material. Due to the surface micro-defects, the filled corrosion medium (electrolyte) and the adjacent layer interface form an electric double layer capacitance, the process is controlled by the charge transfer step, so that the corrosion tends to proceed layer by layer, which has a better protection effect.

The nickel alloy CMMA coating is prepared by electrodeposition. The anode is graphite, nickel plate or DSA, and the cathode is the workpiece. The liquid phase mass transfer process of the electrolyte in the cathode is changed by periodic current density control, so as to obtain periodic changes in composition and structure. Nickel alloy CMMA coating. The computer or automatic control unit is used to automatically control the cathode current density to change cyclically between i ₁ - i _2. The low value i ₁ of the current density is 0.10～2.00A/dm ² , and the high value i ₂ of the current density ranges from 2.50～ 10.00A/dm ² , each deposition period T is 0.2-10s, and the total number of cycles N is 50-1000 in terms of current density cycles, so the total number of layers and deposition cycles to obtain the coating are also 50-1000.

In the present invention, the current density changes continuously between i ₁ - i ₂ , which can be a linear change or a nonlinear change. Fig. 1 shows the continuous nonlinear change of the cathode current between i ₁ - i _2. Similarly, i ₁ - The continuous change between i and ₂ can be a straight line, but it cannot be interrupted. The interruption of the current will have a certain adverse effect on the regulation of the CMMA microstructure.

The present invention uses the mixed solution containing nickel salt, second main salt, nanoparticles, buffering agent, dispersant, wetting agent and auxiliary agent as the electrolyte, and controls the cycle cathode current density (cycle cathode current censities, denoted CCCD's), make CCCD's continuously change cycle between i ₁ - i ₂ , each current cycle is recorded as T, the time is 0.2-10s, electrodeposition is 50-1000 cycles (recorded as N), and CMMA (composition Modulated multilayer alloy, denoted as CMMA) structure coating, denoted as Ni-B/SiC _1/2/n , where 1 and 2 represent the low and high current density values of CCCD's respectively, and the deposition current changes periodically between 1 and 2 In order to obtain layers of different compositions, n represents the total number of layers of the coating. The CMMA multi-layer multi-interface structure makes the defects of each layer terminate at the adjacent interface, and no through hole is formed, which delays the time for the corrosive medium to reach the substrate. Due to the surface micro-defects, the filled corrosion medium (electrolyte) and the adjacent layer interface form an electric double layer capacitance, the process is controlled by the charge transfer step, so that the corrosion tends to proceed layer by layer, which has a better protection effect.

Example 1

Take 250g of nickel sulfate, 2g of trimethylamine borane, 60g of boric acid, 4g of SiC with a particle size of 1 μm, 1g of saccharin and 0.01g of sodium lauryl sulfate, prepare 1 liter of electrolyte with deionized water, and use sodium hydroxide solution Adjust its pH value to 3.5, use a water bath to control the temperature at 45°C, mechanically stir for 1 hour, and ultrasonically disperse for 30 minutes.

Set i ₁ =1A/dm ² , i ₂ =4A/dm ² , T=2s, N=500, graphite is used as anode, Q235 steel is used as cathode, and the current density changes continuously between i ₁ and i ₂ in a straight line, as shown in the figure As shown in 1, Ni-B/SiC _1.0/4.0/50 0 is deposited, where the subscript 1.0 represents i ₁ =1A/dm ² , the subscript 4.0 represents i ₂ =4A/dm ² , and the subscript 500 represents the total coating layer The number is 500.

The Ni-B/SiC _1.0/4.0/500 coating obtained by the above method has a total number of 500 coating layers and a total thickness of about 66 μm. The microstructure shows that the coating contains nanocrystalline phases, and the SiC nanophases are evenly distributed without through holes. The bonding force between the coating and the base material is good, and the corrosion resistance and wear resistance are significantly improved. As shown in Figure 3, the resulting coating is a CMMA multilayer structure with CMMA multilayer, multiinterface and multiscale features.

Example 2

Take 150g of nickel sulfate, 120g of nickel chloride, 6g of trimethylamine borane, 30% of boric acid, 5g of SiC with a particle size of 1 μm, 2g of saccharin, and 0.4g of AES, and prepare 1 liter of electrolyte solution with deionized water, using sodium hydroxide solution Adjust its pH value to 4.0, use a water bath to control the temperature at 60°C, mechanically stir for 1 hour, and ultrasonically disperse for 15 minutes.

Set i ₁ =1.0A/dm ² , i ₂ =5A/dm ² , T=4s, N=250, nickel plate is used as anode, Q235 steel is used as cathode, and the current density changes continuously and nonlinearly between i ₁ and i ₂ , as shown in Figure 2, Ni-B/SiC _1.0/5.0/250 is obtained by deposition, where the subscript 1.0 represents i ₁ =1.0A/dm ² , the subscript 5.0 represents i ₂ =5.0A/dm ² , and the subscript 250 The total number of layers representing the plating is 250.

The Ni-B/SiC _1.0/5.0/250 coating obtained by the above method has a total number of 250 coating layers and a total thickness of about 95 μm. The microstructure shows that the coating contains nanocrystalline phases, and the SiC nanophases are evenly distributed without through holes. The bonding force between the coating and the base material is good, and the corrosion resistance and wear resistance are significantly improved.

Example 3

Get 150g of nickel sulfate, 50g of nickel chloride, 120g of sodium tungstate, 12g of sulfamic acid, 15g of TiO ₂ with a particle size of 1 μm, 65g of ammonium chloride, and 0.4g of AES, and prepare 1 liter of electrolyte with deionized water. The pH value of the sodium hydroxide solution was adjusted to 7.0, the temperature was controlled at 70° C. with a water bath, mechanically stirred for 1 hour, and ultrasonically dispersed for 15 minutes.

Set i ₁ =1.0A/dm ² , i ₂ =5A/dm ² , T=4s, N=250, nickel plate is used as anode, Q235 steel is used as cathode, the current density changes linearly between i ₁ and i ₂ continuously, Deposition obtained Ni-W/TiO _21.0/5.0/250 , where the subscript 1.0 represents i ₁ =1.0A/dm ² , the subscript 5.0 represents i ₂ =5.0A/dm ² , and the subscript 250 represents the total number of layers of the coating. 250.

The Ni-W/TiO _21.0/5.0/250 coating obtained by the above method has a total number of 250 coating layers and a total thickness of about 94 μm. The microstructure shows that the coating contains nanocrystalline phases, and the TiO ₂ nano phases are evenly distributed without through holes. The bonding force between the coating and the base material is good, and the corrosion resistance and wear resistance are significantly improved.

Example 4

Take 350g of nickel sulfate, 100g of sodium tungstate, 20g of boric acid, 2g of α-Al ₂ O ₃ with a particle size of 2 μm, 70g of ammonium chloride, and 1g of DRO, and prepare 1 liter of electrolyte solution with deionized water, and use sodium hydroxide The pH of the solution was adjusted to 7.0, the temperature was controlled at 75° C. with a water bath, mechanically stirred for 1 hour, and ultrasonically dispersed for 30 minutes.

Set i ₁ =1.0A/dm ² , i ₂ =2A/dm ² , T=2 s, N=800, graphite is used as anode, Q235 steel is used as cathode, the current density changes linearly between i ₁ and i ₂ continuously, Deposition obtained Ni-W/Al ₂ O _31.0/2.0/800 , where the subscript 1.0 represents i ₁ =1.0A/dm ² , the subscript 2.0 represents i ₂ =2.0A/dm ² , and the subscript 800 represents the total layer of the coating The number is 800.

The Ni-W/Al ₂ O _31.0/2.0/800 coating obtained by the above method has a total number of 800 coating layers and a total thickness of about 112 μm. The microstructure shows that the coating contains nanocrystalline phases, and the Al ₂ O ₃ nanophases are evenly distributed without through hole. The bonding force between the coating and the base material is good, and the corrosion resistance and wear resistance are significantly improved.

Example 5

Take 300g of nickel sulfate, 100g of zinc phosphate, 4g of trimethylamine borane, 35g of boric acid, 9g of TiN with a particle size of 1μm, 1g of saccharin, and 0.3g of JFC, and prepare 1 liter of electrolyte solution with deionized water, and adjust it with sodium hydroxide solution. Its pH value is 3.8, the temperature is controlled at 40° C. by using a water bath, mechanically stirred for 6 hours, and ultrasonically dispersed for 25 minutes.

Set i ₁ =2.0A/dm ² , i ₂ =8A/dm ² , T=2s, N=100, nickel plate is used as anode, Q235 steel is used as cathode, the current density changes continuously between i ₁ and i ₂ in a straight line, Deposit Ni-B/TiN _2.0/8.0/100 , where the subscript 2.0 represents i ₁ =2.0 A/dm ² , the subscript 8.0 represents i ₂ =8A/dm ² , and the subscript 100 represents the total number of coating layers is 100 .

The Ni-Zn/TiN _2.0/8.0/100 coating obtained by the above method has a total number of 100 coating layers and a total thickness of about 153 μm. The microstructure shows that the coating contains nanocrystalline phases, and the TiN nano phases are evenly distributed without through holes. The bonding force between the coating and the base material is good, and the corrosion resistance and wear resistance are significantly improved.

Claims (10)

1. a nickel alloy CMMA coating, it is characterised in that: this coating is multiple structure, and the number of plies is 50～1000；Containing nano-particle phase and amorphous embedding nano crystalline substance composite construction phase in coating structure.

Nickel alloy CMMA coating the most according to claim 1, it is characterised in that: described nickel alloy is the one in Ni-W, Ni-B or Ni-Zn alloy.

3. the preparation method of the nickel alloy CMMA coating described in claim 1, it is characterized in that: when electro-deposition by periodically-varied electric current density to control the electrolyte mass transfer in liquid phase process at negative electrode, thus obtain the nickel alloy CMMA coating of composition and structural periodicity change.

The preparation method of nickel alloy CMMA coating the most according to claim 3, it is characterised in that: described periodic current density is particularly as follows: electric current existsi ₁- i ₂Between circulation change, the low value of electric current densityi ₁It is 0.10～2.00A/dm², the high level of electric current densityi ₂It is 2.50～10A/dm², each deposition cycle T is 0.2～10s, and total periodicity N is 50～1000.

The preparation method of nickel alloy CMMA coating the most according to claim 3, it is characterized in that: described electrolyte includes in terms of mass concentration: nickel salt 150～350g/L, second main salt 1～6 g/L, nanoparticle 0.01～20g/L, buffer agent 20～50g/L, dispersant 0～1g/L, wetting agent 0～1g/L, auxiliary agent 0.1～2g/L, solvent is water.

The preparation method of nickel alloy CMMA coating the most according to claim 5, it is characterised in that: at least one in nickel sulfate, Nickel dichloride. or basic nickel carbonate of described nickel salt, and nickel sulfate must be contained.

The preparation method of nickel alloy CMMA coating the most according to claim 5, it is characterised in that: described second main salt is the one in sodium tungstate, potassium tungstate, ammonium tungstate, trimethylamine borane, sodium borohydride, zinc sulfate, zinc chloride, zinc nitrate.

The preparation method of nickel alloy CMMA coating the most according to claim 5, it is characterised in that: described nanoparticle is TiO₂、α-Al₂O₃、SiO₂, one in SiC or TiN, particle diameter is 0.005～2 μm.

The preparation method of nickel alloy CMMA coating the most according to claim 5, it is characterised in that: described buffer agent is boric acid；Described dispersant is the one in sodium citrate, citric acid, sodium tartrate, tartaric acid, boric acid, sodium borate or sulfamic acid；Described wetting agent is the one in sodium lauryl sulphate, dodecyl sodium sulfate, polyoxyethylenated alcohol sodium sulfate, polyoxyethylated alkyl phenol sodium sulfate salt, fatty alcohol-polyoxyethylene ether, NPE or OPEO.

The preparation method of nickel alloy CMMA coating the most according to claim 3, it is characterised in that: during electro-deposition, the temperature of electrolyte is 35～75 DEG C.