A design method, coating, preparation and use method of nickel-based coating

Abstract

A design method, coating, preparation method and use method of a nickel-based coating, which belongs to the nickel-based coating in the field of metal materials. The Ni3Al intermetallic compound is modified by using the "cluster plus connecting atom" model, and the cluster composition formula in the nickel-based coating is obtained as [Al-Mn x Pt y Cu z Ni t Ti3, and x + y + z + t = 12, t ≥ 6. The present invention is designed based on the "cluster plus connecting atom" structural model, conducts structural analysis and composition design on the Ni3Al intermetallic compound, selects the atoms of the cluster structure, and selectively adds a certain content of rare earth oxides to obtain the nickel-based composite coating of the present invention, thereby solving the problems of poor wear resistance, low hardness and poor corrosion resistance of the traditional coating.

Description

Technical Field

[0001] The invention relates to a nickel-based coating in the field of metal materials, in particular to a design method, a coating, and a preparation and use method of a nickel-based coating. Background Art

[0002] Nickel-based coatings have the characteristics of toughness, oxidation resistance and machinability, and are widely used in tunnel excavation, marine construction, aerospace and other fields. However, with the continuous development of industrial level, its service environment is becoming more and more complex, and the substrate surface will produce wear, corrosion, fatigue fracture and other failure forms under the influence of working conditions. Therefore, it is very important to select suitable materials to prepare nickel-based coatings.

[0003] In the existing technology, the "cluster plus connected atoms" model can describe the important structural characteristics of complex alloy phases, and on this basis, the cluster composition formula of complex alloy phases including quasicrystals and amorphous phases can be constructed, which can be used to guide the quantitative composition design of various complex alloy phases. Summary of the invention

[0004] The purpose of the present invention is to provide a design method, coating, preparation and use method of a nickel-based coating. The nickel-based coating designed and prepared by this method can effectively improve the surface properties of the substrate after being clad on the surface of a substrate, and greatly improve the surface wear resistance, corrosion resistance and hardness of the substrate.

[0005] The technical solution adopted by the present invention to achieve the above technical purpose is: a design method for a nickel-based coating, using a "cluster plus connected atom" model to 3 Al intermetallic compounds are transformed to obtain the cluster composition formula of [Al-Mn x Pt y Cu z Ni t ]Ti 3 , and x+y+z+t=12, t≥6.

[0006] As an optimization scheme for the above nickel-based coating design method, the Ni 3 The method of transforming Al intermetallic compounds is to use AlNi3 as the alloy phase and Ni as the main body. 3 Al intermetallic compounds, selected clusters [Al-Ni 12 ], with three Al atoms as connecting atoms, and the cluster composition formula [Al-Ni 12 ]Al 3 ; Then Mn, Pt and Cu are used to replace some Ni atoms, and Ti is used to replace 3 Al atoms that serve as connecting atoms.

[0007] As another optimization scheme for the above nickel-based coating design method, the [Al-Mn x Pt y Cu z Ni t ]Ti 3 The number of Mn, Pt or Cu atoms in the quartz crystal is 1-4.

[0008] As another optimization scheme of the above nickel-based coating design method, rare earth components are added to the nickel-based coating.

[0009] As another optimization scheme of the above nickel-based coating design method, the rare earth component is Y 2 O 3 , and its mass content accounts for 0-2% of the total mass of the coating.

[0010] The nickel-based coating designed based on the above nickel-based coating design method has a chemical composition and mass fraction of 0-2% Y 2 O 3 , 3-4% Al, 16-17% Ti, 6-14% Mn, 6-13% Pt, 6-13% Cu, and the balance Ni.

[0011] As an optimization scheme of the above nickel-based coating, the chemical composition and mass fraction of the nickel-based coating are: 1.5% Y 2 O 3 , 3.1% Al, 16.6% Ti, 6.3% Mn, 6.5% Pt, 6.1% Cu, and the balance Ni.

[0012] The preparation method of the above-mentioned nickel-based coating is to weigh each component according to the above-mentioned mass percentage, and the purity of the single element of each selected component is greater than 99.9%. Then, the symmetrically taken components are fully mechanically mixed and vacuum dried at 100°C for 2h to form an alloy powder with a particle size of 45-105 microns, thereby completing the preparation of the coating.

[0013] The method for strengthening the substrate surface using the above-mentioned nickel-based coating comprises the following steps:

[0014] 1) Pre-treat the substrate surface;

[0015] 2) Laser cladding is used to clad the nickel-based coating on the surface of the substrate. During laser cladding, the shielding gas and the powder feeding gas are both argon, with an overlap rate of 25-35%, forming an alloy coating on the surface of the substrate with a coating thickness of 1.3-2.3 mm.

[0016] As an optimization scheme of the above method of strengthening the substrate surface using a nickel-based coating, the operation of pre-treating the substrate surface in step 1) is to first remove the oxide layer, then wash it with anhydrous ethanol and dry it.

[0017] The design idea of ​​the present invention is:

[0018] 1) Ni 3 Al intermetallic compounds have a face-centered cubic structure and have excellent properties such as high melting point, strong oxidation resistance, high high-temperature strength and corrosion resistance. In addition, the yield strength increases with increasing temperature within a certain temperature range. Therefore, they can be used as high-temperature structural materials. Therefore, they are used as the main body of the nickel-based coating.

[0019] 2) In the cluster composition formula [Al-Ni 12 ]Al 3 On this basis, Mn was used to replace Ni atoms, Pt to replace Ni atoms, Cu to replace Ni atoms, and Ti to replace Al atoms. The mass percentage of the corresponding elements was obtained after the atomic percentage of each element was converted. In order to ensure Ni 3 The crystal structure of the Al intermetallic compound is not destroyed, and the number of Ni atoms after replacement must be greater than or equal to 6; the connecting atoms are 3 Al atoms, all of which are replaced by Ti atoms;

[0020] 3) In order to further improve the performance of the nickel-based coating, a certain amount of rare earth elements is added to the designed nickel-based powder. The addition of rare earth elements can refine the grains, improve the wear resistance and corrosion resistance of the coating, promote the formation of oxide film, improve the high-temperature oxidation resistance of the coating, reduce the content of impurities in the coating, reduce cracks, pores and surface active particles, promote consistent surface potential, and improve the corrosion resistance of the coating.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1) This invention is designed based on the concept of "cluster plus connected atoms" model. 3 The Al intermetallic compound is subjected to structural analysis and composition design, the cluster structure atoms are selected, and a certain amount of rare earth oxide is selectively added to obtain the nickel-based composite coating of the present invention, thereby solving the problems of poor wear resistance, low hardness and poor corrosion resistance of the traditional coating;

[0023] 2) Design new coating materials using the “similar component replacement concept” based on the cluster composition formula [Al-Ni 12 ]Al 3 Replacement elements, where Mn replaces Ni atoms, and Mn elements can increase Ni 3The tensile yield strength of Al alloy can be increased, and the hardness and corrosion resistance can be significantly improved; Pt replaces Ni atoms, which can strengthen the matrix and improve the high temperature resistance of the coating; Cu replaces Ni atoms, which can improve its plasticity and corrosion resistance; Ti is the main element forming the γ′ phase and can replace Al. The three Al atoms are connecting atoms, so they are all replaced by Ti atoms to reduce their solubility, promote the precipitation of the γ′ phase, and improve the strength; in order to ensure Ni 3 The crystal structure of the Al intermetallic compound is not destroyed, and the number of Ni atoms must be greater than or equal to 6;

[0024] 3) The present invention realizes precise control and preparation of the cladding layer through laser cladding, so that the coating on the substrate surface is refined and evenly distributed, which plays a role in fine grain strengthening and coating solid solution strengthening, and prepares a cladding coating with good macroscopic morphology and mechanical properties. After testing, the friction coefficient of the nickel-based coating without adding rare earth elements is 0.48, and the self-corrosion current density is 2.37×10 -5 A∙mm -2 、Microhardness 481HV 0.2 It can meet the working conditions of tools in tunnel excavation, large turbine blades, submarine pipeline components in marine engineering, and high-temperature resistant shell coatings for space shuttles in aerospace. The nickel-based coating with rare earth elements has a friction coefficient of 0.41-0.47 and a self-corrosion current density of 1.78×10 -5 A∙mm -2 -2.09×10 -5 A∙mm -2 、Microhardness 492HV 0.2 -528 HV 0.2 In comparison, the wear resistance, corrosion resistance and microhardness of the nickel-based coating with added rare earth oxides are greatly improved compared with the nickel-based coating without added rare earth elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The microstructure of the coating prepared in Example 1;

[0026] Figure 2 The friction coefficient of the coating obtained in Example 1;

[0027] Figure 3 The three-dimensional wear morphology and wear profile of the coating obtained in Example 1;

[0028] Figure 4 This is the potentiodynamic polarization curve of the coating obtained in Example 1;

[0029] Figure 5 The microhardness of the cross section of the coating prepared in Example 1. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further elaborated in detail below in conjunction with specific embodiments. The parts not explained in the following embodiments of the present invention, such as the equipment and method for laser cladding, the single element raw materials used for proportioning alloy powder, etc., are all regarded as the prior art known or should be known to those skilled in the art. Example 1

[0031] A design method for nickel-based coatings using the "cluster plus connected atoms" model 3 Al intermetallic compounds are transformed to use AlNi3 as the alloy phase and the main body is Ni 3 Al intermetallic compounds, selected clusters [Al-Ni 12 ], with three Al atoms as connecting atoms, and the cluster composition formula [Al-Ni 12 ]Al 3 Then, one Mn atom replaces one Ni atom, one Pt atom replaces one Ni atom, one Cu atom replaces one Ni atom, and three Ti atoms replace three Al atoms as connecting atoms, and then rare earth component Y is added to the nickel-based coating. 2 O 3 The final chemical composition and mass fraction of the nickel-based coating are: 1.5% Y 2 O 3 , 3.1% Al, 16.6% Ti, 6.3% Mn, 6.5% Pt, 6.1% Cu, balance Ni;

[0032] The preparation method of the above-mentioned nickel-based coating is to weigh each component according to the above-mentioned mass percentage, and the purity of the single element of each selected component is greater than 99.9%. Then, the symmetrically taken components are mechanically mixed for 6 hours and vacuum dried at 100°C for 2 hours to form an alloy powder with a particle size of 45-105 microns, thereby completing the preparation of the coating.

[0033] The method for strengthening the surface of a high nitrogen steel substrate using the above-mentioned nickel-based coating comprises the following steps:

[0034] 1) Pre-treat the surface of the high nitrogen steel substrate by removing the oxide layer, then clean it with anhydrous ethanol and dry it;

[0035] 2) A cladding experiment was carried out on the surface of high nitrogen steel using XL-F3000 laser cladding equipment. The powder feeding device was a coaxial powder feeding device with closed-loop feedback flow control. The protective gas and the powder feeding gas were argon. The material was prepared by cladding to form an alloy coating on the surface of the substrate. The preparation process was: laser power 1400w, scanning speed 4mm / s, overlap rate 30%, and coating thickness 2.2mm.

[0036] After the laser cladding samples were cut, the coating performance was tested. The experimental results showed that the friction coefficient of the high nitrogen steel surface coating was 0.41 and the self-corrosion current density was 1.78×10 -5 A∙mm -2 , Microhardness 528 HV 0.2 .

[0037] Figure 1 The microstructure of the nickel-based coating containing rare earth elements prepared in this example is given.

[0038] Figure 2 The friction coefficient of the coating in this embodiment is given. As can be seen from the figure, the wear experiment is divided into two stages: running-in and stable wear; at the beginning of the friction experiment, the friction coefficient is small and fluctuates greatly, mainly because at the beginning of the experiment, the contact form between the grinding ball and the coating surface is point contact, and the contact surface is small; as the friction experiment proceeds, the change in surface roughness causes the contact form to change from point contact to surface contact, the contact surface gradually increases, the friction coefficient fluctuates within a certain range, and the wear tends to be stable.

[0039] Figure 3 The three-dimensional morphology and wear profile of the coating in this example are given. The wear depth of the nickel-based cladding layer with a rare earth content of 1.5% is 9.3μm and the width is 0.65μm, indicating that adding an appropriate amount of Y 2 O 3 , which can refine the structure of the coating and play a role in fine grain strengthening;

[0040] Figure 4 The potential polarization curve of the coating in this embodiment is given. At this time, the self-corrosion potential of the nickel-based cladding layer containing rare earth elements is -0.80V, and the self-corrosion current density is 1.78×10 -5 The passivation zone is -0.75~-0.08V, and the passivation zone is relatively wide, that is, the stability of the passivation film is better.

[0041] Figure 5 The cross-sectional microhardness of the coating obtained in this embodiment is given. As can be seen from the figure, the coating hardness change curve can be divided into three regions: coating, heat-affected zone and substrate, which shows a gradual downward trend as a whole; the hardness of the coating transitions to the heat-affected zone, which shows a downward trend, mainly due to the increase in grain size at the bottom of the molten pool and the reduction of the reinforcing phase; the hardness of the heat-affected zone is higher than that of the substrate, mainly because the surface layer of the substrate is affected by the heat of the molten pool and undergoes phase transformation hardening. The hardness of the nickel-based cladding layer containing rare earth elements in this embodiment is about 528HV 0.2 . Example 2

[0042] A design method for nickel-based coatings using the "cluster plus connected atoms" model 3 Al intermetallic compounds are transformed to use AlNi3 as the alloy phase and the main body is Ni3 Al intermetallic compounds, selected clusters [Al-Ni 12 ], with three Al atoms as connecting atoms, and the cluster composition formula [Al-Ni 12 ]Al 3 Then, one Mn atom replaces one Ni atom, two Pt atoms replace two Ni atoms, one Cu atom replaces one Ni atom, and three Ti atoms replace three Al atoms as connecting atoms, and then rare earth component Y is added to the nickel-based coating. 2 O 3 The chemical composition and mass fraction of the nickel-based coating are finally formed as follows: 0.5%Y 2 O 3 , 3.5%Al, 16.9%Ti, 6.5%Mn, 12.6%Pt, 7.2%Cu, and the balance Ni. The material particle size is 45-105μm alloy powder, which is used for laser cladding preparation. The process is exactly the same as that in Example 1 to form an alloy coating.

[0043] The coating performance test showed that the friction coefficient of the coating was 0.46 and the self-corrosion current density was 1.98×10 -5 A∙mm -2 , Microhardness 501 HV 0.2 . Example 3

[0044] A design method for nickel-based coatings using the "cluster plus connected atoms" model 3 Al intermetallic compounds are transformed to use AlNi3 as the alloy phase and the main body is Ni 3 Al intermetallic compounds, selected clusters [Al-Ni 12 ], with three Al atoms as connecting atoms, and the cluster composition formula [Al-Ni 12 ]Al 3 Then two Mn atoms are used to replace two Ni atoms, one Pt atom is used to replace one Ni atom, one Cu atom is used to replace one Ni atom, and three Ti atoms are used to replace three Al atoms as connecting atoms. Then, rare earth component Y is added to the nickel-based coating. 2 O 3 The chemical composition and mass fraction of the nickel-based coating are finally formed as follows: 1%Y 2 O 3 , 3.8%Al, 16.2%Ti, 12.8%Mn, 7.4%Pt, 6.9%Cu, and the balance Ni. The material particle size is 45-105μm alloy powder, which is used for laser cladding preparation. The process is exactly the same as that in Example 1 to form an alloy coating.

[0045] The coating performance test showed that the coating friction coefficient was 0.44 and the self-corrosion current density was 1.88×10 -5 A∙mm -2 , Microhardness 512 HV 0.2 . Example 4

[0046] A design method for nickel-based coatings using the "cluster plus connected atoms" model 3 Al intermetallic compounds are transformed to use AlNi3 as the alloy phase and the main body is Ni 3 Al intermetallic compounds, selected clusters [Al-Ni 12 ], with three Al atoms as connecting atoms, and the cluster composition formula [Al-Ni 12 ]Al 3 Then, one Mn atom replaces one Ni atom, one Pt atom replaces one Ni atom, two Cu atoms replace two Ni atoms, and three Ti atoms replace three Al atoms as connecting atoms, and then rare earth component Y is added to the nickel-based coating. 2 O 3 The final chemical composition and mass fraction of the nickel-based coating are: 2%Y 2 O 3 , 3.9%Al, 16.1%Ti, 7.5%Mn, 8.4%Pt, 12.6%Cu, and the balance Ni. The material particle size is 45-105 μm alloy powder, which is used for laser cladding preparation. The process is exactly the same as that in Example 1 to form an alloy coating.

[0047] The coating performance test showed that the friction coefficient of the coating was 0.47 and the self-corrosion current density was 2.09×10 -5 A∙mm -2 , microhardness 492 HV 0.2 .

[0048] Comparative Example 1

[0049] A design method for nickel-based coatings using the "cluster plus connected atoms" model 3 Al intermetallic compounds are transformed to use AlNi3 as the alloy phase and the main body is Ni 3 Al intermetallic compounds, selected clusters [Al-Ni 12 ], with three Al atoms as connecting atoms, and the cluster composition formula [Al-Ni 12 ]Al 3; Two Mn atoms are used to replace two Ni atoms, two Pt atoms are used to replace two Ni atoms, two Cu atoms are used to replace two Ni atoms, three Ti atoms are used to replace three Al atoms as connecting atoms, and no rare earth component Y is added to the nickel-based coating 2 O 3 The chemical composition and mass fraction of the nickel-based coating are finally formed as follows: 0%Y 2 O 3 , 3.2% Al, 16.2% Ti, 10.7% Mn, 11.2% Pt, 9.5% Cu, and the balance Ni. The process is the same as that in Example 1. The test results show that the friction coefficient of the nickel-based coating without adding rare earth elements is 0.48, and the self-corrosion current density is 2.37×10 -5 A∙mm -2 , microhardness 481 HV 0.2 , which is lower than the performance of coatings with added rare earth elements.

[0050] Comparative Example 2

[0051] Laser cladding process: conventional nickel-based material (material grade: In35, main component NiCrSiFeMo) was selected for laser additive manufacturing on the surface of Q235 steel, with a laser power of 1200 W and a scanning speed of 1 mm / s. The experimental results are: hardness 300 HV 0.2 , friction coefficient is 0.52.

[0052] Results analysis: Comparison of Examples 1, 2, 3, and 4 shows the effects of different rare earth addition amounts on the wear resistance, corrosion resistance, and hardness of the coating. 2 O 3 When the addition amount is 1.5%, the corrosion resistance, wear resistance and hardness performance are the best. From Comparative Examples 1 and 2, it can be seen that the wear resistance, corrosion resistance and hardness of the coating without rare earth element addition are significantly lower than those of the coating with rare earth element addition.

[0053] It can be seen from the above specific embodiments that the present invention is mainly based on the nickel-based material designed based on cluster theory, optimizes laser cladding parameters, and completes high-quality surface treatment technology, which can greatly enhance the wear resistance, corrosion resistance and hardness of the high nitrogen steel surface.

Claims

1. A method for preparing a nickel-based coating, characterized in that: The Ni3Al intermetallic compound was modified using the "cluster plus connecting atom" model, and the cluster composition formula of the nickel-based coating was obtained as [Al-Mn x Pt y Cu z Ni t ]Ti3, and x+y+z+t=12, t≥6; the method for modifying the Ni3Al intermetallic compound is to use AlNi3 as the alloy phase, the main body is the Ni3Al intermetallic compound, and select the cluster [Al-Ni 12 ], with three Al atoms as connecting atoms, and the cluster composition formula [Al-Ni 12 ]Al3; then Mn, Pt and Cu are used to replace part of the Ni atoms, and Ti is used to replace 3 Al atoms as connecting atoms; rare earth components are added to the nickel-based coating, and the rare earth component is Y2O3.

2. The method for preparing a nickel-based coating according to claim 1, characterized in that: The [Al-Mn x Pt y Cu z Ni t ]The number of Mn, Pt or Cu atoms in Ti3 is 1-4.

3. The method for preparing a nickel-based coating according to claim 1, characterized in that: The mass content of Y2O3 accounts for 0-2% of the total mass of the coating and is not 0.

4. A nickel-based coating prepared according to the method for preparing a nickel-based coating according to any one of claims 1 to 3, characterized in that: The chemical composition and mass fraction of the nickel-based coating are 0-2% (not 0) of Y2O3, 3-4% of Al, 16-17% of Ti, 6-14% of Mn, 6-13% of Pt, 6-13% of Cu, and the balance of Ni.

5. The nickel-based coating according to claim 4, characterized in that: The chemical composition and mass fraction of the nickel-based coating are 1.5% Y2O3, 3.1% Al, 16.6% Ti, 6.3% Mn, 6.5% Pt, 6.1% Cu, and the balance Ni.

6. A method for strengthening a substrate surface using the nickel-based coating of claim 4, characterized in that: The steps include: 1) Pre-treat the substrate surface; 2) Laser cladding is used to clad the nickel-based coating on the surface of the substrate. During laser cladding, the shielding gas and the powder feeding gas are both argon, with an overlap rate of 25-35%, forming an alloy coating on the surface of the substrate with a coating thickness of 1.3-2.3 mm.

7. The method for strengthening the surface of a substrate using a nickel-based coating according to claim 6, characterized in that: The operation of pre-treating the substrate surface in step 1) is to first remove the oxide layer, then wash with anhydrous ethanol and perform drying.

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