Damping corrosion-resistant composite coating as well as preparation method and application thereof

Abstract

The invention discloses a damping corrosion-resistant composite coating which comprises a bottom CuNiSi layer and a surface NiTi layer, the raw material of the CuNiSi layer is CuNiSi powder, and the CuNiSi layer comprises, by mass, 19%-35% of Ni, 0.5%-1.0% of Si and the balance Cu and inevitable impurities. The preparation method comprises the steps that S1, the CuNiSi layer is formed on the surface of the base body through laser cladding; and S2, a NiTi layer is formed on the surface of the CuNiSi layer through laser cladding. The damping and corrosion-resistant composite coating can be applied to a reverse osmosis safe rupture disk connecting pipeline, the hardness and corrosion resistance of the connecting pipeline can be improved to meet the corrosion requirement of water treatment engineering, and the damping performance of the connecting pipeline can also be improved; and shock waves generated by safe rupture membrane rupture and water hammer impact are met, and the shock absorption performance is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of coating materials, and particularly relates to a shock-absorbing and corrosion-resistant composite coating, a preparation method thereof, and an application thereof. Background Art

[0002] Reverse osmosis is currently the most precise liquid separation technology and is widely used in various types of water treatment processes. Safety burst membranes are mainly applied to large-scale reverse osmosis in power plants, steel plants, seawater desalination, etc. Due to the inevitable water hammer phenomenon in the system design, the safety burst membrane is extremely vulnerable to water hammer impact and rupture during startup and shutdown. And when the back pressure on the water production side exceeds the threshold value, the safety burst membrane will also rupture. The generated shock wave will cause stress concentration in the surrounding water pipelines, exacerbate the failure of the pipelines, and even cause economic losses. In addition, during the reverse osmosis process, the concentration on the water treatment side increases during water production, which will exacerbate the corrosion of the pipelines.

[0003] Therefore, there is an urgent need for a shock-absorbing and corrosion-resistant coating to extend the service life of related pipelines. Summary of the Invention

[0004] Based on the above technical problems, the present invention provides a shock-absorbing and corrosion-resistant composite coating, and the composite coating includes a bottom CuNiSi layer and a surface NiTi layer. This composite coating can be applied to the connecting pipelines of reverse osmosis safety burst membranes to improve the shock absorption and corrosion resistance of the connecting pipelines.

[0005] The specific solution of the present invention is as follows:

[0006] One of the purposes of the present invention is to provide a shock-absorbing and corrosion-resistant composite coating, including: a bottom CuNiSi layer and a surface NiTi layer; the raw material of the CuNiSi layer is CuNiSi powder, and by mass percentage, it includes: Ni 19-35%, Si 0.5-1.0%, and the balance is Cu and unavoidable impurities.

[0007] Preferably, the raw material of the NiTi layer is NiTi powder, and by mass percentage, it includes: Ni 55.5-56.5%, and the balance is Ti and unavoidable impurities.

[0008] Preferably, the CuNiSi powder is formed by mixing Cu powder and SiNi powder; the particle size of the Cu powder is 50-120 μm, and the particle size of the SiNi powder is 30-120 μm. More preferably, the particle size of the NiTi powder is 30-120 μm.

[0009] Preferably, both the bottom layer and the surface layer are obtained by laser cladding, and a new NiTiCu phase is formed between the bonding surfaces of the CuNiSi layer and the NiTi layer.

[0010] The present invention uses a CuNiSi layer as the bottom layer and a NiTi layer as the top layer. The CuNiSi layer is located between the NiTi layer and the substrate. On the one hand, it can improve the bonding strength between the NiTi layer and the substrate; on the other hand, it can further improve the shock absorption performance of the overall coating.

[0011] In a preferred embodiment, the CuNiSi layer and the NiTi layer are sequentially formed on the surface of the substrate by laser cladding, which has the characteristics of high efficiency, good flexibility, and the ability to fabricate complex shapes. A new phase NiTiCu will be formed at the bonding interface between the CuNiSi layer and the NiTi layer, which has good superelasticity and can ensure that the interface does not become unstable when transmitting external forces, further increasing the impact life of the coating.

[0012] A second object of the present invention is to provide a method for preparing a shock-absorbing and corrosion-resistant composite coating, including: S1, forming a CuNiSi layer on the surface of the substrate by laser cladding; S2, forming a NiTi layer on the surface of the CuNiSi layer by laser cladding.

[0013] Preferably, the laser cladding parameters in S1 and S2 are independently selected from: laser spot diameter 0.8 - 2.0 mm, laser power 1000 - 1200 W, cladding speed 10 - 12 mm / s, and powder feeding rate 0.8 - 1.2 r / min. More preferably, the laser cladding in both S1 and S2 is coaxial powder feeding.

[0014] Preferably, the substrate is selected from at least one of iron-based alloys, titanium alloys, or aluminum alloys.

[0015] Preferably, the substrate is an iron-based alloy; more preferably, the iron-based alloy includes, by mass percentage: Mn 1.09 - 1.16%, Si 0.15 - 0.17%, P 0.07 - 0.08%, Cu 0.02 - 0.04%, Mo 0.07 - 0.08%, and the balance is Fe and unavoidable impurities.

[0016] A third object of the present invention is to provide the application of the above shock-absorbing and corrosion-resistant composite coating in the connecting pipeline of a reverse osmosis safety bursting membrane.

[0017] The beneficial effects of the present invention are as follows:

[0018] In the shock-absorbing and corrosion-resistant composite coating provided by the present invention, the bottom CuNiSi layer and the top NiTi layer cooperate with each other, which not only ensures the bonding strength between the coating and the substrate, enhances the stability and reliability of the overall structure, but also has high corrosion resistance and shock absorption performance.

[0019] The shock-absorbing and corrosion-resistant composite coating described in the present invention can be applied to the connecting pipeline of the reverse osmosis safety bursting membrane, which can not only improve the hardness and corrosion resistance of the connecting pipeline to meet the corrosion requirements of water treatment projects, but also improve the damping performance of the connecting pipeline to better withstand the impact generated by the rupture of the safety bursting membrane and water hammer shock. Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of the combination of the shock-absorbing and corrosion-resistant composite coating and the substrate;

[0021] Figure 2 It is the morphology and element composition data at the interface of Example 1, where (a) is the morphology diagram and (b) is the element composition;

[0022] Figure 3 It is the surface scanning morphology element distribution diagram of the CuNiSi powder used in Example 1;

[0023] Figure 4 It is the surface scanning morphology element distribution diagram of the NiTi powder used in Example 1;

[0024] Figure 5 It is the morphology diagram of the CuNiSi layer after coloring flaw detection obtained in Example 1;

[0025] Figure 6 It is the morphology diagram of the NiTi layer after coloring flaw detection obtained in Example 1;

[0026] Figure 7 It is the interface morphology diagram of the composite coating obtained in Example 1;

[0027] Figure 8 It is the hardness test result of the composite coating obtained in Example 1;

[0028] Figure 9 It is the nano-indentation data of the composite coating obtained in Example 1;

[0029] Figure 10 It is the polarization curve of the composite coating obtained in Example 1;

[0030] Figure 11 It is the morphology diagram of the CuNiSi layer after coloring flaw detection according to Example 2; Detailed Embodiments

[0031] Next, the technical solutions of the present invention will be described in detail through specific examples. However, it should be clearly stated that these examples are for illustrative purposes only and are not to be construed as limiting the scope of the present invention.

[0032] Example 1

[0033] A shock-absorbing and corrosion-resistant composite coating, comprising: a bottom CuNiSi layer and a surface NiTi layer, both the bottom layer and the surface layer are obtained by laser cladding.

[0034] Among them, the raw material of the CuNiSi layer is CuNiSi powder, including by mass percentage: Ni 26.4%, Si 0.7%, and the balance is Cu and inevitable impurities. The CuNiSi powder is formed by mixing Cu powder and SiNi powder; the particle size of the Cu powder is 50 - 120 μm, and the particle size of the SiNi powder is 30 - 120 μm.

[0035] The raw material of the NiTi layer is NiTi powder, including by mass percentage: Ni: 55.5%, and the balance is Ti and inevitable impurities; the particle size of the NiTi powder is 30 - 120 μm.

[0036] The schematic structural diagram of the shock-absorbing and corrosion-resistant composite coating of the present invention combined with the substrate is as Figure 1 shown.

[0037] The morphology and element composition data of the tissue at the interface between the CuNiSi layer and the NiTi layer in this embodiment are as Figure 2 shown, where (a) is the morphology diagram and (b) is the element composition.

[0038] It can be seen that by using the laser cladding method to sequentially form the CuNiSi layer and the NiTi layer on the substrate surface, a new NiTiCu phase will be formed between the bonding surfaces of the CuNiSi layer and the NiTi layer, which has good superelasticity and can ensure that the interface does not become unstable when transmitting external forces, further increasing the impact life of the coating.

[0039] The surface scanning morphology and element distribution of the CuNiSi powder used in this embodiment are as Figure 3 shown, and the surface scanning morphology and element distribution of the NiTi powder are as Figure 4 shown.

[0040] A preparation method of a shock-absorbing and corrosion-resistant composite coating, comprising:

[0041] S1. Use laser cladding to form a CuNiSi layer on the substrate surface. Adopt the coaxial powder feeding method. The parameters of laser cladding are: the laser spot diameter is 1.2 mm, the laser power is 1000 W, the cladding speed is 10 mm / s, and the powder feeding rate is 1.0 r / min;

[0042] S2. Use laser cladding to form a NiTi layer on the surface of the CuNiSi layer. Adopt the coaxial powder feeding method. The parameters of laser cladding are: the laser spot diameter is 1.2 mm, the laser power is 1000 W, the cladding speed is 10 mm / s, and the powder feeding rate is 1.1 r / min.

[0043] Among them, the substrate is a reverse osmosis safety bursting membrane connecting pipeline, the connecting pipeline is an iron-based alloy, and the composition of the substrate is: Mn 1.093%, Si 0.165%, P 0.08%, Cu 0.031%, Mo 0.08%, and the balance is Fe and unavoidable impurities.

[0044] The morphology of the CuNiSi layer obtained in Example S1 after penetrant inspection is as Figure 5 shown. It can be seen that no cracks appear in the clad CuNiSi layer. The morphology of the NiTi layer obtained in S2 after penetrant inspection is as Figure 6 shown. It can be seen that no cracks appear in the clad NiTi layer. The interfacial morphology diagram of the composite coating obtained in this example is as Figure 7 shown. It can be seen that the bonding between the coatings is good.

[0045] The hardness of different positions of the composite coating obtained in this example is tested, and the test results are as Figure 8 shown, where interface 1 is the interface between the substrate and the CuNiSi layer, and interface 2 is the interface between the CuNiSi layer and the NiTi layer.

[0046] It can be seen that the hardness of the NiTi layer increases significantly compared with the substrate.

[0047] The nano-indentation data of the composite coating obtained in this example is as Figure 9 shown.

[0048] It can be seen that compared with the substrate material, the elastic recovery rate of the CuNiSi layer increases, and the elastic recovery rate of the NiTi layer is higher, which provides a buffer for reducing water hammer impact and safety bursting membrane impact of the connecting pipeline.

[0049] The polarization curve of the composite coating obtained in this example is as Figure 10 shown. It can be seen that the corrosion resistance of the coating is significantly improved.

[0050] Example 2

[0051] A shock-absorbing and corrosion-resistant composite coating, including: a bottom CuNiSi layer and a surface NiTi layer.

[0052] Among them, the raw material of the CuNiSi layer is CuNiSi powder, including by mass percentage: Ni 19.6%, Si 0.5%, and the balance is Cu and unavoidable impurities. The CuNiSi powder is mixed by Cu powder and SiNi powder; the particle size of the Cu powder is 50 - 120 μm, and the particle size of the SiNi powder is 30 - 120 μm;

[0053] The raw material of the NiTi layer is the same as the NiTi powder described in Example 1.

[0054] A preparation method of a shock-absorbing and corrosion-resistant composite coating, which is only different from Example 1 in that the CuNiSi powder used to form the CuNiSi layer is the CuNiSi powder described in this example, and other steps and parameters are the same as those in Example 1.

[0055] The morphology diagram of the CuNiSi layer after coloring flaw detection in this example is as Figure 11 shown.

[0056] Example 3

[0057] A preparation method of a shock-absorbing and corrosion-resistant composite coating, comprising:

[0058] S1. Form a CuNiSi layer on the surface of the substrate by laser cladding. The parameters of the laser cladding are: the laser spot diameter is 1.5 mm, the laser power is 1000 W, the cladding speed is 12 mm / s, and the powder feeding rate is 0.9 r / min;

[0059] S2. Form a NiTi layer on the surface of the CuNiSi layer by laser cladding. The parameters of the laser cladding are: the laser spot diameter is 1.2 mm, the laser power is 1000 W, the cladding speed is 12 mm / s, and the powder feeding rate is 0.8 r / min.

[0060] Wherein, the substrate is a connecting pipeline of a reverse osmosis safety bursting membrane, and the composition of the base material of the connecting pipeline is the same as that in Example 1; the raw materials used to form the CuNiSi layer and the NiTi layer are the same as those in Example 1.

[0061] Comparative Example 1 - Comparative Example 3

[0062] A preparation method of a coating, comprising: directly forming a NiTi layer on the surface of the substrate by laser cladding. The specific parameters of the laser cladding are: the laser spot diameter is 1.2 mm, the laser power is 1000 W, the cladding speed is 10 mm / s, and the powder feeding rates are 1.0, 1.1, and 1.2 r / min respectively (corresponding to Comparative Examples 1 - 3). Wherein, the substrate is a connecting pipeline of a reverse osmosis safety bursting membrane, and the composition of the base material of the connecting pipeline is the same as that in Example 1.

[0063] In the above comparative examples, a NiTi layer was directly cladded on the surface of the substrate by laser cladding at different powder feeding rates, and a coating was not successfully obtained, and the coating peeled off from the surface of the substrate. It shows that there is a problem of poor bonding strength between the NiTi layer and the substrate.

[0064] Comparative Example 4 - Comparative Example 5

[0065] A method for preparing a coating, comprising: directly forming a performance layer on the surface of a substrate by laser cladding; the raw materials of the performance layer include: NiTi powder and Cu powder, and the ratio of the two is 92:8. The parameters of laser cladding are specifically: the laser spot diameter is 1.2 mm, the laser power is 1000 W, the cladding speed is 10 mm / s, and the powder feeding rates are 1.0 and 1.2 r / min (corresponding to Comparative Example 4 and Comparative Example 5 respectively).

[0066] Among them, the substrate is a reverse osmosis safety bursting membrane connecting pipeline, and the composition of the base material of the connecting pipeline is the same as that of Example 1.

[0067] Using this method, a performance layer can be obtained on the surface of the substrate, but the coloring flaw detection experiment shows that the material obtained thereby is covered with cracks.

[0068] As mentioned above, the above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A shock-absorbing and corrosion-resistant composite coating, characterized in that, Comprising: A bottom CuNiSi layer and a top NiTi layer; the raw material of the CuNiSi layer is CuNiSi powder, which by mass percentage includes: Ni 19 - 35%, Si 0.5 - 1.0%, and the balance is Cu and unavoidable impurities.

2. The shock-absorbing and corrosion-resistant composite coating according to claim 1, characterized in that, The raw material of the NiTi layer is NiTi powder, which by mass percentage includes: Ni 55.5 - 56.5%, and the balance is Ti and unavoidable impurities.

3. The shock-absorbing and corrosion-resistant composite coating according to claim 1 or 2, characterized in that, The CuNiSi powder is formed by mixing Cu powder and SiNi powder; the particle size of the Cu powder is 50 - 120 μm, and the particle size of the SiNi powder is 30 - 120 μm; preferably, the particle size of the NiTi powder is 30 - 120 μm.

4. The shock-absorbing and corrosion-resistant composite coating according to claim 1 or 2, wherein Both the bottom layer and the top layer are obtained by laser cladding, and a new NiTiCu phase is formed at the interface between the CuNiSi layer and the NiTi layer.

5. The preparation method of the shock-absorbing and corrosion-resistant composite coating according to any one of claims 1-4, characterized in that, Comprising: S1. Form a CuNiSi layer on the surface of the substrate by laser cladding; S2. Form a NiTi layer on the surface of the CuNiSi layer by laser cladding.

6. The preparation method of the shock-absorbing and corrosion-resistant composite coating according to claim 5, characterized in that, The laser cladding parameters in S1 and S2 are each independently selected from: the laser spot diameter is 0.8 - 2.0 mm, the laser power is 1000 - 1200 W, the cladding speed is 10 - 12 mm / s, and the powder feeding rate is 0.8 - 1.2 r / min.

7. The method for preparing the shock-absorbing and corrosion-resistant composite coating according to claim 5 or 6, characterized in that, The laser cladding in S1 and S2 is both coaxial powder feeding.

8. The preparation method of the shock-absorbing and corrosion-resistant composite coating according to claim 5 or 6, characterized in that, The substrate is selected from at least one of iron-based alloys, titanium alloys or aluminum alloys.

9. The preparation method of the shock-absorbing and corrosion-resistant composite coating according to claim 8, wherein The iron-based alloy by mass percentage includes: Mn 1.09 - 1.16%, Si 0.15 - 0.17%, P 0.07 - 0.08%, Cu 0.02 - 0.04%, Mo 0.07 - 0.08%, and the balance is Fe and unavoidable impurities.

10. Application of the shock-absorbing and corrosion-resistant composite coating according to any one of claims 1 - 4 in the connecting pipeline of the reverse osmosis safety bursting membrane.

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