A Cr / TaWMoCrZr nanolayer coating with heterogeneous coherent interface and its preparation method

Abstract

This invention discloses a Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface and its preparation method, belonging to the field of material surface modification. The nanolayered coating comprises alternating layers of Cr and a TaWMoCrZr refractory high-entropy alloy layer. Both the Cr and TaWMoCrZr layers have a BCC crystal phase structure, and the interface between them is a heterogeneous coherent interface. The Cr / TaWMoCrZr nanolayered coating is prepared on a substrate using magnetron sputtering deposition. Due to the template effect of Cr, the originally amorphous TaWMoCrZr undergoes epitaxial growth to form a BCC crystal structure with the same preferred orientation as Cr, greatly controlling the microstructure and forming a heterogeneous coherent interface. This Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface exhibits a uniform microstructure, good corrosion and oxidation resistance, radiation resistance, and excellent high-temperature structural stability and mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of material surface modification, specifically to a Cr / TaWMoCrZr nano-multilayer coating with a heterogeneous coherent interface and its preparation method. Background Technology

[0002] Pure Cr coatings possess excellent corrosion resistance, a high melting point, and superior mechanical strength and wear resistance, making them highly promising for applications in aerospace, nuclear fuel storage, military, and medical devices. However, the presence of numerous grain boundaries at the nanoscale hinders dislocation movement, resulting in poor plasticity in pure Cr coatings, which significantly limits their development and application.

[0003] High-entropy alloys, due to their unique microstructure and excellent comprehensive properties, have broad application prospects and have become a research hotspot in recent years. High-entropy alloy coatings, derived from high-entropy alloys, also exhibit superior properties compared to traditional alloy coatings, such as mechanical properties, corrosion resistance, wear resistance, oxidation resistance, and radiation resistance. To better meet the requirements of high-temperature environments, the elements used in high-entropy alloy coatings should ideally be selected from refractory metals, giving the material excellent thermodynamic properties. High-entropy alloy coatings can be combined with traditional coatings to achieve complementary advantages and joint development.

[0004] Heterogeneous structures can optimize the mechanical properties of materials through the synergistic effect of multiple strengthening mechanisms, including heterogeneous deformation-induced (HDI) strengthening, dislocation modulation in nanostructures, and phase transformation-induced plasticity. They achieve a good balance between strength and plasticity by improving plasticity while maintaining improved strength. Heterogeneous multilayer film structures can further enhance the mechanical properties of materials. The heterogeneous coherent interfaces in multilayer film structures not only improve strength but also provide channels for dislocation movement, thereby enhancing plasticity and meeting application requirements.

[0005] Magnetron sputtering is a relatively mature coating preparation technology due to its low energy, controllable deposition rate, and good process repeatability. It can be used to prepare nanoscale multilayer coatings with heterogeneous structures. However, high-entropy alloys have a high element content, resulting in complex compositions and low controllability. Therefore, preparing a metal / high-entropy alloy nanoscale multilayer coating with a heterogeneous coherent interface remains a technical challenge. Overcoming this challenge relies on the selection and design of the high-entropy alloy composition to achieve good lattice matching with the single-element metal layer, forming a heterogeneous coherent interface. The interface density significantly affects the mechanical properties of the heterogeneous coherent interface nanoscale multilayer coating. This interface density can be controlled by altering the magnetron sputtering process parameters, thereby improving material properties. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a Cr / TaWMoCrZr nano-multilayer coating with a heterogeneous coherent interface and its preparation method. By controlling the microstructure of the Cr / TaWMoCrZr nano-multilayer coating through magnetron sputtering, the Cr / TaWMoCrZr nano-multilayer coating exhibits a uniform microstructure, good corrosion and oxidation resistance, radiation resistance, and excellent high-temperature structural stability and mechanical properties.

[0007] This invention is achieved through the following technical solution:

[0008] A Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface, comprising alternating layers of Cr and TaWMoCrZr refractory high-entropy alloy.

[0009] The crystal phase microstructure of both the Cr layer and the TaWMoCrZr refractory high-entropy alloy layer is BCC, and the interface between the Cr layer and the TaWMoCrZr refractory high-entropy alloy layer is a heterogeneous coherent interface.

[0010] Preferably, the modulation ratio of the Cr layer and the TaWMoCrZr refractory high-entropy alloy layer in the same modulation cycle is 1:1, and the thickness is 10-100 nm.

[0011] Preferably, the thickness of the Cr / TaWMoCrZr nanolayer coating is 1.6~5μm.

[0012] Preferably, in the TaWMoCrZr refractory high-entropy alloy layer, the atomic percentage ratio of the five elements Ta, W, Mo, Cr and Zr is 1:1:1:1:1.

[0013] Preferably, the nanoindentation hardness of the Cr / TaWMoCrZr nanolayered coating is 8-11 GPa, and the Young's modulus is 164-187 GPa.

[0014] A method for preparing a Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface, characterized by comprising the following steps:

[0015] Step 1: After cleaning and drying the substrate, perform vacuum etching;

[0016] Step 2: Prepare a Cr / TaWMoCrZr nano-multilayer coating on the substrate by magnetron sputtering;

[0017] First, a refractory high-entropy alloy layer of TaWMoCrZr was deposited on the substrate by magnetron co-sputtering using a TaWMoCr alloy target and a Zr target.

[0018] Then, a Cr layer was deposited on the TaWMoCrZr refractory high-entropy alloy layer using a Cr target.

[0019] Secondly, repeat the above process, alternately depositing the TaWMoCrZr refractory high-entropy alloy layer and the Cr layer until the thickness of the nano-multilayer coating reaches the predetermined thickness.

[0020] The deposition time of the TaWMoCrZr refractory high-entropy alloy layer is 64~625s, the deposition time of the Cr layer is 72~714s, and the modulation period of the magnetron sputtering is 20~200nm.

[0021] Step 3: Cool the nano-multilayer coating to room temperature to obtain a Cr / TaWMoCrZr nano-multilayer coating with a heterogeneous coherent interface.

[0022] Preferably, the DC power of the TaWMoCr alloy target in step 2 is 100W, the RF power of the Zr target is 100W, and the DC power of the Cr target is 200W.

[0023] Preferably, during the magnetron sputtering process described in step 2, the deposition gas pressure is 0.3 Pa and the substrate rotation speed is 15 r / min.

[0024] Preferably, the cooling time in step 3 is 2-3 hours.

[0025] Application of a Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface, wherein the nanolayered coating is used for the protection of the cladding of a lead-bismuth fast nuclear reactor.

[0026] Compared with the prior art, the present invention has the following beneficial technical effects:

[0027] This application provides a Cr / TaWMoCrZr nanolayered coating with heterogeneous coherent interfaces. Cr and TaWMoCrZr layers are alternately stacked, forming numerous heterogeneous coherent interfaces. These interfaces act as barriers to dislocation movement, effectively hindering dislocation slip and climb, thereby increasing the coating's hardness. Secondly, Zr elements with significantly different atomic radii are introduced into the TaWMoCr matrix. With the increase of Zr, TaWMoCr undergoes significant lattice distortion while maintaining a BCC structure. As a refractory high-entropy alloy, this high-entropy design of TaWMoCrZr leads to severe lattice distortion, increasing the resistance to dislocation movement and thus improving the material's hardness and strength. Simultaneously, the introduction of Zr further increases lattice distortion, but because the BCC structure is still maintained, this distortion enhances the material while preserving structural stability. Furthermore, the Cr layer acts as a template layer, inducing amorphous TaWMoCrZr to form a BCC crystal structure through epitaxial growth, and it shares the same preferred orientation as the Cr layer. The formation of this heterogeneous coherent interface greatly regulates the microstructure and improves the overall performance of the coating.

[0028] The preparation method described in this application regulates the microstructure of Cr / TaWMoCrZr nanolayered coatings with heterogeneous coherent interfaces by controlling the modulation period. Changes in the modulation period affect the interfacial density and consequently, the coating's performance. Controlling the modulation period to regulate the coating's microstructure and preparing high-performance Cr / TaWMoCrZr nanolayered coatings with heterogeneous coherent interfaces is of great significance. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 The image shows the XRD results of the Cr / TaWMoCrZr nanolayered coating with heterogeneous coherent interface of the present invention.

[0031] Figure 2 The images shown are: a low-magnification TEM image of the Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface of the present invention, along with selected area electron diffraction and high-resolution images.

[0032] Figure 3 This is an indentation hardness diagram of the Cr / TaWMoCrZr nano-multilayer coating with heterogeneous coherent interface of the present invention.

[0033] Figure 4 STEM images and EDS elemental distribution diagrams of Cr / TaWMoCrZr nanolayered coatings with heterogeneous coherent interfaces prepared by magnetron sputtering in this invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0036] A Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface, comprising alternating layers of Cr and TaWMoCrZr refractory high-entropy alloy.

[0037] The crystal phase microstructure of both the Cr layer and the TaWMoCrZr refractory high-entropy alloy layer is BCC, and a heterogeneous coherent interface is formed between them through epitaxial growth.

[0038] The TaWMoCrZr refractory high-entropy alloy layer has an atomic percentage ratio of 1:1:1:1:1 for the five elements Ta, W, Mo, Cr and Zr.

[0039] In the same modulation cycle, the modulation ratio of the Cr layer and the TaWMoCrZr refractory high-entropy alloy layer is 1:1, that is, the thickness of the Cr layer and the TaWMoCrZr refractory high-entropy alloy layer is the same, with a thickness of 10 to 100 nm.

[0040] The thickness of the Cr / TaWMoCrZr nanolayer coating is 1.6~5μm.

[0041] The nanoindentation hardness of the Cr / TaWMoCrZr nano-multilayer coating is 8–11 GPa, and the Young's modulus is 164–187 GPa.

[0042] This Cr / TaWMoCrZr nanolayered coating, with alternating Cr and TaWMoCrZr layers, forms numerous heterogeneous coherent interfaces. These interfaces act as barriers to dislocation movement, effectively hindering dislocation slip and climb, thereby increasing the coating's hardness. Secondly, TaWMoCrZr, as a refractory high-entropy alloy, has an atomic percentage ratio of 1:1:1:1:1. This high-entropy design leads to severe lattice distortion, increasing resistance to dislocation movement and thus improving the material's hardness and strength. The introduction of Zr further increases lattice distortion, but because the BCC structure is maintained, this distortion enhances the material while preserving structural stability. Furthermore, the Cr layer acts as a template layer, inducing amorphous TaWMoCrZr to form a BCC crystal structure through epitaxial growth, and it shares the same preferred orientation as the Cr layer. The formation of this heterogeneous coherent interface greatly regulates the microstructure and improves the overall performance of the coating. The nanoindentation hardness of this Cr / TaWMoCrZr nano-multilayer coating is as high as 8-11 GPa and the Young's modulus is 164-187 GPa, showing extremely high hardness and elastic modulus.

[0043] This application achieves high hardness and high strength in a Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface through mechanisms such as solid solution strengthening of high-entropy alloys, interface strengthening of nano-multilayer structures, template effect and epitaxial growth, and modulation period control. Simultaneously, this coating also exhibits good corrosion resistance, wear resistance, and oxidation resistance, as well as a tunable microstructure. Due to its excellent comprehensive performance, this Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface has broad application prospects in aerospace, automotive, energy, and electronics fields.

[0044] Correspondingly, this application also provides a method for preparing a Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface, comprising the following steps:

[0045] Step 1: Clean and dry the substrate.

[0046] First, the substrate is polished. After polishing, the substrate is ultrasonically cleaned in acetone and anhydrous ethanol for 15 minutes each and then dried to remove impurities from the substrate surface.

[0047] Step 2: Vacuum etching is performed on the dried substrate.

[0048] The substrate is either a steel substrate or a single-crystal silicon substrate. The substrate is etched under vacuum conditions, with the back vacuum level reduced to 4.0 × 10⁻⁶. -4 The etching power is 200W, the etching gas pressure is 1.0Pa, and the etching time is 5min.

[0049] Step 3: Using magnetron sputtering, Cr layers and TaWMoCrZr refractory high-entropy alloy layers are alternately deposited on the etched substrate to obtain a surface Cr / TaWMoCrZr nano multilayer coating.

[0050] First, a refractory high-entropy alloy layer of TaWMoCrZr was deposited on the substrate by magnetron co-sputtering using a TaWMoCr alloy target and a Zr target.

[0051] The DC power of the TaWMoCr alloy target is 100W, the RF power of the Zr target is 100W, the thickness of the TaWMoCrZr refractory high-entropy alloy layer is 10~100nm, and the deposition time of the TaWMoCrZr refractory high-entropy alloy layer is 64~625s.

[0052] Then, a Cr layer was deposited on the TaWMoCrZr refractory high-entropy alloy layer using a Cr target.

[0053] The DC power of the Cr target is 200W, the deposition time of the Cr layer is 72~714s, and the thickness of the Cr layer is 10~100nm.

[0054] Next, repeat the above process, alternately depositing the TaWMoCrZr refractory high-entropy alloy layer and the Cr layer until the thickness of the nano-multilayer coating reaches the predetermined thickness.

[0055] During the alternating deposition of TaWMoCrZr refractory high-entropy alloy layer and Cr layer by magnetron sputtering, the deposition gas pressure was 0.3 Pa, the base disk rotation speed was 15 r / min, the modulation period was 20~200 nm, and the thickness of the nano-multilayer coating was 1.6~5 μm.

[0056] Step 4: Cool the Cr / TaWMoCrZr nano-multilayer coating to room temperature in the furnace to obtain a Cr / TaWMoCrZr nano-multilayer coating with a heterogeneous coherent interface.

[0057] After deposition, the substrate is cooled to room temperature in a high-vacuum coating chamber before being removed to prevent debonding and cracking caused by the difference in thermal expansion coefficients between the substrate and the coating material, and to prevent oxidation due to high temperature.

[0058] Example 1

[0059] A method for preparing a Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface includes the following steps:

[0060] S1. The polished monocrystalline silicon substrate was ultrasonically cleaned in acetone and anhydrous ethanol for 15 min each and then dried to remove impurities from the substrate surface.

[0061] S2, vacuum etching is performed on the cleaned and dried substrate. The etching power is 200W, the etching gas pressure is 1.0Pa, the etching time is 5min, and the back vacuum is reduced to below 4.0×10-4 Pa.

[0062] S3, a Cr / TaWMoCrZr nanolayer coating with a heterogeneous coherent interface was prepared on the substrate by magnetron sputtering.

[0063] First, a TaWMoCrZr layer was deposited by co-sputtering a TaWMoCr alloy target and a Zr target. The DC power of the TaWMoCr alloy target was 100W, and the RF power of the Zr target was 100W.

[0064] Then, a Cr layer is deposited using a Cr alloy target with a DC power of 200W.

[0065] Secondly, the above process is repeated, with TaWMoCrZr and Cr layers being sputtered alternately.

[0066] During magnetron sputtering, the deposition gas pressure was 0.3 Pa, the disk rotation speed was 15 r / min, the deposition time for the Cr layer was 72 s, and the deposition time for the TaWMoCrZr layer was 64 s. The thickness of each Cr and TaWMoCrZr layer was 10 nm, the modulation period was 20 nm, the number of cycles was 100, and the total thickness of the nano-multilayer coating was 2 μm.

[0067] S4. After the sample has cooled naturally to room temperature in the vacuum coating chamber for 2-3 hours, it is removed, resulting in a Cr / TaWMoCrZr nanolayered coating with a thickness of approximately 2 μm. The microstructure and performance of the prepared Cr / TaWMoCrZr nanolayered coating are characterized and tested, see [reference needed]. Figure 1-4 .

[0068] Example 2

[0069] A method for preparing a Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface includes the following steps:

[0070] S1. The polished monocrystalline silicon substrate was ultrasonically cleaned in acetone and anhydrous ethanol for 15 min each and then dried to remove impurities from the substrate surface.

[0071] S2, vacuum etching is performed on the cleaned and dried substrate. The etching power is 200W, the etching gas pressure is 1.0Pa, the etching time is 5min, and the back vacuum is reduced to below 4.0×10-4 Pa.

[0072] S3, a Cr / TaWMoCrZr nanolayer coating with a heterogeneous coherent interface was prepared on the substrate by magnetron sputtering.

[0073] First, a TaWMoCrZr layer was deposited by co-sputtering a TaWMoCr alloy target and a Zr target. The DC power of the TaWMoCr alloy target was 100W, and the RF power of the Zr target was 100W.

[0074] Then, a Cr layer is deposited using a Cr alloy target with a DC power of 200W.

[0075] Secondly, the above process is repeated, with TaWMoCrZr and Cr layers being sputtered alternately.

[0076] During magnetron sputtering, the deposition gas pressure was 0.3 Pa, the substrate rotation speed was 15 r / min, the deposition time of the Cr layer was 179 s, the deposition time of the TaWMoCrZr layer was 156 s, the single-layer thickness of the Cr layer and the TaWMoCrZr layer was 25 nm, the modulation period was 50 nm, the number of cycles was 40, and the total thickness of the nano-multilayer coating was 2 μm.

[0077] S4. After the sample has cooled naturally to room temperature in the vacuum coating chamber for 2-3 hours, it is removed, resulting in a Cr / TaWMoCrZr nanolayered coating with a thickness of approximately 2 μm. The microstructure and performance of the prepared Cr / TaWMoCrZr nanolayered coating are characterized and tested, see [reference needed]. Figure 1-4 .

[0078] Example 3

[0079] A method for preparing a Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface includes the following steps:

[0080] S1. The polished monocrystalline silicon substrate was ultrasonically cleaned in acetone and anhydrous ethanol for 15 min each and then dried to remove impurities from the substrate surface.

[0081] S2, vacuum etching is performed on the cleaned and dried substrate. The etching power is 200W, the etching gas pressure is 1.0Pa, the etching time is 5min, and the back vacuum is reduced to below 4.0×10-4 Pa.

[0082] S3, a Cr / TaWMoCrZr nanolayer coating with a heterogeneous coherent interface was prepared on the substrate by magnetron sputtering.

[0083] First, a TaWMoCrZr layer was deposited by co-sputtering a TaWMoCr alloy target and a Zr target. The DC power of the TaWMoCr alloy target was 100W, and the RF power of the Zr target was 100W.

[0084] Then, a Cr layer is deposited using a Cr alloy target with a DC power of 200W.

[0085] Secondly, the above process is repeated, with TaWMoCrZr and Cr layers being sputtered alternately.

[0086] During magnetron sputtering, the deposition gas pressure was 0.3 Pa, the substrate rotation speed was 15 r / min, the deposition time of the Cr layer was 357 s, the deposition time of the TaWMoCrZr layer was 312 s, the single layer thickness of the Cr layer and the TaWMoCrZr layer was 50 nm, the modulation period was 100 nm, the number of cycles was 20, and the total thickness of the nano-multilayer coating was 2 μm.

[0087] S4. After the sample has cooled naturally to room temperature in the vacuum coating chamber for 2-3 hours, it is removed, resulting in a Cr / TaWMoCrZr nanolayered coating with a thickness of approximately 2 μm. The microstructure and performance of the prepared Cr / TaWMoCrZr nanolayered coating are characterized and tested, see [reference needed]. Figure 1-4 .

[0088] Example 4

[0089] A method for preparing a Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface includes the following steps:

[0090] S1. The polished monocrystalline silicon substrate was ultrasonically cleaned in acetone and anhydrous ethanol for 15 min each and then dried to remove impurities from the substrate surface.

[0091] S2, vacuum etching is performed on the cleaned and dried substrate. The etching power is 200W, the etching gas pressure is 1.0Pa, the etching time is 5min, and the back vacuum is reduced to below 4.0×10-4 Pa.

[0092] S3, a Cr / TaWMoCrZr nanolayer coating with a heterogeneous coherent interface was prepared on the substrate by magnetron sputtering.

[0093] First, a TaWMoCrZr layer was deposited by co-sputtering a TaWMoCr alloy target and a Zr target. The DC power of the TaWMoCr alloy target was 100W, and the RF power of the Zr target was 100W.

[0094] Then, a Cr layer is deposited using a Cr alloy target with a DC power of 200W.

[0095] Secondly, the above process is repeated, with TaWMoCrZr and Cr layers being sputtered alternately.

[0096] During magnetron sputtering, the deposition gas pressure was 0.3 Pa, the disk rotation speed was 15 r / min, the deposition time of the Cr layer was 714 s, the deposition time of the TaWMoCrZr layer was 625 s, the single layer thickness of the Cr layer and the TaWMoCrZr layer was 100 nm, the modulation period was 200 nm, the number of cycles was 10, and the total thickness of the nano-multilayer coating was 2 μm.

[0097] S4. After the sample has cooled naturally to room temperature in the vacuum coating chamber for 2-3 hours, it is removed, resulting in a Cr / TaWMoCrZr nanolayered coating with a thickness of approximately 2 μm. The microstructure and performance of the prepared Cr / TaWMoCrZr nanolayered coating are characterized and tested, see [reference needed]. Figure 1-4 .

[0098] Example 5

[0099] The difference between this embodiment and embodiments 1-4 is that the thickness of the prepared nano-multilayer coating is 1.6 μm. The difference in the preparation method is that step 3 is the same as the rest of the steps, and will not be repeated here.

[0100] A method for preparing a Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface includes the following steps:

[0101] S3, a Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface was prepared on the substrate by magnetron sputtering.

[0102] First, a TaWMoCrZr layer was deposited by co-sputtering a TaWMoCr alloy target and a Zr target. The DC power of the TaWMoCr alloy target was 100W, and the RF power of the Zr target was 100W.

[0103] Then, a Cr layer is deposited using a Cr alloy target with a DC power of 200W.

[0104] Secondly, the above process is repeated, with TaWMoCrZr and Cr layers being sputtered alternately.

[0105] During magnetron sputtering, the deposition gas pressure was 0.3 Pa, the disk rotation speed was 15 r / min, the deposition time of the Cr layer was 714 s, the deposition time of the TaWMoCrZr layer was 625 s, the single layer thickness of the Cr layer and the TaWMoCrZr layer was 100 nm, the modulation period was 200 nm, the number of cycles was 8, and the total thickness of the nano-multilayer coating was 1.6 μm.

[0106] S4. After the sample has cooled naturally to room temperature in the vacuum coating chamber for 2-3 hours, it is taken out to obtain a Cr / TaWMoCrZr nano-multilayer coating with a thickness of about 1.6μm.

[0107] Example 6

[0108] The difference between this embodiment and embodiments 1-4 is that the thickness of the prepared nano-multilayer coating is 5 μm. The difference in the preparation method is that step 3 is the same as the rest of the steps, and will not be repeated here.

[0109] A method for preparing a Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface includes the following steps:

[0110] S3, a Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface was prepared on the substrate by magnetron sputtering.

[0111] First, a TaWMoCrZr layer was deposited by co-sputtering a TaWMoCr alloy target and a Zr target. The DC power of the TaWMoCr alloy target was 100W, and the RF power of the Zr target was 100W.

[0112] Then, a Cr layer is deposited using a Cr alloy target with a DC power of 200W.

[0113] Secondly, the above process is repeated, with TaWMoCrZr and Cr layers being sputtered alternately.

[0114] During magnetron sputtering, the deposition gas pressure was 0.3 Pa, the substrate rotation speed was 15 r / min, the deposition time of the Cr layer was 714 s, the deposition time of the TaWMoCrZr layer was 625 s, the single layer thickness of the Cr layer and the TaWMoCrZr layer was 100 nm, the modulation period was 200 nm, the number of cycles was 25, and the total thickness of the nano-multilayer coating was 5 μm.

[0115] S4. After the sample has cooled naturally to room temperature in the vacuum coating chamber for 2-3 hours, it is taken out to obtain a Cr / TaWMoCrZr nano-multilayer coating with a thickness of about 5μm.

[0116] See Figure 1-4 The results are the microstructure characterization and performance test results of the Cr / TaWMoCrZr nanolayer coatings prepared in Examples 1-4 of this application.

[0117] Figure 1 The image shows the XRD pattern of the Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface according to the present invention, with obvious crystal peaks. The prepared Cr / TaWMoCrZr nanolayered coatings with heterogeneous coherent interfaces have the same preferred orientation.

[0118] Figure 2 This image shows a low-magnification TEM image, selected area electron diffraction (SED) image, and high-resolution image of the Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface, as well as the present invention. Combined, the SED image shows two sets of symmetrical diffraction spots, and the high-resolution image reveals a coherent interface with clear epitaxial growth characteristics.

[0119] Figure 3 The indentation hardness of the Cr / TaWMoCrZr nanolayered coating with heterogeneous coherent interfaces exhibits a certain size dependence, gradually decreasing with increasing layer thickness. This is because as the layer thickness increases, the interface density decreases, the elastic strain field near the interface decreases, and the hindering effect on dislocations weakens, leading to a decrease in hardness. Similar size effects are observed at the nanoscale where the single-layer thickness is greater than 5 nm.

[0120] Figure 4 STEM images and EDS elemental distribution maps of the Cr / TaWMoCrZr nanolayered coating with heterogeneous coherent interfaces prepared by magnetron sputtering in this invention are shown. The elements are uniformly distributed within the microstructure, the interfaces are clear and flat, and the coating exhibits excellent mechanical properties and stability.

[0121] This application describes the fabrication of a Cr / TaWMoCrZr nanolayered coating on a clean silicon substrate using magnetron sputtering deposition. Leveraging the advantages of magnetron sputtering technology, a Cr / TaWMoCrZr nanolayered coating with uniform alloy element distribution, diverse microstructures, and excellent performance was prepared. Due to the template effect of Cr, the previously amorphous TaWMoCrZr underwent epitaxial growth to form a BCC crystal structure with the same preferred orientation as Cr, significantly controlling the microstructure and creating a heterogeneous coherent interface. Furthermore, the microstructure of the Cr / TaWMoCrZr nanolayered coating at the heterogeneous interface was controlled by adjusting the modulation period. Changing the modulation period affected the interface density and consequently the coating's performance. This is because the difference in lattice constants between the heterogeneous materials (despite coherence, a slight mismatch still exists) introduces an elastic strain field near the interface. This strain field interacts with the stress field of dislocations, hindering dislocation slip and increasing strength. The resulting elastic strain field allows dislocations to be temporarily stored near the interface, forming a dislocation network. These stored dislocations interact with newly generated dislocations during deformation, enhancing the material's ability to deform uniformly. This demonstrates that interface density significantly influences the mechanical properties of heterogeneous coherent interface nanolayer coatings. Controlling the modulation period to modulate the coating's microstructure and preparing high-performance Cr / TaWMoCrZr nanolayer coatings with heterogeneous coherent interfaces is of great significance.

[0122] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface, characterized in that, This includes alternating layers of Cr and TaWMoCrZr refractory high-entropy alloy; The crystal phase structure of both the Cr layer and the TaWMoCrZr refractory high-entropy alloy layer is BCC, and the interface between the Cr layer and the TaWMoCrZr refractory high-entropy alloy layer is a heterogeneous coherent interface. The TaWMoCrZr refractory high-entropy alloy layer has an atomic percentage ratio of 1:1:1:1:1 for the five elements Ta, W, Mo, Cr and Zr. In the same modulation cycle, the modulation ratio of the Cr layer and the TaWMoCrZr refractory high-entropy alloy layer is 1:1, and the thickness is 10-100 nm. The thickness of the Cr / TaWMoCrZr nanolayer coating is 1.6~5μm.

2. The Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface according to claim 1, characterized in that, The nanoindentation hardness of the Cr / TaWMoCrZr nano-multilayer coating is 8–11 GPa, and the Young's modulus is 164–187 GPa.

3. A method for preparing a Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface as described in any one of claims 1-2, characterized in that, Includes the following steps: Step 1: After cleaning and drying the substrate, perform vacuum etching; Step 2: Prepare a Cr / TaWMoCrZr nano-multilayer coating on the substrate by magnetron sputtering; First, a refractory high-entropy alloy layer of TaWMoCrZr was deposited on the substrate by magnetron co-sputtering using a TaWMoCr alloy target and a Zr target. Then, a Cr layer was deposited on the TaWMoCrZr refractory high-entropy alloy layer using a Cr target; Secondly, repeat the above process, alternately depositing the TaWMoCrZr refractory high-entropy alloy layer and the Cr layer until the thickness of the nano-multilayer coating reaches the predetermined thickness. The deposition time of the TaWMoCrZr refractory high-entropy alloy layer is 64~625s, the deposition time of the Cr layer is 72~714s, and the modulation period of the magnetron sputtering is 20~200nm. Step 3: Cool the nano-multilayer coating to room temperature to obtain a Cr / TaWMoCrZr nano-multilayer coating with a heterogeneous coherent interface.

4. The method for preparing a Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface according to claim 3, characterized in that, In step 2, the DC power of the TaWMoCr alloy target is 100W, the RF power of the Zr target is 100W, and the DC power of the Cr target is 200W.

5. The method for preparing a Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface according to claim 3, characterized in that, During the magnetron sputtering process described in step 2, the deposition gas pressure is 0.3 Pa and the substrate rotation speed is 15 r / min.

6. The method for preparing a Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface according to claim 3, characterized in that, The cooling time for step 3 is 2-3 hours.

7. The application of the Cr / TaWMoCrZr nanolayered coating with a heterogeneous coherent interface as described in any one of claims 1-2, characterized in that, The aforementioned nano-multilayer coating is used for the protection of the cladding of a lead-bismuth fast nuclear reactor.

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