A tantalum-titanium-zirconium-chromium high-entropy alloy and a preparation method thereof

Abstract

The present invention discloses a tantalum-titanium-zirconium-chromium high-entropy alloy and a preparation method thereof. The TaTiZrCr alloy is composed of the following components: 33.2% Ta, 25.7% Ti, 23.4% Zr, and 17.8% Cr. During preparation, the surface of a silicon substrate is first ultrasonically cleaned and dried; the substrate is then placed in a magnetron sputtering coating chamber and evacuated; a DC + RF power supply is then used for co-sputtering to prepare the TaTiZrCr alloy; and the silicon substrate is vacuum-cooled to obtain a tantalum-titanium-zirconium-chromium alloy material. This solves the problem of uneven distribution of alloying elements in the material, resulting in an amorphous material with uniform element distribution. Annealing results in amorphous properties up to 600°C, effectively improving the alloy's comprehensive mechanical properties.

Description

Technical Field

[0001] The present invention belongs to the field of metal structural materials, and specifically relates to a tantalum-titanium-zirconium-chromium high-entropy alloy and a preparation method thereof. Background Art

[0002] The world landscape is undergoing dramatic changes driven by technological advancements. The redistribution of global manufacturing is leading to a gradual upgrade in the energy market, with new and clean energy being a key future demand. Nuclear power, a green, efficient, and safe clean energy source, is a low-carbon energy project in which countries around the world are investing heavily.

[0003] Nuclear power applications require a high-end manufacturing foundation. Nuclear equipment components operate under complex operating conditions. For example, the core equipment in nuclear power plants, the nuclear cladding tubes, are subject to long-term service in oxidizing, high-temperature, and irradiated environments. This places increasingly stringent demands on the materials used to manufacture this equipment, including resistance to oxidation, radiation, and high temperatures. However, current material developments cannot fully meet the requirements of nuclear power plant construction, requiring additional technologies to support this. Therefore, coating protective treatments for nuclear equipment components are one of the most commonly used and effective methods.

[0004] High-entropy alloys (HEAs) possess excellent mechanical properties, friction and wear resistance, corrosion resistance, and high-temperature resistance due to their high-entropy effect, hysteretic diffusion effect, lattice distortion effect, and cocktail effect. They are therefore a key material for protective coatings in nuclear facilities. This effectively protects precision equipment, extending its service life and minimizing financial loss and even personal injury. Therefore, precision equipment components in the nuclear power industry must be effectively protected to prevent damage from the operating environment. Summary of the Invention

[0005] In response to the problems existing in the prior art, the present invention provides a tantalum-titanium-zirconium-chromium high-entropy alloy and a preparation method thereof. The prepared tantalum-titanium-zirconium-chromium high-entropy alloy has a uniform microstructure and excellent mechanical strength, effectively improving the service life of the material.

[0006] The present invention is achieved through the following technical solutions:

[0007] A method for preparing a tantalum-titanium-zirconium-chromium high entropy alloy comprises the following steps:

[0008] Step 1: remove stains and oxidation layers on the substrate surface;

[0009] Step 2: Under vacuum conditions, magnetron sputtering is performed on the substrate using a TaTiZr alloy target and a Cr target, and after the deposition is completed, the TaTiZrCr high entropy alloy is obtained by cooling to room temperature;

[0010] The sum of the atomic percentages of Ti and Zr in the TaTiZr alloy target is greater than 40 at%, with the remainder being Ta atoms. The TaTiZr alloy target is sputtered using DC power supply of 200 W; the Cr target is sputtered using RF power supply of 40-45 W.

[0011] Step 3: vacuum annealing the TaTiZrCr high entropy alloy obtained in step 2 to obtain an annealed TaTiZrCr high entropy alloy.

[0012] Preferably, the method for removing stains and oxide layers on the substrate surface in step 1 is as follows:

[0013] The substrate is polished, and then the polished substrate is cleaned and dried using acetone and alcohol.

[0014] Preferably, during the magnetron sputtering process in step 2, the deposition pressure is 1.0 Pa, the deposition temperature is room temperature, the substrate rotation speed is 15 r / min, and the deposition time is 16000 s.

[0015] Preferably, the vacuum degree of the vacuum environment in step 2 is less than 4.0×10 -4 Pa.

[0016] Preferably, the annealing temperature in step 3 is room temperature to 600° C., and the annealing time is 2-3 hours.

[0017] Preferably, the vacuum degree of the vacuum annealing is less than 7×10 -4 Pa.

[0018] A tantalum-titanium-zirconium-chromium high-entropy alloy is provided. The tantalum-titanium-zirconium-chromium high-entropy alloy has an amorphous structure, the sum of the atomic percentages of titanium and zirconium in the tantalum-titanium-zirconium-chromium high-entropy alloy is greater than 40 at%, and the atomic percentage of chromium is 5-30 at%.

[0019] Preferably, the nanoindentation hardness of the tantalum-titanium-zirconium high entropy alloy is 7 GPa to 14 GPa.

[0020] Compared with the prior art, the present invention has the following beneficial technical effects:

[0021] The present invention provides a preparation method of a tantalum-titanium-zirconium-chromium high-entropy alloy, which adopts a TaTiZr alloy target and a Cr target to perform magnetron sputtering on a substrate, and controls the content of alloy elements by co-sputtering different target materials to prepare a tantalum-titanium-zirconium-chromium high-entropy alloy with uniform alloy element distribution, amorphous structure and excellent performance. The TaTiZr alloy target adopts DC sputtering, and the Cr target adopts radio frequency sputtering. After the sputtering deposition is completed, the tantalum-titanium-zirconium-chromium high-entropy alloy is vacuum annealed. Due to the large number of four components, the mixing entropy is large and the Gibbs free energy is low; the tantalum-titanium-zirconium-chromium high-entropy alloy will have greater original energy at high temperature. The annealing process verifies that the microstructure of the tantalum-titanium-zirconium-chromium high-entropy alloy coating can remain amorphous between room temperature and 600°C, and has high thermal stability. In addition, the elements Ta, Ti, Zr and Cr easily form a dense oxide film, which gives it good resistance to high-temperature oxidation. At the same time, the amorphous, single-phase, low free enthalpy and other characteristics also contribute to its excellent corrosion resistance. In addition, the annealing process also greatly improves the short-range order in the amorphous structure of the microstructure of the titanium-zirconium-chromium high-entropy alloy coating, resulting in a significant increase in the shear stress resistance of the coating, and the hardness and elastic modulus show an upward trend.

[0022] The tantalum-titanium-zirconium-chromium high-entropy alloy prepared by this invention is composed of refractory metals Ta, Ti, Zr, and Cr. It has a high melting point, high strength, and excellent high-temperature resistance, making it particularly suitable for forming protective coatings on the surfaces of precision equipment components. Using magnetron sputtering technology, the oxidation-resistant refractory high-entropy alloy can be coated on the surface of other high-temperature-resistant materials or refractory high-entropy alloy substrates, effectively improving the substrate's oxidation resistance, high-temperature resistance, and radiation resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The XRD results of the tantalum-titanium-zirconium-chromium high entropy alloy of the present invention at different annealing conditions are shown;

[0024] Figure 2 TEM microstructure and diffraction spot images of the deposited tantalum-titanium-zirconium-chromium high entropy alloy of the present invention

[0025] Figure 3 This is an EDS scanning element distribution diagram of the deposited microstructure of the tantalum-titanium-zirconium-chromium high entropy alloy of the present invention;

[0026] Figure 4 The load-displacement curves of the tantalum-titanium-zirconium-chromium high entropy alloy of the present invention under different annealing conditions are shown;

[0027] Figure 5 The nanoindentation hardness results of the tantalum-titanium-zirconium-chromium high entropy alloy of the present invention under different annealing conditions are shown. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below with reference to the accompanying drawings, which are intended to explain rather than limit the present invention.

[0029] A tantalum-titanium-zirconium-chromium high-entropy alloy, comprising 33.2% Ta, 25.7% Ti, 23.4% Zr, and 17.8% Cr in atomic percentages. The alloy is amorphous and can maintain a temperature of up to 600°C. The alloy has a nanoindentation hardness of 7 GPa to 14 GPa.

[0030] A method for preparing a tantalum-titanium-zirconium-chromium high entropy alloy comprises the following steps:

[0031] Step 1: polishing and cleaning the silicon substrate to remove stains and oxide layers on its surface;

[0032] Specifically, the single crystal silicon substrate is polished, and the surface roughness of the single crystal silicon substrate is less than 0.8 nm. Then, the polished substrate is ultrasonically cleaned in pure acetone and ethanol for 10 minutes in sequence, and then quickly dried. The stains and dust on the surface of the substrate are removed by ultrasonic cleaning, so that the surface of the substrate is clean and free of stains and dust, which is beneficial to improving the bonding strength between the alloy and the substrate.

[0033] Step 2: Under vacuum conditions, a TaTiZr alloy target and a Cr target are co-sputtered on a single crystal silicon substrate using magnetron sputtering. After the deposition is completed, the mixture is cooled to room temperature with the furnace, and a TaTiZrCr high entropy alloy is deposited on the single crystal silicon substrate, as follows:

[0034] S1. The single crystal silicon substrate after ultrasonic cleaning is fixed on the base plate and automatically transported into the magnetron sputtering coating chamber. The vacuum is evacuated to the back vacuum of 4.0×10 -4 Below Pa.

[0035] S2. Co-sputtering was performed using a TaTiZr alloy target and a Cr target. The deposition pressure was 1.0 Pa, the deposition temperature was room temperature, the substrate rotation speed was 15 r / min, and the deposition time was 16000 s.

[0036] The sum of the atomic percentages of Ti and Zr in the TaTiZr alloy target is greater than 40 at%, with the remainder being Ta atoms. The TaTiZr alloy target is sputtered using DC with a DC power supply of 200W. The Cr target has a purity of 99.97wt% and is sputtered using RF with a RF power supply of 40-45W.

[0037] S3. After the deposition is completed, the film is fully cooled to room temperature in a high vacuum coating chamber to obtain a TaTiZrCr high entropy alloy.

[0038] Because the sputtered atoms bombard the substrate for a long time during the deposition process, the TaTiZrCr high-entropy alloy causes a certain temperature rise. After the deposition is completed, it is cooled to room temperature in the high vacuum coating chamber before exiting, reducing the internal stress of the TaTiZrCr high-entropy alloy layer and preventing the surface from being oxidized by air.

[0039] Step 3: vacuum annealing the TaTiZrCr high entropy alloy obtained in step 2 to obtain an annealed TaTiZrCr high entropy alloy.

[0040] Specifically, the substrate obtained in step 3 is placed in a vacuum annealing furnace for annealing at a temperature ranging from room temperature to 600°C.

[0041] The present invention adopts the method of co-sputtering of DC and RF power supply to deposit TaTiZrCr alloy on the surface of single crystal silicon wafer cleaned by ultrasonic cleaning, and generates Ar by ionization of Ar gas. + Ions, attracted by the cathode potential, are accelerated to bombard the cathode target (TaTiZrCr), sputtering target atoms and secondary electrons. The target atoms are deposited in opposite directions onto the anode substrate. The motion direction of the secondary electrons in the orthogonal electromagnetic field is perpendicular to the electric and magnetic fields, presenting a circular motion trajectory, which enhances collisions with Ar molecules and increases the probability of Ar ionization. The outstanding advantages of this technology are high ionization rate, fast deposition rate, low operating temperature and adjustable element content. It is not easy to cause agglomeration and back-sputtering of target elements, resulting in uneven microstructure. Finally, it is naturally cooled to room temperature in a high vacuum coating chamber to avoid rapid exposure to oxidation in the air, allowing the deposited atoms to fully diffuse to form the final TaTiZrCr high-entropy alloy. This TaTiZrCr high-entropy alloy is an amorphous material with uniform element distribution. Through the annealing system, it was found that the amorphous maintenance ability is as high as 600°C, which effectively improves the comprehensive mechanical properties of the alloy material.

[0042] Example 1

[0043] A method for preparing a TaTiZrCr high entropy alloy comprises the following steps:

[0044] Step 1: ultrasonically clean the single crystal silicon substrate in analytical grade acetone and ethanol for 10 minutes each, and then quickly dry it with warm air.

[0045] Step 2: Fix the single crystal silicon substrate on the base plate and automatically transport it into the magnetron sputtering vacuum coating chamber until the back vacuum is 4.0×10 -4 Below Pa.

[0046] Step 3, depositing TaTiZrCr alloy on the single crystal silicon substrate by magnetron sputtering with DC and RF power co-sputtering;

[0047] Among them, the atomic percentage of the TaTiZr alloy target is Ta: 30.1%, Ti: 36.8%, Zr: 33.1%, the DC power supply power is 200W, the Cr target purity is 99.97wt%, the RF power supply power is 45W, the deposition gas pressure is 1.0Pa, the deposition temperature is room temperature, the substrate rotation speed is 15r / min, and the deposition time is 16000s.

[0048] Step 4: Cool the single crystal silicon substrate obtained in step 3 naturally in a high vacuum coating chamber for 2-3 hours to room temperature and then exit to obtain a Ta-33.2% at% Ti-25.7at% Zr-23.4at% Cr-17.8at% high entropy alloy.

[0049] Step 5: Place the TaTiZrCr high entropy alloy into a vacuum annealing furnace and anneal at 400° C. for 2 hours to obtain an annealed Ta-33.2% at% Ti-25.7 at% Zr-23.4 at% Cr-17.8 at% high entropy alloy with a thickness of 3 μm.

[0050] The prepared Ta-33.2% at% Ti-25.7at% Zr-23.4at% Cr-17.8at% alloy was characterized by microstructure and tested for mechanical properties. The alloy structure was amorphous, and the alloy Ta, Ti, Zr and Cr elements were evenly distributed. The hardness was measured by nanoindentation under a load of 10000μN to be 8.60±0.12GPa.

[0051] Example 2

[0052] A method for preparing a TaTiZrCr high entropy alloy comprises the following steps:

[0053] Step 1: ultrasonically clean the single crystal silicon substrate in analytical grade acetone and ethanol for 10 minutes each, and then quickly dry it with warm air.

[0054] Step 2: Fix the single crystal silicon substrate on the base plate and automatically transport it into the magnetron sputtering vacuum coating chamber until the back vacuum is 4.0×10 -4 Below Pa.

[0055] Step 3, using a magnetron sputtering method with DC and RF power co-sputtering to deposit TaTiZrCr high entropy alloy on the single crystal silicon substrate after ultrasonic cleaning;

[0056] Among them, the atomic ratio of the TaTiZr alloy target is Ta: 30.1%, Ti: 36.8%, Zr: 33.1%, the DC power supply power is 200W; the Cr target purity is 99.97wt%, the RF power supply power is 45W, the deposition gas pressure is 1.0Pa, the deposition temperature is room temperature, the substrate rotation speed is 15r / min, and the deposition time is 16000s.

[0057] Step 4: Cool the single crystal silicon substrate obtained in step 3 naturally in a high vacuum coating chamber for 2-3 hours to room temperature and then exit to obtain a Ta-33.2% at% Ti-25.7 at% Zr-23.4 at% Cr-17.8 at% alloy.

[0058] Step 5: Place the TaTiZrCr alloy obtained in step 4 into a vacuum annealing furnace and anneal at 500° C. for 2 hours to obtain an annealed Ta-33.2% at% Ti-25.7 at% Zr-23.4 at% Cr-17.8 at% alloy with a thickness of 3 μm.

[0059] The microstructure characterization and mechanical properties testing of the prepared Ta-33.2%at%Ti-25.7at%Zr-23.4at%Cr-17.8at% high entropy alloy were carried out. The alloy structure is amorphous, and the alloy Ta, Ti, Zr and Cr elements are uniformly distributed. Its hardness was measured by nanoindentation under a load of 10000μN to be 9.02±0.11GPa.

[0060] Example 4

[0061] A method for preparing a TaTiZrCr high entropy alloy comprises the following steps:

[0062] Step 1: ultrasonically clean the single crystal silicon substrate in analytical grade acetone and ethanol for 10 minutes each, and then quickly dry it with warm air.

[0063] Step 2: Fix the single crystal silicon substrate on the base plate and automatically transport it into the magnetron sputtering vacuum coating chamber until the back vacuum is 4.0×10 -4 Below Pa.

[0064] Step 3, using magnetron sputtering DC and radio frequency power to co-sputter TaTiZrCr alloy on the single crystal silicon substrate after ultrasonic cleaning;

[0065] Among them, the atomic ratio of TaTiZr alloy target is Ta: 58.9%, Ti: 18%, Zr: 23.1%, the DC power supply power is 200W, the Cr target purity is 99.97wt%, the RF power supply power is 40W, the deposition gas pressure is 1.0Pa, the deposition temperature is room temperature, the substrate rotation speed is 15r / min, and the deposition time is 16000s.

[0066] Step 4: Cool the single crystal silicon substrate obtained in step 3 naturally in a high vacuum coating chamber for 2-3 hours to room temperature and then exit to obtain a TaTiZrCr high entropy alloy.

[0067] Step 5: Place the TaTiZrCr alloy obtained in step 4 into a vacuum annealing furnace and anneal at 100° C. for 2 hours to obtain an annealed TaTiZrCr high entropy alloy with a thickness of 3 μm.

[0068] Example 5

[0069] A method for preparing a TaTiZrCr high entropy alloy comprises the following steps:

[0070] Step 1: ultrasonically clean the single crystal silicon substrate in analytical grade acetone and ethanol for 10 minutes each, and then quickly dry it with warm air.

[0071] Step 2: Fix the single crystal silicon substrate on the base plate and automatically transport it into the magnetron sputtering vacuum coating chamber until the back vacuum is 4.0×10 -4 Below Pa.

[0072] Step 3, using magnetron sputtering DC and radio frequency power to co-sputter TaTiZrCr alloy on the single crystal silicon substrate after ultrasonic cleaning;

[0073] Among them, the atomic ratio of TaTiZr alloy target is Ta: 11.4%, Ti: 38%, Zr: 50.6%, the DC power supply power is 200W, the Cr target purity is 99.97wt%, the RF power supply power is 43W, the deposition gas pressure is 1.0Pa, the deposition temperature is room temperature, the substrate rotation speed is 15r / min, and the deposition time is 16000s.

[0074] Step 4: Cool the single crystal silicon substrate obtained in step 3 naturally in a high vacuum coating chamber for 3 hours to room temperature, and then exit to obtain a TaTiZrCr high entropy alloy.

[0075] Step 5: Place the TaTiZrCr alloy obtained in step 4 into a vacuum annealing furnace and anneal at 50° C. for 2 hours to obtain an annealed TaTiZrCr high entropy alloy with a thickness of 3 μm.

[0076] Comparative Example 1

[0077] The preparation method of this comparative example is different from that of Example 1 in that the TaTiZrCr high entropy alloy is not vacuum annealed, and the other methods are the same.

[0078] A method for preparing a TaTiZrCr high entropy alloy comprises the following steps:

[0079] Step 1: ultrasonically clean the single crystal silicon substrate in analytical grade acetone and ethanol for 10 minutes each, and then quickly dry it with warm air.

[0080] Step 2: Fix the single crystal silicon substrate on the base plate and automatically transport it into the magnetron sputtering vacuum coating chamber until the back vacuum is 4.0×10 -4 Below Pa.

[0081] Step 3, using magnetron sputtering DC and radio frequency power to co-sputter and deposit TaTiZrCr alloy on the single crystal silicon substrate;

[0082] Among them, the atomic ratio of TaTiZr alloy target is Ta: 30.1%, Ti: 36.8%, Zr: 33.1%, the DC power supply power is 200W, the Cr target purity is 99.97wt%, the RF power supply power is 45W, the deposition gas pressure is 1.0Pa, the deposition temperature is room temperature, the substrate rotation speed is 15r / min, and the deposition time is 16000s.

[0083] Step 4: Cool the single crystal silicon substrate obtained in step 3 naturally in a high vacuum coating chamber for 2-3 hours to room temperature and then exit to obtain a Ta-33.2%at%Ti-25.7at%Zr-23.4at%Cr-17.8at% alloy with a thickness of 3μm.

[0084] The prepared Ta-33.2% at% Ti-25.7at% Zr-23.4at% Cr-17.8at% alloy was characterized by microstructure and tested for mechanical properties. The alloy structure was amorphous, and the alloy Ta, Ti, Zr and Cr elements were evenly distributed. The hardness was measured by nanoindentation under a load of 10000μN to be 7.38±0.06GPa.

[0085] Figure 1 The XRD results of the tantalum-titanium-zirconium-chromium high entropy alloy of the present invention at different annealing conditions are shown in FIG. Figure 2 The TEM microstructure and diffraction spot images of the deposited tantalum-titanium-zirconium-chromium high entropy alloy of the present invention are shown. Figure 3 The EDS scanning element distribution map of the deposited microstructure of the tantalum-titanium-zirconium-chromium high entropy alloy is shown; Figure 4 The load-displacement curves of nanoindentation of tantalum-titanium-zirconium-chromium high entropy alloys with different annealing systems are shown. Figure 5 The nanoindentation hardness trends of tantalum-titanium-zirconium-chromium high-entropy alloys under different annealing conditions are shown. The tantalum-titanium-zirconium-chromium high-entropy alloy according to the present invention has an amorphous structure that can be maintained at temperatures up to 600°C. The alloying elements are evenly distributed within the alloy. As the annealing temperature increases, the alloy's hardness gradually increases, while the indentation depth gradually decreases. The tantalum-titanium-zirconium-chromium high-entropy alloy of the present invention exhibits excellent mechanical properties, including high strength and good plastic deformation capacity.

[0086] The above content is only for explaining the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a tantalum-titanium-zirconium-chromium high entropy alloy, characterized in that: The following steps are involved: Step 1: remove stains and oxidation layers on the substrate surface; Step 2: Under vacuum conditions, magnetron sputtering is performed on the substrate using a TaTiZr alloy target and a Cr target, and after the deposition is completed, the TaTiZrCr high entropy alloy is obtained by cooling to room temperature; The sum of the atomic percentages of Ti and Zr in the TaTiZr alloy target is greater than 40 at%, with the remainder being Ta atoms. The TaTiZr alloy target is sputtered using DC power supply of 200 W; the Cr target is sputtered using RF power supply of 40-45 W. Step 3: vacuum annealing the TaTiZrCr high entropy alloy obtained in step 2 to obtain an annealed TaTiZrCr high entropy alloy; The annealing temperature is 50°C to 600°C, and the annealing time is 2-3h; The tantalum-titanium-zirconium-chromium high-entropy alloy has an amorphous structure, the sum of the atomic percentages of titanium and zirconium in the tantalum-titanium-zirconium-chromium high-entropy alloy is greater than 40 at%, and the atomic percentage of chromium is 5-30 at%; the nanoindentation hardness of the tantalum-titanium-zirconium-chromium high-entropy alloy is 7 GPa~14 GPa.

2. The method for preparing a tantalum-titanium-zirconium-chromium high entropy alloy according to claim 1, characterized in that: The method for removing stains and oxide layers from the substrate surface in step 1 is as follows: The substrate is polished, and then the polished substrate is cleaned and dried using acetone and alcohol.

3. The method for preparing a tantalum-titanium-zirconium-chromium high entropy alloy according to claim 1, characterized in that: During the magnetron sputtering process described in step 2, the deposition gas pressure was 1.0 Pa, the deposition temperature was room temperature, the substrate rotation speed was 15 r / min, and the deposition time was 16000 s.

4. The method for preparing a tantalum-titanium-zirconium-chromium high entropy alloy according to claim 1, characterized in that: The vacuum degree of the vacuum environment in step 2 is less than 4.0×10 -4 Pa.

5. The method for preparing a tantalum-titanium-zirconium-chromium high entropy alloy according to claim 1, characterized in that: The vacuum degree of the vacuum annealing is less than 7×10 -4 Pa.

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