A refractory high-entropy alloy with high-temperature ablation resistance and high-temperature oxidation resistance and a preparation method thereof

Abstract

The application discloses a refractory high-entropy alloy with high-temperature ablation resistance and high-temperature oxidation resistance and a preparation method thereof. a W b X c Y d Z e , wherein a=30-60, b=30-50, c=0-20, d=0-20, e=0-5; the X is any one or more of Pt, Pd, Ru, Rh and Os, the Y is any one or more of Mo, Nb, Ta, V, Zr, Hf, Y, Re, and the Z is any one or more of Al, Si, Mg, Co, Ni, Cr, La, Ce, Pr, Sm, Gd, Tb, Dy, Ho, Er. The prepared refractory high-entropy alloy has good mechanical properties and high-temperature oxidation resistance, and has good application prospect in the fields of aerospace, advanced manufacturing, new energy and the like.

Description

Technical Field

[0001] This invention belongs to the field of high-entropy alloy technology, specifically relating to a refractory high-entropy alloy with both high-temperature ablation resistance and high-temperature oxidation resistance, and its preparation method. Background Technology

[0002] The ignition nozzle is a component in aero-engines that enables ignition. It uses a pulsed voltage to break down the semiconductor material between the ignition electrodes, creating an electric spark to ignite the combustible gas in the combustion chamber. The ignition electrode material at the ignition end of the nozzle is constantly exposed to high temperatures, subject to chemical corrosion from fuel and combustion gases, as well as ablation from the electric spark. Therefore, Ir-Pt alloys, known for their excellent chemical stability, mechanical properties, and electrical properties, are commonly chosen as electrode materials. However, both Ir and Pt are precious metals, making them expensive and hindering cost control in aero-engines. Ir also has poor plasticity, making forming and processing difficult. Furthermore, Ir-Pt alloys still exhibit oxidation and ablation as their electrode material over time. Therefore, to extend the lifespan of the ignition nozzle and improve ignition performance, the electrode material must possess high resistance to ablation, high-temperature oxidation resistance, and machinability, while simultaneously controlling its cost.

[0003] High-entropy alloys are defined as alloys made by fusing five or more main elements in equimolar or near-equimolar ratios, breaking away from the traditional alloy designation of one or two main elements. With the continuous development of these multi-principal element alloys, the definition of high-entropy alloys has expanded to include alloys with four or more main elements in non-equimolar ratios. High-entropy alloys tend to form simple solid solution phases, exhibiting a thermodynamic high-entropy effect. Furthermore, high-entropy alloys also possess lattice distortion effects, hysteresis diffusion effects, and "cocktail" effects, thus giving them unique mechanical properties, magnetic properties, oxidation resistance, and corrosion resistance. Among different high-entropy alloy systems, those containing three or more refractory metal elements are called refractory high-entropy alloys, characterized by high melting points, high density, corrosion resistance, and excellent mechanical properties at both room temperature and high temperatures. Relevant patents include: CN112958783A, CN115386774A, CN114774752A, CN111809095B, ​​CN112941356A, etc. The performance characteristics of refractory high-entropy alloys make them suitable for use as high-temperature structures or functional components; however, their poor high-temperature oxidation resistance severely limits their application. If used as electrode materials, they may suffer severe ablation under long-term service conditions, making them not a viable alternative to electrode materials. Summary of the Invention

[0004] The purpose of this invention is to provide a refractory high-entropy alloy with both high-temperature ablation resistance and high-temperature oxidation resistance, and a method for preparing the same, in order to solve the above-mentioned problems.

[0005] This invention is mainly achieved through the following technical solutions:

[0006] A refractory high-entropy alloy possessing both high-temperature ablation resistance and high-temperature oxidation resistance, wherein the compositional formula of the refractory high-entropy alloy is Ir. a W b X c Y d Z e Where: a = 30–60, b = 30–50, c = 0–20, d = 0–20, e = 0–5;

[0007] X is any one or more of Pt, Pd, Ru, Rh, and Os.

[0008] The Y is any one or more of Mo, Nb, Ta, V, Zr, Hf, Y, and Re.

[0009] Z is any one or more of Al, Si, Mg, Co, Ni, Cr, La, Ce, Pr, Sm, Gd, Tb, Dy, Ho, and Er.

[0010] To better realize the present invention, further, a+b=60~90, c+d+e=10~40, a+b+c+d+e=100.

[0011] To better realize the present invention, the refractory high-entropy alloy is further defined as Ir. 40 W 35 Nb5Zr 15 Al5, Ir 45 W 35 Rh 10 Ta5Cr5, Ir 45 W 30 Hf5Nb 10 Al5Si5, Ir 35 W 35 Pt2Mo 10 Nb 10 Al5Ni3, Ir 50 W 30 Pd6V 10 Co2Pr2, Ir 30 W 50 Os5Zr 10 Ce5, Ir 60 W 30 Ru3Hf2Gd5、Ir 30 W 50 Pt5Ta5Ni3Sm2, Ir 40 W 40 Pt 10 Any one of Mo4La4Er2.

[0012] To better realize the present invention, the room temperature compressive properties of the refractory high-entropy alloy are further defined as follows: yield strength of 350–1850 MPa, fracture strength of 400–2200 MPa, and fracture strain of 1.5–40%; the high temperature compressive properties of the refractory high-entropy alloy are defined as follows: yield strength of 100–800 MPa, fracture strength of 150–900 MPa, and fracture strain of 2.0–40%; and the high temperature average oxidation rate of the refractory high-entropy alloy is defined as follows: 0.1–160 mg / (cm³). 2 ·h).

[0013] This invention is mainly achieved through the following technical solutions:

[0014] A method for preparing a refractory high-entropy alloy that combines high-temperature ablation resistance and high-temperature oxidation resistance includes the following steps:

[0015] Step S1: Weigh each elemental metal according to the proportions of the components, ultrasonically clean them, and then dry them for later use.

[0016] Step S2: Refractory high-entropy alloys are prepared by electric arc melting. The metal element and titanium ingot are placed in water-cooled copper crucibles of a non-consumable vacuum electric arc melting furnace. After the furnace body is evacuated, inert gas is introduced.

[0017] Step S3: Under inert gas, first melt the titanium ingot to reduce the oxygen content in the furnace, then perform electric arc melting on the elemental metal, and simultaneously perform electromagnetic stirring on the melt to make the alloy composition uniform, and finally cool to obtain the button ingot; turn the button ingot over and remelt the button ingot several times to make the composition of the button ingot uniform.

[0018] Step S4: Remove the oxide layer on the surface of the button ingot and cut it into block samples. Melt several block samples and place them in a mold to cool and shape them. Hold them at 1250-1500℃ for 1-24 hours. Then, perform heat treatment with furnace cooling to finally obtain a refractory high entropy alloy.

[0019] To better realize the present invention, in step S1, an additional 3 to 10 wt% of elemental Ir metal is added.

[0020] To better realize the present invention, further, in step S2, the furnace body is evacuated to a vacuum degree ≤1.5×10⁻⁶. -3 Pa, then inert gas is introduced to 0.080–0.095 MPa.

[0021] To better realize the present invention, in step S3, the current of the electric arc melting is 200-400A and the melting time is 30-120s; when remelting the button ingot, the alloy is kept in a liquid state for 2-3 minutes before cooling.

[0022] To better realize the present invention, the button ingot is further flipped and remelted more than or equal to 3 times.

[0023] This invention is based on the principle of refractory high-entropy alloys and develops a novel refractory high-entropy alloy. The composition design concept of this invention is as follows: 1. Developing an ablation-resistant refractory high-entropy alloy based on high-melting-point and corrosion-resistant Ir and W elements to ensure that the high-entropy alloy has good high-temperature oxidation resistance and ablation resistance; 2. Adding different types of noble metal elements such as Pt, Pd, Ru, Rh, and Os to the alloy to increase the solubility of solid solution elements, ultimately forming a BCC solid solution phase matrix; 3. Adding transition metal elements to form intermetallic compounds with noble metal elements, which are uniformly distributed in the BCC solid solution phase matrix, improving the high-entropy alloy's high-temperature stability; 4. Adding main group elements and rare earth elements to increase the lattice distortion of the high-entropy alloy. Severe lattice distortion greatly hinders dislocation movement, further improving the strength of the refractory high-entropy alloy.

[0024] The beneficial effects of this invention are as follows:

[0025] This invention utilizes the chemical stability of Ir to optimize the ablation resistance and high-temperature oxidation resistance of refractory high-entropy alloys, proposing a refractory high-entropy alloy system with excellent ablation resistance and high-temperature oxidation resistance. The ablation-resistant refractory high-entropy alloy system of this invention consists of a BCC solid solution phase and a Laves intermetallic compound phase. Ir-based alloys exhibit high high-temperature chemical stability, while W-based alloys possess high melting points, high strength, and high hardness, contributing to improved ablation resistance. Furthermore, the addition of transition metal elements to the refractory high-entropy alloy helps stabilize the Laves intermetallic compound phase at high temperatures. Simultaneously, the addition of small amounts of main group elements and rare earth elements enhances the lattice distortion effect of the refractory high-entropy alloy, helping to ensure its strength. The density, mechanical properties, and chemical properties of the ablation-resistant refractory high-entropy alloy of this invention are highly adjustable, and the content of common refractory elements is relatively high, which helps reduce the alloy price and will have significant application potential in aerospace, advanced manufacturing, and new energy fields. Attached Figure Description

[0026] Figure 1 For Ir 40 W 35 Nb5Zr 15 Microstructure diagram of Al5 high-entropy alloy;

[0027] Figure 2 For Ir 40 W 35 Nb5Zr 15 XRD pattern of Al5 high-entropy alloy;

[0028] Figure 3 For Ir 40 W 35 Nb5Zr 15 Compression performance curves of Al5 high-entropy alloy at room temperature and 1100℃;

[0029] Figure 4 For Ir 40 W 35 Nb5Zr 15 Oxidation weight gain curve of Al5 high-entropy alloy at 1100℃;

[0030] Figure 5 For Ir 45 W 35 Rh 10 Microstructure diagram of Ta5Cr5 high-entropy alloy;

[0031] Figure 6 For Ir 45 W 35 Rh 10 XRD pattern of Ta5Cr5 high-entropy alloy;

[0032] Figure 7 For Ir 45 W 35 Rh 10 Compression performance curves of Ta5Cr5 high-entropy alloy at room temperature and 1100℃;

[0033] Figure 8 For Ir 45 W 35 Rh 10 Oxidation weight gain curve of Ta5Cr5 high-entropy alloy at 1100℃;

[0034] Figure 9 For Ir 45 W 30 Hf5Nb 10 Oxidation weight gain curve of Al5Si5 high-entropy alloy at 1100℃;

[0035] Figure 10 For Ir 35 W 35 Pt2Mo 10 Nb 10 Oxidation weight gain curve of Al5Ni3 high-entropy alloy at 1100℃. Detailed Implementation

[0036] Example 1:

[0037] A refractory high-entropy alloy possessing both high-temperature ablation resistance and high-temperature oxidation resistance, wherein the compositional formula of the refractory high-entropy alloy is Ir. 40 W 35Nb5Zr 15 Al5. The specific preparation method is as follows:

[0038] Weigh out pure metals according to the atomic ratio Ir∶W∶Nb∶Zr∶Al=40∶35∶5∶15∶5, and add 7% more Ir element for burn-off loss.

[0039] Preparation of ablation-resistant refractory high-entropy alloys by electric arc melting:

[0040] ① Place the above-mentioned metallic elements and titanium ingots separately in water-cooled copper crucibles of a non-consumable vacuum arc melting furnace, and wait until the vacuum degree inside the furnace reaches 2.5 × 10⁻⁶. -3 Once the pressure drops below 0.080 MPa, turn off the vacuum pump and purge with argon gas to 0.080 MPa.

[0041] ② Turn on the power and first use electric arc to melt the titanium ingot. After the titanium ingot is completely melted and kept in the molten state for 1 minute, turn off the power. Turn on the power again, and use an electric arc melting current of 200-400A to melt the high-entropy alloy for 60 seconds. Use electromagnetic stirring during the melting process to homogenize the alloy. Keep the alloy in the molten state for 2 minutes, then turn off the power and wait for the alloy ingot to cool.

[0042] ③ Flip the alloy ingot and repeat step ②; repeat step ③ at least 3 times to obtain a high-entropy alloy button ingot;

[0043] ④ Remove the oxide layer from the surface of the button ingot and cut it into block samples. Melt the block samples and place them in a Φ15×50mm copper mold to form the shape. Then, perform heat treatment at 1300℃ for 5 hours and cool in the furnace to finally obtain Ir. 40 W 35 Nb5Zr 15 Al5 high-entropy alloy.

[0044] like Figure 1 As shown, this embodiment successfully prepared the refractory high-entropy alloy Ir. 40 W 35 Nb5Zr 15 Al5 alloys exhibit a dendritic structure. For example... Figure 2 As shown, the prepared refractory high-entropy alloy Ir 40 W 35 Nb5Zr 15 Al5 contains a BCC solid solution phase and a Laves intermetallic compound phase. The properties of the prepared refractory high-entropy alloys are shown in Table 1, such as... Figure 3 As shown, Ir 40 W 35 Nb5Zr 15 The Al5 high-entropy alloy exhibits a room-temperature compressive yield strength of 1560 MPa, a compressive fracture strength of 2035 MPa, and an elongation of 22%; Ir 40 W 35 Nb5Zr15 The Al5 high-entropy alloy exhibits a compressive yield strength of 687 MPa, a compressive fracture strength of 1091 MPa, and an elongation of 25% at 1100℃. Figure 4 As shown, its average oxidation rate is 1.70 mg / (cm²). 2 ·h).

[0045] Example 2:

[0046] A refractory high-entropy alloy possessing both high-temperature ablation resistance and high-temperature oxidation resistance, wherein the compositional formula of the refractory high-entropy alloy is Ir. 45 W 35 Rh 10 Ta5Cr5. The specific preparation method is as follows:

[0047] Weigh out pure metals according to the atomic ratio Ir∶W∶Rh∶Ta∶Cr=45∶35∶10∶5∶5, and add 8% more Ir element for burn-off loss.

[0048] Preparation of ablation-resistant refractory high-entropy alloys by electric arc melting:

[0049] ① Place the above-mentioned metallic elements and titanium ingots separately in water-cooled copper crucibles of a non-consumable vacuum arc melting furnace, and wait until the vacuum degree inside the furnace reaches 2.0 × 10⁻⁶. -3 Once the pressure drops below 0.090 MPa, turn off the vacuum pump and purge with argon gas to 0.090 MPa.

[0050] ② Turn on the power and first use electric arc to melt the titanium ingot. After the titanium ingot is completely melted and kept in the molten state for 1 minute, turn off the power. Turn on the power again, and use an electric arc melting current of 200-400A to melt the high entropy alloy for 90 seconds. Use electromagnetic stirring during the melting process to homogenize the alloy. Keep the alloy in the molten state for 2 minutes, then turn off the power and wait for the alloy ingot to cool.

[0051] ③ Flip the alloy ingot and repeat step ②; repeat step ③ at least 3 times to obtain a high-entropy alloy button ingot;

[0052] ④ Remove the oxide layer from the surface of the button ingot and cut it into block samples. Melt the block samples and place them in a Φ15×50mm copper mold to form the shape. Then, perform heat treatment at 1400℃ for 5 hours and cool in the furnace to finally obtain Ir. 45 W 35 Rh 10 Ta5Cr5 high-entropy alloy.

[0053] like Figure 5 As shown, this embodiment successfully prepared the refractory high-entropy alloy Ir. 45 W 35 Rh 10 Ta5Cr5 alloys exhibit a cellular crystal morphology. For example... Figure 6As shown, the prepared refractory high-entropy alloy Ir 45 W 35 Rh 10 Ta5Cr5 contains a BCC solid solution matrix and a small amount of Laves intermetallic compound phase. The properties of the prepared refractory high-entropy alloys are shown in Table 1. Figure 7 As shown, Ir 45 W 35 Rh 10 The Ta5Cr5 high-entropy alloy has a room temperature compressive yield strength of 1585 MPa, a compressive fracture strength of 1765 MPa, and an elongation of 16%.

[0054] Ir 45 W 35 Rh 10 The Ta5Cr5 high-entropy alloy exhibits a compressive yield strength of 589 MPa, a compressive fracture strength of 989 MPa, and an elongation of 18% at 1100℃. Figure 8 As shown, its oxidation rate is 2.10 mg / (cm²). 2 ·h).

[0055] Example 3:

[0056] A refractory high-entropy alloy possessing both high-temperature ablation resistance and high-temperature oxidation resistance, wherein the compositional formula of the refractory high-entropy alloy is Ir. 45 W 30 Hf5Nb 10 Al5Si5. The specific preparation method is as follows:

[0057] Weigh out pure metals according to the atomic ratio Ir∶W∶Hf∶Nb∶Al∶Si=45∶30∶5∶10∶5∶5, and add 10% more rare earth elements for burn-off.

[0058] Preparation of ablation-resistant refractory high-entropy alloys by electric arc melting:

[0059] ① Place the above-mentioned metallic element and titanium ingot separately in a water-cooled copper crucible in a non-consumable vacuum arc melting furnace, and wait until the vacuum degree inside the furnace reaches 1.5 × 10⁻⁶. -3 Once the pressure drops below 0.085 MPa, turn off the vacuum pump and purge with argon gas to 0.085 MPa.

[0060] ② Turn on the power and first use electric arc to melt the titanium ingot. After the titanium ingot is completely melted and kept in the molten state for 1 minute, turn off the power. Turn on the power again, and use an electric arc melting current of 200-400A to melt the high entropy alloy for 90 seconds. Use electromagnetic stirring during the melting process to homogenize the alloy. Keep the alloy in the molten state for 2 minutes, then turn off the power and wait for the alloy ingot to cool.

[0061] ③ Flip the alloy ingot and repeat step ②; repeat step ③ at least 3 times to obtain a high-entropy alloy button ingot;

[0062] ④ Remove the oxide layer from the surface of the button ingot and cut it into block samples. Melt the block samples and place them in a Φ10×50mm copper mold to form the shape. Then, perform heat treatment at 1350℃ for 4.5 hours and cool with the furnace to finally obtain Ir. 45 W 30 Hf5Nb 10 Al5Si5 high-entropy alloy.

[0063] The properties of the prepared refractory high-entropy alloys are shown in Table 1. 45 W 30 Hf5Nb 10 The microstructure of Al5Si5 high-entropy alloys comprises a BCC solid solution phase and a Laves intermetallic compound phase. Ir 45 W 30 Hf5Nb 10 The Al5Si5 high-entropy alloy exhibits a room-temperature compressive yield strength of 1365 MPa, a compressive fracture strength of 1673 MPa, and an elongation of 18%; Ir 45 W 30 Hf5Nb 10 The Al5Si5 high-entropy alloy exhibits a compressive yield strength of 656 MPa, a compressive fracture strength of 704 MPa, and an elongation of 22% at 1100℃. Figure 9 As shown, its oxidation rate is 1.46 mg / (cm²). 2 ·h).

[0064] Example 4:

[0065] A refractory high-entropy alloy possessing both high-temperature ablation resistance and high-temperature oxidation resistance, wherein the compositional formula of the refractory high-entropy alloy is Ir. 35 W 35 Pt2Mo 10 Nb 10 Al5Ni3. The specific preparation method is as follows:

[0066] Weigh out pure metals according to the atomic ratio Ir∶W∶Pt∶Mo∶Nb∶Al∶Ni=35∶35∶2∶10∶10∶5∶3, and add 8% more rare earth elements for burn-off loss.

[0067] Preparation of erosion-resistant refractory high-entropy alloys by electric arc melting: ① Place the above-mentioned metallic elements and titanium ingots separately in water-cooled copper crucibles of a non-consumable vacuum electric arc melting furnace, and wait until the vacuum degree inside the furnace reaches 2.0 × 10⁻⁶. -3After the pressure drops below 0.090 MPa, turn off the vacuum pump and purge with argon to 0.090 MPa; ② Turn on the power and first arc melt the titanium ingot. After the titanium ingot is completely melted and held in a molten state for 1 minute, turn off the power; turn on the power again, and use an arc melting current of 200-400 A to arc melt the high-entropy alloy for 120 seconds. During the melting process, use electromagnetic stirring to homogenize the alloy. Hold the alloy in a molten state for 2 minutes, then turn off the power and let the alloy ingot cool; ③ Turn over the alloy ingot and repeat step ②; repeat step ③ at least 3 times to obtain a high-entropy alloy button ingot; ④ Remove the oxide layer on the surface of the button ingot and cut it into block samples. After melting the block samples, place them in a Φ15×50 mm copper mold to form them, and then perform heat treatment at 1350℃ for 5 hours and furnace cooling to finally obtain Ir. 35 W 35 Pt2Mo 10 Nb 10 Al5Ni3 high-entropy alloy.

[0068] The properties of the prepared refractory high-entropy alloys are shown in Table 1. 35 W 35 Pt2Mo 10 Nb 10 The microstructure of the Al5Ni3 high-entropy alloy comprises a BCC solid solution phase and a Laves intermetallic compound phase. Ir 35 W 35 Pt2Mo 10 Nb 10 The Al5Ni3 high-entropy alloy exhibits a room-temperature compressive yield strength of 1300 MPa, a compressive fracture strength of 1578 MPa, and an elongation of 20%; Ir 35 W 35 Pt2Mo 10 Nb 10 The Al5Ni3 high-entropy alloy exhibits a compressive yield strength of 712 MPa, a compressive fracture strength of 768 MPa, and an elongation of 24% at 1100℃. Figure 10 As shown, its oxidation rate is 1.98 mg / (cm²). 2 ·h).

[0069] Example 5:

[0070] A refractory high-entropy alloy possessing both high-temperature ablation resistance and high-temperature oxidation resistance, wherein the compositional formula of the refractory high-entropy alloy is Ir. 50 W 30 Pd6V 10 Co2Pr2. The specific preparation method is as follows:

[0071] Weigh out the pure metal according to the atomic ratio, and add more Ir element to account for burn-off.

[0072] Preparation of ablation-resistant refractory high-entropy alloys by electric arc melting:

[0073] ① Place the above-mentioned metallic elements and titanium ingots into water-cooled copper crucibles in a non-consumable vacuum arc melting furnace, evacuate the furnace body, and then introduce inert gas.

[0074] ② Under inert gas protection conditions, titanium ingots are first melted to reduce the oxygen content in the furnace; under inert gas protection conditions, the above-mentioned metal elements are subjected to electric arc melting, and the melt is simultaneously electromagnetically stirred during the electric arc melting process to make the alloy composition uniform. After the electric arc melting is completed, the ingots are cooled to obtain button ingots.

[0075] ③ Flip the alloy ingot and remelt the button ingot at least 3 times to obtain a high-entropy alloy button ingot;

[0076] ④ Remove the oxide layer from the surface of the button ingot and cut it into block samples. Melt the block samples and place them in a mold to cool and shape them. Then, perform a heat treatment process at 1250-1500℃ for 1-24 hours, followed by furnace cooling, to finally obtain Ir. 50 W 30 Pd6V 10 Co2Pr2 high-entropy alloy.

[0077] Prepared refractory high-entropy alloy Ir 50 W 30 Pd6V 10 The properties of Co2Pr2 are shown in Table 1.

[0078] Example 6:

[0079] A refractory high-entropy alloy possessing both high-temperature ablation resistance and high-temperature oxidation resistance, wherein the compositional formula of the refractory high-entropy alloy is Ir. 30 W 50 Os5Zr 10 Ce5. The specific preparation method is as follows:

[0080] Weigh out the pure metal according to the atomic ratio, and add more Ir element to account for burn-off.

[0081] Preparation of ablation-resistant refractory high-entropy alloys by electric arc melting:

[0082] ① Place the above-mentioned metallic elements and titanium ingots into water-cooled copper crucibles in a non-consumable vacuum arc melting furnace, evacuate the furnace body, and then introduce inert gas.

[0083] ② Under inert gas protection conditions, titanium ingots are first melted to reduce the oxygen content in the furnace; under inert gas protection conditions, the above-mentioned metal elements are subjected to electric arc melting, and the melt is simultaneously electromagnetically stirred during the electric arc melting process to make the alloy composition uniform. After the electric arc melting is completed, the ingots are cooled to obtain button ingots.

[0084] ③ Flip the alloy ingot and remelt the button ingot at least 3 times to obtain a high-entropy alloy button ingot;

[0085] ④ Remove the oxide layer from the surface of the button ingot and cut it into block samples. Melt the block samples and place them in a mold to cool and shape them. Then, perform a heat treatment process at 1250-1500℃ for 1-24 hours, followed by furnace cooling, to finally obtain Ir. 30 W 50 Os5Zr 10 Ce5 high-entropy alloy.

[0086] Prepared refractory high-entropy alloy Ir 30 W 50 Os5Zr 10 The performance of Ce5 is shown in Table 1.

[0087] Example 7:

[0088] A refractory high-entropy alloy possessing both high-temperature ablation resistance and high-temperature oxidation resistance, wherein the compositional formula of the refractory high-entropy alloy is Ir. 60 W 30 Ru3Hf2Gd5. The specific preparation method is as follows:

[0089] Weigh out the pure metal according to the atomic ratio, and add more Ir element to account for burn-off.

[0090] Preparation of ablation-resistant refractory high-entropy alloys by electric arc melting:

[0091] ① Place the above-mentioned metallic elements and titanium ingots into water-cooled copper crucibles in a non-consumable vacuum arc melting furnace, evacuate the furnace body, and then introduce inert gas.

[0092] ② Under inert gas protection conditions, titanium ingots are first melted to reduce the oxygen content in the furnace; under inert gas protection conditions, the above-mentioned metal elements are subjected to electric arc melting, and the melt is simultaneously electromagnetically stirred during the electric arc melting process to make the alloy composition uniform. After the electric arc melting is completed, the ingots are cooled to obtain button ingots.

[0093] ③ Flip the alloy ingot and remelt the button ingot at least 3 times to obtain a high-entropy alloy button ingot;

[0094] ④ Remove the oxide layer from the surface of the button ingot and cut it into block samples. Melt the block samples and place them in a mold to cool and shape them. Then, perform a heat treatment process at 1250-1500℃ for 1-24 hours, followed by furnace cooling, to finally obtain Ir. 60 W 30 Ru3Hf2Gd5 high-entropy alloy.

[0095] Prepared refractory high-entropy alloy Ir 60 W 30 The performance of Ru3Hf2Gd5 is shown in Table 1.

[0096] Example 8:

[0097] A refractory high-entropy alloy possessing both high-temperature ablation resistance and high-temperature oxidation resistance, wherein the compositional formula of the refractory high-entropy alloy is Ir. 30 W 50 Pt5Ta5Ni3Sm2. The specific preparation method is as follows:

[0098] Weigh out the pure metal according to the atomic ratio, and add more Ir element to account for burn-off.

[0099] Preparation of ablation-resistant refractory high-entropy alloys by electric arc melting:

[0100] ① Place the above-mentioned metallic elements and titanium ingots into water-cooled copper crucibles in a non-consumable vacuum arc melting furnace, evacuate the furnace body, and then introduce inert gas.

[0101] ② Under inert gas protection conditions, titanium ingots are first melted to reduce the oxygen content in the furnace; under inert gas protection conditions, the above-mentioned metal elements are subjected to electric arc melting, and the melt is simultaneously electromagnetically stirred during the electric arc melting process to make the alloy composition uniform. After the electric arc melting is completed, the ingots are cooled to obtain button ingots.

[0102] ③ Flip the alloy ingot and remelt the button ingot at least 3 times to obtain a high-entropy alloy button ingot;

[0103] ④ Remove the oxide layer from the surface of the button ingot and cut it into block samples. Melt the block samples and place them in a mold to cool and shape them. Then, perform a heat treatment process at 1250-1500℃ for 1-24 hours, followed by furnace cooling, to finally obtain Ir. 30 W 50 Pt5Ta5Ni3Sm2 high-entropy alloy.

[0104] Prepared refractory high-entropy alloy Ir 30 W 50 The properties of Pt5Ta5Ni3Sm2 are shown in Table 1.

[0105] Example 9:

[0106] A refractory high-entropy alloy possessing both high-temperature ablation resistance and high-temperature oxidation resistance, wherein the compositional formula of the refractory high-entropy alloy is Ir. 40 W 40 Pt 10 Mo4La4Er2. The specific preparation method is as follows:

[0107] Weigh out the pure metal according to the atomic ratio, and add more Ir element to account for burn-off.

[0108] Preparation of ablation-resistant refractory high-entropy alloys by electric arc melting:

[0109] ① Place the above-mentioned metallic elements and titanium ingots into water-cooled copper crucibles in a non-consumable vacuum arc melting furnace, evacuate the furnace body, and then introduce inert gas.

[0110] ② Under inert gas protection conditions, titanium ingots are first melted to reduce the oxygen content in the furnace; under inert gas protection conditions, the above-mentioned metal elements are subjected to electric arc melting, and the melt is simultaneously electromagnetically stirred during the electric arc melting process to make the alloy composition uniform. After the electric arc melting is completed, the ingots are cooled to obtain button ingots.

[0111] ③ Flip the alloy ingot and remelt the button ingot at least 3 times to obtain a high-entropy alloy button ingot;

[0112] ④ Remove the oxide layer from the surface of the button ingot and cut it into block samples. Melt the block samples and place them in a mold to cool and shape them. Then, perform a heat treatment process at 1250-1500℃ for 1-24 hours, followed by furnace cooling, to finally obtain Ir. 40 W 40 Pt 10 Mo4La4Er2 high-entropy alloy.

[0113] Prepared refractory high-entropy alloy Ir 40 W 40 Pt 10 The properties of Mo4La4Er2 are shown in Table 1.

[0114] Table 1

[0115]

[0116] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A refractory high-entropy alloy possessing both high-temperature ablation resistance and high-temperature oxidation resistance, characterized in that, The refractory high-entropy alloy is Ir 40 W 35 Nb5Zr 15 Al5, Ir 45 W 35 Rh 10 Ta5Cr5, Ir 45 W 30 Hf5Nb 10 Al5Si5, Ir 35 W 35 Pt2Mo 10 Nb 10 Al5Ni3, Ir 50 W 30 Pd6V 10 Co2Pr2, Ir 30 W 50 Os5Zr 10 Ce5, Ir 60 W 30 Ru3Hf2Gd5、Ir 30 W 50 Pt5Ta5Ni3Sm2, Ir 40 W 40 Pt 10 Any one of Mo4La4Er2.

2. The method for preparing a refractory high-entropy alloy with both high-temperature ablation resistance and high-temperature oxidation resistance according to claim 1, characterized in that, Includes the following steps: Step S1: Weigh each elemental metal according to the proportions of the components, ultrasonically clean them, and then dry them for later use. Step S2: Refractory high-entropy alloys are prepared by electric arc melting. The metal element and titanium ingot are placed in water-cooled copper crucibles of a non-consumable vacuum electric arc melting furnace. After the furnace body is evacuated, inert gas is introduced. Step S3: Under inert gas, first melt the titanium ingot to reduce the oxygen content in the furnace, then perform electric arc melting on the elemental metal, and simultaneously perform electromagnetic stirring on the melt to make the alloy composition uniform, and finally cool to obtain the button ingot; turn the button ingot over and remelt the button ingot several times to make the composition of the button ingot uniform. Step S4: Remove the oxide layer on the surface of the button ingot and cut it into block samples. Melt several block samples and place them in a mold to cool and shape them. Hold them at 1250~1500℃ for 1~24h. Then, perform heat treatment with furnace cooling to finally obtain a refractory high entropy alloy.

3. The method for preparing a refractory high-entropy alloy with both high-temperature ablation resistance and high-temperature oxidation resistance according to claim 2, characterized in that, In step S1, an additional 3-10 wt% of elemental Ir is added.

4. The method for preparing a refractory high-entropy alloy with both high-temperature ablation resistance and high-temperature oxidation resistance according to claim 2, characterized in that, In step S2, the furnace body is evacuated to a vacuum level ≤1.5×10⁻⁶. -3 Pa, then fill with inert gas to 0.080~0.095 MPa.

5. The method for preparing a refractory high-entropy alloy with both high-temperature ablation resistance and high-temperature oxidation resistance according to claim 2, characterized in that, In step S3, the current for arc melting is 200~400A and the melting time is 30~120s; when remelting the button ingot, the alloy is kept in a liquid state for 2~3 minutes before cooling.

6. The method for preparing a refractory high-entropy alloy with both high-temperature ablation resistance and high-temperature oxidation resistance according to claim 5, characterized in that, Flip and remelt the button ingots more than or equal to 3 times.

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