Three-dimensional network carbide reinforced refractory alloy and preparation method thereof

Abstract

The invention relates to a three-dimensional network carbide reinforced refractory alloy and a preparation method thereof, and belongs to the technical field of alloy material preparation. The three-dimensional network carbide reinforced refractory alloy is composed of a BCC matrix phase and a large number of dispersed three-dimensional network carbide reinforced phases, and the crystal structure of the carbide is M2C or MC type and is in a complete coherent relationship with the BCC matrix. The method has high adaptability, the applicable refractory alloy material range is wide, particularly fine component design is not needed, the process window is wide, and operation is easy. According to the material prepared by the method, a carbide phase and a matrix are coherent, the bonding strength is high, the stability is good, and repeated thermal cycle can be endured. According to the method, integration of material preparation and component forming can be achieved, high-freedom-degree direct forming of complex three-dimensional parts is directly achieved, and the forming requirement in the actual using process can be met to a great extent.

Description

Technical Field

[0001] The invention relates to a three-dimensional network carbide reinforced refractory alloy and a preparation method thereof, belonging to the technical field of alloy material preparation. Background Art

[0002] In recent years, the aerospace industry, nuclear industry and other fields have an urgent need for high-temperature resistant alloy materials. However, with the continuous development of science and technology, the temperature of the industrial environment has continued to rise, exceeding the melting point of nickel-based high-temperature alloys and cobalt-based high-temperature alloys. Traditional high-temperature alloys can no longer meet the needs of service in high-temperature environments. Therefore, a series of refractory alloys with refractory metal elements such as Nb, Mo, Ta, and W have attracted widespread attention from scientific researchers. Refractory alloys have a high melting point and still have high yield strength and creep resistance when exceeding 1200°C. They are expected to become excellent high-temperature resistant materials for service in high and ultra-high temperature fields such as the aerospace industry, nuclear industry, and national defense industry.

[0003] However, there is a serious inverted relationship between the high temperature strength and room temperature plasticity of refractory alloys, and the high temperature strength still does not fully meet the needs of practical applications. How to improve the high temperature strength of refractory alloys while ensuring that they have good room temperature plasticity is still a problem that needs further research and resolution.

[0004] Many scholars have tried to improve the high-temperature strength of refractory alloys by adding carbides. However, high-carbon alloys are often accompanied by severe carbon segregation during solidification. Carbon is very active at high temperatures, has strong diffusion ability, and the size of carbides is often large. Therefore, the addition of carbides, while improving the high-temperature strength of refractory alloys, is usually accompanied by severe deterioration of room-temperature plasticity. Traditional methods for preparing carbide-reinforced refractory alloys mainly include vacuum arc melting and powder metallurgy. Due to its low cooling rate, vacuum arc melting is prone to problems such as coarse structure and severe component segregation in the prepared alloys, resulting in the carbide ceramic phase mostly existing in the form of eutectic phase, which deteriorates its room-temperature plasticity. Although the carbide-reinforced refractory alloy prepared by powder metallurgy has a finer structure, its carbide ceramic phase also has aggregated precipitation, and impurity elements are easily introduced during the ball milling stage, resulting in a decrease in the mechanical properties of the alloy.

[0005] If a refractory alloy with fine carbides, coherent with the matrix, and dispersed distribution can be prepared, it will be possible to improve the high-temperature strength while ensuring good room-temperature plasticity, which has significant practical application value. Summary of the invention

[0006] In view of the problems and shortcomings of the above-mentioned prior art, the present invention provides a three-dimensional network carbide reinforced refractory alloy and a preparation method thereof. The present invention can obtain a three-dimensional network carbide reinforced refractory alloy containing dispersedly distributed carbide precipitation phases coherent with the matrix, which effectively improves the high temperature strength while ensuring good room temperature plasticity.

[0007] The present invention is achieved through the following technical solutions.

[0008] A three-dimensional carbide network reinforced refractory alloy, which consists of a BCC matrix phase and a large number of dispersed three-dimensional carbide network reinforcement phases. The carbide crystal structure is of M2C or MC type and is in a completely coherent relationship with the BCC matrix.

[0009] A method for preparing a three-dimensional network carbide reinforced refractory alloy, the steps comprising:

[0010] (1) Raw material preparation: The target alloy rod is obtained by electron beam melting, and then spherical powder particles with a particle size of 15 to 100 μm are prepared by a rotating electrode method;

[0011] (2) Additive manufacturing: using a laser beam or electron beam with high energy density as a heat source, the spherical powder particles in step (1) are used to prepare a refractory alloy by coaxial powder feeding or selective melting;

[0012] (3) The refractory alloy obtained in step (2) is kept at 800-1000° C. for 1-2 hours to obtain a spatial network coherent carbide-reinforced refractory alloy.

[0013] In the step (1), the target component alloy is composed of metal elements and C non-metal elements, the metal elements are composed of 3-6 of Ta, W, Mo, Hf, Zr, Nb, and Re, and the content of C non-metal elements is 10% to 80% of the maximum carbon solubility at the eutectic temperature of the target component alloy.

[0014] The target alloy composition is a Hf-Nb-Mo-C refractory alloy composed of Hf, Nb, Mo and C in a molar ratio of 0.01-0.5:1.6:0.3:0.02-0.15.

[0015] The target alloy composition is a Re-Hf-Ta-WC refractory alloy composed of Re, Hf, Ta, W and C in a molar ratio of 0.01-0.1:0.01-0.5:1.0-2.0:0.2-1.0:0.005-0.2.

[0016] In the step (2) of additive manufacturing, the cooling rate of the solidification front is set to ≥1200°C / s, thereby increasing the temperature gradient of the solid-liquid interface and ensuring that the solidification is performed layer by layer without the formation of primary carbides.

[0017] When the laser beam is used as the heat source for additive manufacturing in step (2), the following controls are applied: laser power 5000-8000 W, spot diameter 2.5-3.5 mm, scanning speed 10-35 mm / s, powder feeding rate 20-30 g / min, layer lift 0.5-1 mm, and spacing between each cladding layer 1-2 mm.

[0018] When the electron beam is used as the heat source for additive manufacturing in step (2), the electron beam current is controlled to be 10-30 mA, the focusing current is 400-800 mA, the acceleration voltage is 30-60 kV, the beam spot diameter is 3-8 mm, the scanning speed is 200-800 mm / min, and the vacuum degree is 1×10 -5 ~1×10 -2 Pa.

[0019] The principle of the present invention is:

[0020] First, the alloy composition is determined, which is required to include 3-6 metal elements from Ta, W, Mo, Hf, Zr, Nb, and Re, as well as C non-metallic elements. Through the specific alloy composition, on the one hand, it is ensured that the carbides precipitated in the solid phase are MC and M2C types, and at the same time as the solid phase precipitation, the lattice parameters of the carbides can be adaptively adjusted through carbon vacancies to ensure coherence with the matrix. On the other hand, it is ensured that the carbon content does not exceed 80% of the carbon dissolved in the pseudo-binary matrix alloy, and that no carbides are precipitated during the solidification process.

[0021] Then, based on high-energy beam additive manufacturing technology, laser metal deposition or electron beam selective melting and other methods, the temperature change rate of the solidification interface is ensured to be ≥1200℃ / s, so that the alloy solidification process is layer-by-layer solidification, and due to the solute entrapment effect in the non-equilibrium rapid solidification process, the carbon in the solidified alloy is in a state of high supersaturation, and no primary carbide precipitation.

[0022] Finally, low-temperature aging treatment is carried out at 800-1000°C to promote the precipitation of carbides that are coherent with the matrix and ensure that the precipitates are small in size and evenly distributed, ultimately ensuring the alloy's good high-temperature strength and room-temperature plasticity.

[0023] In the method provided by the present invention, the carbide is coherent with the matrix, and the type of carbide is affected by the proportion of Hf and Zr in the alloy. There are two types of carbides: MC and M2C. When the molar ratio of Hf and Zr elements is respectively lower than 1 / 5 of the carbon content, the carbide precipitated in the BCC matrix is ​​an M2C carbide phase (the structure is an HCP structure), and the crystal structure changes during the carbide precipitation process as follows: within the matrix phase (110) plane, the BCC crystal structure is compressed along the

[001] direction to 0.8660254 times the previous one (all compressions can be regarded as the (110) crystal plane being compressed in the

[001] direction, and at the same time, the crystal plane is elongated perpendicular to the

[001] direction to 1.06082037 times the previous one ( Direction, or The actual total volume is reduced by 0.9189189 times, which is consistent with the density of HCP and BCC structures). The (110) plane of the original BCC structure becomes the (0001) plane of the HCP structure, and the interplanar spacing remains unchanged, that is, the (0001) interplanar spacing is equal to the (110) interplanar spacing. It is only stretched and contracted within the (110) plane, and the close-packed plane does not change, with an orientation relationship of (110) / / (0001).

[0024] When the molar ratio of Hf and Zr elements is higher than 3 / 5 of the carbon content, the carbides precipitated in the BCC matrix are MC carbide phases (the structure is FCC rock salt structure), and the crystal structure changes during the carbide precipitation process as follows: the BCC lattice is elongated about 1.41 times along the Z axis (

[001] direction), and the lattice constant of the FCC lattice is times the BCC lattice constant, the spatial orientation of FCC carbides

[001] is consistent with BCC, but the XY plane is rotated 45°. The orientation relationship is

[100] BCC / /

[110] FCC ,

[010] FCC / /

[110] BCC ,

[001] FCC / /

[001] BCC , the interface is on the (001) plane of the BCC phase (which is also the (001) crystal plane of the FCC phase).

[0025] The beneficial effects of the present invention are:

[0026] (1) The method of the present invention has strong adaptability and is applicable to a wide range of refractory alloy materials. It does not require particularly sophisticated composition design, and has a wide process window and is simple to operate.

[0027] (2) The material prepared by the method of the present invention has a coherent carbide phase and a matrix, has high bonding strength and good stability, and can withstand repeated thermal cycles.

[0028] (3) The method of the present invention can realize the integration of material preparation and component forming, directly realize the high-degree-of-freedom direct forming of complex three-dimensional parts, and can meet the forming requirements in actual use to a great extent.

[0029] (6) The three-dimensional carbide network reinforced refractory alloy prepared by the present invention has good high temperature strength and can meet the high temperature use requirements of components. The three-dimensional carbide network reinforced refractory alloy prepared by the present invention still has a compressive yield strength of 308.9 MPa or 522.7 MPa at 1450°C.

[0030] (7) The material prepared by the method of the present invention has a carbide phase coherent with the matrix. During the macroscopic plastic deformation of the material, the stacking fault can pass through the carbide to achieve a certain degree of plastic deformation, giving the material good strain coordination ability and showing outstanding room temperature plasticity. Compared with other refractory alloys, the three-dimensional network carbide reinforced refractory alloy prepared by the present invention has outstanding plasticity. Its carbide ceramic phase is coherent with the matrix. While the carbide strengthens the matrix, it does not cause plasticity degradation. The three-dimensional network carbide reinforced refractory alloy prepared by the present invention has a room temperature compressive fracture strain of more than 50%, which is more than 25 times that of the NbMoTaW refractory high entropy alloy. Good plasticity, on the one hand, makes it not easy to crack during the additive forming process, and has strong adaptability to additive manufacturing processes; on the other hand, it also gives the material good room temperature damage tolerance.

[0031] (8) The three-dimensional network carbide reinforced refractory alloy prepared by the present invention has good room temperature plasticity and high high temperature strength, and the preparation process is simple, which can realize the integrated preparation of material components and is expected to be used in the forming of hot-end complex structural components in the fields of aerospace, national defense, military industry, nuclear industry, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a 1000-fold metallographic image of the Hf-Nb-Mo-C refractory alloy prepared in Example 1 of the present invention;

[0033] Figure 2 This is a room temperature compressive stress-strain curve of the Hf-Nb-Mo-C refractory alloy prepared in Example 1 of the present invention;

[0034] Figure 3 This is a 1450°C compressive stress-strain curve of the Hf-Nb-Mo-C refractory alloy prepared in Example 1 of the present invention;

[0035] Figure 4 This is a SEM image of the Hf-Nb-Mo-C refractory alloy prepared in Example 1 of the present invention;

[0036] Figure 5This is a high-resolution TEM photograph of the interface between the matrix and the carbide in the Hf-Nb-Mo-C refractory alloy prepared in Example 1 of the present invention;

[0037] Figure 6 This is the XRD spectrum of the Hf-Nb-Mo-C refractory alloy prepared in Example 1 of the present invention.

[0038] Figure 7 This is a 1000-fold metallographic image of the Re-Hf-Ta-WC refractory alloy prepared in Example 2 of the present invention;

[0039] Figure 8 This is a room temperature compressive stress-strain curve of the Re-Hf-Ta-WC refractory alloy prepared in Example 2 of the present invention;

[0040] Fig. 9 This is a 1450°C compressive stress-strain curve of the Re-Hf-Ta-WC refractory alloy prepared in Example 2 of the present invention;

[0041] Fig.10 This is a SEM image of the Re-Hf-Ta-WC refractory alloy prepared in Example 2 of the present invention;

[0042] Fig.11 This is the XRD spectrum of the Re-Hf-Ta-WC refractory alloy prepared in Example 2 of the present invention. DETAILED DESCRIPTION

[0043] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods.

[0044] Example 1

[0045] The three-dimensional carbide network reinforced refractory alloy consists of a BCC matrix phase and a large amount of dispersed three-dimensional carbide network reinforcement phases. The carbide crystal structure is of MC type and is in a completely coherent relationship with the BCC matrix.

[0046] The preparation method of the three-dimensional network carbide reinforced refractory alloy comprises the following steps:

[0047] (1) Raw material preparation: using an electron beam melting method, Hf, Nb, Mo, and C powders with a molar ratio of 0.05:1.6:0.3:0.05 were electron beam melted at a temperature of 2800°C to obtain a target composition alloy rod, and then a rotating electrode method (electrode rod diameter 60 mm, length 700 mm, surface roughness Ra ≤ 1.2 μm, electrode speed 20000 r / min, inert gas argon + helium with a volume ratio of 1:8 as protective gas, protective gas flow rate of 80 L / min, working pressure 0.15 MPa, plasma arc current 1.0 KA, voltage 45 V) was used to prepare spherical powder particles with a particle size of 15 to 100 μm;

[0048] (2) Additive manufacturing: Using laser metal deposition additive method with high energy density laser beam as heat source, using spherical powder particles in step (1), based on coaxial powder feeding, and stacking layer by layer according to the scanning path of short grating arch to form refractory alloy; within the process window with good forming, at appropriate power, try to increase the scanning rate to increase the solidification rate, so that the cooling rate of the solidification front is ≥1200℃ / s, increase the temperature gradient of the solid-liquid interface, and ensure that the solidification method is layer-by-layer solidification; the process parameters of laser metal deposition are: laser power 6000W, spot diameter 2.8mm, scanning speed 10mm / s, powder feeding rate 26.5g / min, layer lift 0.7mm, and each cladding layer spacing 1.3mm. The whole process is carried out in a high-purity argon protective atmosphere, and the oxygen content and moisture content are <100ppm;

[0049] (3) The refractory alloy obtained in step (2) is kept at 900° C. for 1 hour to obtain a spatial network coherent carbide-reinforced refractory alloy.

[0050] The three-dimensional network carbide reinforced refractory alloy prepared in this embodiment is composed of BCC matrix phase + FCC carbide reinforcement phase, and the orientation relationship is

[100] BCC / /

[110] FCC ,

[010] FCC / /

[110] BCC ,

[001] FCC / /

[001] BCC The interface is on the (001) plane of the BCC phase (which is also the (001) crystal plane of the FCC phase). The two phases are completely coherent (FCC lattice, which is equivalent to the BCC lattice being stretched about 1.41 times along the Z axis (

[001] direction). The lattice constant of the FCC lattice is times the BCC lattice constant).

[0051] The 1000-fold metallographic image of the Hf-Nb-Mo-C refractory alloy prepared in this embodiment is as follows: Figure 1 As shown, from Figure 1It can be seen that there are many carbide ceramic phases precipitated inside the alloy grains, and the grain size is small.

[0052] The room temperature compressive stress-strain curve of the Hf-Nb-Mo-C refractory alloy prepared in this embodiment is shown in Figure 2 As shown, from Figure 2 It can be seen that the compressive yield strength σ of the alloy at room temperature 0.2 It is 762.3MPa, the compressive fracture strain exceeds 50%, and it has good room temperature plasticity.

[0053] The 1450°C compressive stress-strain curve of the Hf-Nb-Mo-C refractory alloy prepared in this example is shown in FIG. Figure 3 As shown, from Figure 3 It can be seen that the compressive yield strength σ of the alloy at 1450℃ 0.2 It is 308.9Mpa and has higher high temperature strength.

[0054] The SEM image of the Hf-Nb-Mo-C refractory alloy prepared in this example is as follows Figure 4 As shown, from Figure 4 It can be seen that a large amount of three-dimensional network carbide ceramic phase is precipitated inside the alloy grains, and has obvious orientation.

[0055] The TEM high-resolution photograph of the interface between the precipitate phase and the matrix in the Hf-Nb-Mo-C refractory alloy prepared in this example is as follows: Figure 5 As shown, from Figure 5 It can be seen that the matrix and the precipitated phase are coherent.

[0056] The XRD pattern of the Hf-Nb-Mo-C refractory alloy prepared in this example is as follows: Figure 6 As shown, from Figure 6 It can be seen that the alloy is a dual-phase structure consisting of BCC matrix phase and FCC phase (MC type carbide).

[0057] Example 2

[0058] The three-dimensional carbide network reinforced refractory alloy consists of a BCC matrix phase and a large amount of dispersed three-dimensional carbide network reinforcement phase. The carbide crystal structure is of MC+M2C type and is in a completely coherent relationship with the BCC matrix.

[0059] The preparation method of the three-dimensional network carbide reinforced refractory alloy comprises the following steps:

[0060] (1) Raw material preparation: Re, Hf, Ta, W, C powders with a molar ratio of 0.07:0.13:1.6:0.2:0.13 were electron beam melted at a temperature of 3200°C to obtain a target alloy rod, and then a rotating electrode method (electrode rod diameter 60 mm, length 700 mm, surface roughness Ra ≤ 1.2 μm, electrode speed 20000 r / min, inert gas argon + helium with a volume ratio of 1:8 as protective gas, protective gas flow rate of 80 L / min, working pressure 0.15 MPa, plasma arc current 1.0 KA, voltage 45 V) was used to prepare spherical powder particles with a particle size of 15 to 100 μm;

[0061] (2) Additive manufacturing: Using laser metal deposition additive method with high energy density laser beam as heat source, using spherical powder particles in step (1), based on coaxial powder feeding, and stacking layer by layer according to the scanning path of short grating arch to form refractory alloy; within the process window with good forming, at appropriate power, try to increase the scanning rate to increase the solidification rate, so that the cooling rate of the solidification front is ≥1200℃ / s, increase the temperature gradient of the solid-liquid interface, and ensure that the solidification method is layer-by-layer solidification; the process parameters of laser metal deposition are: laser power 7500W, spot diameter 2.8mm, scanning speed 11mm / s, powder feeding rate 26.8g / min, layer lift 0.8mm, and each cladding layer spacing 1.5mm. The whole process is carried out in a high-purity argon protective atmosphere, and the oxygen content and moisture content are less than 100ppm;

[0062] (3) The refractory alloy obtained in step (2) is kept at 950° C. for 1.2 h to obtain a spatial network coherent carbide-reinforced refractory alloy.

[0063] The three-dimensional network carbide reinforced refractory alloy prepared in this embodiment consists of BCC matrix phase + (FCC + HCP) carbide reinforcement phase.

[0064] The metallographic image of the Re-Hf-Ta-WC refractory alloy prepared in this embodiment at a magnification of 1000 is as follows Figure 7 As shown, from Figure 7 It can be seen that there are many carbide ceramic phases precipitated inside the alloy grains, and the grain size is small.

[0065] The room temperature compressive stress-strain curve of the Re-Hf-Ta-WC refractory alloy prepared in this embodiment is shown in Figure 8 As shown, from Figure 8 It can be seen that the compressive yield strength σ of the alloy at room temperature 0.2 It is 1195.2Mpa, the compression fracture strain exceeds 50%, and it has good room temperature plasticity.

[0066] The 1450°C compressive stress-strain curve of the Re-Hf-Ta-WC refractory alloy prepared in this embodiment is shown in FIG. Fig. 9 As shown, from Fig. 9 It can be seen that the compressive yield strength σ of the alloy at 1450℃ 0.2 It is 522.7Mpa and has higher high temperature strength.

[0067] The SEM image of the Re-Hf-Ta-WC refractory alloy prepared in this embodiment is as follows Fig.10 As shown, from Fig.10 It can be seen that a large amount of three-dimensional network carbide ceramic phase is precipitated inside the alloy grains, and has obvious orientation.

[0068] The XRD pattern of the Re-Hf-Ta-WC refractory alloy prepared in this embodiment is shown in Fig.11 As shown, from Fig.11 It can be seen that the alloy is composed of BCC matrix phase, FCC phase (MC type carbide) and HCP phase (M2C type carbide).

[0069] Example 3

[0070] The three-dimensional carbide network reinforced refractory alloy consists of a BCC matrix phase and a large amount of dispersed three-dimensional carbide network reinforcement phase. The carbide crystal structure is of M2C type and is in a completely coherent relationship with the BCC matrix.

[0071] The preparation method of the three-dimensional network carbide reinforced refractory alloy comprises the following steps:

[0072] (1) Raw material preparation: Re, Mo, Ta, W, C powders with a molar ratio of 0.05:0.07:1.8:0.5:0.12 were electron beam melted at a temperature of 2800°C to obtain target alloy rods, and then a rotating electrode method (electrode rod diameter 65 mm, length 750 mm, surface roughness Ra ≤ 1.4 μm, electrode speed 25000 r / min, inert gas argon + helium with a volume ratio of 1:10 as protective gas, protective gas flow rate of 75 L / min, working pressure 0.16 MPa, plasma arc current 1.1 KA, voltage 55 V) was used to prepare spherical powder particles with a particle size of 15 to 100 μm;

[0073] (2) Additive manufacturing: Using an electron beam with high energy density as the heat source, the spherical powder particles in step (1) are used to form a refractory alloy by layer-by-layer stacking based on a powder bed and an S-shaped scanning strategy; within a good forming process window, at an appropriate power, the scanning rate is increased as much as possible to increase the solidification rate, so that the cooling rate at the solidification front is ≥1200°C / s, the temperature gradient at the solid-liquid interface is increased, and the solidification method is ensured to be layer-by-layer solidification; the process parameters when the electron beam is used as the heat source are: electron beam current of 20 mA, focusing current of 600 mA, acceleration voltage of 50 kV, beam spot diameter of 5 mm, scanning speed of 600 mm / min, and vacuum degree of 1×10 -2 Pa;

[0074] (3) The refractory alloy obtained in step (2) is kept at 1000° C. for 1.5 hours to obtain a spatial network coherent carbide-reinforced refractory alloy.

[0075] In this embodiment, the three-dimensional network carbide reinforced refractory alloy is composed of BCC matrix phase + M2C close-packed hexagonal carbide reinforcement phase. In the process of BCC to HCP, the BCC crystal structure is compressed along the

[001] direction in the (110) plane to 0.8660254 times the previous one (all compression can be regarded as the (110) crystal plane being compressed in the

[001] direction, and at the same time, the crystal plane is elongated perpendicular to the

[001] direction to 1.06082037 times the previous one ( Direction, or The actual total volume is reduced by 0.9189189 times, which is consistent with the density of HCP and BCC structures). The (110) plane of the original BCC structure becomes the (0001) plane of the HCP structure, and the interplanar spacing remains unchanged, that is, the (0001) interplanar spacing is equal to the (110) interplanar spacing. It only stretches and shrinks within the (110) plane, and the close-packed plane does not change. The basic orientation relationship is (110) / / (0001).

[0076] The specific implementation modes of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above implementation modes, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A three-dimensional network carbide reinforced refractory alloy, characterized in that: It is composed of a BCC matrix phase and a large number of dispersed three-dimensional network carbide reinforcement phases. The carbide crystal structure is of M2C or MC type and is completely coherent with the BCC matrix.

2. A method for preparing a three-dimensional network carbide reinforced refractory alloy according to claim 1, characterized in that the steps include: (1) Raw material preparation: The target alloy rod is obtained by electron beam melting, and then spherical powder particles with a particle size of 15 to 100 μm are prepared by a rotating electrode method; (2) Additive manufacturing: using a laser beam or electron beam with high energy density as a heat source, the spherical powder particles in step (1) are used to prepare a refractory alloy by coaxial powder feeding or selective melting; (3) The refractory alloy obtained in step (2) is kept at 800-1000° C. for 1-2 hours to obtain a spatial network coherent carbide-reinforced refractory alloy.

3. The method for preparing a three-dimensional network carbide reinforced refractory alloy according to claim 2, characterized in that: In the step (1), the target component alloy is composed of metal elements and C non-metal elements, the metal elements are composed of 3-6 of Ta, W, Mo, Hf, Zr, Nb, and Re, and the content of C non-metal elements is 10% to 80% of the maximum carbon solubility at the eutectic temperature of the target component alloy.

4. The method for preparing a three-dimensional network carbide reinforced refractory alloy according to claim 3, characterized in that: The target alloy composition is a Hf-Nb-Mo-C refractory alloy composed of Hf, Nb, Mo and C in a molar ratio of 0.01-0.5:1.6:0.3:0.02-0.

15.

5. The method for preparing the three-dimensional network carbide reinforced refractory alloy according to claim 3, characterized in that: The target alloy composition is a Re-Hf-Ta-WC refractory alloy composed of Re, Hf, Ta, W and C in a molar ratio of 0.01-0.1:0.01-0.5:1.0-2.0:0.2-1.0:0.005-0.

2.

6. The method for preparing a three-dimensional network carbide reinforced refractory alloy according to claim 2, characterized in that: In the step (2) of additive manufacturing, the cooling rate of the solidification front is set to be ≥1200°C / s.

7. The method for preparing a three-dimensional network carbide reinforced refractory alloy according to claim 2, characterized in that: When the laser beam is used as the heat source for additive manufacturing in step (2), the following controls are applied: laser power 5000-8000 W, spot diameter 2.5-3.5 mm, scanning speed 10-35 mm / s, powder feeding rate 20-30 g / min, layer lift 0.5-1 mm, and spacing between each cladding layer 1-2 mm.

8. The method for preparing a three-dimensional network carbide reinforced refractory alloy according to claim 2, characterized in that: When the electron beam is used as the heat source for additive manufacturing in step (2), the electron beam current is controlled to be 10-30 mA, the focusing current is 400-800 mA, the acceleration voltage is 30-60 kV, the beam spot diameter is 3-8 mm, the scanning speed is 200-800 mm / min, and the vacuum degree is 1×10 -5 ~1×10 -2 Pa.

Images