A method for preparing MIM high-temperature alloy nozzle ring blades

Abstract

The present invention discloses a method for preparing a MIM high-temperature alloy nozzle ring blade, wherein a high-temperature alloy powder and a binder are mixed and granulated to obtain a uniform feed, and then the feed is injected into a mold cavity by injection molding technology to obtain a green body, and then the binder in the green body is removed by solvent degreasing and thermal degreasing processes, and finally sintering densification, solid solution, and aging are performed in sequence to obtain a nozzle ring blade product. Compared with the prior art, the solid solution strengthening of elements such as C and N and the precipitation strengthening of carbides greatly improve the performance of the alloy, and at the same time improve the production efficiency, and have the advantages of excellent comprehensive performance, simple process, and easy to realize mass production, etc., which can well meet the needs of MIM high-temperature alloy nozzle ring blades.

Description

Technical Field

[0001] The present invention relates to a method for preparing a nozzle ring blade, in particular to a method for preparing a MIM high-temperature alloy nozzle ring blade. Background Art

[0002] The main function of a turbocharger is to increase the engine's air intake by compressing air. The working principle is that the engine's exhaust gas drives the turbine wheel inside the turbine chamber to rotate. The rotating turbine wheel in turn drives the compressor impeller on the other side. The rotating compressor impeller forcibly draws in air delivered from the air filter duct. The inhaled air is compressed and enters the cylinder, thereby burning more fuel and achieving the purpose of increasing the engine's output.

[0003] Nozzle ring vanes are critical components in turbochargers, primarily used to regulate exhaust gas intake volume. Engine exhaust temperatures reach approximately 650°C, with transient operating temperatures reaching 850°C. Therefore, the blade material must possess high-temperature strength, high-temperature oxidation resistance, and corrosion resistance, with HK30 stainless steel typically used. Furthermore, nozzle ring vanes primarily consist of two parts: the blade body and the tenon. The blade body has a complex spatial shape, often composed of various curved surfaces, while the tenon is typically cylindrical, T-shaped, or fork-shaped. Metal injection molding (MIM) is a process that enables the mass production of high-performance, custom-shaped metal parts with complex shapes at a low cost. Introducing MIM into turbocharger blade production effectively addresses efficiency and cost challenges. Therefore, He Hao of Hunan Yingjie High-Tech Co., Ltd. uses MIM technology to manufacture HK30 stainless steel turbocharger nozzle ring vanes, eliminating subsequent machining and shaping, effectively shortening the process, reducing production costs, and improving product yield (CN108311701A).

[0004] As vehicle exhaust temperatures gradually rise, the operating environment becomes increasingly harsh, placing higher demands on blade performance. To further enhance high-temperature performance, researchers used HK30 stainless steel powder as the base material, mixing it with varying proportions of Ti powder. This allowed the Ti and carbon to form relatively stable carbides, thereby improving high-temperature mechanical properties. The high-temperature tensile strength (800°C) exceeded 500 MPa (CN109014214A, CN102211193A). Other researchers have experimented with introducing an appropriate amount of CrN into HK30 and applying this material to high-strength turbocharger nozzle ring blades. Through the synergistic effects of the various components and the preparation process, solid solution strengthening was employed to enhance the high-temperature strength of the material, resulting in a superior product. The resulting product exhibits a HV rating of greater than or equal to 250 and a tensile strength of greater than or equal to 230 MPa at 800°C (CN109513930A). Based on the MIM process, Ni3Al dispersion strengthening technology combined with spark plasma sintering technology was used to produce HK30-based turbine blades (CN112756610A). However, these alloying methods cannot significantly improve the high-temperature performance of HK30, and the difficulty of process control increases. In addition, researchers have also reported other material systems for the preparation of nozzle ring blades, such as silicon nitride, silicon carbide, alumina or zirconium oxide ceramics (CN102777214A) and niobium-containing 420 martensitic stainless steel (CN110791696A). However, the plasticity of these two types of materials is poor, which is not conducive to processing and is not an ideal choice to replace HK30 materials. In summary, proposing a new type of high-temperature alloy and using MIM technology to achieve the preparation of high-performance nozzle ring blades is an urgent problem that needs to be solved. Summary of the Invention

[0005] In order to address the deficiencies in the prior art, the present invention provides a method for preparing high-temperature alloy nozzle ring blades. Based on an Fe-Cr-Ni-Co alloy and with the addition of elements such as Mo, W, and Nb, the present invention adopts metal injection molding (MIM) technology combined with solution aging heat treatment to prepare nozzle ring blades with excellent high-temperature performance, high production efficiency, and suitability for large-scale production, thereby overcoming the shortcomings of the above-mentioned processes.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides a method for preparing a MIM high-temperature alloy nozzle ring blade, comprising the following steps:

[0008] The high-temperature alloy powder and the binder are mixed and granulated to obtain a uniform feed, and then the feed is injected into the mold cavity using injection molding technology to obtain a product green body. The binder in the green body is then removed by solvent degreasing and thermal degreasing processes. Finally, sintering densification, solid solution treatment, and aging are carried out in sequence to obtain the nozzle ring blade product;

[0009] The composition of the high-temperature alloy powder is: Cr: 18-23wt.%, Co: 17-23wt.%, Ni: 19-22wt.%, W: 2-4wt.%, Mo: 2-4wt.%, Nb: 0.5-1.5wt.%, C: 0.1-0.3wt.%, Mn: 1-1.5wt.%, S: ≤0.04wt.%, P: ≤0.04wt.%, Si: ≤1.0wt.%, and the balance is iron;

[0010] The sintering process is as follows: under nitrogen atmosphere protection, heating to 1200-1300°C at a heating rate of 5-10°C / min, a pressure of 0.1-0.5 MPa (provided by nitrogen), and a holding time of 1-6 hours;

[0011] The solution treatment process is as follows: in a vacuum heat treatment furnace, under nitrogen atmosphere protection, the solution temperature is 1000-1200°C, the holding time is 1-4 hours, the pressure is 0.05-0.2 MPa (provided by nitrogen), and the quenching medium is water or oil;

[0012] The aging process is as follows: in a vacuum heat treatment furnace, the vacuum degree is ≤10 -1 Pa, aging temperature is 700~900℃, holding time is 1~30h, cooling method is air cooling or air cooling.

[0013] As a preferred embodiment, the present invention provides a method for preparing a MIM high-temperature alloy nozzle ring blade, wherein the average particle size of the high-temperature alloy powder is 8-15 μm; the high-temperature alloy powder is prepared by a water atomization method or a gas atomization method.

[0014] As a preferred embodiment, the present invention provides a method for preparing a MIM high-temperature alloy nozzle ring blade, wherein the binder is composed of the following components by mass percentage:

[0015] Paraffin 50~65%;

[0016] Polydioxolane 20~35%;

[0017] Polylactide 5~20%.

[0018] As a preferred embodiment, the present invention provides a method for preparing a MIM high-temperature alloy nozzle ring blade. In the mixing process, the mixing temperature is 100-160°C, the mixing time is 1-4 hours, and the mixer speed is 40-80 r / min.

[0019] As a preferred embodiment, the present invention provides a method for preparing a MIM high-temperature alloy nozzle ring blade, wherein the volume ratio of the binder in the feed prepared by the binder and powder is in the range of 35% to 45%.

[0020] As a preferred embodiment, the present invention provides a method for preparing a MIM high-temperature alloy nozzle ring blade. In the injection molding process, the injection temperature is 110~160°C, the injection pressure is 80~130MPa, the injection speed is 40~100g / s, and the mold temperature is 30~70°C.

[0021] As a preferred embodiment, the present invention provides a method for preparing a MIM high-temperature alloy nozzle ring blade, wherein in the solvent degreasing process, the solvent is n-heptane, the degreasing time is 2 to 8 hours, and the temperature is 40 to 60°C;

[0022] The thermal degreasing comprises: first heating to 450-600°C at a heating rate of 5-10°C / min and keeping the temperature for 1-4 hours under the protection of argon atmosphere, then heating to 950-1100°C at a heating rate of 5-10°C / min and keeping the temperature for 1-4 hours, and then cooling to room temperature with the furnace.

[0023] As a preferred embodiment, the present invention provides a method for preparing a MIM high-temperature alloy nozzle ring blade, wherein the obtained nozzle ring blade product has a room temperature tensile strength of ≥750MPa, an elongation of ≥10%, and an 800°C tensile strength of ≥650MPa, and an elongation of ≥20%.

[0024] Principles and advantages

[0025] In the present invention, the composition design of the nozzle ring vanes utilizes heat-resistant austenitic stainless steel, based on the requirements for excellent high-temperature strength, ductility, and corrosion resistance. Regarding corrosion resistance, nickel is the primary austenite-forming element. Cr, combined with oxygen, forms a corrosion-resistant Cr2O3 passivation film, making it one of the essential elements for maintaining corrosion resistance. Furthermore, its combination with nickel mitigates corrosion of the steel. Regarding strengthening, the inventors unexpectedly discovered that a high content of cobalt and the appropriate addition of tungsten, molybdenum, niobium, and carbon, aided by heat treatment, induce excellent solid solution strengthening and precipitation strengthening effects. Therefore, this composition design meets the material composition requirements for nozzle ring vanes.

[0026] The process parameters of each link will have an impact on the performance of the final product, and each process parameter needs to be optimized. In the mixing process, ultrafine powder (average particle size 8-15um) and binder are fully mixed to obtain uniform feed, prevent feed component segregation, and ensure uniform shrinkage and good shape retention after sintering. In the injection molding process, injection parameters such as injection temperature, injection pressure, and injection speed are adjusted to obtain a good injection blank to prevent uneven density of the formed blank caused by injection. In the degreasing process, the present invention utilizes a degreasing method that combines solvent degreasing and thermal degreasing. N-heptane solvent is used to dissolve the paraffin component in the binder. The remaining high molecular weight binder is removed through a thermal degreasing process that reaches the target degreasing temperature through a two-stage heating program. The corresponding heating rate and holding time are controlled to effectively control the degreasing rate, so that the binder is removed as cleanly as possible, avoiding defects such as deformation and cracks in the blank during the degreasing process.

[0027] Sintering is a key process in MIM, which eliminates the pores between powder particles. It makes the MIM product fully dense or nearly fully dense, and obtains the required final physical and mechanical properties through sintering. The inventors found that in Fe-Cr-Ni-Co based high temperature alloys, nitrogen sintering was used, and the performance was improved by controlling the nitrogen pressure and sintering temperature. N atoms entered the Fe lattice, forming nitrides on the one hand, and the dispersed second phase can refine the grains. On the other hand, due to the difference in atomic radius between the N element and the Fe matrix element, the internal lattice is distorted, which has an obstructive effect on the movement of dislocations on the slip plane, thereby increasing the strength and hardness of the metal. At the same time, a reasonable boat loading method is adopted to ensure that each part is reasonably supported and heated evenly, ensuring the sintering density and surface finish, and effectively avoiding defects such as deformation and cracking of the blank during the heating and sintering process.

[0028] Due to the slow cooling after sintering and holding, a large amount of second phase will be precipitated. The inventors found that these are mainly carbides, nitrides and intermetallic compounds. By setting a reasonable solution temperature and holding time, these phases can be dissolved in the matrix as much as possible at high temperature, causing solute atoms N, C, W, Mo, etc. to cause lattice distortion in the iron lattice, forming a strong stress field. This stress field hinders the movement of dislocations, thereby improving the strength and hardness of the steel.

[0029] Precipitation strengthening occurs during the aging process, where nanometer-sized second-phase particles are dispersed and precipitated from the matrix. During plastic deformation, dislocation lines cannot directly cut through the second-phase particles. However, under external forces, dislocation lines can bend around them. This bending increases the lattice distortion energy in the dislocation-affected zone, increasing the resistance to dislocation movement and the slip resistance. This acts to pin dislocations and hinder dislocation migration, significantly improving the material's strength while minimizing the decrease in plasticity and toughness. The inventors discovered five precipitated phases: carbides Cb (C, N), M23C6, X phase, and M6C phase, and the intermetallic compound Laves phase. The primary precipitates responsible for age hardening are the M23C6 and X phase carbides, while the M6C and Laves phases contribute little to hardening. By employing appropriate aging temperatures and holding times, the inventors achieved a microstructure dominated by M23C6 and X phases, further enhancing the performance of nozzle ring vanes.

[0030] Compared with the prior art, the advantages of the present invention are as follows:

[0031] 1) Excellent performance. Its room temperature and high temperature performance is 2 to 3 times that of HK30, which well meets the requirements of MIM high-temperature alloy nozzle rings and blades;

[0032] 2) Nitrogen sintering, high production efficiency;

[0033] 3) The process is simple, no plastic processing technology is required, and it is easy to mass produce.

[0034] In summary, the present invention is based on Fe-Cr-Ni-Co alloy, and adds elements such as Mo, W, and Nb. It adopts metal injection molding (MIM) technology in combination with solid solution aging heat treatment. The solid solution strengthening of elements such as C and N and the precipitation strengthening of carbides greatly improve the performance of the alloy, while improving production efficiency. It has the advantages of excellent comprehensive performance, simple process, and easy batch production. It solves the problems of low product performance and high cost in the existing technology and can well meet the needs of MIM high-temperature alloy nozzle ring blades. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is the SEM morphology of high-temperature alloy powder.

[0036] Figure 2 This is a metallographic photograph of a high-temperature alloy in the aging state. DETAILED DESCRIPTION

[0037] The method of the present invention is further illustrated below with reference to three examples.

[0038] The high-temperature alloy powder and the binder are mixed and granulated to obtain a uniform feed, and then the feed is injected into the mold cavity using injection molding technology to obtain a product green body. The binder in the green body is then removed by solvent degreasing and thermal degreasing processes. Finally, sintering densification, solid solution and aging are carried out in sequence to obtain the nozzle ring blade product.

[0039] Example 1:

[0040] A method for preparing a MIM high-temperature alloy nozzle ring blade, the process is as follows:

[0041] A. Raw material preparation: Use atomized high-temperature alloy powder with an average particle size of 12um. Figure 1 This is the SEM morphology of the high-temperature alloy powder;

[0042] B. Preparation of adhesive: Take 55% paraffin wax, 30% polydioxolane, and 15% polylactide by mass percentage, and mix them in a mixer at 120°C for 4 hours to prepare the adhesive;

[0043] C. Prepare feed: Mix the binder and powder in a volume ratio of 44%:56%, granulate and prepare feed. The mixing temperature is 120°C, the mixer speed is 60 r / min, and the mixing time is 4 hours.

[0044] D. Injection molding: The feed material is injected into the mold cavity using an injection molding machine to obtain a product green body; the injection temperature is 140°C, the injection pressure is 120MPa, the injection speed is 50g / s, and the mold temperature is 60°C;

[0045] E. Degreasing: The green body is first degreased with n-heptane solvent to remove the paraffin component therein. The degreasing time is 6 hours and the degreasing temperature is 50°C. Then, thermal degreasing is carried out in a vacuum degreasing furnace. In an argon atmosphere, the body is first heated to 500°C at a heating rate of 8°C / min and kept warm for 2 hours. Then, the body is heated to 1000°C at a heating rate of 5°C / min and kept warm for 3 hours. After that, the body is cooled to room temperature with the furnace.

[0046] F. Sintering: Place the degreased blank in a sintering furnace for sintering; heat to 1280°C at a heating rate of 5°C / min, a pressure of 0.4 MPa (provided by nitrogen), and hold for 2 hours;

[0047] G. Solution treatment: Under nitrogen atmosphere protection, the sintered billet is placed in a heat treatment furnace with a solution temperature of 1150°C, a holding time of 2 hours, a pressure of 0.1 MPa (provided by nitrogen), and oil as the quenching medium;

[0048] H. Aging: In vacuum heat treatment furnace, vacuum degree ≤10 -1Pa, aging temperature is 900℃, holding time is 2h, cooling method is air cooling. Testing performance, room temperature tensile strength is 780MPa, elongation is 15%, 800℃ tensile strength is 687MPa, elongation is 28%.

[0049] Example 2:

[0050] A method for preparing a MIM high-temperature alloy nozzle ring blade, the process is as follows:

[0051] A. Raw material preparation: Use atomized high-temperature alloy powder with an average particle size of 12um. Figure 1 This is the SEM morphology of the high-temperature alloy powder;

[0052] B. Preparation of adhesive: Take 60% paraffin wax, 32% polydioxolane, and 8% polylactide by mass percentage, and mix them in a mixer at 120°C for 4 hours to prepare the adhesive;

[0053] C. Prepare feed: Mix the binder and powder in a volume ratio of 40%:60%, granulate and prepare feed. The mixing temperature is 140°C, the mixer speed is 70 r / min, and the mixing time is 3 hours.

[0054] D. Injection molding: The feed material is injected into the mold cavity using an injection molding machine to obtain a product green body; the injection temperature is 155°C, the injection pressure is 85MPa, the injection speed is 60g / s, and the mold temperature is 60°C;

[0055] E. Degreasing: The green body is first degreased with n-heptane solvent to remove the paraffin component therein. The degreasing time is 6 hours and the degreasing temperature is 55°C. Then, thermal degreasing is carried out in a vacuum degreasing furnace. In an argon atmosphere, the temperature is first heated to 450°C at a heating rate of 8°C / min and kept at this temperature for 2 hours. Then, the temperature is heated to 1100°C at a heating rate of 5°C / min and kept at this temperature for 2 hours. After that, the temperature is cooled to room temperature with the furnace.

[0056] F. Sintering: Place the degreased blank in a sintering furnace for sintering; heat to 1250°C at a heating rate of 5°C / min, a pressure of 0.3 MPa (provided by nitrogen), and hold for 3 hours;

[0057] G. Solution treatment: Under nitrogen atmosphere protection, the sintered billet is placed in a heat treatment furnace with a solution temperature of 1100°C, a holding time of 3 hours, a pressure of 0.1 MPa (provided by nitrogen), and oil as the quenching medium;

[0058] H. Aging: In vacuum heat treatment furnace, vacuum degree ≤10 -1Pa, aging temperature is 850℃, holding time is 10h, cooling method is air cooling. Testing performance, room temperature tensile strength is 835MPa, elongation is 12%, 800℃ tensile strength is 730MPa, elongation is 22%.

[0059] Example 3:

[0060] A method for preparing a MIM high-temperature alloy nozzle ring blade, the process is as follows:

[0061] A. Raw material preparation: Use atomized high-temperature alloy powder with an average particle size of 12um. Figure 1 This is the SEM morphology of the high-temperature alloy powder;

[0062] B. Preparation of adhesive: Take 58% paraffin wax, 30% polydioxolane, and 12% polylactide by mass percentage, and mix them in a mixer at 120°C for 4 hours to prepare the adhesive;

[0063] C. Prepare feed: Mix the binder and powder in a volume ratio of 38%:62%, granulate and prepare feed. The mixing temperature is 160°C, the mixer speed is 60 r / min, and the mixing time is 1 hour.

[0064] D. Injection molding: The feed material is injected into the mold cavity using an injection molding machine to obtain a product green body; the injection temperature is 150°C, the injection pressure is 90MPa, the injection speed is 60g / s, and the mold temperature is 60°C;

[0065] E. Degreasing: The green body is first degreased with n-heptane solvent to remove the paraffin component therein. The degreasing time is 4 hours and the degreasing temperature is 60°C. Then, thermal degreasing is carried out in a vacuum degreasing furnace. In an argon atmosphere, the body is first heated to 600°C at a heating rate of 8°C / min and kept warm for 1 hour. Then, the body is heated to 1100°C at a heating rate of 5°C / min and kept warm for 2 hours. After that, the body is cooled to room temperature with the furnace.

[0066] F. Sintering: Place the degreased blank in a sintering furnace for sintering; heat to 1200°C at a heating rate of 5°C / min, a pressure of 0.2 MPa (provided by nitrogen), and hold for 4 hours;

[0067] G. Solution treatment: Under nitrogen atmosphere protection, the sintered billet is placed in a heat treatment furnace with a solution temperature of 1100°C, a holding time of 3 hours, a pressure of 0.1 MPa (provided by nitrogen), and oil as the quenching medium;

[0068] H. Aging: In vacuum heat treatment furnace, vacuum degree ≤10 -1Pa, aging temperature is 750℃, holding time is 24h, cooling method is air cooling. Testing performance, room temperature tensile strength is 766MPa, elongation is 20%, 800℃ tensile strength is 669MPa, elongation is 30%.

[0069] Comparative Example 1-1:

[0070] The only difference from Example 2 is that the Cr content is 15wt.% and the Mo content is 1wt.%. The room-temperature tensile strength is 576MPa and the elongation is 20%. This is likely due to the relatively low Cr and Mo contents, resulting in relatively weak solid solution and precipitation strengthening effects.

[0071] Comparative Example 1-2:

[0072] The only difference from Example 2 is that the W content is 5 wt.% and the Nb content is 3 wt.%. The room-temperature tensile strength is 580 MPa and the elongation is 18%. This is likely because excessive W content has no strengthening effect, while Nb forms more NbC, which affects the improvement of the carbon solid solution strength.

[0073] Comparative Examples 1-3:

[0074] The only difference from Example 2 is the carbon content of 0.8 wt.%. The room-temperature tensile strength is 530 MPa and the elongation is 8%. This is likely due to the excessive carbon content forming carbides such as NbC, which significantly reduce the strength.

[0075] Comparative Example 2-1:

[0076] The only difference from Example 2 is that the vacuum sintering was performed without nitrogen. When testing the properties, the room temperature tensile strength was 552 MPa and the elongation was 12%. This is likely due to the loss of the solid solution strength of nitrogen and the precipitation strengthening effect of nitrides.

[0077] Comparative Example 2-2:

[0078] The only difference from Example 2 is that the nitrogen sintering pressure was 1 MPa. Testing revealed room-temperature tensile strength of 522 MPa and elongation of 7%. This excessive pressure likely caused nitrogen to form a large amount of grain boundary nitrides, weakening its solid solubility and making the brittle phase a source of fracture.

[0079] Comparative Example 3:

[0080] Comparative experiment Solution temperature Aging temperature Experimental results 1 1100℃ 600℃ The aging temperature is too low and no precipitation phase is generated. The performance test shows that the room temperature tensile strength is 588MPa and the elongation is 15%. 2 1100℃ 1000℃ The aging temperature is too high, the precipitated phase is Laves phase, and there is no strengthening effect. The test performance shows that the room temperature tensile strength is 585MPa and the elongation is 15%. 3 900℃ 850℃ The solution temperature is too low, and the carbides and nitrides are not completely dissolved. The performance test shows that the room temperature tensile strength is 545MPa and the elongation is 11%. 4 1250℃ 850℃ The solution temperature is too high, the grains grow, and the performance is tested. The room temperature tensile strength is 542MPa and the elongation is 10%.

[0081] The above-mentioned examples are only preferred implementation methods of the present invention, and therefore cannot be used to limit the scope of implementation of the present invention. Other equivalent changes, modifications, substitutions and combinations made in accordance with the principles and contents of the present invention still fall within the scope of protection of the present invention.

Claims

1. A method for preparing a MIM high-temperature alloy nozzle ring blade, characterized in that: The following steps are involved: The high-temperature alloy powder and the binder are mixed and granulated to obtain uniform feed, and then the feed is injected into the mold cavity by injection molding technology to obtain a green body, and then the binder in the green body is removed by solvent degreasing and thermal degreasing processes, and finally sintering densification, solid solution and aging are carried out in sequence to obtain the nozzle ring blade product; The composition of the high temperature alloy powder is: Cr: 18-23wt.%, Co: 17-23wt.%, Ni: 19-22wt.%, W: 2-4wt.%, Mo: 2-4wt.%, Nb: 0.5-1.5wt.%, C: 0.1-0.3wt.%, Mn: 1-1.5wt.%, S: ≤0.04wt.%, P: ≤0.04wt.%, Si: ≤1.0wt.%, and the balance is iron; The binder is composed of the following components by mass percentage: Paraffin 50-65%; Polydioxolane 20-35%; Polylactide 5-20%; The sintering process is as follows: under the protection of nitrogen atmosphere, heating to 1200-1300°C at a heating rate of 5-10°C / min, a pressure of 0.1-0.5MPa, and a holding time of 1-6h; The solution treatment process is as follows: in a vacuum heat treatment furnace, under the protection of nitrogen atmosphere, the solution temperature is 1000-1200°C, the holding time is 1-4h, the pressure is 0.05-0.2MPa, and the quenching medium is water or oil; The aging process is as follows: in a vacuum heat treatment furnace, the vacuum degree is ≤10 -1 Pa, the aging temperature is 700-900℃, the holding time is 1-30h, and the cooling method is wind cooling or air cooling.

2. The method for preparing a MIM high-temperature alloy nozzle ring blade according to claim 1, characterized in that: The average particle size of the high-temperature alloy powder is 8-15 um; the high-temperature alloy powder is prepared by a water atomization method or a gas atomization method.

3. The method for preparing a MIM high-temperature alloy nozzle ring blade according to claim 1, characterized in that: In the mixing process, the mixing temperature is 100-160° C., the mixing time is 1-4 hours, and the mixer speed is 40-80 r / min.

4. The method for preparing a MIM high-temperature alloy nozzle ring blade according to claim 1, characterized in that: The volume ratio of the binder in the feed prepared by the binder and the powder is in the range of 35% to 45%.

5. The method for preparing a MIM high-temperature alloy nozzle ring blade according to claim 1, characterized in that: In the injection molding process, the injection temperature is 110-160°C, the injection pressure is 80-130 MPa, the injection speed is 40-100 g / s, and the mold temperature is 30-70°C.

6. The method for preparing a MIM high-temperature alloy nozzle ring blade according to claim 1, characterized in that: In the solvent degreasing process, the solvent is n-heptane, the degreasing time is 2 to 8 hours, and the temperature is 40 to 60°C; the thermal degreasing is: under the protection of argon atmosphere, first heating to 450 to 600°C at a heating rate of 5 to 10°C / min and keeping warm for 1 to 4 hours, then heating to 950 to 1100°C at a heating rate of 5 to 10°C / min and keeping warm for 1 to 4 hours, and then cooling to room temperature with the furnace.

7. A method for preparing a MIM high-temperature alloy nozzle ring blade according to any one of claims 1 to 6, characterized in that: The room temperature tensile strength of the obtained nozzle ring blade product is ≥750MPa, and the elongation is ≥10%, and the 800°C tensile strength is ≥650MPa, and the elongation is ≥20%.

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