A method of manufacturing a high temperature alloy

Abstract

The application discloses a preparation method of a high-temperature alloy, which comprises the following steps: (1) mixing high-temperature alloy raw material powder with a granulating agent to perform granulation to obtain granulated raw material; and (2) under vacuum conditions, the granulated raw material is sintered by using oscillation hot pressing, and during sintering, an alternating load is adopted to control the grain growth process, so that the high-temperature alloy is obtained. The preparation method of the high-temperature alloy first performs granulation on alloy powder, and then controls the grain growth process of the product by controlling the alternating load of the oscillation hot sintering process, so that the grain refinement is facilitated, the fine-grain strengthening effect is generated, and the mechanical properties of the high-temperature alloy product are greatly improved. In addition, through the mutual synergistic effect of the granulation and the alternating load, the compactness of the product can be improved.

Description

Technical Field

[0001] This invention belongs to the field of alloy materials, and particularly relates to a processing method for high-temperature alloys. Background Technology

[0002] Currently, in the field of aero-engines, turbine disks are usually made of high-temperature alloys, and the aviation industry has an urgent need to improve the production efficiency of turbine disks and reduce the manufacturing cost.

[0003] Traditional powder metallurgy superalloy preparation employs a process flow of hot isostatic pressing (HIP) followed by cladding / heat treatment. This technology requires forming in HIP equipment at pressures exceeding 1200 atmospheres, involving numerous steps, long processing times, high energy consumption, complex equipment, and inherent risks due to the use of high-pressure equipment. This significantly limits production expansion and keeps costs high. Furthermore, the mechanical properties of superalloys prepared using this technology require further improvement.

[0004] Therefore, a method for preparing high-temperature alloys that is simple in process and equipment, has a high safety factor, and excellent mechanical properties has broad market application prospects. Summary of the Invention

[0005] The technical problem to be solved by this invention is to overcome the deficiencies and defects mentioned in the background art above, and to provide a method for preparing a high-temperature alloy with excellent mechanical properties. To solve the above technical problem, the technical solution proposed by this invention is as follows:

[0006] A method for preparing a high-temperature alloy includes the following steps:

[0007] (1) High-temperature alloy raw material powder is mixed with granulating agent and granulated to obtain granulated raw material;

[0008] (2) Under vacuum conditions, the raw material is granulated by oscillating hot pressing. During sintering, alternating load is used to control the grain growth process, thus obtaining the high-temperature alloy.

[0009] In the above preparation method, preferably, the high-temperature alloy raw material powder includes FGH95, FGH96, FGH97 or FGH99, the granulating agent includes one or more of polyethylene glycol, nitrocellulose, stearic acid or paraffin mixture, and the mass ratio of the high-temperature alloy raw material powder to the granulating agent is (95-99):(1-5).

[0010] In the above preparation method, preferably, the granulation process includes the following steps: mixing high-temperature alloy raw material powder, granulating agent and ethanol by ball milling, then vacuum drying and sieving to complete granulation.

[0011] In the above preparation method, preferably, the mixing time during ball milling is 2-6 hours, and the drying temperature during vacuum drying is controlled at 80-100℃.

[0012] In the above preparation method, preferably, the sieve size is controlled during sieving so that the particle size of the granulation raw material is 50-150 μm.

[0013] In the above preparation method, preferably, the oscillating hot pressing sintering includes a first step of degreasing sintering and a second step of strengthening sintering, and after the oscillating hot pressing sintering, constant temperature and constant pressure heat treatment is performed.

[0014] In the above preparation method, preferably, the first step of degreasing and sintering involves holding at 150-250℃ for 1-4 hours while simultaneously applying a bidirectional oscillating pressure of 50-150MPa and a frequency of 2-15HZ, with the vacuum degree controlled at 10. -3 -10 -1 Pa.

[0015] In the above preparation method, preferably, the second step of strengthening sintering involves holding at 1000-1300℃ for 2-10 hours while simultaneously applying an oscillating pressure of 50-150 MPa and a frequency of 2-15 Hz, with the vacuum degree controlled at 10. -3 -10 -1 Pa.

[0016] In the above preparation method, preferably, the second step of strengthening sintering includes a single / bidirectional oscillating hot-pressing alternating process and a second low-frequency high-pressure / high-frequency low-pressure oscillating hot-pressing alternating process; specifically,

[0017] The alternating unidirectional / bidirectional oscillating hot pressing process involves alternating unidirectional and bidirectional oscillating hot pressing, with a sintering temperature of 1000-1300℃, a sintering time of 1-5 hours, a pressure of 50-150 MPa, a frequency of 2-15 Hz, and a vacuum degree of 10. -3 -10 -1 Pa, first use unidirectional oscillating hot pressing, the duration of unidirectional oscillating hot pressing is t1, the duration of bidirectional synchronous oscillating hot pressing is t2, 5min≤t1≤20min, 5min≤t2≤20min;

[0018] The alternating low-frequency high-pressure and high-frequency low-pressure oscillating hot pressing process employs bidirectional oscillating hot pressing, alternating between low-frequency high-pressure and high-frequency low-pressure. The sintering temperature is 1000-1300℃, the sintering time is 1-5 hours, and the vacuum degree is 10. -3 -10 -1Pa, firstly, low frequency and high pressure are used, with a low frequency and high pressure duration of t3 and a high frequency and low pressure duration of t4, where 5min≤t3≤20min and 5min≤t4≤20min; when using low frequency and high pressure, the sintering pressure is 120-150MPa and the frequency is 2-8HZ; when using high frequency and low pressure, the sintering pressure is 50-80MPa and the frequency is 12-15HZ.

[0019] In the above preparation method, preferably, the constant temperature and constant pressure heat treatment involves first heating the furnace temperature to 1150-1350℃, then placing the sample that has undergone oscillating hot pressing sintering into the furnace, and heat treating it at a constant temperature and constant pressure of 60-80MPa for 1-6 hours, and then taking it out to cool it, with the cooling method being air cooling or quenching.

[0020] This invention proposes a novel vacuum oscillating hot pressing sintering integrated molding technology for powder superalloys. This technology improves formability by granulating the raw material powder and simultaneously uses alternating mechanical impact to replace high-pressure gas for densification of the superalloy. The synergistic effect of granulation and alternating load controls the crystal growth process, resulting in advantages such as low process requirements, short steps, high efficiency, and good product mechanical properties. It can be applied to the manufacturing of powder superalloys for aerospace applications. Specifically, this invention first granulates the raw material powder, which improves powder flowability and reduces forming resistance, significantly improving powder formability. However, a debinding process is required after granulation, which easily leads to porosity and organic residue, resulting in low density. Therefore, this invention uses an oscillating hot pressing process to extrude the material during the first step of debinding and sintering. This effectively eliminates porosity formed during debinding, improves density, and increases the debinding rate and debinding percentage, which is beneficial for improving product density. After the first step of degreasing and sintering, the product undergoes a second step of strengthening sintering. This second step of strengthening sintering can cause particle rearrangement, increase density, reduce the continuous growth rate of grain boundaries, break grain boundaries, and achieve a fine grain effect. Finally, this invention uses constant temperature and constant pressure heat treatment to further ensure the mechanical properties of the material.

[0021] In a more preferred embodiment, the second step of the enhanced sintering process of the present invention employs a process of alternating between single / bidirectional oscillating hot pressing and a process of alternating between low-frequency high-pressure and high-frequency low-pressure oscillating hot pressing. First, a process of alternating between single / bidirectional oscillating hot pressing is used, employing a scheme of alternating between unidirectional oscillating hot pressing and bidirectional synchronous oscillating hot pressing. This fully utilizes the advantages of both methods. Unidirectional oscillating hot pressing improves the degassing effect during the rearrangement of particles in the sintered material, avoiding residual bubbles in the sintered product and increasing density. Bidirectional synchronous oscillating hot pressing improves the density and density uniformity of the sintered material, especially for thicker sintered workpieces, significantly improving processing quality and yield. The alternation between unidirectional and bidirectional synchronous oscillating hot pressing further improves the sintering yield and efficiency, enhancing the mechanical properties of the material. Then, a secondary low-frequency high-pressure / high-frequency low-pressure oscillation hot pressing process is adopted. The alternation of low-frequency high pressure and high-frequency low pressure can fully control the crystal growth process of the material, and can realize the process of grain growth, crushing, growth and crushing. This is conducive to grain refinement, produces fine grain strengthening effect, and significantly improves the mechanical properties of high-temperature alloy products.

[0022] Furthermore, the high-temperature alloy preparation process of the present invention can realize the integration of forming, sintering and heat treatment, which greatly simplifies the preparation process of powder high-temperature alloys, reduces costs and cycle time, and reduces equipment requirements.

[0023] Compared with the prior art, the advantages of the present invention are as follows:

[0024] 1. The method for preparing the high-temperature alloy of the present invention first granulates the alloy powder, and then controls the grain growth process of the product by controlling the alternating load of the oscillating hot sintering process. This is beneficial to grain refinement, resulting in fine grain strengthening and significantly improving the mechanical properties of the high-temperature alloy product. Furthermore, the synergistic effect of granulation and alternating load can improve the density of the product.

[0025] 2. The high-temperature alloy preparation method of the present invention is beneficial to strengthening the sintering process, beneficial to the interdiffusion process of elements, faster sintering densification, and improved sintering activation energy, thereby promoting sintering densification.

[0026] 3. The method for preparing the high-temperature alloy of the present invention has the advantages of convenient processing and simple operation, and has broad market application prospects. Detailed Implementation

[0027] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0028] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0029] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0030] Example 1:

[0031] A method for preparing a high-temperature alloy includes the following steps:

[0032] (1) The high-temperature alloy raw material powder, granulating agent and ethanol are mixed by ball milling, then vacuum dried and sieved to obtain granulated raw material; wherein, the mass ratio of high-temperature alloy raw material powder to granulating agent is 95:5, the amount of ethanol is the same as the total mass of high-temperature alloy raw material powder and granulating agent, the mixing time during ball milling is 3h, the drying temperature during vacuum drying is controlled at 90℃, the high-temperature alloy raw material powder is FGH95, the granulating agent is polyethylene glycol, and the particle size of the final granulated raw material is about 100μm.

[0033] (2) Under vacuum conditions, the raw material is granulated by oscillating hot pressing sintering. Alternating loads are used during sintering to control the grain growth process. The material is then cooled in the furnace to obtain a high-temperature alloy. The oscillating hot pressing sintering includes a first-step debinding sintering and a second-step strengthening sintering, followed by isothermal and constant-pressure heat treatment. The first-step debinding sintering is held at 180℃ for 2 hours, while a bidirectional oscillating pressure of 80MPa and a frequency of 15Hz is applied, with a vacuum degree of 10... -1 Pa; During the second step of strengthening sintering, the sintering vacuum degree is controlled at 10. -3 The sintering pressure was 80 MPa, the frequency was 15 Hz, the temperature was 1260℃, and the sintering time was 5 h. The sample was then removed and air-cooled. The third step was constant temperature and constant pressure heat treatment. First, the furnace temperature was heated to 1180℃. Then, the sample was placed in the furnace and heat-treated at 80 MPa for 4 h. The sample was then removed and cooled by air cooling.

[0034] The high-temperature alloy obtained in this embodiment was characterized, and the results are as follows: the grain size is grade 10, the room temperature tensile strength is 1615 MPa, and the tensile strength at 650℃ is 1409 MPa.

[0035] Example 2:

[0036] A method for preparing a high-temperature alloy includes the following steps:

[0037] (1) The high-temperature alloy raw material powder, granulating agent and ethanol are mixed by ball milling, then vacuum dried and sieved to obtain granulated raw material; wherein, the mass ratio of high-temperature alloy raw material powder to granulating agent is 96:4, the amount of ethanol is the same as the total mass of high-temperature alloy raw material powder and granulating agent, the mixing time during ball milling is 6h, the drying temperature during vacuum drying is controlled at 100℃, the high-temperature alloy raw material powder is FGH95, the granulating agent is polyethylene glycol, and the particle size of the final granulated raw material is about 90μm.

[0038] (2) Under vacuum conditions, the raw material is granulated by oscillating hot pressing sintering. Alternating loads are used during sintering to control the grain growth process. The material is then cooled in the furnace to obtain a high-temperature alloy. The oscillating hot pressing sintering includes a first-step debinding sintering and a second-step strengthening sintering, followed by isothermal and constant-pressure heat treatment. The first-step debinding sintering is held at 150℃ for 1 hour, while a bidirectional oscillating pressure of 60MPa and a frequency of 10Hz is applied, with a vacuum degree of 10... -1 Pa; During the second step of strengthening sintering, the sintering vacuum degree is controlled at 10. -3 The sintering pressure was 120 MPa, the frequency was 10 Hz, the temperature was 1100 ℃, and the sintering time was 8 h. The sample was then removed and air-cooled. The third step was constant temperature and constant pressure heat treatment. First, the furnace temperature was heated to 1300 ℃. Then, the sample was placed in the furnace and heat-treated at 70 MPa for 2 h. The sample was then removed and cooled by air cooling.

[0039] The high-temperature alloy obtained in this embodiment was characterized, and the results are as follows: the grain size is grade 10, the room temperature tensile strength is 1603 MPa, and the tensile strength at 650℃ is 1400 MPa.

[0040] Example 3:

[0041] A method for preparing a high-temperature alloy includes the following steps:

[0042] (1) The high-temperature alloy raw material powder, granulating agent and ethanol are mixed by ball milling, then vacuum dried and sieved to obtain granulated raw material; wherein, the mass ratio of high-temperature alloy raw material powder to granulating agent is 95:5, the amount of ethanol is the same as the total mass of high-temperature alloy raw material powder and granulating agent, the mixing time during ball milling is 3h, the drying temperature during vacuum drying is controlled at 90℃, the high-temperature alloy raw material powder is FGH95, the granulating agent is polyethylene glycol, and the particle size of the final granulated raw material is about 100μm.

[0043] (2) Under vacuum conditions, the raw material is granulated by oscillating hot pressing sintering. Alternating loads are used during sintering to control the grain growth process. The material is then cooled in the furnace to obtain a high-temperature alloy. The oscillating hot pressing sintering includes a first-step debinding sintering and a second-step strengthening sintering, followed by isothermal and constant-pressure heat treatment. The first-step debinding sintering is held at 180℃ for 2 hours, while a bidirectional oscillating pressure of 80MPa and a frequency of 15Hz is applied, with a vacuum degree of 10... -1 Pa; The second step of intensified sintering includes a single / bidirectional oscillating hot-pressing alternating process and a second bidirectional oscillating hot-pressing process; the single / bidirectional oscillating hot-pressing alternating process is carried out using alternating single and bidirectional oscillating hot-pressing at a temperature of 1260℃, a sintering time of 1h, a pressure of 80MPa, a frequency of 15HZ, and a vacuum degree of 10. -3 Pa, firstly, unidirectional oscillatory hot pressing is used, with a duration of t1, followed by bidirectional synchronous oscillatory hot pressing with a duration of t2. t1 is 10 min, and t2 is 10 min. During the second bidirectional oscillatory hot pressing process, the sintering vacuum degree is controlled at 10. -3 The sintering pressure was 80 MPa, the frequency was 15 Hz, the temperature was 1260 ℃, and the sintering time was 4 h. The sample was then removed and air-cooled. The third step was constant temperature and constant pressure heat treatment. First, the furnace temperature was heated to 1180 ℃. Then, the sample was placed in the furnace and heat-treated at 80 MPa for 4 h. The sample was then removed and cooled by air cooling.

[0044] The high-temperature alloy obtained in this embodiment was characterized, and the results are as follows: the grain size is grade 11, the room temperature tensile strength is 1641 MPa, and the tensile strength at 650℃ is 1436 MPa.

[0045] Example 4:

[0046] A method for preparing a high-temperature alloy includes the following steps:

[0047] (1) The high-temperature alloy raw material powder, granulating agent and ethanol are mixed by ball milling, then vacuum dried and sieved to obtain granulated raw material; wherein, the mass ratio of high-temperature alloy raw material powder to granulating agent is 95:5, the amount of ethanol is the same as the total mass of high-temperature alloy raw material powder and granulating agent, the mixing time during ball milling is 3h, the drying temperature during vacuum drying is controlled at 90℃, the high-temperature alloy raw material powder is FGH95, the granulating agent is polyethylene glycol, and the particle size of the final granulated raw material is about 100μm.

[0048] (2) Under vacuum conditions, the raw material is granulated by oscillating hot pressing sintering. Alternating loads are used during sintering to control the grain growth process. The material is then cooled in the furnace to obtain a high-temperature alloy. The oscillating hot pressing sintering includes a first-step debinding sintering and a second-step strengthening sintering, followed by isothermal and constant-pressure heat treatment. The first-step debinding sintering is held at 180℃ for 2 hours, while a bidirectional oscillating pressure of 80MPa and a frequency of 15Hz is applied, with a vacuum degree of 10... -1 Pa; The second step of strengthening sintering employs an alternating process of low-frequency high-pressure / high-frequency low-pressure oscillating hot pressing at a temperature of 1260℃ for 5 hours, with a vacuum degree of 10. -3 The first step involves a low-frequency, high-pressure sintering process, with a duration of t3 and a duration of t4, both t3 and t4 being 20 min each. During the low-frequency, high-pressure process, the sintering pressure is 140 MPa and the frequency is 5 Hz. During the high-frequency, low-pressure process, the sintering pressure is 80 MPa and the frequency is 15 Hz. The third step involves constant-temperature and constant-pressure heat treatment. First, the furnace temperature is heated to 1180℃. Then, the sample is placed inside the furnace and subjected to constant-temperature and constant-pressure heat treatment at 80 MPa for 4 hours. Afterward, the sample is removed and cooled by air cooling.

[0049] The high-temperature alloy obtained in this embodiment was characterized, and the results are as follows: the grain size is grade 11, the room temperature tensile strength is 1655 MPa, and the tensile strength at 650℃ is 1450 MPa.

[0050] Example 5:

[0051] A method for preparing a high-temperature alloy includes the following steps:

[0052] (1) The high-temperature alloy raw material powder, granulating agent and ethanol are mixed by ball milling, then vacuum dried and sieved to obtain granulated raw material; wherein, the mass ratio of high-temperature alloy raw material powder to granulating agent is 95:5, the amount of ethanol is the same as the total mass of high-temperature alloy raw material powder and granulating agent, the mixing time during ball milling is 3h, the drying temperature during vacuum drying is controlled at 90℃, the high-temperature alloy raw material powder is FGH95, the granulating agent is polyethylene glycol, and the particle size of the final granulated raw material is about 100μm.

[0053] (2) Under vacuum conditions, the raw material is granulated by oscillating hot pressing sintering. Alternating loads are used during sintering to control the grain growth process. The material is then cooled in the furnace to obtain a high-temperature alloy. The oscillating hot pressing sintering includes a first-step debinding sintering and a second-step strengthening sintering, followed by isothermal and constant-pressure heat treatment. The first-step debinding sintering is held at 180℃ for 2 hours, while a bidirectional oscillating pressure of 80MPa and a frequency of 15Hz is applied, with a vacuum degree of 10... -1The second step of intensified sintering includes a single / bidirectional oscillating hot-pressing alternating process and a low-frequency high-pressure / high-frequency low-pressure oscillating hot-pressing alternating process. The single / bidirectional oscillating hot-pressing alternating process is carried out using single / bidirectional oscillating hot-pressing alternating process, with a temperature of 1260℃, a sintering time of 1h, a pressure of 80MPa, a frequency of 15HZ, and a vacuum degree of 10. -3 Pa, firstly, unidirectional oscillatory hot pressing is used, with a duration of t1, followed by bidirectional synchronous oscillatory hot pressing with a duration of t2, where t1 is 10 min and t2 is 10 min; then, alternating low-frequency high-pressure and high-frequency low-pressure oscillatory hot pressing is performed, with a temperature of 1260℃, a sintering time of 4 h, and a vacuum degree of 10. -3 The first step involves a low-frequency, high-pressure sintering process, with a duration of t3 and a duration of t4, both t3 and t4 being 20 min each. During the low-frequency, high-pressure process, the sintering pressure is 140 MPa and the frequency is 5 Hz. During the high-frequency, low-pressure process, the sintering pressure is 80 MPa and the frequency is 15 Hz. The third step involves constant-temperature and constant-pressure heat treatment. First, the furnace temperature is heated to 1180℃. Then, the sample is placed inside the furnace and subjected to constant-temperature and constant-pressure heat treatment at 80 MPa for 4 hours. Afterward, the sample is removed and cooled by air cooling.

[0054] The high-temperature alloy obtained in this embodiment was characterized, and the results are as follows: the grain size is grade 12, the room temperature tensile strength is 1680 MPa, and the tensile strength at 650℃ is 1479 MPa.

[0055] Example 6:

[0056] A method for preparing a high-temperature alloy includes the following steps:

[0057] (1) The high-temperature alloy raw material powder, granulating agent and ethanol are mixed by ball milling, then vacuum dried and sieved to obtain granulated raw material; wherein, the mass ratio of high-temperature alloy raw material powder to granulating agent is 95:5, the amount of ethanol is the same as the total mass of high-temperature alloy raw material powder and granulating agent, the mixing time during ball milling is 3h, the drying temperature during vacuum drying is controlled at 90℃, the high-temperature alloy raw material powder is FGH95, the granulating agent is polyethylene glycol, and the particle size of the final granulated raw material is about 100μm.

[0058] (2) Under vacuum conditions, the raw material is granulated by oscillating hot pressing sintering. Alternating loads are used during sintering to control the grain growth process. The material is then cooled in the furnace to obtain a high-temperature alloy. The oscillating hot pressing sintering includes a first-step debinding sintering and a second-step strengthening sintering, followed by isothermal and constant-pressure heat treatment. The first-step debinding sintering is held at 250℃ for 4 hours, while a bidirectional oscillating pressure of 120MPa and a frequency of 10Hz is applied, with a vacuum degree of 10... -1Pa; The second step of intensified sintering includes a single / bidirectional oscillating hot-pressing alternating process and a low-frequency high-pressure / high-frequency low-pressure oscillating hot-pressing alternating process; the single / bidirectional oscillating hot-pressing alternating process is carried out using single / bidirectional oscillating hot-pressing alternating process, with a temperature of 1300℃, a sintering time of 2h, a pressure of 100MPa, a frequency of 12HZ, and a vacuum degree of 10 -3 Pa, firstly, unidirectional oscillatory hot pressing is used, with a duration of t1, followed by bidirectional synchronous oscillatory hot pressing with a duration of t2, where t1 is 15 min and t2 is 15 min; then, alternating low-frequency high-pressure and high-frequency low-pressure oscillatory hot pressing is performed, with a temperature of 1300℃, a sintering time of 3 h, and a vacuum degree of 10. -3 The first step involves a low-frequency, high-pressure sintering process, with a duration of t3 and a duration of t4, both 10 min and 10 min respectively. During the low-frequency, high-pressure process, the sintering pressure is 150 MPa and the frequency is 3 Hz. During the high-frequency, low-pressure process, the sintering pressure is 50 MPa and the frequency is 14 Hz. The third step involves constant-temperature and constant-pressure heat treatment. First, the furnace temperature is heated to 1150℃. Then, the sample is placed inside the furnace and subjected to constant-temperature and constant-pressure heat treatment at 60 MPa for 5 hours. Afterward, the sample is removed and cooled by air cooling.

[0059] The high-temperature alloy obtained in this embodiment was characterized, and the results are as follows: the grain size is grade 12, the room temperature tensile strength is 1668 MPa, and the tensile strength at 650℃ is 1466 MPa.

[0060] Comparative Example 1:

[0061] A method for preparing a high-temperature alloy includes the following steps:

[0062] High-temperature alloy raw material powder is directly sintered under vacuum conditions using oscillating hot pressing. Alternating loads are used during sintering to control the grain growth process, and the alloy is obtained by cooling in the furnace. The oscillating hot pressing sintering includes strengthening sintering, followed by isothermal and isothermal heat treatment. The sintering vacuum degree is controlled at 10 during strengthening sintering. -3 The sintering pressure was 80 MPa, the frequency was 15 Hz, the temperature was 1260 ℃, and the sintering time was 5 h. The sample was then removed and air-cooled. The constant temperature and constant pressure heat treatment was carried out by first heating the furnace to 1180 ℃, then placing the sample in the furnace and heat-treating it at 80 MPa for 4 h. The sample was then removed and cooled by air cooling.

[0063] The high-temperature alloy obtained in this comparative example was characterized, and the results are as follows: the grain size is grade 9, the room temperature tensile strength is 1570 MPa, and the tensile strength at 650℃ is 1374 MPa.

Claims

1. A method for preparing a high-temperature alloy, characterized in that, Includes the following steps: (1) The high-temperature alloy raw material powder is mixed with a granulating agent and granulated to obtain granulated raw material; (2) Under vacuum conditions, the raw material is granulated by oscillating hot pressing sintering. During sintering, alternating load is used to control the grain growth process, thus obtaining the high-temperature alloy. The high-temperature alloy raw material powder is FGH95, FGH96, FGH97 or FGH99, and the granulating agent includes one or more of polyethylene glycol, nitrocellulose, stearic acid or paraffin wax mixture. The mass ratio of the high-temperature alloy raw material powder to the granulating agent is (95-99):(1-5). Control the screen size during sieving to ensure that the particle size of the granulated raw material is 50-150μm; The oscillating hot pressing sintering includes a first step of degreasing sintering and a second step of strengthening sintering, and after the oscillating hot pressing sintering, constant temperature and constant pressure heat treatment is carried out. The first step, degreasing and sintering, involves holding at 150-250℃ for 1-4 hours while simultaneously applying bidirectional oscillating pressure of 50-150MPa and 2-15HZ, with the vacuum level controlled at 10. -3 -10 -1 Pa; The second step of strengthening sintering involves holding at 1000-1300℃ for 2-10 hours while simultaneously applying oscillating pressure of 50-150MPa and 2-15Hz, with the vacuum level controlled at 10. -3 -10 -1 Pa.

2. The preparation method according to claim 1, characterized in that, The granulation process includes the following steps: mixing high-temperature alloy raw material powder, granulating agent, and ethanol by ball milling, followed by vacuum drying and sieving to complete granulation.

3. The preparation method according to claim 2, characterized in that, The mixing time during ball milling is 2-6 hours, and the drying temperature during vacuum drying is controlled at 80-100℃.

4. The preparation method according to claim 1, characterized in that, The second step of strengthening sintering includes a single / bidirectional oscillating hot pressing alternating process and a second low-frequency high-pressure / high-frequency low-pressure oscillating hot pressing alternating process; The alternating unidirectional / bidirectional oscillating hot pressing process involves alternating unidirectional and bidirectional oscillating hot pressing, with a sintering temperature of 1000-1300℃, a sintering time of 1-5 hours, a pressure of 50-150 MPa, a frequency of 2-15 Hz, and a vacuum degree of 10. -3 -10 -1 Pa, first use unidirectional oscillating hot pressing, the duration of unidirectional oscillating hot pressing is t1, the duration of bidirectional synchronous oscillating hot pressing is t2, 5min≤t1≤20min, 5min≤t2≤20min; The alternating low-frequency high-pressure and high-frequency low-pressure oscillating hot pressing process employs bidirectional oscillating hot pressing, alternating between low-frequency high-pressure and high-frequency low-pressure. The sintering temperature is 1000-1300℃, the sintering time is 1-5 hours, and the vacuum degree is 10. -3 -10 -1 Pa, firstly, low frequency and high pressure are used, with a low frequency and high pressure duration of t3 and a high frequency and low pressure duration of t4, where 5min≤t3≤20min and 5min≤t4≤20min; when using low frequency and high pressure, the sintering pressure is 120-150MPa and the frequency is 2-8HZ; when using high frequency and low pressure, the sintering pressure is 50-80MPa and the frequency is 12-15HZ.

5. The preparation method according to claim 1, characterized in that, The constant temperature and constant pressure heat treatment involves first heating the furnace to 1150-1350℃, then placing the sample, which has undergone oscillating hot pressing sintering, into the furnace and heat-treating it at a constant temperature and constant pressure of 60-80MPa for 1-6 hours, and then taking it out to cool. The cooling method is air cooling or quenching.