Device and method for high-efficiency and low-energy-consumption recovery and regeneration of high-temperature alloy powder

Abstract

The invention belongs to the technical field of metal powder preparation, particularly relates to a high-efficiency and low-energy-consumption device and method for recycling and regenerating high-temperature alloy powder, and aims to solve the problems of high energy consumption, low efficiency, degraded powder performance, low cyclic utilization rate and the like in the existing recycling technology. A ceramic flash sintering technology and a metal material current-assisted sintering device are innovatively combined, a special device with a unique current-assisted sintering mechanism is developed, the device can efficiently and rapidly sinter large-size metal blanks under the low-pressure condition, the sintering time is shortened by 30%-50%, the temperature is reduced by 100-200 DEG C, the energy consumption of a unit product is reduced by 40% or above, and the production efficiency is improved. And meanwhile, by accurately controlling the sintering atmosphere and pressure, it is ensured that the oxygen content of circulating powder is lower than 50 ppm. According to the method, through the pressing-sintering-hot isostatic pressing treatment process, the recycled powder can be directly returned to the powder manufacturing procedure, the cyclic utilization rate of 95% or above can be achieved without re-smelting, and an innovative solution is provided for sustainable utilization of the high-value metal powder.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal powder preparation, and specifically relates to a device and method for high-temperature alloy powder recycling with high efficiency and low energy consumption, which is particularly suitable for recycling waste powder in additive manufacturing. Background Art

[0002] High-temperature alloy powders are key materials in aerospace, energy equipment, and other fields, primarily used to manufacture core components such as high-performance turbine blades and combustion chamber parts. With the rapid development of additive manufacturing and powder metallurgy technologies, the demand for high-temperature alloy powders has increased dramatically. However, during the powder preparation and use process, a large amount of non-target particle size powder (such as ultrafine powder or coarse powder) or process waste (such as unmelted powder and sintering waste) is generated, accounting for up to 30% to 50% of the original powder. If this powder is not effectively recycled, it not only wastes precious metal resources (such as nickel, cobalt, and tantalum) but also significantly increases production costs.

[0003] Currently commonly used powder recovery technology routes all have significant defects: although the traditional physical screening method is easy to operate, it is only suitable for powders with low oxygen content and no contamination, but it cannot handle waste powders that are severely oxidized or have changed composition; although chemical cleaning combined with high-temperature reduction process can reduce the oxygen content, it has high energy consumption (it requires long-term annealing at >1000℃, with energy consumption higher than 120 kWh / kg) and is prone to volatilization loss of γ' phase strengthening elements; and although remelting atomization recovery technology can obtain recycled powder with a quality close to that of new powder, the powder return material must be smelted with bulk bulk material, resulting in low material utilization, slow smelting speed and serious oxygen and nitrogen increase during the smelting process.

[0004] Existing patent technologies, such as publication number CN114472885A, are titled "A Method for Recycling Metal Powder Return Materials." This patent first presses the metal powder into bulk materials, and then directly melts the bulk materials to obtain finished products. Although this simplifies the process flow, due to the lack of effective deoxidation measures, the oxygen content of the recycled materials is generally high and cannot meet aviation-grade application requirements; CN119076958A proposes a method for recycling waste high-temperature alloy powder. This method first obtains smelting electrode rods through hot isostatic pressing, and then obtains powdered electrode rods through vacuum consumable melting. Although this method can obtain electrode rods with higher purity and achieve efficient recycling of waste powder, it has low production efficiency and high cost due to the high-temperature treatment for dozens of hours.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and to propose a device and method for the efficient and low-energy recycling of high-temperature alloy powders, which can effectively solve the key technical problems existing in traditional recycling processes, such as high energy consumption, low efficiency, deterioration of powder performance, and low recycling rate.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: On the one hand, the present invention provides a device for high-efficiency and low-energy recycling of high-temperature alloy powder, comprising a sintering mechanism for sintering blanks, a pulse power supply, a hydraulic control mechanism, a water-cooling control mechanism, a vacuum control mechanism, an inflation component and a heating component, wherein the heating wire of the heating component is arranged on the inner side of the sintering mechanism, the water-cooling pipeline of the water-cooling control mechanism is arranged between the heating wire and the sintering mechanism, and is used to cool the outer wall of the sintering mechanism, the pulse power supply is electrically connected to the sintering mechanism, and the hydraulic control mechanism, the vacuum control mechanism and the inflation component are all connected to the sintering mechanism.

[0008] Furthermore, the sintering mechanism includes a sintering chamber, and the interior of the sintering chamber is provided with an upper pressure head, a first mica insulating sheet, a first platinum sheet electrode, an upper electrode, a sintering mold, a lower electrode, a second platinum sheet electrode, a second mica insulating sheet and a lower pressure head in sequence from top to bottom, wherein the outer diameters of the upper electrode and the lower electrode are both smaller than the inner diameter of the sintering mold; one end of the pulse power supply is connected to the first platinum sheet electrode, and the other end is connected to the second platinum sheet electrode.

[0009] Furthermore, the inflation assembly and the vacuum control mechanism are both connected to the sintering chamber, the hydraulic rod of the hydraulic control mechanism passes through the sintering chamber and is connected to the upper pressure head; and an oxygen content monitoring probe is provided on the sintering chamber.

[0010] Furthermore, the water cooling control mechanism also includes a water storage tank, which is connected to the water cooling pipeline through a pipe, and a water outlet is opened on the outer wall of the sintering chamber.

[0011] Furthermore, the pulse power supply is a DC power supply, and the parameters of its pulse current are: frequency 1 to 500 kHz, pulse width 1 to 100 μs, and current 1 to 5000 A.

[0012] In another aspect, the present invention provides a method for efficiently and energy-efficiently recycling and regenerating high-temperature alloy powder, based on the above-mentioned apparatus for efficiently and energy-efficiently recycling and regenerating high-temperature alloy powder, comprising the following steps: Step 1: mixing high-temperature alloy powders of different particle sizes according to a set ratio to obtain mixed powder; Step 2: The mixed powder obtained in step 1 is placed into a pressing mold and pressed using a pressing device to obtain a blank to be sintered; Step 3: Place the blank to be sintered obtained in step 2 in a sintering mold of a sintering mechanism, then start the vacuum control mechanism to evacuate the sintering chamber of the sintering mechanism, perform a leak rate test after the vacuum degree in the sintering chamber reaches a set value, then fill argon gas through the inflation component, and then start the heating wire of the heating component to pre-sinter the blank to be sintered. After reaching the set temperature, turn on the pulse power supply to sinter, and obtain a sintered blank; Step 4: The sintered blank obtained in step 3 is first subjected to hot isostatic pressing, and then turned to remove the oxide scale on the outer surface, thereby finally obtaining an electrode rod.

[0013] Furthermore, in step 1, high-temperature alloy powders with a particle size segment of <15 μm and a particle size segment of >180 μm are placed in a mixer and mixed in a mass ratio of 1:1; during the mixing process, the speed is set to 40 ~120 r / min and the time is 20 ~60 min; and 0.5 ~1 wt.% of lubricant is added at the same time.

[0014] Furthermore, in step 2, the pressing process is as follows: Use a hydraulic press to pre-press one end of the pressing mold containing the mixed powder at a pressure of 180~240 MPa, holding the pressure for 2~5 minutes, and then perform final pressing at a pressure of 550~650 MPa, holding the pressure for 5~8 minutes; after the pressing is completed, turn the pressing mold around and pre-press the other end at a pressure of 180~240 MPa, holding the pressure for 2~5 minutes, and then perform final pressing at a pressure of 550~650 MPa, holding the pressure for 5~8 minutes.

[0015] Furthermore, in step 3, the process of placing the blank to be sintered in the sintering mold is as follows: wrapping the outside of the blank to be sintered with flexible graphite paper, and laying flexible graphite paper on the top and bottom of the blank to be sintered, and then placing the blank into the sintering mold after wrapping; When the vacuum degree in the sintering chamber reaches ≤1.0×10 -3 Pa and the pressure rise rate is ≤ 0.05 Pa / min, argon is filled into the sintering chamber, and the gas pressure in the sintering chamber is 0.05~0.2 MPa; During the pre-sintering process, the temperature is raised to 950-1100°C at a rate of 5-10°C / min, and the sintering pressure is 60-120 MPa (i.e., the pressure applied by the hydraulic control mechanism). The pressure is maintained constant during the pre-sintering process. During the sintering process, the pulse current parameters were set as follows: frequency 100–500 kHz, pulse width 2–8 μs, current 1000–5000 A, and sintering time 5–15 min; During the pre-sintering and sintering processes, the oxygen content in the sintering chamber is controlled to be less than 50 ppm.

[0016] Furthermore, in step 4, during the hot isostatic pressing process, the process parameters are set as follows: temperature 1150-1230°C, pressure 150-200 MPa, holding time 2-4 hours, and cooling with the furnace after the hot isostatic pressing is completed.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention discloses a device for efficiently and efficiently recycling high-temperature alloy powder with low energy consumption. This device innovatively integrates the advantages of ceramic flash sintering technology with current-assisted sintering of metal materials. Through the synergistic effect of a heating assembly and a pulsed power supply, uniform heating is achieved, reducing local overheating or underheating caused by uneven heat conduction during traditional electric field-assisted sintering. This enables efficient and rapid sintering of large metal billets under low pressure, breaking through the size and efficiency bottlenecks of traditional sintering processes. Furthermore, by optimizing the synergistic effect of the current and temperature fields, the device's unique current-assisted sintering mechanism significantly shortens sintering time by approximately 30% to 50%, while lowering sintering temperatures by 100 to 200°C, reducing energy consumption per unit product by over 40% and improving production efficiency. Furthermore, this low-temperature, rapid sintering feature reduces the volatilization loss of γ'-phase strengthening elements in the high-temperature alloy, ensuring the compositional stability of the material. It also effectively suppresses abnormal grain growth, resulting in a uniform, fine, submicron grain structure, significantly improving the density, mechanical strength, and fatigue properties of the sintered body.

[0018] 2. The present invention provides a device for efficiently and energy-efficiently recycling and regenerating high-temperature alloy powder. By precisely controlling the atmosphere and pressure during the sintering process, the device effectively inhibits powder oxidation, ensuring that the oxygen content of the recycled powder is always below 50 ppm, thereby maintaining the material's excellent mechanical properties and stability.

[0019] 3. The present invention provides a method for efficiently and energy-efficiently recycling high-temperature alloy powder. Based on the present invention's apparatus for efficiently and energy-efficiently recycling high-temperature alloy powder, the method offers the advantage of returning the recovered powder directly to the powder-making process after a pressing, sintering, and hot isostatic pressing process, eliminating the need for remelting. This method achieves a recycling rate of over 95% of the raw material, far exceeding the recycling rate achieved by conventional processes. This overcomes the shortcomings of conventional recycling methods and achieves high-value utilization of non-target powder. This method not only significantly reduces raw material loss and waste disposal costs, but also significantly enhances sustainable resource utilization, making it particularly suitable for the large-scale production of high-value metal powders (such as high-temperature alloys and titanium alloys). BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are incorporated in and constitute a part of this specification and, together with the description, serve to explain the principles of the invention.

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0022] Figure 1 This is a schematic structural diagram of a device for efficiently and efficiently recycling and regenerating high-temperature alloy powder according to the present invention; Figure 2 This is a schematic diagram of the internal structure of the sintering chamber of the present invention; Figure 3 This is a flow chart of the method for high-temperature alloy powder recycling with high efficiency and low energy consumption according to the present invention; Figure 4 This is a scanned image of the recycled powder obtained using the final electrode rod prepared in Example 1; Figure 5 This is a scanned image of the recycled powder obtained using the final electrode rod prepared in Example 2; Figure 6 This is a scanned image of the recycled powder obtained using the final electrode rod prepared in Example 3; Figure 7 This is a scanned image of the recycled powder obtained using the final electrode rod prepared in the comparative example.

[0023] Among them: 1 is the sintering mechanism; 2 is the pulse power supply; 3 is the hydraulic control mechanism; 4 is the water cooling control mechanism; 5 is the vacuum control mechanism; 6 is the inflation component; 7 is the heating component; 8 is the oxygen content monitoring probe; 9 is the flexible graphite paper; 10 is the lower pressure head; 11 is the sintering chamber; 12 is the upper pressure head; 13 is the first mica insulating sheet; 14 is the first platinum electrode; 15 is the upper electrode; 16 is the sintering mold; 17 is the lower electrode; 18 is the second platinum electrode; 19 is the second mica insulating sheet; 41 is the water storage tank; 42 is the water cooling pipeline; 43 is the water outlet; 71 is the heating wire; 72 is the heating control equipment. DETAILED DESCRIPTION

[0024] Here, exemplary embodiments will be described in detail, and the embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are only examples consistent with some aspects of the present invention described in detail in the appended claims.

[0025] See also Figure 1 and Figure 2The present invention provides a device for high-temperature alloy powder recycling and regeneration with high efficiency and low energy consumption, comprising a sintering mechanism 1 for billet sintering, a pulse power supply 2, a hydraulic control mechanism 3, a water-cooling control mechanism 4, a vacuum control mechanism 5, an inflation component 6 and a heating component 7, wherein the water-cooling pipeline 42 of the water-cooling control mechanism 4 is arranged on the inner side of the sintering mechanism 1, the heating wires 71 of the heating component 7 are evenly arranged and connected to the outer wall of the water-cooling pipeline 42, the pulse power supply 2 is electrically connected to the sintering mechanism 1, and the hydraulic control mechanism 3, the vacuum control mechanism 5 and the inflation component 6 are all connected to the sintering mechanism 1.

[0026] Furthermore, the sintering mechanism 1 includes a sintering chamber 11, and the interior of the sintering chamber 11 is provided with an upper pressure head 12, a first mica insulating sheet 13, a first platinum sheet electrode 14, an upper electrode 15, a sintering mold 16, a lower electrode 17, a second platinum sheet electrode 18, a second mica insulating sheet 19 and a lower pressure head 10 from top to bottom, wherein the outer diameters of the upper electrode 15 and the lower electrode 17 are both smaller than the inner diameter of the sintering mold 16; the positive electrode of the pulse power supply 2 is electrically connected to the first platinum sheet electrode 14 through a platinum wire, and the negative electrode is electrically connected to the second platinum sheet electrode 18 through a platinum wire, wherein the diameter of the platinum wire is 1~3 mm.

[0027] The lower pressure head 10 is fixed on the inner surface of the sintering chamber 11 .

[0028] Specifically, the hydraulic control mechanism 3 is an existing technology, which is connected to the upper pressure head 12 through the sintering chamber 11 through a hydraulic rod to provide pressure for the entire system; the vacuum control mechanism 5 is an existing technology, specifically, composed of a vacuum control system and a diffusion pump, which is connected to the sintering chamber 11 through a vacuum pipeline.

[0029] Furthermore, the inflation assembly 6 and the vacuum control mechanism 5 are both connected to the sintering chamber 11 , and the hydraulic rod of the hydraulic control mechanism 3 passes through the sintering chamber 11 and is connected to the upper pressure head 12 ; an oxygen content monitoring probe 8 is provided on the sintering chamber 11 .

[0030] Furthermore, the water cooling control mechanism 4 is used to cool the outer shell of the sintering mechanism 1. Specifically, the water cooling control mechanism 4 also includes a water storage tank 41, which is connected to the water cooling pipeline 42 through a pipe. A water outlet 43 is provided on the outer wall of the sintering chamber 11. The heating component 7 also includes a heating control device 72 arranged outside the sintering chamber 11. The heating control device 72 is electrically connected to the heating wire 71 and controls the temperature of the heating wire 71.

[0031] Specifically, the sintering mold 16 is a hollow cylindrical structure, the middle part of which is used to place the blank to be sintered. The material is graphite. The inner diameter of the sintering mold 16 is Φ66±0.1 mm, the length is 850±0.5 mm, and the wall thickness is 30 mm; when installed and used, a circular layer of flexible graphite paper 9 (with a thickness of 0.5 mm) is laid on the top and bottom of the blank to be sintered respectively, and a layer of flexible graphite paper 9 is wrapped around the entire circumference of the blank to be sintered. The flexible graphite paper 9 is used to isolate the blank to be sintered from the upper electrode 15, the lower electrode 17 and the inner wall of the sintering mold 16. In order to effectively conduct the heat generated by the Joule effect to the blank to be sintered during the sintering process, thereby avoiding the temperature difference between the part of the blank to be sintered that contacts the upper electrode 15 and the lower electrode 17 and the middle core due to different heat conduction conditions, and improving the uniformity of the finally prepared sintered blank; in addition, the flexible graphite paper 9 can lubricate the sintered blank and the mold after sintering is completed, which facilitates demolding after sintering and ensures the integrity of the final sintered blank.

[0032] Furthermore, the pulse power supply 2 is a DC power supply, and the parameters of its pulse current are: frequency 1 to 500 kHz, pulse width 1 to 100 μs, and current 1 to 5000 A. The pulse power supply 2 provides pulse current for sintering, and the pulse current flows to the blank to be sintered through the upper electrode 15 and the lower electrode 17.

[0033] Specifically, the upper electrode 15 and the lower electrode 17 are made of a high melting point high entropy alloy with a size of Φ65.8×100 mm. Their function is to pass current through the sintered blank to densify it. The length and width of the first platinum electrode 14 and the second platinum electrode 18 are both 70 mm, and the thickness is 10 mm; the length and width of the first mica insulating sheet 13 and the second mica insulating sheet 19 are both 75 mm, and the thickness is 8 mm.

[0034] On the other hand, Figure 3 As shown, the present invention provides a method for efficiently and energy-efficiently recycling and regenerating high-temperature alloy powder, based on the apparatus for efficiently and energy-efficiently recycling and regenerating high-temperature alloy powder as described above, comprising the following steps: Step 1: mixing high-temperature alloy powders of different particle sizes according to a set ratio to obtain mixed powder; Step 2: The mixed powder obtained in step 1 is placed into a pressing mold and pressed using a pressing device to obtain a blank to be sintered; Step 3: Place the blank to be sintered obtained in step 2 in the sintering mold 16 of the sintering mechanism 1, then start the vacuum control mechanism 5 to evacuate the sintering chamber 11, and perform a leak rate test after the vacuum degree in the sintering chamber 11 reaches the set value. Subsequently, high-purity argon gas is filled into the sintering chamber 11 through the inflation component 6, and then the heating wire 71 is started to pre-sinter the blank to be sintered. After reaching the set temperature, the pulse power supply 2 is turned on for sintering to obtain a sintered blank. Step 4: The sintered blank obtained in step 3 is first subjected to hot isostatic pressing, and then turned to remove the oxide scale on the outer surface, thereby finally obtaining an electrode rod.

[0035] Furthermore, in step 1, high-temperature alloy powders with a particle size segment of <15 μm and a particle size segment of >180 μm are placed in a mixer and mixed in a mass ratio of 1:1; during the mixing process, the speed is set to 40 r / min ~120 r / min, and the time is 20 min ~ 60 min; at the same time, 0.5 wt.% ~ 1 wt.% of lubricant is added.

[0036] Wherein, the lubricant is zinc stearate.

[0037] Furthermore, in step 2, the pressing process is as follows: Use a cold press or a fast forging machine to pre-press one end of the pressing die containing the mixed powder at a pressure of 180MPa~240MPa, holding the pressure for 2 min~5 min, and then perform final pressing at a pressure of 550MPa~650MPa, holding the pressure for 5 min~8 min; after the pressing is completed, turn the pressing die around and pre-press the other end at a pressure of 180MPa~240MPa, holding the pressure for 2 min~5 min, and then perform final pressing at a pressure of 550MPa~650MPa, holding the pressure for 5min~8min.

[0038] Specifically, the pressing mold is made of M2 high-speed steel or H13 high-speed steel. The pressing mold is divided into three parts: upper, middle and lower parts. The upper and lower parts of the mold are pressure heads, and the middle part of the mold is a hollow pressing area. The inner diameter of the hollow pressing area is Φ65±1 mm, the length is 1050±0.5 mm, and the wall thickness is 20 mm.

[0039] Specifically, the diameter of the sintered blank obtained after pressing in step 2 is Φ65±0.5 mm, the length is 750-830 mm, and the density is 78%-87%.

[0040] Furthermore, in step 3, the process of placing the blank to be sintered in the sintering mold 16 is as follows: wrapping the outside of the blank to be sintered with flexible graphite paper 9, and laying flexible graphite paper 9 on the top and bottom of the blank to be sintered, and then placing it into the sintering mold 16 after wrapping; When the vacuum degree in the sintering chamber 11 reaches ≤1.0×10 -3 Pa and the pressure rise rate is ≤ 0.05 Pa / min, argon is filled into the sintering chamber 11, and the gas pressure in the sintering chamber 11 is 0.05~0.2 MPa; During the pre-sintering process, the temperature is heated to 950-1100 °C at a heating rate of 5-10 °C / min and the sintering pressure is 60-120 MPa. The pressure is maintained constant during the pre-sintering process. During the sintering process, the pulse current parameters are set as follows: frequency 100-500 kHz, pulse width 2-8 μs, current 1000-5000 A, sintering time 5-15 min, and constant pressure is maintained during the sintering process. The waveform generated by the pulse power supply can be a variety of waveforms, such as triangular wave, square wave, and sine wave. During the pre-sintering and sintering processes, the oxygen content in the sintering chamber 11 is controlled to be less than 50 ppm.

[0041] Specifically, the sintered blank obtained after sintering in step 3 has a diameter of Φ65.5±0.5 mm, a length of 645~660 mm, and a density of >98%.

[0042] Furthermore, in step 4, during the hot isostatic pressing process, the process parameters are set as follows: temperature 1150-1230°C, pressure 150-200 MPa, holding time 2-4 hours, and cooling with the furnace after the hot isostatic pressing is completed.

[0043] Specifically, the electrode rod finally obtained in step 4 has a diameter of Φ60±0.5 mm, a length of 630-650 mm, and a density of >99.5%. The electrode rod can be used for argon atomization powder making or plasma rotating electrode powder making.

[0044] In order to prove the efficacy of the present invention, the present invention has done the following test:

[0045] Example 1

[0046] This embodiment provides a method for recycling and regenerating high-temperature alloy powder with high efficiency and low energy consumption, using the device of the present invention, including the following steps: Step 1. GH4169 powder with a particle size range of <15 μm and >180 μm was weighed in a mass ratio of 1:1, placed in a mixer and mixed at a speed of 40 r / min for 60 min. 0.5 wt.% zinc stearate was added as a lubricant during the mixing process; after mixing, the mixed powder was loaded into an M2 high-speed steel mold; Step 2: Place the pressing die into a fast forging machine for pressing. The pressing process is to first apply pressure from the upper die. After the pressing is completed, the pressing die is turned 180 degrees and then pressurized from the lower die to obtain a sintered blank with relatively uniform density. Each pressing process adopts a two-step pressing process, that is, pre-pressing at a pressure of 180 MPa, holding time for 5 minutes, and then final pressing at a pressure of 650 MPa, holding time for 5 minutes. After the GH4169 powder is pressed, a sintered blank is obtained, which has a diameter of Φ65±0.5 mm, a length of 830 mm, and a density of 78%; Step 3: Wrap a layer of flexible graphite paper 9 around the outside of the blank to be sintered, then place the blank to be sintered into a sintering mold 16, and place a circular piece of flexible graphite paper 9 on the upper and lower end surfaces of the blank to be sintered, respectively. Then, place the upper electrode 15 and the first platinum electrode 14 on the top of the upper flexible graphite paper 9 from bottom to top, and place the lower electrode 17 and the second platinum electrode 18 on the bottom of the lower flexible graphite paper 9 from top to bottom. Step 4: Start the vacuum control mechanism 5 to evacuate the sintering chamber 11 to make the vacuum degree in the sintering chamber 11 ≤ 1.0×10 -3 After the leak rate test is performed on the sintering chamber 11 and the pressure rise rate is confirmed to be ≤0.05 Pa / min, high-purity argon gas is filled into the sintering chamber 11 to ensure that the internal pressure is maintained at 0.05 MPa, the heating wire 71 is then turned on for heating and the hydraulic control mechanism 3 is turned on for pressurization, so that the blank to be sintered is heated to 1050°C at a heating rate of 5°C / min, and a constant sintering pressure of 90 MPa is maintained. The pulse power supply 2 is then turned on for sintering to obtain a sintered blank; The pulse current parameters during the sintering process are: frequency 100 kHz, pulse width 8 μs, current 1000 A, sintering time 15 min, the waveform generated by the pulse power supply 2 is a triangular wave, the oxygen content in the sintering chamber 11 is <50 ppm throughout the sintering process, the diameter of the sintered billet is Φ65.5±0.5 mm, the length is 660 mm, and the density is 98.3%; Step 5: placing the sintered blank into a hot isostatic pressing device for hot isostatic pressing to densify and remove sintering internal stress; The hot isostatic pressing process parameters are as follows: temperature 1180°C, pressure 180 MPa, holding time 2 h, and furnace cooling after hot isostatic pressing. Step 6: The hot isostatically pressed electrode is turned to remove the oxide scale on the outer surface to obtain a final electrode rod with a diameter of Φ60±0.5 mm, a length of 650 mm, and a density of 99.7%. The electrode rod is then used for argon atomization to obtain GH4169 powder.

[0047] Example 2

[0048] This embodiment provides a method for recycling and regenerating high-temperature alloy powder with high efficiency and low energy consumption, using the device of the present invention, including the following steps: Step 1. GH4099 powder with a particle size range of <15 μm and >180 μm was weighed in a mass ratio of 1:1, placed in a mixer and mixed at a speed of 80 r / min for 40 min. 0.8 wt.% zinc stearate was added as a lubricant during the mixing process. After mixing, the mixed powder was loaded into an M2 high-speed steel mold. Step 2: Place the pressing die into a fast forging machine for pressing. The pressing process is to first apply pressure from the upper die. After the pressing is completed, the pressing die is turned 180 degrees and then pressurized from the lower die to obtain a sintered blank with relatively uniform density. Each pressing process adopts a two-step pressing process, that is, pre-pressing at a pressure of 210 MPa, holding time for 3 minutes, and then final pressing at a pressure of 600 MPa, holding time for 6 minutes. After the GH4099 powder is pressed, a sintered blank is obtained, which has a diameter of Φ65±0.5 mm, a length of 800 mm, and a density of 83%; Step 3: Wrap a layer of flexible graphite paper 9 around the outside of the blank to be sintered, then place the blank to be sintered into a sintering mold 16, and place a circular piece of flexible graphite paper 9 on the upper and lower end surfaces of the blank to be sintered, respectively. Then, place the upper electrode 15 and the first platinum electrode 14 on the top of the upper flexible graphite paper 9 from bottom to top, and place the lower electrode 17 and the second platinum electrode 18 on the bottom of the lower flexible graphite paper 9 from top to bottom. Step 4: Start the vacuum control mechanism 5 to evacuate the sintering chamber 11 to make the vacuum degree in the sintering chamber 11 ≤ 1.0×10 -3 After the leak rate test is performed on the sintering chamber 11 and the pressure rise rate is confirmed to be ≤0.05 Pa / min, high-purity argon gas is filled into the sintering chamber 11 to ensure that the internal pressure is maintained at 0.08 MPa, the heating wire 71 is then turned on for heating and the hydraulic control mechanism 3 is turned on for pressurization, so that the blank to be sintered is heated to 1100°C at a heating rate of 8°C / min, and a constant sintering pressure of 60 MPa is maintained. Then, the pulse power supply 2 is turned on for sintering to obtain a sintered blank; The pulse current parameters during the sintering process are: frequency 300 kHz, pulse width 5 μs, current 3000 A, sintering time 10 min, the waveform generated by the pulse power supply 2 is a sine wave, the oxygen content in the sintering chamber 11 is <50 ppm throughout the sintering process, the diameter of the sintered billet is Φ65.5±0.5 mm, the length is 650 mm, and the density is 98.7%; Step 5: placing the sintered blank into a hot isostatic pressing device for hot isostatic pressing to densify and remove sintering internal stress; The hot isostatic pressing process parameters are as follows: temperature 1230°C, pressure 150 MPa, holding time 3 h, and furnace cooling after hot isostatic pressing. Step 6: The hot isostatically pressed electrode is turned to remove the oxide scale on the outer surface to obtain a final electrode rod with a diameter of Φ60±0.5 mm, a length of 640 mm, and a density of 99.6%. The electrode rod is then used for plasma rotary electrode powder making to obtain GH4099 powder.

[0049] Example 3

[0050] This embodiment provides a method for recycling and regenerating high-temperature alloy powder with high efficiency and low energy consumption, using the device of the present invention, including the following steps: Step 1. GH3536 powder with a particle size range of <15 μm and >180 μm was weighed in a mass ratio of 1:1, placed in a mixer and mixed at a speed of 120 r / min for 20 min. 1 wt.% zinc stearate was added as a lubricant during the mixing process; after mixing, the mixed powder was loaded into an H13 high-speed steel mold; Step 2: Place the pressing die into a fast forging machine for pressing. During the pressing process, pressurize the upper die first. After the pressing is completed, turn the pressing die 180 degrees and then pressurize the lower die to obtain a sintered blank with relatively uniform density. Each pressing process adopts a two-step pressing process, that is, pre-pressing at a pressure of 240 MPa for 2 minutes, and then final pressing at a pressure of 550 MPa for 8 minutes. After pressing, the GH3536 powder is pressed to obtain a sintered blank with a diameter of Φ65±0.5 mm, a length of 750 mm, and a density of 83%. Step 3: Wrap a layer of flexible graphite paper 9 around the outside of the blank to be sintered, then place the blank to be sintered into a sintering mold 16, and place a circular piece of flexible graphite paper 9 on the upper and lower end surfaces of the blank to be sintered, respectively. Then, place the upper electrode 15 and the first platinum electrode 14 on the top of the upper flexible graphite paper 9 from bottom to top, and place the lower electrode 17 and the second platinum electrode 18 on the bottom of the lower flexible graphite paper 9 from top to bottom. Step 4: Start the vacuum control mechanism 5 to evacuate the sintering chamber 11 to make the vacuum degree in the sintering chamber 11 ≤ 1.0×10 -3 After the leak rate test is performed on the sintering chamber 11 and the pressure rise rate is confirmed to be ≤0.05 Pa / min, high-purity argon gas is filled into the sintering chamber 11 to ensure that the internal pressure is maintained at 0.1 MPa, the heating wire 71 is then turned on for heating and the hydraulic control mechanism 3 is turned on for pressurization, so that the blank to be sintered is heated to 950°C at a heating rate of 10°C / min, and a constant sintering pressure of 120 MPa is maintained. Then, the pulse power supply 2 is turned on for sintering to obtain a sintered blank; The pulse current parameters during the sintering process were as follows: frequency 500 kHz, pulse width 2 μs, current 5000 A, sintering time 5 min, the waveform generated by the pulse power supply 2 was a square wave, the oxygen content in the sintering chamber 11 was <50 ppm throughout the sintering process, the diameter of the sintered billet was Φ65.5±0.5 mm, the length was 645 mm, and the density was 99.0%; Step 5: placing the sintered blank into a hot isostatic pressing device for hot isostatic pressing to densify and remove sintering internal stress; The hot isostatic pressing process parameters are as follows: temperature 1150°C, pressure 200 MPa, holding time 4 h, and furnace cooling after hot isostatic pressing. Step 6: The hot isostatically pressed electrode is turned to remove the oxide scale on the outer surface to obtain a final electrode rod with a diameter of Φ60±0.5 mm, a length of 630 mm, and a density of 99.9%. The electrode rod is then used for plasma rotary electrode powder making to obtain GH3536 powder.

[0051] Comparative Example The difference between this comparative example and Example 2 is that the device of the present invention is not used, and the sintering is performed using a traditional electric field assisted sintering device, that is, there is a difference in step 4.

[0052] In this comparative example, the raw material is GH4099 alloy. Specifically, step 4 is to start the vacuum control mechanism 5 to evacuate the sintering chamber 11 so that the vacuum degree in the sintering chamber 11 is ≤1.0×10 -3After confirming that the pressure rise rate of the sintering chamber 11 was ≤0.05 Pa / min, high-purity argon gas was introduced into the sintering chamber 11 to maintain the internal pressure at 0.08 MPa. The hydraulic control mechanism 3 was then activated for pressurization, and the pulse power supply 2 was turned on to sinter, resulting in a sintered billet. The sintering parameters were consistent with those of Example 2. However, due to uneven current density and temperature distribution during the sintering of the large billet, the billet edge regions overheated due to the current skin effect, while the center region of the billet was incompletely densified due to insufficient resistance heating. The overall sintering uniformity of the billet was poor. The sintered billet had a diameter of Φ65.5±0.5 mm, a length of 735 mm, and a density of 88.2%. After hot isostatic pressing and machining, the final electrode rod had a diameter of Φ60±0.5 mm, a length of 680 mm, and a density of 97.6%. This electrode rod was used in a plasma rotating electrode mill to produce GH4099 powder.

[0053] To demonstrate the beneficial effects of the present invention, the oxygen content of the final electrode rods obtained in Examples 1 to 3 and the comparative example, as well as the powder prepared using the electrode rods, was tested with reference to GJB 8604-2015, Standard for Allowable Deviations in Chemical Composition of Finished High-Temperature Alloys for Aerospace Use. The test results are shown in Table 1.

[0054] Table 1 Oxygen content of the final electrode rod and the powder prepared using the electrode rod

[0055]

[0056] As shown in Table 1, the oxygen content of the final recycled powder is less than 50 ppm by precisely controlling the sintering atmosphere and pressure, while the oxygen content of the recycled powder in the comparative example is as high as 136 ppm. Figures 4 to 7 It can be seen that the recycled powder prepared by the method provided by the present invention has a smooth surface and good sphericity, while the recycled powder obtained in the comparative example has a rough surface and contains a large amount of irregularly shaped powder.

[0057] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0058] It should be understood that the present invention is not limited to the above description and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A device for high-temperature alloy powder recycling with high efficiency and low energy consumption, characterized in that: The invention comprises a sintering mechanism (1) for sintering blanks, a pulse power supply (2), a hydraulic control mechanism (3), a water cooling control mechanism (4), a vacuum control mechanism (5), an air filling assembly (6) and a heating assembly (7), wherein the heating wire (71) of the heating assembly (7) is arranged on the inner side of the sintering mechanism (1), the water cooling pipeline (42) of the water cooling control mechanism (4) is arranged between the heating wire (71) and the sintering mechanism (1) and is used to cool the outer wall of the sintering mechanism (1), the pulse power supply (2) is electrically connected to the sintering mechanism (1), and the hydraulic control mechanism (3), the vacuum control mechanism (5) and the air filling assembly (6) are all connected to the sintering mechanism (1).

2. The device for high-efficiency and low-energy-consumption recycling of high-temperature alloy powder according to claim 1, characterized in that: The sintering mechanism (1) includes a sintering chamber (11), wherein the interior of the sintering chamber (11) is provided with an upper pressure head (12), a first mica insulating sheet (13), a first platinum sheet electrode (14), an upper electrode (15), a sintering mold (16), a lower electrode (17), a second platinum sheet electrode (18), a second mica insulating sheet (19) and a lower pressure head (10) in sequence from top to bottom, wherein the outer diameters of the upper electrode (15) and the lower electrode (17) are both smaller than the inner diameter of the sintering mold (16); one end of the pulse power supply (2) is connected to the first platinum sheet electrode (14), and the other end is connected to the second platinum sheet electrode (18).

3. The device for high-efficiency and low-energy-consumption recycling of high-temperature alloy powder according to claim 2, characterized in that: The inflation assembly (6) and the vacuum control mechanism (5) are both connected to the sintering chamber (11), and the hydraulic rod of the hydraulic control mechanism (3) passes through the sintering chamber (11) and is connected to the upper pressure head (12); an oxygen content monitoring probe (8) is provided on the sintering chamber (11).

4. The device for high-efficiency and low-energy recycling of high-temperature alloy powder according to claim 2, characterized in that: The water cooling control mechanism (4) further comprises a water storage tank (41), the water storage tank (41) being connected to a water cooling pipeline (42) via a pipe, and a water outlet (43) being provided on the outer wall of the sintering chamber (11).

5. The device for high-efficiency and low-energy recycling of high-temperature alloy powder according to claim 1, characterized in that: The pulse power supply (2) is a DC power supply, and the parameters of its pulse current are: frequency 1 to 500 kHz, pulse width 1 to 100 μs, and current 1 to 5000 A.

6. A method for recycling and regenerating high-temperature alloy powder with high efficiency and low energy consumption, characterized in that: The device for high-efficiency and low-energy-consumption recycling of high-temperature alloy powder according to any one of claims 1 to 5 comprises the following steps: Step 1: mixing high-temperature alloy powders of different particle sizes according to a set ratio to obtain mixed powder; Step 2: The mixed powder obtained in step 1 is placed into a pressing mold and pressed using a pressing device to obtain a blank to be sintered; Step 3, placing the blank to be sintered obtained in step 2 in the sintering mold (16) of the sintering mechanism (1), then starting the vacuum control mechanism (5) to evacuate the sintering chamber (11) of the sintering mechanism (1), and performing a leak rate test after the vacuum degree in the sintering chamber (11) reaches a set value, then filling argon gas through the inflation component (6), and then starting the heating wire (71) of the heating component (7) to pre-sinter the blank to be sintered, and after reaching the set temperature, starting the pulse power supply (2) to sinter, thereby obtaining a sintered blank; Step 4: The sintered blank obtained in step 3 is first subjected to hot isostatic pressing, and then turned to remove the oxide scale on the outer surface, thereby finally obtaining an electrode rod.

7. The method for high-efficiency and low-energy consumption recycling of high-temperature alloy powder according to claim 6, characterized in that: In step 1, high-temperature alloy powders with a particle size range of <15 μm and a particle size range of >180 μm are placed in a mixer and mixed in a mass ratio of 1:

1. During the mixing process, the speed is set to 40 r / min ~120 r / min and the mixing time is 20 min ~ 60 min. At the same time, 0.5 wt.% ~ 1 wt.% of lubricant is added.

8. The method for high-efficiency and low-energy-consumption recycling of high-temperature alloy powder according to claim 6, characterized in that: In step 2, the pressing process is as follows: Use a hydraulic press to pre-press one end of the pressing mold containing the mixed powder at a pressure of 180~240 MPa, holding the pressure for 2~5 minutes, and then perform final pressing at a pressure of 550~650 MPa, holding the pressure for 5~8 minutes; after the pressing is completed, turn the pressing mold around and pre-press the other end at a pressure of 180~240 MPa, holding the pressure for 2~5 minutes, and then perform final pressing at a pressure of 550~650 MPa, holding the pressure for 5~8 minutes.

9. The high-efficiency and low-energy-consumption recycling method for high-temperature alloy powder according to claim 6, characterized in that: In step 3, the process of placing the blank to be sintered in the sintering mold (16) is as follows: wrapping the flexible graphite paper (9) on the outside of the blank to be sintered, and arranging the flexible graphite paper (9) on the top and bottom of the blank to be sintered, and placing the blank into the sintering mold (16) after wrapping; When the vacuum degree in the sintering chamber (11) reaches ≤1.0×10 -3 Pa and the pressure rise rate is ≤ 0.05 Pa / min, argon is filled into the sintering chamber (11), and the gas pressure in the sintering chamber (11) is 0.05~0.2 MPa; During the pre-sintering process, the temperature is heated to 950-1100°C at a heating rate of 5-10°C / min and the sintering pressure is 60-120 MPa. The pressure is maintained constant during the pre-sintering process. During the sintering process, the pulse current parameters were set as follows: frequency 100–500 kHz, pulse width 2–8 μs, current 1000–5000 A, and sintering time 5–15 min; During the pre-sintering and sintering processes, the oxygen content in the sintering chamber (11) is controlled to be less than 50 ppm.

10. The method for high-temperature alloy powder recycling with high efficiency and low energy consumption according to claim 6, characterized in that: In step 4, during the hot isostatic pressing process, the process parameters are set as follows: temperature 1150-1230°C, pressure 150-200 MPa, holding time 2-4 hours, and cooling with the furnace after the hot isostatic pressing is completed.

Images