A pulse detonation wave-based pulverizing device and a pulverizing method

Abstract

The application provides a kind of based on pulse detonation wave powder preparation equipment and powder preparation method, belongs to metal powder preparation field.Powder preparation equipment includes: detonation reaction chamber, material melting feeding module, pulse detonation generation module and powder collection chamber;Material melting feeding module is processed into the molten metal stream of metal bar material and enters the detonation reaction chamber, under the action of pulse detonation wave of pulse detonation generation module, cavitation is broken into small metal droplets, and under the action of high-speed inert gas flow, it enters the powder collection chamber through the outlet of detonation reaction chamber, and metal powder is obtained.The application applies pulse detonation technology to metal powder preparation, compared with traditional metal powder preparation process, pulse detonation wave powder preparation can significantly improve production efficiency, and ensure the uniformity of metal powder morphology and granularity, improve the machinability of metal powder.The equipment and method of the application are widely applicable to various common metals and alloy materials, and have good popularization and application prospect.

Description

Technical Field

[0001] This invention belongs to the technical field of metal powder preparation, specifically relating to a powder preparation device and method based on pulse detonation waves. Background Technology

[0002] Metal powder preparation is a technological process that produces metal powders through methods such as atomization, reduction, and electrolysis. These powders can be used as raw materials to manufacture metallic materials, composite materials, and products through powder metallurgy. With increasingly demanding material performance requirements, traditional casting and forging processes are insufficient to meet certain special needs (such as complex structures, compositional gradients, or ultrafine grain structures). Powder metallurgy technology, by precisely controlling the composition, particle size, and morphology of raw material powders, combined with subsequent process control, can prepare functional materials with high hardness, high wear resistance, corrosion resistance, optimized conductivity, and specific magnetic properties, which are widely used in aerospace, energy electronics, and biomedical fields.

[0003] Traditional methods for producing metal powders include atomization, reduction, and mechanical pulverization. These methods suffer from high energy consumption, low material utilization, and pollution during production (such as waste gas and residue). Furthermore, the resulting powders often exhibit uneven particle size distribution and irregular shapes (such as flakes or fibrous powders), leading to poor flowability and low density in subsequent molding processes, thus limiting their application in precision manufacturing. In addition, traditional metal powder preparation methods also suffer from low production efficiency when preparing alloy powders with high hardness or complex compositions.

[0004] Based on this, a new method that can simultaneously achieve efficient, low-pollution, and highly uniform metal powder preparation is provided, which is a key technical issue in overcoming the bottleneck of precision manufacturing applications. Summary of the Invention

[0005] One of the objectives of this invention is to provide a pulse detonation wave-based powder making device that can significantly improve the efficiency of metal powder making and ensure the uniformity of the particle size and morphology of the metal powder and the applicability of the process.

[0006] The second objective of this invention is to provide a pulse detonation wave-based powder preparation method that can significantly improve the efficiency of metal powder preparation and ensure the uniformity of the particle size and morphology of the prepared metal powder as well as the applicability of the process.

[0007] One of the technical solutions adopted to achieve the objective of this invention is to provide a powder making device based on pulse detonation waves, comprising: a detonation reaction chamber, a material melting and feeding module, a pulse detonation generation module, and a powder collection chamber; The inlet of the detonation reaction chamber is connected to the pulse detonation generating module, and the outlet is connected to the powder collection chamber; the top of the detonation reaction chamber is provided with a molten metal inlet and an inert gas inlet; The material melting feed module is connected to the molten metal inlet and is used to feed the metal rod at a certain speed and heat the front end of the metal rod to generate a molten metal flow. The pulse detonation generating module includes a detonation initiation device, a fuel inlet, an oxidizer inlet, a rotary valve, and a thrust wall. The fuel and oxidizer in the pulse detonation generating module generate pulse detonation waves under the action of the detonation initiation device. The molten metal flow dripped into the detonation reaction chamber is cavitated and broken into fine metal droplets under the action of the pulse detonation waves, and enters the powder collection chamber through the outlet of the detonation reaction chamber under the action of a high-speed inert gas flow to obtain metal powder.

[0008] The overall concept and inventive principle of this invention are as follows: This invention introduces pulse detonation wave technology into the field of metal powder preparation to address the technical bottlenecks of traditional powder preparation methods in terms of energy consumption, pollution, powder uniformity, and composition control. The powder preparation equipment provided by this invention employs a metal melting method combining rotary feeding and localized focused heating, coupled with pulse detonation frequency to achieve continuous-pulse coupled powder preparation, significantly improving the utilization rate of metal rods. This invention utilizes the high-energy instantaneous impact of pulse detonation waves generated by a pulse detonation generation module to replace traditional mechanical crushing or continuous atomization energy input, achieving directional and efficient energy utilization. In the detonation reaction chamber, the molten metal stream undergoes dual fragmentation under the synergistic effect of the supersonic airflow and cavitation effect generated by the pulse detonation wave, ultimately obtaining metal powder with high sphericity and good uniformity.

[0009] Furthermore, the material melting feed module includes an induction heating coil, an induction heater, and a rotary feed mechanism; the induction heating coil is connected to the induction heater and is arranged around the front end of the metal rod; the rotary feed mechanism is used to control the metal rod to rotate at a certain speed and move forward.

[0010] Furthermore, a one-way valve is provided at the molten metal inlet, comprising a valve core and a valve body. The one-way valve is designed to ensure the airtightness of the detonation reaction chamber and prevent molten metal droplets from backflowing at the inlet.

[0011] Furthermore, the inert gas entering through the inert gas inlet includes nitrogen or argon, preferably argon. The inert gas inlet is used to provide an inert gas environment for the detonation reaction chamber: on the one hand, molten metal or newly formed metal powder has extremely high chemical reactivity and will rapidly react with oxygen to form oxides when exposed to air; the inert atmosphere can prevent the metal powder from being oxidized or contaminated; on the other hand, the inert gas generates a high-speed gas flow under the action of the pulse detonation wave, which can impact and break the molten metal flow, pulverizing it into fine droplets, which are then cooled and solidified in the inert atmosphere and spheroidized to form powder.

[0012] Furthermore, the fuel entering via the fuel inlet includes short-chain hydrocarbons and / or hydrogen. The short-chain hydrocarbons include one or more combinations of methane, propane, and butane.

[0013] Furthermore, the oxidant entering through the oxidant inlet includes oxygen or an oxygen-enriched gas composed of oxygen and an inert gas; in the oxygen-enriched gas, the volume percentage of oxygen is ≥50%, and the inert gas is nitrogen or argon.

[0014] Furthermore, the detonation initiation device is a spark plug used to ignite the mixture of fuel and oxidant gas, so that the pulse detonation generation module generates a detonation wave.

[0015] Furthermore, the rotary valve mainly includes a rotary valve body, a valve core shaft, and a valve core hole on the valve core shaft. The periodic rotation of the valve core shaft enables the on / off control of fuel and oxidizer. In addition, the rotary valve also includes the following auxiliary functional modules: a timing control unit, a drive unit, and an airflow optimization unit. The timing control unit includes an ignition timing disc for synchronization with the detonation initiation device signal; the drive unit includes pulleys and bearings for receiving external power and maintaining stable rotation of the valve core shaft; the airflow optimization unit is a blade bushing on the valve core shaft, whose circumferential blade structure improves the mixing uniformity of fuel and oxidizer.

[0016] In the pulverizing equipment provided by this invention, a rotary valve controls the flow of fuel and oxidizer into the detonation reaction chamber at a set frequency through the periodic rotation of the valve core shaft and its valve core hole. A pulley connects to a drive motor, providing rotational power to the valve core shaft; bearings support the valve core shaft to ensure stable operation; a blade bushing optimizes the uniformity of airflow mixing through circumferential blades; and an ignition timing disc is linked to the detonation initiation device, precisely triggering ignition when the valve core hole aligns with the air inlet. The overall structural design of the rotary valve, through the coordination of mechanical rotation and gas path control, achieves high-frequency and stable generation of detonation waves, providing a periodic high-pressure impact source for the breakup of the molten metal flow.

[0017] The second technical solution adopted by the present invention to achieve the objective is: to provide a powder making method based on pulse detonation wave based on the powder making equipment described in the first objective of the present invention, comprising the following steps: S1. Place the front end of the metal rod into the induction heating coil of the material melting feed module, adjust the temperature of the induction heating coil and the rotational feed speed to melt the metal rod, and obtain the molten metal flowing through the molten metal inlet into the detonation reaction chamber. S2. Fuel and oxidizer are periodically injected into the fuel inlet and oxidizer inlet, and the mixture is ignited by the detonation initiation device to trigger intermittent detonation combustion and generate pulse detonation waves. S3. The molten metal flow dripped into the detonation reaction chamber is cavitated and broken into fine metal droplets under the action of the pulse detonation wave, and is ejected from the outlet of the detonation reaction chamber under the action of the high-speed inert gas flow. S4. Tiny metal droplets cool and solidify as they are ejected into the powder collection chamber, forming metal powder.

[0018] Furthermore, in step S1, the detonation reaction chamber has a diameter of 10-30 cm and an aspect ratio of 5-30; the detonation reaction chamber adopts a Laval tube structure that contracts first and then expands. This structure, through changes in the shape and size of the inner cavity, accelerates the gas to form a high-speed jet, causing the molten metal droplets to undergo secondary breakage in the contraction section, significantly improving the sphericity and particle size uniformity of the powder. The structural design of the detonation reaction chamber can focus the detonation wave energy, reducing energy loss and suppressing powder backmixing, ensuring the preparation of high-purity alloys. In addition, the gradual curvature can adapt to the dynamic propagation characteristics of the detonation wave, maintaining a stable high-temperature and high-pressure environment, solving the problem of bimodal particle size distribution caused by insufficient end-breakage in traditional straight tube structures, and facilitating the preparation of efficient, low-consumption, and highly consistent metal powders.

[0019] Furthermore, the material melting and feeding module controls the feeding speed of the metal rod to be 10-60 mm / min and the rotation speed of the metal rod to be 5-15 r / min.

[0020] Furthermore, the heating power of the induction heating coil is 20-350kW. Specifically, the appropriate heating power can be selected according to the melting point of the metal rod. Preferably, the ratio of the inner diameter of the induction heating coil to the diameter of the metal rod is 1.1-1.4:1, and the winding length of the induction heating coil should account for 5%-15% of the total length of the metal rod to provide sufficient heating time for the front end of the metal rod, avoid underheating or overheating, and ensure a stable flow of molten metal.

[0021] In this invention, by controlling the feeding speed of the metal rod to match the heating power, the front end of the metal rod is fully melted but not overheated, ensuring a continuous and uniform melt flow and improving the detonation crushing efficiency. The metal rod is controlled to rotate at a speed of 5-15 r / min during the feeding process, so that the metal rod is uniformly heated in the circumference, avoiding local overheating or uneven melting that could cause component segregation, and improving the sphericity and particle size consistency of the metal powder.

[0022] Furthermore, in step S2, the output frequency of the pulse detonation wave is between 3kHz and 10kHz; the cycle frequency of the pulse detonation wave is 100-200Hz; and the propagation speed of the pulse detonation wave is 1500-3000m / s.

[0023] In the powder-making method provided by this invention, the synergistic effect of high-frequency pulse detonation and rapid circulation creates a continuous high-energy crushing environment in the reaction chamber. Specifically, the high-frequency detonation wave ensures that the molten metal stream is instantaneously and uniformly crushed, preventing droplet agglomeration and improving powder sphericity; the supersonic propagation of the detonation wave generates strong shear force, allowing the powder particle size (D50) to be stably controlled within the range of 0.1-50 μm, preferably 10-50 μm; the rapid circulation frequency of the pulse detonation matches the feeding speed, improving powder-making efficiency and enabling continuous production.

[0024] Furthermore, in step S4, during the process of spraying fine metal droplets into the powder collection chamber, an inert gas is introduced to accelerate the cooling solidification and spheroidization process.

[0025] Further, the length of the metal rod is 0.5-3m and the diameter is 50-200mm; the material of the metal rod includes one or more combinations of stainless steel, aluminum alloy, nickel-based alloy, copper alloy, and titanium alloy; the particle size of the metal powder obtained in step S4 is 0.1-50μm.

[0026] Furthermore, the steel includes 304 stainless steel and 316L stainless steel; the aluminum alloy includes 6061 aluminum alloy and 7075 aluminum alloy; the nickel-based alloy includes Inconel 625 nickel-based alloy and Inconel 718 nickel-based alloy; the copper alloy includes H62 brass and C1100 pure copper; and the titanium alloy includes TC4 titanium alloy and TA2 titanium alloy. Specifically, the heating power, detonation frequency, and protective gas in the above-mentioned powder preparation method can be adjusted according to the specific material category of the metal rod to ensure powder quality and process economy.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The powder-making equipment based on pulse detonation waves provided by this invention introduces pulse detonation technology into the field of metal powder preparation, thereby solving the technical bottlenecks of traditional powder-making methods in terms of energy consumption, pollution, powder uniformity, and composition control. The powder-making equipment processes metal rods into molten metal streams through a material melting feed module, and utilizes a pulse detonation generation module to generate pulse detonation waves in the detonation reaction chamber. In the detonation reaction chamber, the molten metal stream undergoes double breakage under the synergistic effect of the supersonic airflow and cavitation effect generated by the pulse detonation waves, ultimately obtaining metal powders with high sphericity and good uniformity. The powder-making equipment provided by this invention has high detonation combustion efficiency, sufficient energy release, and extremely high pulse detonation wave velocity, thus improving the efficiency of metal powder preparation. In addition, the powder-making equipment provided by this invention has a simple structure and can use a variety of fuels, improving the flexibility and applicability of the equipment.

[0028] (2) The powder preparation method based on pulse detonation waves provided by this invention adopts a metal melting method of rotary feeding and local focused heating, combined with pulse detonation frequency to achieve continuous-pulse coupled powder preparation, which significantly improves the utilization rate of metal rods. Compared with traditional powder preparation methods, this invention uses the high-energy instantaneous impact of pulse detonation waves generated by the pulse detonation generation module to replace the energy input of traditional mechanical crushing or continuous atomization, realizing the directional and efficient utilization of energy and improving the preparation efficiency of metal powder. In addition, compared with traditional powder preparation methods, this invention significantly improves the preparation efficiency and quality of high-hardness metal (such as nickel-based alloy Inconel 625, titanium alloy TC4, high-strength stainless steel 316L, etc.) powders through the high-energy instantaneous impact of pulse detonation waves and supersonic airflow shearing. The obtained ultrafine metal powder has advantages such as uniform morphology and particle size and good processing performance, and has good prospects for promotion and application. Attached Figure Description

[0029] Figure 1 A schematic diagram of the overall structure of a powder-making device based on pulse detonation waves provided in an embodiment of the present invention; Figure 2 A schematic diagram of the structure of the induction heating coil arranged around the metal rod in the pulverizing equipment based on pulse detonation wave provided in the embodiment of the present invention; Figure 3 A schematic diagram of the one-way valve in a pulverizing device based on pulse detonation waves provided in an embodiment of the present invention; Figure 4 A schematic diagram of the rotary valve in a pulverizing device based on pulse detonation waves, provided in an embodiment of the present invention; Figure 5 This is a light micrograph of the TC4 titanium alloy powder prepared in Example 1 of the present invention; Figure 6 This is a light micrograph of the GH4099 nickel-based alloy powder prepared in Example 2 of the present invention; Figure 7 This is a light microscope image of the magnesium alloy powder obtained in Example 3 of the present invention; The components are as follows: 1-Detonation reaction chamber; 11-Molten metal inlet; 12-One-way valve; 121-Valve core; 122-Valve body; 13-Inert gas inlet; 2-Material melting feed module; 21-Induction heating coil; 22-Induction heater; 3-Pulse detonation generation module; 31-Detonation initiation device; 32-Fuel inlet; 33-Oxidant inlet; 34-Rotary valve; 341-Pulley; 342-Blade bushing; 343-Ignition timing disc; 344-Rotary valve; 345-Valve core hole; 346-Valve core shaft; 347-Timing positioning mark; 348-Bearing; 35-Thrust wall; 4-Powder collection chamber; 5-Metal rod. Detailed Implementation

[0030] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0032] Please see Figure 1-3 This invention provides a powder-making device based on pulse detonation waves, comprising: a detonation reaction chamber 1, a material melting and feeding module 2, a pulse detonation generating module 3, and a powder collection chamber 4; the inlet of the detonation reaction chamber 1 is connected to the pulse detonation generating module 3, and the outlet is connected to the powder collection chamber 4; the top of the detonation reaction chamber 1 is provided with a molten metal inlet 11 and an inert gas inlet 13; in this invention, the diameter of the detonation reaction chamber 1 is 10-30 cm, and the length-to-diameter ratio is 5-30; the detonation reaction chamber 1 adopts a Laval tube structure that first contracts and then expands, and the inert gas introduced through the inert gas inlet 13 is argon.

[0033] like Figure 2 As shown, the material melting feed module 2 is connected to the molten metal inlet 11 and is used to feed the metal rod 5 at a certain speed and heat the front end of the metal rod 5 to generate a molten metal flow; the material melting feed module 2 includes an induction heating coil 21, an induction heater 22 and a rotary feed mechanism; the induction heating coil 21 is arranged around the front end of the metal rod 5.

[0034] like Figure 3 As shown, the molten metal inlet 11 is equipped with a one-way valve 12, which includes a valve core 121 and a valve body 122. The one-way valve 12 is designed to ensure the airtightness of the detonation reaction chamber. During the feeding process, the molten metal is periodically controlled by opening and closing the valve core and valve body, thereby ensuring the airtightness of the inlet and preventing molten metal droplets from backflowing at the inlet.

[0035] In this embodiment of the invention, the metal rod 5 has a length of 0.5-3m and a diameter of 50-200mm. The material melting and feeding module 2 controls the feeding speed of the metal rod 5 to be 10-60mm / min and the rotation speed to be 5-15r / min; the ratio of the inner diameter of the induction heating coil to the diameter of the metal rod is 1.1-1.4:1; the winding length of the induction heating coil 21 should account for 5%-15% of the total length of the metal rod 5, and the heating power of the induction heating coil 21 is 20-350kW.

[0036] The pulse detonation generating module 3 includes a detonation initiation device 31, a fuel inlet 32, an oxidizer inlet 33, a rotary valve 34, and a thrust wall 35. The detonation initiation device 31 is a spark plug used to ignite the mixture of fuel and oxidizer, generating a pulse detonation wave. The fuel entering through the fuel inlet 32 ​​includes short-chain hydrocarbons and / or hydrogen, with the short-chain hydrocarbons including one or more combinations of methane, propane, and butane. The oxidizer entering through the oxidizer inlet 33 includes oxygen or an oxygen-enriched gas composed of oxygen and an inert gas; the oxygen volume percentage in the oxygen-enriched gas is ≥50%. In embodiments of the present invention, the output frequency of the pulse detonation wave generated by the pulse detonation generating module 3 is between 3kHz and 10kHz; the cycle frequency of the pulse detonation wave is 100-200Hz; and the propagation speed of the pulse detonation wave is 1500-3000m / s.

[0037] like Figure 4 As shown, the rotary valve 34 includes a rotary valve 344, a valve spindle 346, and a valve core hole 345 on the valve spindle 346. The periodic rotation of the valve spindle 346 controls the flow of fuel and oxidizer. In addition, the rotary valve includes the following auxiliary structures: an ignition timing disc 343 for synchronizing with the detonation initiation device signal; a pulley 341 and a bearing 348 for receiving external power and maintaining stable rotation of the valve spindle; a blade sleeve 342 on the valve spindle, whose circumferential blade structure improves the mixing uniformity of fuel and oxidizer; and a timing positioning mark 347 on the centerline of the valve spindle.

[0038] In the detonation reaction chamber 1, the molten metal flow dripped into the detonation reaction chamber 1 is cavitated and broken into fine metal droplets under the action of the pulse detonation wave of the pulse detonation generation module 3, and then enters the powder collection chamber 4 through the outlet of the detonation reaction chamber 1 under the action of the high-speed inert gas flow, and cools and solidifies to obtain metal powder.

[0039] The present invention will be further described below with reference to specific embodiments, but these are not intended to limit the scope of the invention.

[0040] Example 1 This embodiment provides a powder-making method based on pulse detonation waves using the aforementioned powder-making equipment. The detonation reaction chamber 1 has a diameter of 10 cm and a length-to-diameter ratio of 10:1; the metal rod 5 is a TC4 titanium alloy rod with a length of 1 m and a diameter of 50 mm. The powder-making method includes the following steps: Step 1: Vertically place the TC4 titanium alloy rod into the induction heating coil 21. The ratio of the inner diameter of the coil to the diameter of the TC4 titanium alloy rod is 1.2:1. The length of the coil sleeved at the front end of the metal rod accounts for 8% of the total length of the metal rod. Adjust the heating power of the induction heating coil 21 to 120kW so that the induction heating coil 21 heats the metal rod at a temperature of 1700℃. At the same time, control the rotary feeding mechanism so that the metal rod is fed at a rotation speed of 12r / min and a speed of 20mm / min. During the rotary feeding process, the front end of the metal rod melts, and the molten metal flows through the molten metal inlet 11 into the detonation reaction chamber 1. Step 2: Propane fuel, oxygen, and 80% oxygen-enriched gas are periodically injected into the fuel inlet 32 ​​and oxidant inlet 33. The mixture is ignited by the detonation initiation device 31, triggering intermittent detonation combustion and generating a pulse detonation wave with transient high pressure characteristics. The output frequency of the pulse detonation wave is 5kHz, the cycle frequency is 120Hz, and the propagation speed is approximately 1700m / s.

[0041] Step 3: The molten metal flow dripped into the detonation reaction chamber 1 is cavitated and broken into fine metal droplets under the action of the pulse detonation wave, and then ejected from the outlet of the detonation reaction chamber 1 under the action of the high-speed argon gas flow. Step 4: As the tiny metal droplets are ejected into the powder collection chamber 4, they are accelerated to cool, solidify, and spheroidize under the action of inert gas, thus obtaining TC4 titanium alloy powder.

[0042] Figure 5 This is a light micrograph of the TC4 titanium alloy powder prepared in this embodiment. Figure 5 As shown, the obtained TC4 titanium alloy powder particles are highly regular spherical, with smooth and clean surfaces, free of oxides or other adhering substances, and there is no obvious adhesion between the particles; the sphericity of the metal powder is >95%, the particle size distribution range is 10-35μm, the particle size distribution is concentrated, and the particle size uniformity of the powder is excellent. This indicates that the morphology and particle size of the TC4 titanium alloy powder obtained in this embodiment have high consistency.

[0043] Example 2 This embodiment provides a powder-making method based on pulse detonation waves using the aforementioned powder-making equipment. The detonation reaction chamber 1 has a diameter of 20 cm and a length-to-diameter ratio of 15:1; the metal rod 5 is a GH4099 nickel-based alloy rod with a length of 1.5 m and a diameter of 100 mm. The powder-making method includes the following steps: Step 1: Vertically place the GH4099 nickel-based alloy rod into the induction heating coil 21. The ratio of the inner diameter of the coil to the diameter of the GH4099 nickel-based alloy rod is 1.36:1. The length of the coil sleeved at the front end of the metal rod accounts for 10% of the total length of the metal rod. Adjust the heating power of the induction heating coil 21 to 80kW so that the induction heating coil 21 heats the metal rod at a temperature of 1400℃. At the same time, control the rotary feeding mechanism so that the metal rod is fed at a rotation speed of 15r / min and a speed of 15mm / min. During the rotary feeding process, the front end of the metal rod melts, and the molten metal flows through the molten metal inlet 11 into the detonation reaction chamber 1. Step 2: Periodically inject fuel methane and oxygen into fuel inlet 32 ​​and oxidizer inlet 33, ignite the mixture through detonation initiation device 31 and trigger intermittent detonation combustion to generate a pulse detonation wave with transient high pressure characteristics; the output frequency of the pulse detonation wave is 8kHz, the cycle frequency is 150Hz, and the propagation speed is about 2000m / s.

[0044] Step 3: The molten metal flow dripped into the detonation reaction chamber 1 is cavitated and broken into fine metal droplets under the action of the pulse detonation wave, and then ejected from the outlet of the detonation reaction chamber 1 under the action of the high-speed argon gas flow. Step 4: As the tiny metal droplets are ejected into the powder collection chamber 4, they are accelerated to cool, solidify, and spheroidize under the action of inert gas, thus obtaining GH4099 nickel-based alloy powder.

[0045] Figure 6 This is a light micrograph of the GH4099 nickel-based alloy powder prepared in this embodiment. Figure 6 As shown, the obtained GH4099 nickel-based alloy powder particles are highly regular spherical, with smooth and clean surfaces, free of oxides or other adhering substances, and there is no obvious adhesion between the particles; the sphericity of the metal powder is >95%, the particle size distribution range is 15-40μm, the particle size distribution is concentrated, and the particle size uniformity of the powder is excellent. This indicates that the morphology and particle size of the GH4099 nickel-based alloy powder obtained in this embodiment have high consistency.

[0046] Example 3 This embodiment provides a powder-making method based on pulse detonation waves using the aforementioned powder-making equipment. The detonation reaction chamber 1 has a diameter of 30 cm and a length-to-diameter ratio of 20:1; the metal rod 5 is a magnesium alloy rod with a length of 2 m and a diameter of 150 mm. The powder-making method includes the following steps: Step 1: Vertically place the magnesium alloy rod into the induction heating coil 21. The ratio of the inner diameter of the coil to the diameter of the magnesium alloy rod is 1.4:1. The length of the coil sleeved at the front end of the metal rod accounts for 15% of the total length of the metal rod. Adjust the heating power of the induction heating coil 21 to 30kW so that the induction heating coil 21 heats the metal rod at a temperature of 700℃. At the same time, control the rotary feeding mechanism so that the metal rod is fed at a rotation speed of 20r / min and a speed of 30mm / min. During the rotary feeding process, the front end of the metal rod melts, and the molten metal flows through the molten metal inlet 11 into the detonation reaction chamber 1. Step 2: Periodically inject oxygen-enriched gas with a volume percentage of 75% hydrogen and oxygen into fuel inlet 32 ​​and oxidizer inlet 33. The mixture is ignited by detonation initiation device 31 and intermittent detonation combustion is triggered to generate a pulse detonation wave with transient high pressure characteristics. The output frequency of the pulse detonation wave is 10kHz, the cycle frequency is 170Hz, and the propagation speed is about 2500m / s.

[0047] Step 3: The molten metal flow dripped into the detonation reaction chamber 1 is cavitated and broken into fine metal droplets under the action of the pulse detonation wave, and then ejected from the outlet of the detonation reaction chamber 1 under the action of the high-speed argon gas flow. Step 4: As the tiny metal droplets are ejected into the powder collection chamber 4, they are accelerated to cool, solidify, and spheroidize under the action of inert gas, thus obtaining magnesium alloy powder.

[0048] Figure 7 This is a light microscope image of the magnesium alloy powder prepared in this embodiment. Figure 7 As shown, the obtained magnesium alloy powder particles are highly regular spherical, with smooth and clean surfaces, free of oxides or other adhering substances, and there is no obvious adhesion between the particles; the sphericity of the metal powder is >95%, the particle size distribution range is 15~45μm, the particle size distribution is concentrated, and the particle size uniformity of the powder is excellent. This indicates that the morphology and particle size of the magnesium alloy powder obtained in this embodiment have high consistency.

[0049] As can be seen from the above embodiments, the powder-making equipment and method based on pulse detonation waves provided by the present invention apply pulse detonation waves to the molten metal flow, causing it to undergo dual breakage under the synergistic effect of the supersonic airflow and cavitation effect generated by the pulse detonation waves. This ultimately yields metal powder with high sphericity and good uniformity. Furthermore, the pulse detonation wave technology employed in this application, through high-frequency impact and instantaneous atomization, can achieve an ultrafine metal powder production efficiency of 1-6 kg / min, with the potential to reach the 100 kg / h level. It also balances particle size control with low energy consumption. Compared to traditional metal powder preparation methods, it has significant advantages in both production efficiency and metal powder quality, and has good prospects for promotion and application.

[0050] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should recognize that any equivalent substitutions and obvious changes made based on the content of this specification should be included within the protection scope of the present invention.

Claims

1. A powder preparation method based on pulse detonation waves, characterized in that, The powder making method employs a powder making device based on pulse detonation wave, comprising: a detonation reaction chamber (1), a material melting and feeding module (2), a pulse detonation generation module (3), and a powder collection chamber (4). The inlet of the detonation reaction chamber (1) is connected to the pulse detonation generating module (3), and the outlet is connected to the powder collection chamber (4); the top of the detonation reaction chamber (1) is provided with a molten metal inlet (11) and an inert gas inlet (13); the material melting feed module (2) is connected to the molten metal inlet (11) and is used to feed the metal rod (5) at a certain speed and heat the front end of the metal rod (5) to generate a molten metal flow; the pulse detonation generating module (3) includes a detonation initiation device (31), a fuel inlet (32), an oxidant inlet (33), a rotary valve (34), and a thrust wall (35); the fuel and oxidant in the pulse detonation generating module (3) generate pulse detonation waves under the action of the detonation initiation device (31); The powder preparation method includes the following steps: S1. Place the front end of the metal rod (5) into the induction heating coil (21) of the material melting feed module (2), adjust the temperature and rotational feed speed of the induction heating coil (21) to melt the front end of the metal rod (5), and obtain molten metal flowing through the molten metal inlet (11) into the detonation reaction chamber (1); the detonation reaction chamber (1) adopts a Laval tube structure that first contracts and then expands; the feeding speed of the metal rod (5) is 10-60 mm / min, the rotational speed is 5-15 r / min; the heating power of the induction heating coil (21) is 20-350 kW; S2. Fuel and oxidizer are periodically injected into the fuel inlet (32) and oxidizer inlet (33). The mixture is ignited by the detonation initiation device (31) and intermittent detonation combustion is triggered to generate a pulse detonation wave. The output frequency of the pulse detonation wave is between 3kHz and 10kHz. The propagation speed of the pulse detonation wave is 1500-3000m / s. S3. The molten metal flow dripped into the detonation reaction chamber (1) is cavitated and broken into fine metal droplets under the action of the pulse detonation wave, and is ejected from the outlet of the detonation reaction chamber (1) under the action of the high-speed inert gas flow. S4. Tiny metal droplets cool and solidify as they are ejected into the powder collection chamber (4), forming metal powder. The metal rod (5) is made of nickel-based alloy or titanium alloy; the metal powder obtained in step S4 has a particle size of 10-50 μm.

2. The powder preparation method according to claim 1, characterized in that, The material melting feed module (2) includes an induction heating coil (21), an induction heater (22), and a rotary feed mechanism; the induction heating coil (21) is arranged around the front end of the metal rod (5); the molten metal inlet (11) is provided with a one-way valve (12), which includes a valve core (121) and a valve body (122).

3. The powder preparation method according to claim 1, characterized in that, The fuel entering via fuel inlet (32) includes short-chain hydrocarbons and / or hydrogen; the short-chain hydrocarbons include one or more combinations of methane, propane, and butane.

4. The powder preparation method according to claim 3, characterized in that, The oxidant entering through the oxidant inlet (33) includes oxygen or an oxygen-enriched gas composed of oxygen and an inert gas; in the oxygen-enriched gas, the volume percentage of oxygen is ≥50%.

5. The powder preparation method according to claim 4, characterized in that, The detonation initiation device (31) is a spark plug used to ignite the mixture of fuel and oxidant gas so that the pulse detonation generation module (3) generates a detonation wave.

6. The powder-making method according to claim 1, characterized in that, In step S1, the diameter of the detonation reaction chamber (1) is 10-30cm and the length-to-diameter ratio is 5-30.

7. The powder-making method according to claim 1, characterized in that, In step S2, the cycle frequency of the pulse detonation wave is 100-200Hz.

8. The powder-making method according to claim 1, characterized in that, In step S1, the length of the metal rod (5) is 0.5-3m and the diameter is 50-200mm.

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