High specific gravity alloy powder for additive manufacturing, preparation method and application

Abstract

The present invention provides a high-density alloy powder for additive manufacturing, a preparation method and an application. The method comprises: mixing tungsten powder, nickel powder and iron powder and ball milling them to obtain a mixed powder. Among them, the particle size of the tungsten powder is 1-3 microns, the particle size of the nickel powder is 1-3 microns, and the particle size of the iron powder is 1-3 microns. The mixed powder is granulated and pressed to obtain a material blank. After the material blank is degreased at 800°C, it is sintered in a hydrogen atmosphere at 1450-1530°C for 2-4 hours to obtain a rod. The rod is pulverized to obtain a high-density alloy powder, and the high-density alloy powder includes tungsten particles and a metal layer covering the tungsten particles, and the metal layer is a nickel and iron metal layer. In the above-mentioned method for preparing high-density alloy powder for additive manufacturing, the tungsten particles are 20-40 microns, the average thickness between the tungsten particles after heat treatment is relatively large, and the toughness of the alloy is good. Therefore, it is suitable for preparing high-toughness high-density alloy parts.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to a high specific gravity alloy powder for additive manufacturing, a preparation method and an application thereof. Background Art

[0002] At present, the high-density alloy (WNiFe) powder material used in additive manufacturing is made of fine-grained tungsten, nickel, and iron powders, which are formed by spray drying granulation, sintering, and agglomeration. In order to improve the sphericity and fluidity of the powder material, plasma spheroidization can also be used. However, the high-density alloy (WNiFe) parts printed by this powder have poor comprehensive mechanical properties. Summary of the invention

[0003] The main purpose of the present invention is to provide a high-density alloy powder for additive manufacturing, a preparation method and an application thereof, so as to solve the technical problem that the high-density alloy (WNiFe) parts in the related art have poor comprehensive mechanical properties.

[0004] To achieve the above object, the first aspect of the present invention provides a method for preparing a high specific gravity alloy powder for additive manufacturing, comprising:

[0005] Mix tungsten powder, nickel powder and iron powder and grind them to obtain mixed powder; wherein the particle size of the tungsten powder is 1-3 microns, the particle size of the nickel powder is 1-3 microns, and the particle size of the iron powder is 1-3 microns;

[0006] Granulating and pressing the mixed powder to obtain a material body;

[0007] After degreasing the material blank at 800° C., sintering it in a hydrogen atmosphere at 1450-1530° C. for 2-4 hours to obtain a rod;

[0008] The rod is powdered to obtain a high-density alloy powder, wherein the high-density alloy powder comprises tungsten particles and a metal layer covering the tungsten particles, wherein the metal layer is a nickel and iron metal layer.

[0009] According to an embodiment of the present application, the step of milling the rod material comprises:

[0010] Processing the rod into a target rod that meets the size requirements of a non-transferred arc rotating electrode atomization device; the non-transferred arc rotating electrode atomization device includes an atomization furnace and a plasma gun;

[0011] The target rod is placed in the atomizing furnace, which is in a protective gas atmosphere with a vacuum degree of 5×10 -3 Pa, temperature is 25-30°C, humidity is ≤75%RH;

[0012] One end of the target rod is heated and melted under the action of the transferred arc formed by the plasma gun to form alloy powder; wherein the target rod is rotated at a speed of 25000-30000 r / min, the feed speed is 1.6 mm / s, the current of the plasma gun is 1500 A, and the distance between the plasma gun and the target rod is 15-25 mm;

[0013] The atomizing furnace is maintained at a high pressure of 120 KPa for 4 hours, and the alloy powder is cooled in the atomizing furnace to obtain a high specific gravity alloy powder.

[0014] According to the implementation mode of the present application, it also includes:

[0015] The cooled alloy powder was passed through a 200-mesh sieve to obtain a high specific gravity alloy powder.

[0016] According to an embodiment of the present application, in the mixed powder, the mass percentage of tungsten powder is 93-95%, the mass percentage of nickel powder is 3.5-5%, and the mass percentage of iron powder is 1.5-2.1%.

[0017] According to the implementation mode of the present application, after the material blank is degreased at 800° C., it is sintered at 1450-1530° C. in a hydrogen atmosphere for 2-4 hours to obtain a rod.

[0018] According to the embodiment of the present application, in the step of ball-milling the mixture of tungsten powder, nickel powder and iron powder, the ball-milling medium is ethanol, and 1-3% paraffin is added to the ethanol. The ball-milling time is 24-36 hours, the ball-to-material ratio of the ball mill is 4:1, and the material is the sum of tungsten powder, nickel powder and iron powder.

[0019] According to an embodiment of the present application, the step of granulating the mixed powder includes: spray-drying and granulating the mixed powder at a gas temperature of 150-200°C.

[0020] According to the implementation mode of the present application, the mixed powder particles formed by granulation are pressed into a material green body under a pressure of 150-200 MPa, and the material green body is a sphere with a diameter of 20-50 mm or a block with a width of 20-50 mm.

[0021] The second aspect of the present invention provides a high specific gravity alloy powder obtained by the above-mentioned preparation method.

[0022] A third aspect of the present invention provides an application of the high specific gravity alloy powder obtained by the above-mentioned preparation method in additive manufacturing of metal parts.

[0023] In the above-mentioned method for preparing high-density alloy powder for additive manufacturing, tungsten powder, nickel powder and iron powder are used as raw materials to sinter to obtain rods. During the sintering process, the sintering time is appropriate, the particle size of the tungsten powder increases, and spherical tungsten powder particles with larger particles are formed, and the nickel powder and iron powder are melted and coated on the surface of the spherical tungsten powder particles. In the above-mentioned method for preparing high-density alloy powder for additive manufacturing, the tungsten particles are 20-40 microns, the average thickness between the tungsten particles after heat treatment is relatively large, and the toughness of the alloy is good. Therefore, it is suitable for preparing high-toughness high-density alloy parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0025] Figure 1 is a scanning electron microscope image of a high specific gravity alloy powder for additive manufacturing according to an embodiment of the present application at a magnification of 60x;

[0026] Figure 2 This is a scanning electron microscope image of a high-density alloy powder for additive manufacturing according to an embodiment of the present application at a magnification of 2000x.

[0027] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with the implementation methods and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that all directional indications (such as up, down, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0030] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0031] Furthermore, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in the field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0032] After extensive research, the applicant found that the high-density alloy (WNiFe) parts printed by powder in the related art have poor comprehensive mechanical properties. The main reason is that the molding time of additive manufacturing is short, the fine tungsten powder has no time to grow, the average liquid phase thickness between tungsten particles is small, and the toughness of the alloy is poor. Based on this, the applicant has made targeted improvements.

[0033] To achieve the above object, the first aspect of the present invention provides a method for preparing a high specific gravity alloy powder for additive manufacturing, comprising:

[0034] S10: ball-milling tungsten powder, nickel powder and iron powder to obtain mixed powder, wherein the particle size of the tungsten powder is 1-3 microns, the particle size of the nickel powder is 1-3 microns, and the particle size of the iron powder is 1-3 microns.

[0035] In this step, 1-3 micron tungsten powder, 1-3 micron nickel powder, and 1-3 micron iron powder can be mixed and ball-milled. During the ball-milling process, the tungsten powder, nickel powder, and iron powder are further crushed to form finer particles, and the tungsten powder, nickel powder, and iron powder are mixed more evenly.

[0036] S20: granulating and pressing the mixed powder to obtain a material body.

[0037] In this step, the mixed powder is granulated to form small particles of mixed powder particles, and then pressed into shape, for example, by grinding or cold isostatic pressing, so that the mixed powder particles form a material body with a certain shape. The material body can be spherical, square, cylindrical, etc., and the specific shape is not limited. The volume of the material body is relatively small, and its maximum three-dimensional size is not too large to facilitate calcination. In some embodiments, the maximum size and minimum size of the material body in three dimensions are similar.

[0038] S30: After degreasing the material blank at 800° C., sintering it in a hydrogen atmosphere at 1450-1530° C. for 2-4 hours to obtain a rod.

[0039] The melting point of nickel powder is 212° C., the melting point of iron powder is 1538° C., and the melting point of tungsten powder is 3400° C. In this step, during the sintering process, the tungsten grains gradually grow, so the particle size of the tungsten powder gradually increases, forming a relatively regular spherical structure, that is, forming spherical tungsten powder particles.

[0040] The melting points of nickel powder and iron powder are relatively low, forming a molten state and coating the surface of the spherical tungsten powder particles. That is, the rod includes a plurality of spherical tungsten powder particles, and the space between adjacent spherical tungsten powder particles is filled with molten iron and nickel.

[0041] Sintering in hydrogen atmosphere at 1450-1530℃ for 2-4 hours, the sintering degree is good, the melting point of nickel powder and iron powder is relatively low, forming a molten state, covering the surface of spherical tungsten powder particles. That is, the rod includes multiple spherical tungsten powder particles, and the adjacent spherical tungsten powder particles are filled with molten iron and nickel.

[0042] If the temperature is too high and the time is too long, a large amount of tungsten, nickel and iron may melt together, destroying the iron and nickel wrapped around the tungsten particles. The subsequent rods are not easy to break, and the tungsten particles are larger and irregular in shape. If the temperature is too low and the time is too short, the tungsten particles may not grow or may not grow to the target range.

[0043] S40: Powdering the rod to obtain a high-density alloy powder, wherein the high-density alloy powder includes tungsten particles and a metal layer covering the tungsten particles, wherein the metal layer is a nickel and iron metal layer.

[0044] In the above-mentioned method for preparing high-density alloy powder for additive manufacturing, tungsten powder, nickel powder and iron powder are used as raw materials to sinter to obtain rods. During the sintering process, the particle size of the tungsten powder increases to form spherical tungsten powder particles with larger particles, and the nickel powder and iron powder are melted and coated on the surface of the spherical tungsten powder particles. In the above-mentioned method for preparing high-density alloy powder for additive manufacturing, the tungsten particles are 20-40 microns, the average thickness between the tungsten particles after heat treatment is relatively large, the toughness of the alloy is good, and the elongation is ≥25%. Therefore, it is suitable for preparing high-toughness high-density alloy parts.

[0045] In some embodiments, in the mixed powder, the step of powdering the rod material comprises:

[0046] S41: Processing the rod into a target rod that meets the size requirements of a non-transferred arc rotating electrode atomization device; the non-transferred arc rotating electrode atomization device includes an atomization furnace and a plasma gun.

[0047] In this step, since the rod is used as the positive electrode in the non-transferred arc rotating electrode atomization device, the size of the rod needs to meet the corresponding size requirements, such as the rod can be processed into a specification of 70mm in diameter and 300mm in length. The non-transferred arc rotating electrode atomization device includes an atomization furnace and a plasma gun, and its specific structure is not limited. For example, it can be a brushless conductive high-speed plasma rotary atomization powder making device in application number 202110832524.7.

[0048] S42: placing the target rod in the atomizing furnace, wherein the atomizing furnace is provided with a protective gas atmosphere and a vacuum degree of 5×10 -3 Pa, temperature is 25~30℃, humidity ≤75%RH.

[0049] In this step, the ambient temperature can be kept at 25-30°C and the ambient humidity can be kept at ≤75%RH. The target rod is placed in the atomizing furnace as the positive electrode, and the protective gas argon is filled in. The atomizing furnace is evacuated to a vacuum degree of 5×10 -3 Pa.

[0050] S43: One end of the target rod is heated and melted under the action of the transferred arc formed by the plasma gun to form an alloy powder; wherein the target rod is rotated at a speed of 25000-30000 r / min, the feed speed is 1.6 mm / s, the current of the plasma gun is 1500 A, and the distance between the plasma gun and the target rod is 15-25 mm.

[0051] In this step, the process parameters are set to start the non-transferred arc rotating electrode atomization (NTA-PREP) equipment. The target rod is rotated at a speed of 25,000 to 30,000 r / min, the target rod feed speed is 1.6 mm / s, and the current of the plasma gun is 1500 A. The plasma gun forms a transferred arc to heat and melt one end of the target rod, so that the alloy droplets after the target rod is melted in the atomization chamber are thrown out under the action of centrifugal force, and the alloy droplets are cooled to form alloy powder under the action of surface tension.

[0052] S44: maintaining a high pressure of 120 KPa in the atomizing furnace for 4 hours, and cooling the alloy powder in the atomizing furnace to obtain a high specific gravity alloy powder.

[0053] In this step, after the powder making is completed, the high pressure of 120 KPa is maintained in the atomizing furnace for 4 hours and cooled along with the furnace.

[0054] In some embodiments, the method further comprises: passing the cooled alloy powder through a 200-mesh screen to obtain a high-density alloy powder. For example, after the powder is cooled, it can be sieved using an ultrasonic vibrating sieve machine and then vacuum packaged.

[0055] In some embodiments, in the mixed powder, the mass percentage of tungsten powder is 93-95%, the mass percentage of nickel powder is 3.5-5%, and the mass percentage of iron powder is 1.5-2.1%.

[0056] In some embodiments, the material blank is degreased at 800° C. and then sintered at 1450-1530° C. in a hydrogen atmosphere for 2-4 hours to obtain a rod.

[0057] In some embodiments, in the step of ball-milling the mixed tungsten powder, nickel powder and iron powder, the ball-milling medium is ethanol, and 1-3% paraffin is added to the ethanol. The ball-milling time is 24-36 hours, the ball-to-material ratio of the ball mill is 4:1, and the material is the sum of tungsten powder, nickel powder and iron powder.

[0058] According to an embodiment of the present application, the step of granulating the mixed powder comprises: spray drying and granulating the mixed powder at a gas temperature of 150-200°C.

[0059] According to the embodiment of the present application, the mixed powder particles formed by granulation are pressed into a material body under a pressure of 150-200 MPa, and the material body is a sphere with a diameter of 20-50 mm or a block with a width of 20-50 mm.

[0060] According to an embodiment of the present application, the rod is subjected to plasma rotating electrode atomization to obtain a high specific gravity alloy powder, comprising:

[0061] The rod is subjected to plasma rotary electrode atomization at 25,000 to 30,000 revolutions to obtain a high specific gravity alloy powder.

[0062] The present invention also provides a high specific gravity alloy powder obtained by the above preparation method.

[0063] The above-mentioned high-density alloy powder has a tungsten particle size of 35-40 microns, and nickel powder and iron powder are coated on the surface of the spherical tungsten powder particles. When additive manufacturing is performed, such as through 3D printing, nickel and iron melt to form a bonding phase layer; therefore, the bonding phase layer of the above-mentioned high-density alloy powder is thick and has good mechanical properties; 3D printing promotes uniform distribution of tungsten particles and good consistency; on this basis, the connection between adjacent high-density alloy powders is between bonding phases rather than between tungsten particles, thereby reducing laser power and thermal stress. Therefore, it is more conducive to 3D printing.

[0064] The present invention also provides an application of the high specific gravity alloy powder obtained by the above-mentioned preparation method in additive manufacturing of metal parts.

[0065] The technical solution of the present application is described below in conjunction with specific embodiments.

[0066] Example 1

[0067] S101 ball milling: tungsten powder, nickel powder and iron powder are mixed and ball milled to obtain a mixed powder. The particle size of the tungsten powder is 1-3 microns, the particle size of the nickel powder is 1-3 microns, and the particle size of the iron powder is 1-3 microns. The mixed powder is 93% tungsten + 4.9% nickel + 2.1% iron powder.

[0068] S102 Spray drying: The mixed powder is dried and granulated by using a closed spray drying method with a centrifugal nozzle at a gas temperature of 150°C.

[0069] S103 pressing: Press by grinding or cold isostatic pressing, with a pressure of 150MPa, into small balls or small cubes with a diameter of 20mm.

[0070] S104 sintering: After the material body is degreased at 800℃, it is sintered at 1530℃ in a hydrogen atmosphere for 4 hours to obtain a sintered rod. The sintered rod contains 35-40 micron tungsten particles.

[0071] Example 2

[0072] S101 ball milling: tungsten powder, nickel powder and iron powder are mixed and ball milled to obtain a mixed powder. The particle size of the tungsten powder is 1-3 microns, the particle size of the nickel powder is 1-3 microns, and the particle size of the iron powder is 1-3 microns. The mixed powder is 93% tungsten + 4.9% nickel + 2.1% iron powder.

[0073] S102 Spray drying: The mixed powder is dried and granulated by using a closed spray drying method with a centrifugal nozzle at a gas temperature of 180°C.

[0074] S103 pressing: Press by grinding or cold isostatic pressing, with a pressure of 170MPa, into small balls or small cubes with a diameter of 30mm.

[0075] S104 sintering: After the material body is degreased at 800℃, it is sintered at 1450℃ in a hydrogen atmosphere for 2 hours to obtain a sintered rod. The sintered rod contains 20-30 micron tungsten particles.

[0076] Example 3

[0077] S101 ball milling: tungsten powder, nickel powder and iron powder are mixed and ball milled to obtain a mixed powder. The particle size of the tungsten powder is 1-3 microns, the particle size of the nickel powder is 1-3 microns, and the particle size of the iron powder is 1-3 microns. The mixed powder is 93% tungsten + 4.9% nickel + 2.1% iron powder.

[0078] S102 Spray drying: The mixed powder is dried and granulated by using a closed spray drying method and a centrifugal nozzle at a gas temperature of 200°C.

[0079] S103 pressing: Press by grinding or cold isostatic pressing, with a pressure of 200 MPa, into small balls or small cubes with a diameter of 50 mm.

[0080] S104 sintering: After the material body is degreased at 800℃, it is sintered at 1530℃ in a hydrogen atmosphere for 3 hours to obtain a sintered rod. The sintered rod contains 30-35 micron tungsten particles.

[0081] Example 4

[0082] 1) The rod of Example 1 was processed according to the requirements of the non-transferred arc rotating electrode atomization (NTA-PREP) equipment to form a target rod with a diameter of 70 mm and a length of 300 mm;

[0083] 2). Ensure that the ambient temperature is 25-30℃ and the ambient humidity is ≤75%RH. Place the target rod as the positive electrode in the atomizing furnace, fill it with protective gas argon, and evacuate the atomizing furnace. The vacuum degree in the atomizing furnace is 5×10 -3 Pa;

[0084] 3). Set the process parameters to start the non-transferred arc rotating electrode atomization (NTA-PREP) equipment. The target rod rotates at a speed of 25000r / min, the target rod feed speed is 1.6mm / s, the current of the plasma gun is 1500A, and the plasma gun forms a transferred arc to heat and melt one end of the target rod, so that the alloy droplets of the target rod melted in the atomization chamber are thrown out under the action of centrifugal force, and the alloy droplets are cooled to form alloy powder under the action of surface tension;

[0085] 4). After the powder making is completed, the high pressure of 120KPa is maintained in the atomizing furnace for 4 hours. After the powder is cooled, it is sieved with a sieving ultrasonic vibrating sieve machine, passed through a 200-mesh sieve, and vacuum packaged.

[0086] The final powder obtained has a sphericity of 98.36%, an oxygen content of 258 ppm, and a particle size between 15 and 53 μm.

[0087] Example 5

[0088] 1) The target rod of Example 1 is processed according to the requirements of the non-transferred arc rotating electrode atomization (NTA-PREP) equipment to form a target rod with a diameter of 70 mm and a length of 300 mm;

[0089] 2). Ensure that the ambient temperature is 25-30℃ and the ambient humidity is ≤75%RH. Place the target rod as the positive electrode in the atomizing furnace, fill it with protective gas argon, and evacuate the atomizing furnace. The vacuum degree in the atomizing furnace is 5×10 -3 Pa;

[0090] 3). Set the process parameters to start the non-transferred arc rotating electrode atomization (NTA-PREP) equipment. The target rod rotates at a speed of 30,000 r / min, the target rod feed speed is 1.8 mm / s, the current of the plasma gun is 2000 A, and the plasma gun forms a transferred arc to heat and melt one end of the target rod, so that the alloy droplets after the target rod is melted in the atomization chamber are thrown out under the action of centrifugal force, and the alloy droplets are cooled to form alloy powder under the action of surface tension;

[0091] 4). After the powder making is completed, the high pressure of 120KPa is maintained in the atomizing furnace for 4 hours. After the powder is cooled, it is sieved with a sieving ultrasonic vibrating sieve machine, passed through a 200-mesh sieve, and vacuum packaged.

[0092] The final powder obtained has a sphericity of 98.42%, an oxygen content of 231 ppm, and a particle size between 15 and 53 μm.

[0093] Example 6

[0094] 1) The target rod of Example 1 is processed according to the requirements of the non-transferred arc rotating electrode atomization (NTA-PREP) equipment to form a target rod with a diameter of 70 mm and a length of 300 mm;

[0095] 2). Ensure that the ambient temperature is 25-30℃ and the ambient humidity is ≤75%RH. Place the target rod as the positive electrode in the atomizing furnace, fill it with protective gas argon, and evacuate the atomizing furnace. The vacuum degree in the atomizing furnace is 5×10 -3 Pa;

[0096] 3). Set the process parameters to start the non-transferred arc rotating electrode atomization (NTA-PREP) equipment. The target rod rotates at a speed of 30,000 r / min, the target rod feed speed is 1.8 mm / s, the current of the plasma gun is 2000 A, and the plasma gun forms a transferred arc to heat and melt one end of the target rod, so that the alloy droplets after the target rod is melted in the atomization chamber are thrown out under the action of centrifugal force, and the alloy droplets are cooled to form alloy powder under the action of surface tension;

[0097] 4). After the powder making is completed, the high pressure of 120KPa is maintained in the atomizing furnace for 4 hours. After the powder is cooled, it is sieved with a sieving ultrasonic vibrating sieve machine, passed through a 200-mesh sieve, and vacuum packaged.

[0098] The final powder obtained has a sphericity of 98.31%, an oxygen content of 218 ppm, and a particle size between 15 and 53 μm.

[0099] Test Case

[0100] The high specific gravity alloy powder in step S105 of Example 1 was tested using a scanning electron microscope. The results are as follows: Figure 1 and Figure 2 As shown. Figure 1 It can be seen that the surface of the spherical tungsten powder is relatively smooth, the shape is relatively regular, and the particle size is relatively uniform, basically around 32 microns.

[0101] from Figure 2 It can be seen more clearly that the surface of the spherical tungsten powder is relatively smooth and spherical, basically around 32 microns.

[0102] The above technical solutions of the present invention are only preferred embodiments of the present invention, and the patent scope of the present invention is not limited thereto. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for preparing a high specific gravity alloy powder for additive manufacturing, characterized in that: include: Mix tungsten powder, nickel powder and iron powder and grind them to obtain mixed powder; wherein the particle size of the tungsten powder is 1-3 microns, the particle size of the nickel powder is 1-3 microns, and the particle size of the iron powder is 1-3 microns; the mass percentage of the tungsten powder is 93-95%, the mass percentage of the nickel powder is 3.5-5%, and the mass percentage of the iron powder is 1.5-2.1%; Granulating and pressing the mixed powder to obtain a material body; After degreasing the material blank at 800° C., sintering it in a hydrogen atmosphere at 1450-1530° C. for 2-4 hours to obtain a rod; Powdering the rod material to obtain a high-density alloy powder, wherein the high-density alloy powder includes tungsten particles and a metal layer covering the tungsten particles, wherein the metal layer is a nickel and iron metal layer; The step of milling the rod material comprises: Processing the rod into a target rod that meets the size requirements of a non-transferred arc rotating electrode atomization device; the non-transferred arc rotating electrode atomization device includes an atomization furnace and a plasma gun; The target rod is placed in the atomizing furnace, which is in a protective gas atmosphere with a vacuum degree of 5×10 - 3 Pa, temperature is 25~30℃, humidity ≤75%RH; One end of the target rod is heated and melted under the action of the transferred arc formed by the plasma gun to form alloy powder; wherein the target rod is rotated at a speed of 25000-30000 r / min, the feed speed is 1.6 mm / s, the current of the plasma gun is 1500 A, and the distance between the plasma gun and the target rod is 15-25 mm; The atomizing furnace is maintained at a high pressure of 120 KPa for 4 hours, and the alloy powder is cooled in the atomizing furnace to obtain a high specific gravity alloy powder; The cooled alloy powder was passed through a 200-mesh sieve to obtain a high specific gravity alloy powder.

2. The preparation method according to claim 1, characterized in that: In the step of mixing tungsten powder, nickel powder and iron powder for ball milling, the ball milling medium is ethanol, and 1-3% paraffin is added to the ethanol; the ball milling time is 24-36 hours, and the ball-to-material ratio of the ball milling is 4:1, and the material is the sum of the tungsten powder, the nickel powder and the iron powder.

3. The preparation method according to claim 1, characterized in that: The step of granulating the mixed powder comprises: spray drying and granulating the mixed powder at a gas temperature of 150-200°C.

4. The preparation method according to claim 3, characterized in that: The mixed powder particles formed by granulation are pressed into a material green body under a pressure of 150-200 MPa. The material green body is a sphere with a diameter of 20-50 mm or a block with a width of 20-50 mm.

5. A high specific gravity alloy powder obtained by the preparation method according to any one of claims 1 to 4.

6. Use of a high-density alloy powder obtained by the preparation method according to any one of claims 1 to 5 in additive manufacturing of metal parts.

Images