Treatment method of 3D printing nickel-based alloy waste powder

Abstract

The invention discloses a treatment method for 3D printing nickel-based alloy waste powder, and relates to the field of nickel-based alloy powder processing. The treatment method of the 3D printing nickel-based alloy waste powder comprises the following steps that firstly, acid leaching is conducted on the nickel-based alloy waste powder through acid liquor, after the acid liquor is separated out, alkali liquor is added into the nickel-based alloy waste powder for alkali leaching, then cleaning and drying are conducted, and pretreated nickel-based alloy powder is obtained; the pretreated nickel-based alloy powder is sprayed on the plate, and then sprayed objects are collected; screening the sprayed objects to obtain primary nickel-based alloy powder; and adding the primary nickel-based alloy powder into water, carrying out ultrasonic treatment, then screening again, and drying residues on the screen until the weight change of the residues on the screen is less than 0.01 g, so as to obtain the nickel-based alloy powder. When the method is used for removing the oxide impurities in the nickel-based alloy waste powder, high-cost equipment does not need to be invested, the treatment condition is mild and not harsh, energy consumption is small, and the method can be popularized and applied in a large range.

Description

Technical Field

[0001] The present application relates to the field of nickel-based alloy powder processing, and in particular to a method for processing waste nickel-based alloy powder produced by 3D printing. Background Art

[0002] Nickel-based alloys containing nickel, titanium and aluminum are one of the important 3D printing materials and are widely used in aerospace, medical and other fields.

[0003] During the 3D printing process of nickel-based alloy powder, a large amount of nickel-based alloy waste powder will be generated. An oxide layer will be formed on the surface of these nickel-based alloy waste powders, which is usually a mixture of nickel oxide, titanium oxide and aluminum oxide. When the oxygen content in the nickel-based alloy waste powder is too high, the recycling and reuse of the nickel-based alloy waste powder will be limited, because the high oxygen content in the nickel-based alloy waste powder will affect the ductility and plastic deformation ability of the nickel-based alloy, and it is easy to crack during the 3D printing process.

[0004] At present, in order to reduce the oxygen content in nickel-based alloy waste powder, the relevant technology adopts heat treatment reduction method to reduce the oxides on the surface of nickel-based alloy waste powder. Although this can reduce the oxygen content of nickel-based alloy waste powder to a certain extent, the temperature requirement during the reduction process is as high as 500°C or above, which has high requirements on equipment and high energy consumption, making it difficult to promote on a large scale. Summary of the invention

[0005] In order to improve the problem of high equipment requirements and high energy consumption in the recycling and reuse of nickel-based alloy waste powder in the related art, the present application provides a method for processing 3D printing nickel-based alloy waste powder.

[0006] A method for processing waste nickel-based alloy powder for 3D printing, comprising the following steps: S1, pretreatment: firstly, acid leaching the nickel-based alloy waste powder with acid solution, and after separating the acid solution, adding alkali solution to the nickel-based alloy waste powder for alkali leaching, and then washing and drying to obtain pretreated nickel-based alloy powder; S2, spraying: spraying the pretreated nickel-based alloy powder onto the plate, and then collecting the sprayed material; S3, screening: screening the sprayed material, separating the oxide impurities by using the particle size difference between the nickel-based alloy powder and the oxide impurities, and obtaining a preliminary nickel-based alloy powder; S4, ultrasound: adding the preliminary nickel-based alloy powder to water and ultrasound-treating it to cause the oxide impurities attached to the surface of the nickel-based alloy powder to fall off and be suspended in the water, and then sieving again, and then drying the sieve residue; repeating step S4 until the weight change of the sieve residue is less than 0.01g, to obtain the nickel-based alloy powder.

[0007] In the present application, the nickel-based alloy waste powder is firstly acid-leached with acid solution, which can remove the nickel oxide or aluminum oxide mixed on the surface of the oxide layer. After acid leaching, alkali leaching is continued, which can remove oil on the one hand, and react with the acid solution remaining in the nickel-based alloy waste powder on the other hand, and improve the performance of the alkali solution entering the internal structure of the oxide layer through the heat released by the reaction instantaneously, so as to better remove the aluminum oxide in the internal structure of the oxide layer, so that the oxide layer becomes an oxide layer with a porous structure. After the pretreatment of acid leaching and alkali leaching is completed, the pretreated nickel-based alloy powder is loaded into the sandblasting equipment, and the pretreated nickel-based alloy powder is sprayed on the plate. Through the collision between the pretreated nickel-based alloy powders or the collision between the pretreated nickel-based alloy powders and the plate, the oxide layer with a porous structure on the surface of the pretreated nickel-based alloy powder becomes crushed powder and is removed from the surface of the pretreated nickel-based alloy powder, so as to obtain a mixture of nickel-based alloy powder and oxide impurities, i.e., spraying material. Then, the spraying material is screened to remove most of the oxide impurities, and a preliminary nickel-based alloy powder is obtained. At this time, oxide impurities are still attached to the surface of the preliminary nickel-based alloy powder. Finally, the oxide impurities attached to the surface of the preliminary nickel-based alloy powder are separated into water through an ultrasonic step, and a sieve is used to directly separate the water and the oxide impurities suspended in the water. The residue is dried and the S4 step is repeated until the weight change of the residue is less than 0.01g, thereby obtaining a nickel-based alloy powder with high purity.

[0008] When the above method is used to remove oxide impurities in nickel-based alloy powder, there is no need to invest in high-cost equipment, and the treatment conditions are mild and not harsh, the energy consumption is low, and it can be widely promoted and applied.

[0009] In some specific embodiments, in step S1, the acid solution is any one of a hydrochloric acid solution or a sulfuric acid solution, the acid concentration in the acid solution is controlled at 0.02-0.05 mol / L, and the acid leaching time is 20-60 min.

[0010] In the present application, the acid solution is preferably a hydrochloric acid solution or a sulfuric acid solution with a concentration range of 0.02-0.05 mol / L, which can not only remove the acid-soluble components in the oxide layer, such as aluminum oxide and nickel oxide, but also prevent the nickel-based alloy substrate from being damaged.

[0011] In some specific embodiments, in step S1, the alkali solution is any one of a sodium hydroxide solution or a potassium hydroxide solution, the concentration of the alkali in the alkali solution is controlled at 0.01-0.02 mol / L, and the alkali leaching time is 15-30 min.

[0012] In the present application, the alkali solution is preferably a sodium hydroxide solution or a potassium hydroxide solution with a concentration range of 0.01-0.02 mol / L, which can not only remove the alkali-soluble components in the oxide layer, such as aluminum oxide, but also prevent the nickel-based alloy substrate from being damaged and achieve the purpose of degreasing.

[0013] In some specific implementations, in step S1, fatty alcohol polyoxyethylene ether is further added to the alkali solution, and the mass concentration of the fatty alcohol polyoxyethylene ether is 0.01-0.02%.

[0014] In the present application, fatty alcohol polyoxyethylene ether can be further added to the alkali solution, and the mass concentration of fatty alcohol polyoxyethylene ether is controlled to be 0.01-0.02%, which can further improve the degreasing effect of nickel-based alloy waste powder.

[0015] In some specific embodiments, in step S1, the acid leaching and the alkali leaching are both performed in an ultrasonic device with an ultrasonic power of 15-20 KW.

[0016] In the present application, both acid leaching and alkaline leaching are carried out in ultrasonic equipment, which is beneficial to the breakage and shedding of the oxide layer on the surface of the nickel-based alloy powder and further refinement of the particle size of the oxide knocked off in step S2, thereby increasing the particle size difference between the nickel-based alloy powder and the oxide impurities, and facilitating the separation of the oxide impurities from the nickel-based alloy powder in step S3.

[0017] In step S2, the hardness of the plate is 240-280 HB.

[0018] In the present application, the hardness of the plate in step S2 is controlled to be 240-280 HB, which can reduce the loss of nickel-based alloy powder and prevent the nickel-based alloy powder from being damaged due to impact and crushing.

[0019] In step S2, the spraying pressure is 0.25-0.45 MPa, and the spraying distance is 45-100 cm.

[0020] In the present application, the injection pressure of step S2 is controlled to be 0.25-0.45 MPa and the injection distance is 45-100 cm, which is beneficial to refine the particle size of the oxide knocked off in step S2, increase the particle size difference between the nickel-based alloy powder and the oxide impurities, and facilitate the separation of the oxide impurities from the nickel-based alloy powder in step S3.

[0021] In step S2, the spraying pressure is 0.25-0.35 MPa, and the spraying distance is 65-75 cm.

[0022] In the present application, the injection pressure of step S2 is controlled to be 0.25-0.35MPa and the injection distance is 65-75cm, which can increase the particle size difference between the nickel-based alloy powder and the oxide impurities while reducing the defect problem of the nickel-based alloy powder caused by impact and crushing, thereby reducing the loss of the nickel-based alloy powder.

[0023] In step S1, the particle size of the nickel-based alloy waste powder is 100-120 μm, and in steps S3 and S4, the aperture of the screen used for screening is 75-80 μm.

[0024] In step S4, the ultrasonic treatment power of the spray is 25-30KW.

[0025] In the present application, the ultrasonic treatment power of step S4 is controlled to be 25-30KW, which is conducive to transferring the oxide impurities attached to the surface of the nickel-based alloy powder into water.

[0026] In summary, this application includes the following beneficial technical effects: (1) In the present application, the nickel-based alloy waste powder is first acid-leached with an acid solution, and then alkaline leaching is continued after acid leaching, so that the oxide layer can be changed into an oxide layer with a porous structure. Then, the pretreated nickel-based alloy powder is sprayed on the plate, and the oxide layer with a porous structure on the surface of the pretreated nickel-based alloy powder is changed into powder and removed from the surface of the pretreated nickel-based alloy powder through collision between the pretreated nickel-based alloy powders or collision between the pretreated nickel-based alloy powders and the plate, so that a mixture of nickel-based alloy powder and oxide impurities, i.e., sprayed material, is obtained. Next, the sprayed material is sieved to remove most of the oxide impurities, and a preliminary nickel-based alloy powder is obtained. At this time, the surface of the preliminary nickel-based alloy powder still has oxide impurities attached to it. Finally, through the ultrasonic step, the oxide impurities attached to the surface of the preliminary nickel-based alloy powder are separated into water, and the water and the oxide impurities suspended in the water are directly separated by a sieve. The residue is dried and the S4 step is repeated until the weight change of the residue is less than 0.01g, and a nickel-based alloy powder with high purity can be obtained.

[0027] (2) In the present application, the plate hardness in step S2 is controlled to be 240-280 HB, which can reduce the loss of nickel-based alloy powder and prevent the nickel-based alloy powder from being damaged due to impact and crushing.

[0028] (3) In the present application, the injection pressure of step S2 is controlled to be 0.25-0.35 MPa and the injection distance is 65-75 cm, which can increase the particle size difference between the nickel-based alloy powder and the oxide impurities while reducing the defect problem of the nickel-based alloy powder caused by impact and crushing, thereby reducing the loss of the nickel-based alloy powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic flow chart of a method for treating waste nickel-based alloy powder in 3D printing is provided for this application. DETAILED DESCRIPTION

[0030] The present application is further described below in conjunction with specific experiments. The nickel-based alloy powder used in each embodiment of the present application is an alloy powder recovered from the application of nickel-based alloy IN718. Example

[0031] [Example 1] A method for treating waste powder of nickel-based alloy in 3D printing, referring to Figure 1 , including the following steps: S1, pretreatment: firstly, using a hydrochloric acid solution with a concentration of 0.005mol / L to acid-leach the nickel-based alloy waste powder with a particle size of 100-120μm, the acid-leach time is 120min, after separating the hydrochloric acid solution, adding a sodium hydroxide solution with a concentration of 0.005mol / L to the nickel-based alloy waste powder for alkali leaching, the alkali leaching time is 120min, after separating the sodium hydroxide solution, then washing and drying the solid to obtain a pretreated nickel-based alloy powder; S2, spraying: spray the pretreated nickel-based alloy powder on a plate with a hardness of 200 HB, and control the spraying pressure to 0.25 MPa, the spraying distance to 100 cm, and then collect the sprayed material; S3, screening: the sprayed material is screened, the aperture of the screen is 75 μm, and the oxide impurities are separated by using the particle size difference between the nickel-based alloy powder and the oxide impurities to obtain a preliminary nickel-based alloy powder; S4, ultrasound: add the preliminary nickel-based alloy powder into water and perform ultrasound with an ultrasonic power of 25KW to cause the oxide impurities attached to the surface of the nickel-based alloy powder to fall off and be suspended in the water, and then sieve again, and then dry the sieve residue; repeat step S4 until the weight change of the sieve residue is less than 0.01g to obtain the nickel-based alloy powder.

[0032] [Example 2] A method for treating waste nickel-based alloy powder from 3D printing, which differs from [Example 1] in that step S1 is different. Step S1 in this embodiment is as follows: S1. Pretreatment: First, a 0.02 mol / L hydrochloric acid solution is used to acid-leach the nickel-based alloy waste powder with a particle size of 100-120 μm. The acid-leach time is 60 min. After separating the hydrochloric acid solution, a 0.01 mol / L sodium hydroxide solution is added to the nickel-based alloy waste powder for alkaline leaching. The alkaline leaching time is 30 min. After separating the sodium hydroxide solution, the solid is then washed and dried to obtain a pretreated nickel-based alloy powder.

[0033] [Example 3] A method for treating waste nickel-based alloy powder from 3D printing, which differs from [Example 1] in that step S1 is different. Step S1 in this embodiment is as follows: S1. Pretreatment: First, a 0.05 mol / L hydrochloric acid solution is used to acid-leach the nickel-based alloy waste powder with a particle size of 100-120 μm. The acid-leach time is 20 min. After separating the hydrochloric acid solution, a 0.02 mol / L sodium hydroxide solution is added to the nickel-based alloy waste powder for alkaline leaching. The alkaline leaching time is 15 min. After separating the sodium hydroxide solution, the solid is then washed and dried to obtain a pretreated nickel-based alloy powder.

[0034] [Example 4] A method for treating waste powder of nickel-based alloy for 3D printing, which differs from [Example 3] in that: the acid leaching and alkali leaching in step S1 are respectively carried out in ultrasonic equipment, and the ultrasonic power is 18KW.

[0035] [Example 5] A method for treating waste nickel-based alloy powder from 3D printing, which differs from [Example 4] in that step S2 is different. In this embodiment, step S2 is as follows: S2. Spraying: Spray the pretreated nickel-based alloy powder onto a plate with a hardness of 240 HB, and control the spraying pressure to 0.25 MPa, the spraying distance to 100 cm, and then collect the sprayed material.

[0036] [Example 6] A method for treating waste nickel-based alloy powder from 3D printing, which differs from [Example 5] in that step S2 is different. In this embodiment, step S2 is as follows: S2. Spraying: Spray the pretreated nickel-based alloy powder onto a plate with a hardness of 240 HB, and control the spraying pressure to 0.25 MPa, the spraying distance to 70 cm, and then collect the sprayed material.

[0037] [Example 7] A method for treating waste nickel-based alloy powder from 3D printing, which differs from [Example 5] in that step S2 is different. In this embodiment, step S2 is as follows: S2. Spraying: Spray the pretreated nickel-based alloy powder onto a plate with a hardness of 240 HB, and control the spraying pressure to 0.35 MPa, the spraying distance to 70 cm, and then collect the sprayed material.

[0038] [Example 8] A method for treating waste nickel-based alloy powder from 3D printing, which differs from [Example 5] in that step S2 is different. In this embodiment, step S2 is as follows: S2. Spraying: Spray the pretreated nickel-based alloy powder onto a plate with a hardness of 240 HB, and control the spraying pressure to 0.45 MPa, the spraying distance to 70 cm, and then collect the sprayed material.

[0039] Comparative Example [Comparative Example 1] A method for treating waste nickel-based alloy powder from 3D printing, which differs from [Example 1] in that step S1 is omitted.

[0040] [Comparative Example 2] A method for treating waste nickel-based alloy powder from 3D printing, which differs from [Example 1] in that the acid leaching step in step S1 is omitted.

[0041] [Comparative Example 3] A method for treating waste nickel-based alloy powder from 3D printing, which differs from [Example 1] in that the alkaline leaching step in step S1 is omitted.

[0042] [Comparative Example 4] A method for treating waste nickel-based alloy powder from 3D printing, which differs from [Example 1] in that step S4 is omitted.

[0043] Performance testing 1. Oxygen content: The nickel-based alloy powder obtained in step S4 of each embodiment and comparative example was randomly selected for oxygen content testing, wherein the lower the oxygen content, the higher the purity of the nickel-based alloy powder. In this application, an oxygen content lower than 1200 ppm is qualified.

[0044] 2. Nickel content: Oxide impurities screened out in step S3 of each embodiment and comparative example were randomly selected for nickel content testing, wherein the higher the nickel content, the greater the loss of nickel-based alloy.

[0045] Table 1 S4 step nickel-based alloy powder Oxygen content / ppm Example 1 1125 Example 2 1089 Example 3 1066 Example 4 948 Example 5 825 Example 6 445 Example 7 413 Example 8 402 Comparative Example 1 1658 Comparative Example 2 1425 Comparative Example 3 1511 Comparative Example 4 1322 Table 2 The difference between Comparative Examples 1-3 and Example 1 is that: Comparative Example 1 omits step S1, Comparative Example 2 omits the acid leaching step in step S1, and Comparative Example 3 omits the alkali leaching step in step S1. Combined with the test data in Table 1, it can be seen that omitting the acid leaching or alkali leaching step easily leads to an increase in the oxygen content in the nickel-based alloy powder. The reason may be that when the acid leaching or alkali leaching step is omitted, the particle size of the oxide impurities is uneven, and some oxide impurities cannot be separated by screening due to their large diameter, which is not conducive to effectively reducing the oxygen content.

[0046] The difference between Comparative Example 4 and Example 1 is that the ultrasonic step in S4 is omitted in Comparative Example 4. Combined with the detection data in Table 1, it can be seen that omitting the ultrasonic step in S4 easily leads to the inability to remove oxide impurities adhering to the surface of the nickel-based alloy powder, resulting in an increase in the oxygen content in the nickel-based alloy powder.

[0047] The difference between Example 4 and Example 3 is that in Example 4, ultrasonic vibration operation is added to the acid leaching and alkali leaching in step S1. Combined with the detection data in Table 1, it can be seen that the acid leaching and alkali leaching are both carried out in an ultrasonic device, which is conducive to breaking and shedding the surface oxide layer of the nickel-based alloy waste powder in step S2 and further refining the particle size of the oxide knocked off in step S2, increasing the particle size difference between the nickel-based alloy powder and the oxide impurities, and facilitating the separation of the oxide impurities from the nickel-based alloy powder in step S3, thereby further reducing the oxygen content in the nickel-based alloy powder.

[0048] The difference between Examples 5-8 is that the injection pressure and injection distance in step S2 are different. Combined with the detection data in Table 1, it can be seen that controlling the injection pressure of step S2 to 0.25-0.35 MPa and the injection distance to 65-75 cm can increase the particle size difference between the nickel-based alloy powder and the oxide impurities while reducing the defect problem of the nickel-based alloy powder caused by impact crushing, thereby reducing the loss of the nickel-based alloy powder.

[0049] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A method for treating waste nickel-based alloy powder from 3D printing, characterized in that: The following steps are involved: S1, pretreatment: firstly, acid leaching the nickel-based alloy waste powder with acid solution, and after separating the acid solution, adding alkali solution to the nickel-based alloy waste powder for alkali leaching, and then washing and drying to obtain pretreated nickel-based alloy powder; S2, spraying: spraying the pretreated nickel-based alloy powder onto the plate, and then collecting the sprayed material; S3, screening: screening the sprayed material, separating the oxide impurities by using the particle size difference between the nickel-based alloy powder and the oxide impurities, and obtaining a preliminary nickel-based alloy powder; S4, ultrasound: adding the preliminary nickel-based alloy powder to water and ultrasound-treating it to cause the oxide impurities attached to the surface of the nickel-based alloy powder to fall off and be suspended in the water, and then sieving again, and then drying the sieve residue; repeating step S4 until the weight change of the sieve residue is less than 0.01g, to obtain the nickel-based alloy powder.

2. The method for treating waste nickel-based alloy powder produced by 3D printing according to claim 1, characterized in that: In step S1, the acid solution is any one of a hydrochloric acid solution or a sulfuric acid solution, the acid concentration in the acid solution is controlled at 0.02-0.05 mol / L, and the acid leaching time is 20-60 min.

3. The method for treating waste nickel-based alloy powder produced by 3D printing according to claim 1, characterized in that: In step S1, the alkali solution is any one of a sodium hydroxide solution or a potassium hydroxide solution, the concentration of the alkali in the alkali solution is controlled at 0.01-0.02 mol / L, and the alkali leaching time is 15-30 min.

4. The method for treating waste nickel-based alloy powder produced by 3D printing according to claim 3, characterized in that: In step S1, fatty alcohol polyoxyethylene ether is also added to the alkali solution, and the mass concentration of the fatty alcohol polyoxyethylene ether is 0.01-0.02%.

5. The method for treating waste nickel-based alloy powder produced by 3D printing according to claim 1, characterized in that: In step S1, the acid leaching and the alkali leaching are both carried out in an ultrasonic device with an ultrasonic power of 15-20 KW.

6. The method for treating waste nickel-based alloy powder produced by 3D printing according to claim 1, characterized in that: In step S2, the hardness of the plate is 240-280 HB.

7. The method for treating waste nickel-based alloy powder produced by 3D printing according to claim 1, characterized in that: In step S2, the spraying pressure is 0.25-0.45 MPa, and the spraying distance is 45-100 cm.

8. The method for treating waste nickel-based alloy powder produced by 3D printing according to claim 7, characterized in that: In step S2, the spraying pressure is 0.25-0.35 MPa, and the spraying distance is 65-75 cm.

9. The method for treating waste nickel-based alloy powder produced by 3D printing according to claim 1, characterized in that: In step S1, the particle size of the nickel-based alloy waste powder is 100-120 μm, and in steps S3 and S4, the aperture of the screen used for screening is 75-80 μm.

10. The method for treating waste nickel-based alloy powder for 3D printing according to claim 1, characterized in that: In step S4, the ultrasonic treatment power of the spray is 25-30KW.

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