Metal powder for laser additive manufacturing and method for producing and use thereof

Abstract

The application relates to the technical field of laser additive manufacturing, in particular to a metal powder for laser additive manufacturing and a preparation method and application thereof. The chemical composition of the metal powder comprises Ni, Fe, Cr and Cu; the content of the Fe is 3.0-5.0 wt%, and the content of the Cr is 10.0-15.0 wt%. The application solves the technical problem of high smelting cost of the existing cupronickel material, and improves the corrosion resistance and hardness of the cupronickel material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser additive manufacturing, in particular to a metal powder for laser additive manufacturing and a preparation method and application thereof. BACKGROUND

[0002] Additive manufacturing technology is a new manufacturing technology based on the principle of layered manufacturing, which directly manufactures digital models into physical parts by layer-by-layer accumulation of materials. The materials applied in laser additive manufacturing technology have covered titanium alloy, high-temperature alloy, iron-based alloy, aluminum alloy, refractory alloy, amorphous alloy, ceramic and gradient material, etc. According to the forming principle, the laser additive manufacturing technology is classified, and the most representative is the laser selective melting (SLM) with powder bed powdering as the technical feature and the laser metal direct forming (LMDF) with synchronous powder feeding as the technical feature.

[0003] B30 material, also known as white copper material, has good corrosion resistance and mechanical properties, and is suitable for marine manufacturing industry. At present, the addition of various alloy elements in B30 material increases the smelting cost. SUMMARY

[0004] The present application provides a metal powder for laser additive manufacturing and a preparation method and application thereof, to solve the technical problem of high smelting cost of existing white copper material.

[0005] In a first aspect, the present application provides a metal powder for laser additive manufacturing, the chemical composition of the metal powder comprising:

[0006] Ni, Fe, Cr and Cu; wherein,

[0007] The content of Fe is 3.0 wt% to 5.0 wt%, and the content of Cr is 10.0 wt% to 15.0 wt%.

[0008] Optionally, in the chemical composition of the metal powder, the content of Fe is 3.5 wt% to 4.0 wt%, and the content of Cr is 10.0 wt% to 12.0 wt%.

[0009] Optionally, in the chemical composition of the metal powder, the content of Ni is 29.0 wt% to 32.0 wt%.

[0010] Optionally, the particle size of the metal powder satisfies a normal distribution.

[0011] In a second aspect, the present application provides an application of the metal powder of the first aspect in laser additive manufacturing of white copper parts.

[0012] In a third aspect, the application provides a method for preparing a metal powder for laser additive manufacturing, for preparing the metal powder according to any one of the embodiments of the first aspect, the method comprising:

[0013] melting and stirring the raw material under a set temperature;

[0014] atomizing the raw material after melting and stirring under a set pressure of inert gas to obtain the metal powder.

[0015] Optionally, the set temperature is 1700-1900°C.

[0016] Optionally, the set pressure is 6 MPa.

[0017] Optionally, the inert gas comprises argon or helium.

[0018] The above technical solutions provided by the embodiments of the application have the following advantages compared with the prior art:

[0019] The metal powder for laser additive manufacturing provided by the embodiments of the application, on the basis of ensuring the formability of laser additive manufacturing, increases the Fe content to further improve the hardness of the material, increases the Cr content to further improve the corrosion resistance of the material, removes elements such as Mn, Pb, S, C, Zn, P, Si, Sn, etc. to reduce the cost, and improves the corrosion resistance and hardness of the material after processing, which is conducive to the application and promotion in the fields of marine engineering and shipbuilding. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the application and, together with the specification, serve to explain the principles of the application.

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, for those skilled in the art, other drawings can also be obtained based on these drawings without creative labor.

[0022] Figure 1 A flowchart of a method for preparing a metal powder for laser additive manufacturing according to the embodiments of the application;

[0023] Figure 2 The morphology of the metal powder for laser additive manufacturing according to Example 1 of the application;

[0024] Figure 3 The microstructure of the sample for laser additive manufacturing according to Example 1 of the application;

[0025] Figure 4 Metal powder topography for Example 1 of the present application laser additive manufacturing;

[0026] Figure 5 Microstructure of the laser additive manufacturing sample for Example 2 of the present application. DETAILED DESCRIPTION

[0027] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0028] Various embodiments of the present application can exist in the form of a range; it should be understood that the description in the form of a range is merely for the convenience and brevity, and should not be understood as a hard limit on the scope of the present application; therefore, it should be considered that the described range has specifically disclosed all possible sub-ranges and single values within the range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the described range, such as 1, 2, 3, 4, 5 and 6, which applies to any range. In addition, whenever a numerical range is indicated in this document, it refers to any cited number (fraction or integer) within the indicated range.

[0029] In the present application, the orientation words such as "upper" and "lower" are specifically the directions of the drawing surface in the drawings unless otherwise stated. In addition, in the description of the present application, the terms "include", "contain" and the like mean "including but not limited to". In the present text, the relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. In the present text, "and / or" describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent: the case of A alone, the case of A and B together, and the case of B alone. Wherein A, B can be singular or plural. In the present text, "at least one" means one or more, and "multiple" means two or more. "At least one", "at least one of the following" or the like means any combination of the items, including any combination of single item or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can represent: a, b, c, a-b (i.e. a and b), a-c, b-c, or a-b-c, wherein a, b, c can be single or multiple.

[0030] Unless otherwise specifically stated, the various raw materials, reagents, instruments and equipment used in the present application can be purchased on the market or can be prepared by existing methods.

[0031] In a first aspect, the present application provides a metal powder for laser additive manufacturing, the chemical composition of the metal powder comprising:

[0032] Ni, Fe, Cr and Cu; wherein,

[0033] The content of Fe is 3.0 wt% to 5.0 wt%, and the content of Cr is 10.0 wt% to 15.0 wt%.

[0034] B30 material, also known as white copper material, generally refers to a copper-nickel alloy containing 29-32% nickel, which has good corrosion resistance and mechanical properties and is suitable for marine manufacturing. Laser additive manufacturing is a fast and efficient manufacturing method with short manufacturing cycle and can realize the design and manufacturing of complex structures. With the increasing design requirements of copper-nickel alloy, the application of additive manufacturing to B30 material has a good development prospect. At present, the research on laser additive manufacturing of B30 and B30 quenched and tempered material is still blank, and there is no B30 component optimization for laser additive manufacturing design. The addition of various alloy elements in traditional B30 material increases the smelting cost, and there is still a demand for improving the corrosion resistance. In the embodiments of the present application, the composition of the white copper material is adjusted, and the elements such as Mn, Pb, S, C, Zn, P, Si and Sn are removed under the condition of meeting the performance requirements of B30 material, thereby optimizing the process and reducing the cost.

[0035] The positive effect of controlling the content of Fe to be 3.0-5.0 wt% is that a certain amount of strengthening phase can be formed, and the increased Fe content compared with the national standard can significantly improve the wear resistance. If the Fe content is too high, the weldability and formability of the material will be reduced to some extent; if the Fe content is too low, the wear resistance and hardness of the metal powder will be reduced to some extent. Specifically, the Fe content can be 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt%, 5.0 wt%, etc.

[0036] The positive effect of controlling the content of Cr to be 10.0-15.0 wt% is that the formability is ensured while better corrosion resistance is obtained. If the Cr content is too high, the cost will be increased and the formability will be affected to some extent; if the Cr content is too low, the corrosion resistance of the metal powder will be reduced to some extent. Specifically, the Cr content can be 10.0 wt%, 11.0 wt%, 12.0 wt%, 13.0 wt%, 14.0 wt%, 15.0 wt%, etc.

[0037] In some embodiments, in the chemical composition of the metal powder, the content of Fe is 3.5-4.0 wt%, and the content of Cr is 10.0-12.0 wt%.

[0038] In the embodiments of the present application, preferably, the Fe content can be 3.5 wt%, 3.6 wt%, 3.7 wt%, 3.8 wt%, 3.9 wt%, 4.0 wt%, etc.; and the Cr content can be 10.0 wt%, 11.0 wt%, 12.0 wt%, etc.

[0039] In some embodiments, in the chemical composition of the metal powder, the content of Ni is 29.0-32.0 wt%.

[0040] The positive effect of controlling the content of Ni to be 29.0 wt% to 32.0 wt% is to improve the strength, corrosion resistance, hardness, resistance and thermoelectricity of the metal powder, and to reduce the temperature coefficient of resistivity. Specifically, the content of Ni can be 29.0 wt%, 30.0 wt%, 31.0 wt%, 32.0 wt% and the like.

[0041] In some embodiments, the particle size of the metal powder satisfies a normal distribution.

[0042] In the embodiments of the present application, the particle size of the metal powder satisfies a normal distribution, and the particle size of the metal powder is sieved according to different process requirements of laser additive manufacturing, and is used for laser coaxial powder feeding additive manufacturing samples or laser selective melting additive manufacturing samples. For specific parameters, see Embodiments 1-2. The metal powder has a spherical micro-morphology, which can be seen from Figure 2 、 Figure 4 .

[0043] In a second aspect, based on the same inventive concept, the embodiments of the present application provide an application of the metal powder of the first aspect in laser additive manufacturing of white copper parts.

[0044] The application of the metal powder of the first aspect in laser additive manufacturing of white copper parts reduces the cost of raw materials, optimizes the process, improves the corrosion resistance of the parts after processing, and is beneficial to the application and promotion in the fields of marine engineering and shipbuilding.

[0045] In a third aspect, based on the same inventive concept, the present application provides a preparation method of a metal powder for laser additive manufacturing, which is used to prepare the metal powder of any one of the embodiments of the first aspect. Please see Figure 1 , the method comprises:

[0046] S1, under a set temperature, melting and stirring the raw material;

[0047] S2, under the condition of inert gas with a set pressure, gas atomization powdering the raw material after melting and stirring to obtain a metal powder.

[0048] In the embodiments of the present application, the raw material can be one of the above metal powders for laser additive manufacturing. The melting and stirring is carried out in a vacuum, and the melting method is to melt in a crucible by using electrode induction heating, and then to stir the raw material in a molten state. "Gas atomization powdering" refers to breaking the liquid metal stream into small droplets by high-speed gas flow, and then rapidly condensing to obtain a shaped powder. The positive effect of inert gas is to ensure the surface quality of the metal powder.

[0049] In some embodiments, the set temperature is 1700℃ to 1900℃.

[0050] The "set temperature" refers to the temperature of smelting, and the positive effect of controlling the temperature of smelting is to ensure sufficient melting of raw materials. If the smelting temperature is too high, it will waste cost to some extent; if the smelting temperature is too low, it will not ensure sufficient melting to some extent. Specifically, the smelting temperature can be 1700℃, 1750℃, 1800℃, 1850℃, 1900℃, etc. In the embodiments of the present application, the smelting temperature is preferably 1780℃.

[0051] In some embodiments, the set pressure is 6 MPa.

[0052] The "set pressure" refers to the pressure of inert gas, and the positive effect of controlling the pressure of inert gas to 6 MPa is that the metal powder has good morphology; if the inert gas pressure is too high, it will cause the metal droplet flow rate to be too fast to some extent, the powder per unit time is less, and the morphology is affected; if the inert gas pressure is too low, it will cause the droplet flow rate to be slow and uneven to some extent, affecting the morphology.

[0053] In some embodiments, the inert gas includes argon or helium.

[0054] In the embodiments of the present application, the inert gas can be argon or helium to obtain metal powder with good morphology.

[0055] The laser additive manufacturing metal powder is realized based on the preparation method of the laser additive manufacturing metal powder described above. The specific steps of the preparation method of the laser additive manufacturing metal powder can refer to the above embodiments. Since the laser additive manufacturing metal powder adopts part or all of the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0056] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present application and not to limit the scope of the present application. The experimental methods not specified in the following examples are generally determined according to national standards. If there is no corresponding national standard, the international standard, the conventional condition, or the condition suggested by the manufacturer is used.

[0057] Table 1 Chemical composition (wt%) of laser additive manufacturing metal powder of the embodiments

[0058] Serial number Ni Fe Cr Cu Example 1 30 3.5 10 Balance Example 2 32 4 12 Balance Example 3 29 3.0 13 Balance

[0059] Table 2 Chemical composition (wt%) of laser additive manufacturing metal powder of the comparative examples

[0060] Serial number Ni Fe Mn Pb P S C Si Zn Sn Cu Comparative Example 1 31 0.8 1.2 0.05 - 0.01 0.01 0.01 - - Balance

[0061] From Table 1 and Table 2, it can be seen that the addition of various alloying elements of the existing B30 material increases the smelting cost, and the method adjusts the composition used, removes elements such as Mn, Pb, S, C, Zn, P, Si, Sn, and the like under the condition of meeting the required performance of the B30 material, optimizes the process, and reduces the cost.

[0062] In the present application, the preparation method of the metal powder for laser additive manufacturing in Examples 1-2 is described in detail:

[0063] Example 1

[0064] After mixing the raw materials according to the chemical composition, high-temperature smelting and stirring are performed in a vacuum, the temperature is 1780℃, and then gas atomization is performed using 6MPa argon gas to prepare the powder. Subsequently, the powder is sieved to obtain a particle size of 50μm-150μm.

[0065] The above-mentioned metal powder for laser additive manufacturing is used for laser coaxial powder feeding additive manufacturing samples;

[0066] The process parameters of the laser coaxial powder feeding additive manufacturing samples are shown in Table 3:

[0067] Table 3 Process parameters of laser coaxial powder feeding additive manufacturing samples

[0068] Power (w) Scan rate (mm / s) Overlap amount (%) Spot size (pm) Layer thickness (pm) 1600 20 60％ 4500 800

[0069] The microstructure of the cladding layer is as shown in Figure 3 From Figure 3 It can be seen that no defects such as pores, cracks, and poor fusion are found in the microstructure, and the microstructure is uniform and refined.

[0070] Example 2, the metal powder for laser additive manufacturing is composed of the following mass fraction of chemical composition:

[0071] Ni: 32%, Fe: 4%, Cr: 12%, and Cu: balance

[0072] After mixing the raw materials according to the chemical composition, high-temperature smelting and stirring are performed in a vacuum, the temperature is 1780℃, and then gas atomization is performed using 6MPa argon gas to prepare the powder.

[0073] Subsequently, the powder is sieved to obtain a particle size of 30μm-50μm.

[0074] The above-mentioned metal powder for laser additive manufacturing is used for laser selective melting additive manufacturing samples;

[0075] The process parameters of the laser selective melting additive manufacturing samples are shown in Table 4:

[0076] Table 4 Process parameters for laser selective melting additive manufacturing samples

[0077] Power (w) Scan rate (mm / s) Overlap amount (%) Spot size (pm) Layer thickness (pm) 400 200 65％ 100 100

[0078] The microstructure of the cladding layer, such as Figure 5 As shown, from Figure 5 It can be seen that no defects such as pores, cracks, or poor fusion were found in the microstructure, and the structure is relatively uniform and fine.

[0079] Table 5 Corrosion resistance of Examples 1-3 and Comparative Example 1

[0080] Serial number Corrosion rate (mm / a) Hardness (HB) Example 1 0.032 102 Example 2 0.025 120 Example 3 0.022 98 Comparative Example 1 0.14 76

[0081] The corrosion resistance test method was as follows: the prepared samples were subjected to a full immersion corrosion test using natural seawater as the medium at a temperature of 20±3℃ for a period of 336 hours, with the medium being replaced every 7 days. Table 5 shows that the metal powder in this embodiment exhibits a lower corrosion rate and higher hardness.

[0082] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A metal powder for laser additive manufacturing, characterized in that, The chemical composition of the metal powder consists of: It is composed of Ni, Fe, Cr, and Cu; among which, The Fe content is 3.0% to 5.0% by weight, the Cr content is 10.0% to 15.0% by weight, the Ni content is 29.0% to 32.0% by weight, and the balance is Cu. The particle size of the metal powder follows a normal distribution; The method for preparing the metal powder for laser additive manufacturing includes: Under a set temperature condition, the raw materials are melted and stirred; Under the condition of an inert gas with a set pressure, the raw material after melting and stirring is atomized into powder to obtain metal powder. The set temperature is 1700℃~1900℃; The set pressure is 6 MPa; The inert gas is argon or helium.

2. The metal powder according to claim 1, characterized in that, The metal powder contains 3.5% to 4.0% Fe and 10.0% to 12.0% Cr.

3. The application of the metal powder according to claim 1 or 2 in laser additive manufacturing of cupronickel parts.

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