阅读说明：本技术 3d打印用镍基合金粉末的制备方法 (Preparation method of nickel-based alloy powder for 3D printing ) 是由 沈宝祥 于 2019-09-26 设计创作，主要内容包括：本发明提出了一种3D打印用镍基合金粉末的制备方法,包括以下步骤：1)原料准备：按照重量百分数计算,称取铁粉10～18％、铜粉2～5％、锆粉0.6～1.3％、钨粉4～8％、钛粉4.6～7.8％及锡粉3～6％,余量为镍粉；2)预处理：将原料加入真空感应炉并加入精炼剂熔炼,熔炼结束后,得纯化液；3)雾化；4)脱氧：将筛选后的粉末,进行脱氧处理,得到金属粉末。该方法制备的镍基合金粉末具有含氧量低、球形度高、空心球率低的优点。(The invention provides a preparation method of nickel-based alloy powder for 3D printing, which comprises the following steps: 1) preparing raw materials: weighing 10-18% of iron powder, 2-5% of copper powder, 0.6-1.3% of zirconium powder, 4-8% of tungsten powder, 4.6-7.8% of titanium powder, 3-6% of tin powder and the balance of nickel powder according to weight percentage; 2) pretreatment: adding the raw materials into a vacuum induction furnace, adding a refining agent, smelting, and obtaining a purified liquid after smelting is finished; 3) atomizing; 4) and (3) deoxidation: and deoxidizing the screened powder to obtain the metal powder. The nickel-based alloy powder prepared by the method has the advantages of low oxygen content, high sphericity and low hollow sphere rate.)

1. The preparation method of the nickel-based alloy powder for 3D printing is characterized by comprising the following steps of:

1) preparing raw materials: weighing 10-18% of iron powder, 2-5% of copper powder, 0.6-1.3% of zirconium powder, 4-8% of tungsten powder, 4.6-7.8% of titanium powder, 3-6% of tin powder and the balance of nickel powder according to weight percentage;

2) pretreatment: adding the raw materials into a vacuum induction furnace, adding a refining agent, smelting, and obtaining a purified liquid after smelting is finished;

3) atomizing: preparing the purified liquid into alloy powder by an atomization powder preparation method, wherein the technological parameters of the atomization powder preparation method are as follows: the temperature of powder spraying is 1450-1560 ℃, the heat preservation time is 10-26 min, the mass flow rate is 2-4 kg/min, the powder spraying gas is nitrogen, and the powder spraying pressure is 4-10 MPa; carrying out vacuum drying and grading screening on the alloy powder;

4) and (3) deoxidation: and deoxidizing the screened powder to obtain the metal powder.

2. The method for preparing the nickel-based alloy powder for 3D printing according to claim 1, wherein the refining agent is composed of the following components in percentage by weight:

CaSi₂ 10～20％、WC 5～10％、Na₂SiF₆3-6% of barium silicate, 4-8% of barium silicate and the balance of NaCl.

3. The method for preparing the nickel-based alloy powder for 3D printing according to claim 1, wherein the particle size of the iron powder is 60 to 80 μm, the particle size of the copper powder is 40 to 70 μm, the particle size of the zirconium powder is 20 to 40 μm, the particle size of the tungsten powder is 30 to 50 μm, the particle size of the titanium powder is 45 to 65 μm, the particle size of the tin powder is 30 to 50 μm, and the particle size of the nickel powder is 75 to 95 μm.

4. The method for preparing nickel-based alloy powder for 3D printing according to claim 1, wherein the deoxidation treatment of the step 4) is to deoxidize the screened alloy powder at a low temperature and then to keep it at a high temperature.

5. The method for preparing the nickel-based alloy powder for 3D printing according to claim 4, wherein the low temperature is 300 to 400 ℃ and the high temperature is 500 to 600 ℃.

Technical Field

The invention belongs to the technical field of 3D printing, and particularly relates to a preparation method of nickel-based alloy powder for 3D printing.

Background

The metal raw materials commonly used for 3D printing are divided into a powder form and a wire form, and the metal powder can be used for various 3D printing processes such as Selective Laser Melting (SLM), near net laser forming (LENS), selective Electron Beam Melting (EBM) and the like, so that the metal powder is a material commonly used in 3D printing. The 3D metal printing material mainly comprises powder and metal wires, and the metal powder is more widely applied. The method for preparing the superfine metal powder mainly comprises a ball milling method, a jet milling method, a plasma rotating electrode method, a physical and chemical method and a gas atomization method.

Gas atomization is one of the major methods for producing ultra-fine metal and alloy powders. The basic principle of gas atomization is the process of breaking up a liquid metal stream into small droplets with a high velocity gas stream and solidifying into a powder. The existing gas atomization method adopts gas for atomization in an atomization stage, and the gas flow velocity of the gas is low, so that the prepared metal or alloy powder has coarse granularity (the yield of the powder with the granularity of 50 mu m is about 30 percent), the powder preparation with the granularity of less than 50 mu m and even finer needs to be pressurized, and the yield of the powder with the granularity of 20 mu m prepared by pressurization is only about 10 percent.

The nickel-based high-temperature alloy has excellent high-temperature corrosion resistance, fatigue resistance, wear resistance and high strength. In order to improve the utilization rate of powder materials, the nickel-based high-temperature alloy powder for laser forming is mainly prepared by an air atomization method at present. However, the nickel-based superalloy has complex components and high melting point, and very complex physical and chemical changes in the gas atomization process, so that the defect of powder hollowness is easily caused, and gas inclusion is caused. Meanwhile, the powder required by laser forming in the powder bed selection area has the particle size of less than 45 μm, large specific surface area, easy oxygen adsorption and increased oxygen content, which leads to the performance reduction of the formed sample. At present, satellite powder and non-metal impurities can also appear in the powder prepared by the AA method, the yield of fine powder (the particle size is less than 50 mu m) is lower and generally does not exceed 40 percent, and the production cost of laser forming in a powder bed selection area is increased; the powder with the grain diameter of 45-106 mu m required by laser cladding forming often has more hollow defects, and the defects are easy to become crack sources in the laser forming process, so that the quality and the performance of a formed sample are reduced.

Disclosure of Invention

The invention provides a preparation method of nickel-based alloy powder for 3D printing, and the nickel-based alloy powder prepared by the method has the advantages of low oxygen content, high sphericity and low hollow sphere rate.

The technical scheme of the invention is realized as follows:

a preparation method of nickel-based alloy powder for 3D printing comprises the following steps:

1) preparing raw materials: weighing 10-18% of iron powder, 2-5% of copper powder, 0.6-1.3% of zirconium powder, 4-8% of tungsten powder, 4.6-7.8% of titanium powder, 3-6% of tin powder and the balance of nickel powder according to weight percentage;

2) pretreatment: adding the raw materials into a vacuum induction furnace, adding a refining agent, smelting, and obtaining a purified liquid after smelting is finished;

3) atomizing: preparing the purified liquid into alloy powder by an atomization powder preparation method, wherein the technological parameters of the atomization powder preparation method are as follows: the temperature of powder spraying is 1450-1560 ℃, the heat preservation time is 10-26 min, the mass flow rate is 2-4 kg/min, the powder spraying gas is nitrogen, and the powder spraying pressure is 4-10 MPa; carrying out vacuum drying and grading screening on the alloy powder;

4) and (3) deoxidation: and deoxidizing the screened powder to obtain the metal powder.

Preferably, the refining agent consists of the following components in percentage by weight:

CaSi₂10～20％、WC 5～10％、Na₂SiF₆3-6% of barium silicate, 4-8% of barium silicate and the balance of NaCl.

Preferably, the particle size of the iron powder is 60-80 μm, the particle size of the copper powder is 40-70 μm, the particle size of the zirconium powder is 20-40 μm, the particle size of the tungsten powder is 30-50 μm, the particle size of the titanium powder is 45-65 μm, the particle size of the tin powder is 30-50 μm, and the particle size of the nickel powder is 75-95 μm.

Preferably, the deoxidation treatment of the step 4) is to deoxidize the screened alloy powder at a low temperature and then to keep the temperature at a high temperature.

Preferably, the low temperature is 300-400 ℃, and the high temperature is 500-600 ℃.

The invention has the beneficial effects that:

1. in the preparation method of the invention, a refining agent is added into the raw materials during smelting, particularly the refining agent in some embodiments is CaSi₂10～20％、WC 5～10％、Na₂SiF₆3-6% of barium silicate, 4-8% of barium silicate and the balance of NaCl, the probability that metals such as aluminum and alloys can contact and react with water can be reduced, and metal powder is reducedThe oxygen content in the end, in addition, is less than 150 ppm.

2. The preparation method of the invention selects iron powder, copper powder, zirconium powder, tungsten powder, titanium powder and tin powder, and the balance of nickel powder as raw material metal, prolongs the cooling and forming time of the molten metal liquid after being crushed into liquid drops by the atomizing gas, reduces the shrinkage cavity phenomenon and the probability of forming the hollow powder, and the hollow powder rate is only below 7.5%.

Detailed Description