Laser additive and method of manufacturing thereof

Abstract

The application relates to the technical field of laser additive manufacturing, in particular to a laser additive and a manufacturing method thereof. The preparation raw material of the laser additive is modified raw material, the modified raw material is prepared by mixing modified ceramic powder and metal powder and adding a modified additive; wherein the weight ratio of the modified ceramic powder and the metal powder is 1-3:10; the modified raw material is prepared by the following method: uniformly mixing ceramic powder and metal powder with water to obtain a mixture; adding a modified additive into the mixture and uniformly mixing to obtain a mixed slurry; putting the mixed slurry into a ball mill for ball milling for 1-3 hours to obtain a ball-milled slurry; filtering and drying the ball-milled slurry to obtain the modified raw material. The application can directly obtain good compactness, and solves the technical problem that the existing technology needs to separately use metal powder outside the mixed powder and realizes the technical problem through repeated preparation in multiple steps.

Description

Technical Field

[0001] This invention relates to the field of laser additive manufacturing technology, specifically to a laser additive manufacturing method therein. Background Technology

[0002] Additive manufacturing is a process of building objects by adding layers of materials together using 3D data models. It is characterized by high processing precision, short manufacturing cycles, excellent physical and chemical properties of the products, and the ability to integrate design and manufacturing, thus leading to its rapid development.

[0003] Additive manufacturing of metallic materials is the most challenging technology in the field of additive manufacturing; in particular, the preparation of cermet additives by adding ceramic powder to a metal matrix to improve the overall performance of metallic additives is even more difficult. Currently, the main methods for additive manufacturing of metallic materials include laser additive manufacturing, electron beam additive manufacturing, and arc additive manufacturing.

[0004] Chinese invention patent 201810820848.7 discloses a laser additive manufacturing method, which includes the following steps: S1 heating a metal-ceramic composite material to prepare a metal-ceramic layer of thickness s. Due to the presence of ceramics, the prepared metal-ceramic layer has pores; S2 heating a metal material to melt it, and the molten metal material fills the pores under the action of gravity and capillary force to obtain a dense solid layer; S3 repeating steps S1 and S2 to complete the preparation of each dense solid layer to obtain a high-density metal-ceramic composite part. Although this patent can prepare metal-ceramic additives with high density, it requires the separate use of metal powder in addition to the mixed powder, and requires repeated preparation through multiple steps. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a laser additive manufacturing method thereof.

[0006] The technical problem to be solved by this invention is achieved by the following technical solution:

[0007] A laser additive manufacturing process is provided, wherein the raw material is a modified raw material, which is prepared by mixing modified ceramic powder and metal powder and then adding a modifying agent; wherein the weight ratio of the modified ceramic powder to the metal powder is 1 to 3:10.

[0008] Preferably, the modified raw material is prepared as follows:

[0009] Step (S11) involves mixing the modified ceramic powder and metal powder with water to obtain a uniform mixture;

[0010] Step (S12) involves adding a modifying agent to the mixture and mixing it thoroughly to obtain a mixed slurry;

[0011] Step (S13) The mixed slurry is placed in a ball mill and ball-milled for 1 to 3 hours to obtain a ball-milled slurry;

[0012] Step (S14) involves filtering and drying the ball-milled slurry to obtain the modified raw material.

[0013] Preferably, in step (S1), the total weight ratio of the modified ceramic powder and metal powder to the weight ratio of water is 1:1 to 2.

[0014] Preferably, the weight ratio of the mixture to the modifying agent in step (S2) is 100:5 to 10.

[0015] Preferably, the weight ratio of the mixture to the modifying agent is 100:8.

[0016] Preferably, the modifying agent in step (S2) is composed of triethanolamine monostearate and sodium cocoyl oxyethyl sulfonate, and the weight ratio of triethanolamine monostearate to sodium cocoyl oxyethyl sulfonate is 1-3:1-3.

[0017] Preferably, the weight ratio of the modified ceramic powder to the metal powder is 2:10.

[0018] Preferably, the modified ceramic powder is prepared by modifying silicon dioxide powder and boron carbide powder in a weight ratio of 1 to 2:1. The preparation method of the modified ceramic powder is as follows:

[0019] Step (S21) Take silica powder and boron carbide powder, mix them, add them to water and disperse them evenly to obtain a dispersion;

[0020] Step (S22): Add neodymium nitrate hexahydrate and ammonium fluoride to the dispersion and stir for 2-4 hours. After stirring, evaporate the solvent in the reaction solution to obtain a solid product.

[0021] In step (S23), the solid product is first calcined at 500-700°C for 3-5 hours in a nitrogen atmosphere, and then calcined at 1400-1600°C for 3-5 hours to obtain modified ceramic powder.

[0022] Preferably, the metal powder is aluminum powder.

[0023] A method for manufacturing laser additives, used to manufacture the aforementioned laser additives, includes the following steps: laying the raw material flat on a substrate, and using a laser with a power of 1000W at a scanning speed of 1000mm / s to melt and process the raw material to obtain the laser additive.

[0024] The beneficial effects of this invention are:

[0025] This invention provides a laser additive manufacturing method, which uses modified raw materials composed of aluminum powder, silicon dioxide powder and boron carbide powder to prepare laser additives. This method can directly achieve better density and solves the technical problem that existing methods require the separate use of metal powders in addition to mixed powders and repeated preparation through multiple steps. Detailed Implementation

[0026] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to embodiments.

[0027] A laser additive manufacturing process is provided, wherein the raw material is a modified raw material, which is prepared by mixing modified ceramic powder and metal powder and then adding a modifying agent; wherein the weight ratio of the modified ceramic powder to the metal powder is 1 to 3:10.

[0028] Research has shown that the selection of metal raw materials and ceramic powders plays a significant role in the density of the prepared metal-ceramic additives during the manufacturing process.

[0029] The modified raw material is prepared as follows:

[0030] Step (S11) involves mixing the modified ceramic powder and metal powder with water to obtain a uniform mixture;

[0031] Step (S12) involves adding a modifying agent to the mixture and mixing it thoroughly to obtain a mixed slurry;

[0032] Step (S13) The mixed slurry is placed in a ball mill and ball-milled for 1 to 3 hours to obtain a ball-milled slurry;

[0033] Step (S14) involves filtering and drying the ball-milled slurry to obtain the modified raw material.

[0034] Furthermore, in step (S1), the total weight ratio of the modified ceramic powder and metal powder to the weight ratio of water is 1:1 to 2.

[0035] Further, in step (S2), the weight ratio of the mixture to the modifying agent is 100:5 to 10.

[0036] Furthermore, the weight ratio of the mixture to the modifying agent is 100:8.

[0037] Further, in step (S2), the modifying agent is composed of triethanolamine monostearate and sodium cocoyl oxyethyl sulfonate, with a weight ratio of triethanolamine monostearate to sodium cocoyl oxyethyl sulfonate of 1-3:1-3.

[0038] Furthermore, the weight ratio of the modified ceramic powder to the metal powder is 2:10.

[0039] Furthermore, the modified ceramic powder is prepared by modifying silicon dioxide powder and boron carbide powder in a weight ratio of 1 to 2:1. The preparation method of the modified ceramic powder is as follows:

[0040] Step (S21) Take silica powder and boron carbide powder, mix them, add them to water and disperse them evenly to obtain a dispersion;

[0041] Step (S22): Add neodymium nitrate hexahydrate and ammonium fluoride to the dispersion and stir for 2-4 hours. After stirring, evaporate the solvent in the reaction solution to obtain a solid product.

[0042] In step (S23), the solid product is first calcined at 500-700°C for 3-5 hours in a nitrogen atmosphere, and then calcined at 1400-1600°C for 3-5 hours to obtain modified ceramic powder.

[0043] Further, in step (S21), the total weight ratio of silicon dioxide powder and boron carbide powder to water is 1:4 to 6.

[0044] Further, in step (S21), the total weight ratio of silicon dioxide powder and boron carbide powder to water is 1:5.

[0045] Further, in step (S22), the weight ratio of the dispersion to neodymium nitrate hexahydrate and ammonium fluoride is 1000:43:3.7.

[0046] The metal powder is aluminum powder.

[0047] A method for manufacturing laser additives, used to manufacture the aforementioned laser additives, includes the following steps: laying the raw material flat on a substrate, and using a laser with a power of 1000W at a scanning speed of 1000mm / s to melt and process the raw material to obtain the laser additive.

[0048] To demonstrate that using modified ceramic powder obtained by modifying silicon dioxide powder and boron carbide powder in this invention to replace unmodified ceramic powder, and preparing modified raw materials by mixing modified ceramic powder and aluminum powder with modifying additives, and using laser additives prepared with modified raw materials, can significantly improve the density of the prepared metal-ceramic additives compared with laser additives prepared by existing technologies, thus giving the prepared metal-ceramic additives a higher degree of fabrication, the following five sets of experiments were conducted.

[0049] Experiment 1:

[0050] The unmodified raw material is selected from the mixture of unmodified ceramic powder and metal powder in a weight ratio of 2:10. The unmodified ceramic powder is composed of silicon dioxide powder and boron carbide powder in a weight ratio of 1:1, and the metal powder is aluminum powder.

[0051] Laser additive manufacturing: Unmodified raw materials are laid flat on a substrate, and a 1000W laser is used to melt the raw materials at a scanning speed of 1000mm / s to obtain metal-ceramic additives, namely laser additives.

[0052] Experiment 2:

[0053] The modified raw material was prepared by mixing unmodified ceramic powder and metal powder with a modifying agent. The weight ratio of unmodified ceramic powder to metal powder was 2:10; the weight ratio of the total weight of unmodified ceramic powder and metal powder to water was 1:1.5; the unmodified ceramic powder consisted of silicon dioxide powder and boron carbide powder in a weight ratio of 1:1; the weight ratio of the mixture to the modifying agent was 100:8; the modifying agent was prepared as triethanolamine monostearate; and the mixture was ball-milled for 2 hours.

[0054] Laser additive manufacturing: The modified raw materials described above are laid flat on a substrate, and a laser with a power of 1000W is used to melt and process the raw materials at a scanning speed of 1000mm / s to obtain metal-ceramic additives, namely laser additives.

[0055] Experiment 3:

[0056] The modified raw material was prepared by mixing unmodified ceramic powder and metal powder with a modifying agent. The weight ratio of unmodified ceramic powder to metal powder was 2:10; the weight ratio of the total weight of unmodified ceramic powder and metal powder to water was 1:1.5; the unmodified ceramic powder consisted of silicon dioxide powder and boron carbide powder in a weight ratio of 1:1; the weight ratio of the mixture to the modifying agent was 100:8; the modifying agent was sodium cocoyl oxyethyl sulfonate; and the mixture was ball-milled for 2 hours.

[0057] Laser additive manufacturing: The modified raw materials described above are laid flat on a substrate, and a laser with a power of 1000W is used to melt and process the raw materials at a scanning speed of 1000mm / s to obtain metal-ceramic additives, namely laser additives.

[0058] Experiment 4:

[0059] The modified raw material was prepared by mixing unmodified ceramic powder and metal powder with a modifying agent. The weight ratio of unmodified ceramic powder to metal powder was 2:10; the weight ratio of the total weight of unmodified ceramic powder and metal powder to water was 1:1.5; the unmodified ceramic powder consisted of silica powder and boron carbide powder in a weight ratio of 1:1; the weight ratio of the mixture to the modifying agent was 100:8; the modifying agent was prepared by mixing triethanolamine monostearate and sodium cocoyl oxyethyl sulfonate in a weight ratio of 1:1; and the mixture was ball-milled for 2 hours.

[0060] Laser additive manufacturing: The modified raw materials described above are laid flat on a substrate, and a laser with a power of 1000W is used to melt and process the raw materials at a scanning speed of 1000mm / s to obtain metal-ceramic additives, namely laser additives.

[0061] Experiment 5:

[0062] The modified raw material is prepared by mixing modified ceramic powder and metal powder with a modifying agent, wherein the weight ratio of modified ceramic powder to metal powder is 2:10; the weight ratio of the total weight of modified ceramic powder and metal powder to water is 1:1.5; the weight ratio of the mixture to the modifying agent is 100:8; and the modifying agent is composed of triethanolamine monostearate and sodium cocoyl oxyethyl sulfonate in a weight ratio of 1:1.

[0063] The selected modified ceramic powder was prepared by mixing silica powder and boron carbide powder in a weight ratio of 1:1 and dispersing them evenly in water to obtain a dispersion. The total weight ratio of silica powder and boron carbide powder to water was 1:5. Neodymium nitrate hexahydrate and ammonium fluoride were added to the dispersion and stirred for 3 hours. After stirring, the solvent in the reaction solution was evaporated to dryness to obtain a solid product. The weight ratio of the dispersion to neodymium nitrate hexahydrate and ammonium fluoride was 1000:43:3.7. The solid product was calcined at 600°C for 4 hours in a nitrogen atmosphere and then calcined at 1450°C for 4 hours to obtain the final product.

[0064] Laser additive manufacturing: The modified raw materials described above are laid flat on a substrate, and a laser with a power of 1000W is used to melt and process the raw materials at a scanning speed of 1000mm / s to obtain metal-ceramic additives, namely laser additives.

[0065] The following table shows the density results after the above five sets of experiments.

[0066] Density Laser additive manufacturing process prepared in Experiment 1 80.8％ Laser additive manufacturing process prepared in Experiment 2 85.9％ Laser additive manufacturing process prepared in Experiment 3 87.1％ Laser additive manufacturing process prepared in Experiment 4 96.5％ Laser additive manufacturing process prepared in Experiment 5 99.2％

[0067] As can be seen from the density experiment results in the table above, the density of the laser additives prepared in Experiments 2 and 3 is improved compared to that prepared in Experiment 1. This indicates that, in the manufacturing process of laser additives, the modified raw materials obtained by modifying the raw materials composed of aluminum powder, silicon dioxide powder, and boron carbide powder using the method described in this invention can further improve the density of the prepared metal-ceramic additives compared to the unmodified raw materials composed of aluminum powder, silicon dioxide powder, and boron carbide powder.

[0068] The density of the laser additive prepared in Experiment 4 was significantly higher than that prepared in Experiment 1, and also significantly higher than that prepared in Experiments 2 and 3. This indicates that the choice of modifying agent plays a crucial role in the preparation of the modified raw material and its ability to further significantly improve the density of the metal-ceramic additive. When a mixed modifying agent consisting of triethanolamine monostearate and sodium cocooxyethyl sulfonate is used, the modified raw material prepared can significantly improve the density of the metal-ceramic additive. The degree of improvement in density is significantly higher than that of the modified raw material prepared using triethanolamine monostearate or sodium cocooxyethyl sulfonate alone. The modified raw material prepared using a mixed modifying agent consisting of triethanolamine monostearate and sodium cocooxyethyl sulfonate can synergistically improve the density of the metal-ceramic additive.

[0069] The density of the laser additive prepared in Experiment 5 was significantly improved compared to that prepared in Experiment 4, exhibiting excellent density. This indicates that using modified ceramic powder obtained by modifying silicon dioxide powder and boron carbide powder according to the method described in this invention to replace unmodified ceramic powder can further significantly improve the density of the prepared metal-ceramic additive, resulting in a higher degree of fabrication.

[0070] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely prisms of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A laser additive manufacturing process, characterized in that: The raw material for its preparation is a modified raw material, which is prepared by mixing modified ceramic powder and metal powder and adding a modifying agent; wherein, the weight ratio of the modified ceramic powder to the metal powder is 1 to 3:

10. The modified raw material is prepared as follows: Step (S11) involves mixing the modified ceramic powder and metal powder with water to obtain a uniform mixture; Step (S12) Add the modifying agent to the mixture and mix evenly to obtain a mixed slurry; The modifying agent is composed of triethanolamine monostearate and sodium cocoyl oxyethyl sulfonate, with a weight ratio of 1-3:1-3 between the two. Step (S13) The mixed slurry is placed in a ball mill and ball-milled for 1 to 3 hours to obtain a ball-milled slurry; Step (S14) involves filtering and drying the ball-milled slurry to obtain the modified raw material; The modified ceramic powder is prepared by modifying silicon dioxide powder and boron carbide powder in a weight ratio of 1 to 2:

1. The preparation method of the modified ceramic powder is as follows: Step (S21) Take silica powder and boron carbide powder, mix them, add them to water and disperse them evenly to obtain a dispersion; Step (S22): Add neodymium nitrate hexahydrate and ammonium fluoride to the dispersion and stir for 2-4 hours. After stirring, evaporate the solvent in the reaction solution to obtain a solid product. Step (S23) involves calcining the solid product in a nitrogen atmosphere at 500–700°C for 3–5 hours, followed by calcination at 1400–1600°C for 3–5 hours to obtain modified ceramic powder. The metal powder is aluminum powder.

2. The laser additive manufacturing process according to claim 1, characterized in that: In step (S11), the total weight ratio of the modified ceramic powder and metal powder to water is 1:1 to 2.

3. The laser additive manufacturing process according to claim 1, characterized in that: In step (S12), the weight ratio of the mixture to the modifying agent is 100:5 to 10.

4. The laser additive manufacturing process according to claim 3, characterized in that: The weight ratio of the mixture to the modifying agent is 100:

8.

5. The laser additive manufacturing process according to claim 1, characterized in that: The weight ratio of the modified ceramic powder to the metal powder is 2:

10.

6. A method for manufacturing laser additives, characterized in that: The laser additive manufacturing process for any one of claims 1 to 5 comprises the following steps: laying the raw material flat on a substrate, and melting the raw material with a laser of power of 1000W at a scanning speed of 1000mm / s to obtain the laser additive.