Method for additive manufacturing of diamond-M2 high-speed steel composite material

Abstract

The invention discloses a method for additive manufacturing of a diamond-M2 high-speed steel composite material. The method comprises the following steps: 1, plating a layer of metal film on the surface of a diamond particle; secondly, the coating diamond particles and M2 high-speed steel powder are mixed; thirdly, the mixed raw materials are put into a stock bin of electron beam additive manufacturing equipment, and layer cutting data and layer cutting scanning data are imported; and fourthly, a base plate is preheated, then powder laying and presintering are conducted, then melting scanning is conducted, layer-by-layer preparation is repeatedly conducted, finally solidification is conducted, and the diamond-M2 high-speed steel composite material is obtained. Diamond particles are added into M2 high-speed steel powder, and the composite material is prepared through electron beam additive manufacturing, so that diamond and carbide have a synergistic effect in the friction process, a wide and continuous wear-resistant layer is formed, the islanding effect of the diamond is effectively solved, the comprehensive performance of the obtained composite material is comprehensively improved, and the service life of the composite material is prolonged. The manufacturing period is short and the cost is low.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of superhard material manufacturing, and particularly relates to a method for additive manufacturing of diamond-M2 high-speed steel composite material. BACKGROUND

[0002] M2 high-speed steel has become an ideal high-speed cutting tool material due to its excellent hardness, wear resistance and red hardness, and plays an irreplaceable role in the precision forming field of complex components. With the high-quality development of major projects such as manned spaceflight, deep-sea drilling and mountain tunnel in China, the processing precision of superhard components is increasingly required. Therefore, higher demands are put forward for the wear resistance of M2 high-speed steel tools.

[0003] Currently, there are three common methods to improve the wear resistance of M2 high-speed steel: first, organization control or composition design, which improves the metallurgical reaction between carbon elements and metals in M2 high-speed steel by adding elements, thereby optimizing the size, distribution and hardness of carbides and other properties to improve surface wear resistance. However, due to the fact that the hardness of carbides in M2 high-speed steel can only reach 32 GPa, it is difficult to further improve the wear resistance of M2 high-speed steel by controlling its morphology and distribution, and a new type of high-hardness second phase needs to be explored to meet the future demand for higher wear resistance. Second, a high-hardness wear-resistant layer is coated on the surface of M2 high-speed steel by surface spraying or laser welding. However, the reliability of the coating material is greatly affected by the substrate composition and coating process, and peeling may occur under harsh conditions. Third, hard particles are directly added to M2 high-speed steel to improve wear resistance. The main principle of hard particle reinforced metal matrix composite is to utilize the good heat resistance and high hardness of metal, and the hard particles are bonded together. Under the action of external force, the metal phase produces a certain plastic deformation or grain boundary displacement, absorbs part of the energy, and relieves stress concentration, thereby achieving the purpose of improving wear resistance and hardness while increasing toughness.

[0004] Currently, the materials that can be used as reinforcing phases mainly include oxides, borides, nitrides and diamonds. Among them, the microhardness of diamond is 98 GPa, which can effectively improve the hardness of M2 high-speed steel, and the dispersed distribution of carbides in M2 high-speed steel can effectively fill the isolated gaps between diamonds. In the friction process, diamonds and carbides work together to form a wide and continuous wear-resistant layer, effectively solving the "island effect" of diamonds. Thus, it can better meet the high-speed and efficient processing requirements of cutting tools. SUMMARY

[0005] The technical problem to be solved by this invention is to address the shortcomings of the prior art by providing a method for additive manufacturing diamond-M2 high-speed steel composite materials. This method uses a mixture of M2 high-speed steel powder and diamond particles as raw material. Utilizing the rapid solidification and powder bed preheating techniques of electron beam additive manufacturing, the carbide particle size can be effectively controlled, reducing the internal stress generated after the composite material solidifies, thus obtaining a diamond-M2 high-speed steel composite material. In this composite material, diamond not only improves the wear resistance of the composite material due to its high hardness, but also works synergistically with the carbides in the M2 high-speed steel to form a broad and continuous wear-resistant layer.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for additive manufacturing of diamond-M2 high-speed steel composite materials, characterized in that the method includes the following steps: Step 1: Apply a metal film to the surface of diamond particles using methods such as thermal diffusion, vacuum evaporation, magnetron sputtering, chemical coating, or electroplating to obtain coated diamond particles. Step 2: The coated diamond particles obtained in Step 1 are mixed with M2 high-speed steel powder using a powder mixer to obtain a mixed raw material; Step 3: Place the mixed raw materials obtained in Step 2 into the hopper of the electron beam additive manufacturing equipment, and import the layer cutting data and layer cutting scanning data to obtain the loaded electron beam additive manufacturing equipment; Step 4: Using the electron beam additive manufacturing equipment obtained in Step 3, the substrate is first preheated with an electron beam, then powder is spread and pre-sintered, followed by melting scanning. The powder spreading, pre-sintering and melting scanning processes are repeated layer by layer to prepare the material. Finally, the material is solidified to obtain the diamond-M2 high-speed steel composite material.

[0007] This invention increases the bonding strength between diamond and the matrix by depositing a metal film and suppressing the graphitization of diamond during additive manufacturing. It also improves the quality of electron beam additive manufacturing by preheating and enables diffusion sintering between M2 high-speed steel powders through pre-sintering, thereby strengthening the stability of the M2 high-speed steel powder bed and avoiding powder splashing during electron beam melting. Finally, it melts the M2 high-speed steel powder through melting scanning to obtain a diamond-M2 high-speed steel composite material.

[0008] The aforementioned method for additive manufacturing of diamond-M2 high-speed steel composite materials is characterized in that the diamond particles in step one have a particle size of 10μm to 150μm. This invention, by controlling the particle size of the diamond particles, ensures that the diamond particles match the grain size of the carbides in M2 high-speed steel under different preparation conditions, thereby enabling the diamond and carbides to synergistically improve wear resistance during friction.

[0009] The above-mentioned method for additive manufacturing diamond-M2 high-speed steel composite material is characterized in that the mass fraction of coated diamond particles in the mixed raw materials in step two is 10%~50%. This invention, by controlling the mass fraction of diamond particles, can be adjusted according to different requirements for wear resistance and toughness, making it suitable for various conditions.

[0010] The aforementioned method for additive manufacturing diamond-M2 high-speed steel composite materials is characterized by the following method for acquiring the layer cutting data and layer scanning data in step three: A three-dimensional model of the target product is established using three-dimensional modeling software; then, the three-dimensional model is sliced ​​into equal-thickness transverse layers using layering software, with each layer having a thickness of 50μm to 150μm, yielding layer cutting data including the cross-sectional contour information of each layer; finally, the scanning processing path for each layer is designed to obtain the layer scanning data. This invention ensures the molding quality of the diamond-M2 high-speed steel composite material by controlling the acquisition method of the layer cutting data and layer scanning data. By controlling the thickness of each layer, it ensures coverage of the molten pool depth and guarantees that 80% of the powder is evenly spread on the powder bed, preventing the powder from being scraped away by the scraper.

[0011] The aforementioned method for additive manufacturing of diamond-M2 high-speed steel composite materials is characterized in that the preheating temperature in step four is 500℃~800℃, and the electron beam scanning current used for both preheating and pre-sintering is 30mA~50mA, with a scanning speed of 8000mm / s~10000mm / s. This invention ensures the smooth progress of subsequent pre-sintering and melting scanning by controlling the preheating temperature. By controlling the parameters of preheating and pre-sintering, diffusion sintering occurs between the M2 high-speed steel powders, strengthening the stability of the M2 high-speed steel powder bed and avoiding powder splashing during electron beam melting.

[0012] The aforementioned method for additive manufacturing of diamond-M2 high-speed steel composite materials is characterized in that, in step four, during the melting scan, the melting scan path of each layer forms an angle of 0° to 90° with the path of the previous layer. This invention optimizes the microstructure of the diamond-M2 high-speed steel composite material, reduces anisotropy, minimizes defects in the microstructure, and controls stress and deformation by controlling the angle between the melting scan path of each layer and the path of the previous layer.

[0013] The aforementioned method for additive manufacturing of diamond-M2 high-speed steel composite materials is characterized by the following parameters for the melting and scanning process in step four: electron beam scanning current of 5mA~10mA, scanning speed of 1m / s~5m / s, scanning spacing of 0.1mm~0.2mm, voltage of 60kV, and linear energy density of 150J / m~250J / m. This invention, by controlling the melting and scanning parameters, melts M2 high-speed steel powder while ensuring that the diamond particles do not graphitize. This allows the dispersed carbides in the M2 high-speed steel to effectively fill the isolated gaps between the diamond particles and suppress stress crack formation, thereby forming a high-quality diamond-M2 high-speed steel composite material.

[0014] The aforementioned method for additive manufacturing of diamond-M2 high-speed steel composite materials is characterized in that the solidification process in step four involves: introducing an inert gas into the forming zone of the electron beam additive manufacturing equipment, rapidly cooling to below 60°C, and then removing the layer-by-layer formed parts and continuing to cool to room temperature. This invention further improves the performance of diamond-M2 high-speed steel composite materials by controlling the solidification process.

[0015] Compared with the prior art, the present invention has the following advantages: 1. This invention employs electron beam additive manufacturing, using an electron beam as a heat source and a mixture of M2 high-speed steel powder and diamond particles as raw materials. Through alternating processes of powder spreading, pre-sintering, and melting scanning, the diamond-M2 high-speed steel composite material is prepared layer by layer, effectively solving the problem of a large amount of thermal stress generated during the preparation of diamond composite M2 high-speed steel.

[0016] 2. This invention is based on electron beam additive manufacturing and designs a diamond-M2 high-speed steel composite material. By controlling the thermal field of pre-sintering and melting scanning, the size and morphology of carbides are adjusted so that the dispersed carbides in M2 high-speed steel can effectively fill the isolated gaps between diamonds, thus obtaining a diamond-M2 high-speed steel composite material.

[0017] 3. In the diamond-M2 high-speed steel composite material of the present invention, diamond not only improves the wear resistance of the composite material due to its high hardness, but also diamond and carbides can work together to form a wide and continuous wear-resistant layer. This diamond-M2 high-speed steel composite material provides a new approach to improving the wear resistance of M2 high-speed steel.

[0018] The technical solution of the present invention will be further described in detail below through embodiments. Detailed Implementation

[0019] Example 1 This embodiment includes the following steps: Step 1: A metal film is deposited on the surface of diamond particles with a particle size of 10μm using thermal diffusion to obtain coated diamond particles. Step 2: The coated diamond particles obtained in Step 1 are mixed with M2 high-speed steel powder using a powder mixer to obtain a mixed raw material; the mass fraction of the coated diamond particles in the mixed raw material is 50%. Step 3: Place the mixed raw materials obtained in Step 2 into the hopper of the electron beam additive manufacturing equipment. Use 3D modeling software to create a 3D model of the target product. Then, use layering software to perform transverse layering and slicing of the 3D model with equal thickness, and the thickness of each slice is 50μm. Obtain slice data including the cross-sectional contour information of each slice. Then, design the scanning processing path of each slice to obtain slice scanning data. Use layering software to import the slice data and slice scanning data into the electron beam additive manufacturing equipment to obtain the loaded electron beam additive manufacturing equipment. Step 4: Evacuate the electron beam additive manufacturing equipment obtained in Step 3 to a vacuum level of 5×10⁻⁶. -2 Below Pa, an electron gun emits an electron beam with a beam diameter of 0.1 mm. Under the action of focusing and deflection coils, the stainless steel substrate is preheated to 500℃. The electron beam scanning current used for preheating is 30 mA, and the scanning speed is 10000 mm / s. Then, a 50 μm thick layer of mixed powder is deposited on the preheated substrate. The deposited mixed powder is pre-sintered using an electron beam scanning current of 40 mA, a scanning speed of 10000 mm / s, and a pre-sintering time of 20 s. Finally, an electron beam with a beam diameter of 0.1 mm is used to further sinter the pre-sintered substrate. The sintered mixed powder was subjected to melting scanning. The electron beam scanning current was 8mA, the scanning speed was 1m / s, the scanning spacing was 0.1mm, the voltage was 60kV, and the linear energy density was 250J / m. The powder spreading, pre-sintering, and melting scanning processes were repeated to prepare the material layer by layer. The melting scanning path of each layer was at a 0° angle to the path of the previous layer. Finally, inert gas was introduced into the forming area of ​​the electron beam additive manufacturing equipment, and the material was rapidly cooled to below 60°C. The layer-by-layer formed part was then removed and cooled to room temperature to obtain the diamond-M2 high-speed steel composite material.

[0020] In this embodiment, a metal film can also be deposited on the surface of the diamond particles by vacuum evaporation, magnetron sputtering, chemical plating, or electroplating.

[0021] Example 2 This embodiment includes the following steps: Step 1: A metal film is deposited on the surface of diamond particles with a particle size of 50μm using vacuum evaporation to obtain coated diamond particles. Step 2: The coated diamond particles obtained in Step 1 are mixed with M2 high-speed steel powder using a powder mixer to obtain a mixed raw material; the mass fraction of the coated diamond particles in the mixed raw material is 20%. Step 3: Place the mixed raw materials obtained in Step 2 into the hopper of the electron beam additive manufacturing equipment. Use 3D modeling software to create a 3D model of the target product. Then, use layering software to perform transverse layering and slicing of the 3D model with equal thickness, and the thickness of each slice is 80μm. Obtain slice data including the cross-sectional contour information of each slice. Then, design the scanning processing path of each slice to obtain slice scanning data. Use layering software to import the slice data and slice scanning data into the electron beam additive manufacturing equipment to obtain the loaded electron beam additive manufacturing equipment. Step 4: Evacuate the electron beam additive manufacturing equipment obtained in Step 3 to a vacuum level of 5×10⁻⁶. -2 Below Pa, an electron gun emits an electron beam with a beam diameter of 0.1 mm. Under the action of focusing and deflection coils, the stainless steel substrate is preheated to 650°C. The electron beam scanning current used for preheating is 40 mA, and the scanning speed is 9000 mm / s. Then, a mixed powder layer with a thickness of 80 μm is deposited on the preheated substrate. The deposited mixed powder is pre-sintered using an electron beam scanning current of 40 mA, a scanning speed of 9000 mm / s, and a pre-sintering time of 20 s. Finally, an electron beam with a beam diameter of 0.1 mm is used to finish the pre-sintering process. The mixed powder was then subjected to melting scanning. The electron beam scanning current was 5mA, the scanning speed was 3m / s, the scanning spacing was 0.15mm, the voltage was 60kV, and the linear energy density was 200J / m. The powder spreading, pre-sintering, and melting scanning processes were repeated to prepare the material layer by layer. The melting scanning path of each layer was at a 45° angle to the path of the previous layer. Finally, inert gas was introduced into the forming area of ​​the electron beam additive manufacturing equipment, and the material was rapidly cooled to below 60°C. The layer-by-layer formed part was then removed and cooled to room temperature to obtain the diamond-M2 high-speed steel composite material.

[0022] In this embodiment, a metal film can also be deposited on the surface of the diamond particles by thermal diffusion, magnetron sputtering, chemical plating, or electroplating.

[0023] Example 3 This embodiment includes the following steps: Step 1: A metal film is deposited on the surface of diamond particles with a particle size of 150μm using magnetron sputtering to obtain coated diamond particles. Step 2: The coated diamond particles obtained in Step 1 are mixed with M2 high-speed steel powder using a powder mixer to obtain a mixed raw material; the mass fraction of the coated diamond particles in the mixed raw material is 10%. Step 3: Place the mixed raw materials obtained in Step 2 into the hopper of the electron beam additive manufacturing equipment. Use 3D modeling software to create a 3D model of the target product. Then, use layering software to perform transverse layering and slicing of the 3D model with equal thickness. The thickness of each slice is 150μm. Obtain slice data including the cross-sectional contour information of each slice. Then, design the scanning processing path of each slice to obtain slice scanning data. Use layering software to import the slice data and slice scanning data into the electron beam additive manufacturing equipment to obtain the loaded electron beam additive manufacturing equipment. Step 4: Evacuate the electron beam additive manufacturing equipment obtained in Step 3 to a vacuum level of 5×10⁻⁶. -2 Below Pa, an electron gun emits an electron beam with a beam diameter of 0.1 mm. Under the action of focusing and deflection coils, the stainless steel substrate is preheated to 800℃. The electron beam scanning current used for preheating is 50 mA, and the scanning speed is 8000 mm / s. Then, a 150 μm thick layer of mixed powder is deposited on the preheated substrate. The deposited mixed powder is pre-sintered using an electron beam scanning current of 50 mA, a scanning speed of 8000 mm / s, and a pre-sintering time of 20 s. Finally, an electron beam with a beam diameter of 0.1 mm is used to further sinter the pre-sintered material. The mixed powder after sintering was subjected to melting scanning. The electron beam scanning current was 10mA, the scanning speed was 5m / s, the scanning spacing was 0.2mm, the voltage was 60kV, and the linear energy density was 150J / m. The powder spreading, pre-sintering, and melting scanning processes were repeated to prepare the material layer by layer. The melting scanning path of each layer was at a 90° angle to the path of the previous layer. Finally, inert gas was introduced into the forming area of ​​the electron beam additive manufacturing equipment, and the material was rapidly cooled to below 60°C. The layer-by-layer formed part was then removed and cooled to room temperature to obtain the diamond-M2 high-speed steel composite material.

[0024] In this embodiment, a metal film can also be deposited on the surface of the diamond particles by thermal diffusion, vacuum evaporation, chemical coating, or electroplating.

[0025] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for additive manufacturing diamond-M2 high-speed steel composite materials, characterized in that, The method includes the following steps: Step 1: Apply a metal film to the surface of diamond particles using methods such as thermal diffusion, vacuum evaporation, magnetron sputtering, chemical coating, or electroplating to obtain coated diamond particles. Step 2: The coated diamond particles obtained in Step 1 are mixed with M2 high-speed steel powder using a powder mixer to obtain a mixed raw material; Step 3: Place the mixed raw materials obtained in Step 2 into the hopper of the electron beam additive manufacturing equipment, and import the layer cutting data and layer cutting scanning data to obtain the loaded electron beam additive manufacturing equipment; Step 4: Using the electron beam additive manufacturing equipment obtained in Step 3, the substrate is first preheated with an electron beam, then powder is spread and pre-sintered, followed by melting scanning. The powder spreading, pre-sintering and melting scanning processes are repeated layer by layer to prepare the material. Finally, the material is solidified to obtain the diamond-M2 high-speed steel composite material.

2. The method for additive manufacturing of diamond-M2 high-speed steel composite material according to claim 1, characterized in that, The diamond particles mentioned in step one have a particle size of 10μm to 150μm.

3. The method for additive manufacturing of diamond-M2 high-speed steel composite material according to claim 1, characterized in that, In step two, the mass fraction of the coated diamond particles in the mixed raw materials is 10% to 50%.

4. A method for additive manufacturing diamond-M2 high-speed steel composite material according to claim 1, characterized in that, The method for obtaining the slice data and slice scanning data in step three is as follows: a three-dimensional model of the target product is established using three-dimensional modeling software, and then the three-dimensional model is sliced ​​into equal-thickness transverse layers using layering software, with the thickness of each layer being 50μm~150μm, to obtain slice data including the cross-sectional contour information of each layer. Then, the scanning processing path of each layer is designed to obtain slice scanning data.

5. A method for additive manufacturing diamond-M2 high-speed steel composite material according to claim 1, characterized in that, The preheating temperature in step four is 500℃~800℃, and the electron beam scanning current used for both preheating and pre-sintering is 30mA~50mA, and the scanning speed is 8000mm / s~10000mm / s.

6. A method for additive manufacturing of diamond-M2 high-speed steel composite material according to claim 1, characterized in that, In the melting scan described in step four, the melting scan path of each layer forms an angle of 0° to 90° with the path of the previous layer.

7. A method for additive manufacturing of diamond-M2 high-speed steel composite material according to claim 1, characterized in that, The parameters for the melting scan in step four are: electron beam scanning current of 5mA~10mA, scanning speed of 1m / s~5m / s, scanning spacing of 0.1mm~0.2mm, and linear energy density of 150J / m~250J / m.

8. A method for additive manufacturing of diamond-M2 high-speed steel composite material according to claim 1, characterized in that, The solidification process described in step four is as follows: inert gas is introduced into the forming area of ​​the electron beam additive manufacturing equipment, and the temperature is rapidly cooled to below 60°C. Then, the formed parts prepared layer by layer are taken out and cooled to room temperature.