Method for manufacturing ceramic material by adopting laser additive and subtractive synergistic process

Abstract

The invention provides a method for manufacturing a ceramic material by adopting a laser additive and subtractive synergistic process, which comprises the following steps: S1, spreading ceramic powder on a carrier plate, heating the carrier plate by adopting a laser preheating module, and transferring heat to the ceramic powder through the carrier plate to realize preheating; and S2, in the inert gas environment, the material increasing procedure and the material decreasing procedure are alternately carried out till the ceramic part is formed. Through in-situ alternation and dynamic coupling of four links of preheating, material adding, material reducing and monitoring, integrated manufacturing of the ceramic parts from forming to fine trimming is achieved, and a reliable technical path is provided for direct forming and engineering application of the high-performance ceramic parts in the fields of aerospace, biomedical treatment and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ceramic material surface, and particularly relates to a method for manufacturing ceramic materials by adopting a laser additive and subtractive collaborative process. BACKGROUND

[0002] Ceramic materials have important application value in high-end fields such as aerospace, medical devices, energy equipment, etc. due to their excellent mechanical properties, high-temperature stability, corrosion resistance and biocompatibility. However, the inherent hard and brittle characteristics of the material make the manufacturing process face severe challenges. Traditional ceramic part manufacturing processes (such as injection molding, dry pressing, etc.) rely on high-temperature sintering, and have inherent limitations such as high mold cost, difficulty in forming complex structures, long processing cycle, etc., which are difficult to meet the modern manufacturing needs of personalized and high-precision structural parts.

[0003] Additive manufacturing technology provides a new way for ceramic complex structure forming, but single laser additive manufacturing is limited by the “step effect” and process precision, and it is difficult to directly form high-verticality through holes and high-aspect-ratio thin-wall columns, and the surface quality is poor, which relies on additional post-processing procedures, resulting in a long process chain and easy to introduce defects. Although single subtractive manufacturing has high precision, it cannot manufacture internal cavities, flow channels and other complex features, and has problems such as tool interference and difficulty in removing powder, and low material utilization.

[0004] Additive and subtractive collaborative manufacturing technology has become an important direction to break through the limitations of single process. Existing collaborative manufacturing technologies are mostly concentrated in the field of metal materials (such as the alternative integration of laser cladding additive and milling subtractive), but when applied to ceramic materials, laser additive and subtractive collaborative manufacturing faces the following core bottlenecks: 1. Poor process compatibility: The light path system, processing parameters and motion control strategy of traditional metal additive and subtractive equipment are difficult to adapt to the high melting point and low thermal conductivity characteristics of ceramic materials, which easily causes defects such as cracks and delamination; 2. Accumulation of thermal stress: The rapid heating / cooling of ceramic under laser action leads to local thermal stress concentration, and the superposition of thermal stress will exacerbate the unevenness of the microstructure; 3. Weak interface bonding: During the process of layer-by-layer additive and subtractive manufacturing, the interface between new and old materials is prone to produce pores or weak bonding areas due to temperature field fluctuations, which reduces the overall mechanical properties of the part.

[0005] Currently, the research on laser additive and subtractive collaborative manufacturing technology of ceramic materials is still in the exploratory stage, especially in the aspects of laser parameter matching, process optimization strategy, real-time temperature field control, etc. There is a lack of systematic solutions, which seriously restricts the direct forming and engineering application of high-performance ceramic parts.

[0006] In view of the above problems, the existing technology needs to be improved. SUMMARY

[0007] Therefore, the present application proposes a method for manufacturing ceramic materials by laser additive and subtractive collaborative process, aiming at the problems of low forming accuracy, serious thermal stress accumulation, poor interface bonding performance and long process chain in the existing additive / subtractive independent manufacturing process of ceramic materials. The present application integrates the alternative collaborative process of laser additive forming and laser subtractive finishing, avoids the multiple sintering, debinding and secondary processing links in the traditional process, and significantly improves the integrated manufacturing efficiency of complex structure ceramic parts. The present application aims to provide a technical solution for short process, high precision and high densification manufacturing of high-performance ceramic parts, and promote its large-scale application.

[0008] The technical solution of the present application is: A method for manufacturing ceramic materials by laser additive and subtractive collaborative process, characterized in that it comprises the following steps: S1, spreading ceramic powder on a carrier plate, heating the carrier plate by a laser preheating module, transferring heat from the carrier plate to the ceramic powder to achieve preheating; S2, alternately performing additive and subtractive processes in an inert gas environment until the ceramic part is formed; specifically as follows: Additive process: using laser selective melting, melting ceramic powder layer by layer by a laser additive module to realize the forming of the main body of the part; Subtractive process: after completing a certain number of additive processes, switch to laser subtractive mode, and remove the excess amount and profile finish on the surface of the current layer by a laser subtractive module; Wherein, the surface morphology of the ceramic material and the real-time process parameters are monitored in real time by an online monitoring system; after completing 1-5 layers of additive process, 1-5 layers of subtractive process are performed, and real-time adjustment is made according to the online detection data; if the layer thickness deviation of the current layer is greater than 10-80 μm or the surface morphology has obvious defects, then the next layer powder spreading speed or laser power is adjusted for compensation.

[0009] The application in-situ manufactures ceramic parts under inert gas environment through the alternating synergistic process of laser additive and laser subtractive. The preheating in step S1 indirectly heats the ceramic powder through the carrier plate, aiming to reduce the thermal gradient of the powder bed, reduce the risk of thermal stress caused by the high melting point and low thermal conductivity of ceramic materials during subsequent laser processing, and provide stable thermal initial conditions for additive manufacturing. The alternating processing logic in step S2 is that the additive process is responsible for the layer-by-layer accumulation forming of the part body, and the intermittently introduced subtractive process is used for finishing the formed surface to remove the excess amount and correct the profile error. This alternating process, i.e. 1-5 layers of additive followed by 1-5 layers of subtractive, realizes the dynamic integration of "forming-finish". Its role is to redistribute the local heat generated by the previous additive process through the intervention of the subtractive process, which helps to reduce residual stress. At the same time, through the real-time feedback of the online monitoring system, a closed-loop control is formed to realize dynamic compensation of the processing process, thereby synchronously improving the density and dimensional accuracy of the part, and avoiding the long process problem caused by multiple sintering, debinding and secondary processing in traditional processes. The whole process is carried out under inert gas protection to prevent the oxidation of ceramic materials at high temperature.

[0010] Further, in step S2, the layer thickness of the ceramic powder melted layer-by-layer in the additive process is 30-100 μm. In the application, the range of layer thickness is based on the balance between the characteristics of ceramic powder and the laser processing capacity. Too thin layer thickness will lead to low processing efficiency of single layer and is easy to cause over-melting due to excessive energy accumulation; too thick layer thickness may cause laser energy unable to completely penetrate the powder layer, resulting in insufficient melting, weak interlayer bonding force and porosity defects.

[0011] Further, in step S2, the layer thickness adjustment range of each additive process or subtractive process is ±3-10 μm when the additive process and subtractive process are alternately performed. In the application, when the layer thickness deviation or surface topography anomaly is detected, the dynamic allocation of processing allowance and error compensation is realized by small amplitude adjustment of layer thickness. The layer thickness adjustment range of ±3-10 μm provides sufficient flexibility to compensate for the geometric error accumulated in the previous process, while avoiding the process instability that may be caused by excessive adjustment.

[0012] Further, if the layer thickness deviation of the current layer is greater than 10-80 μm or the surface topography has obvious defects, the laser power for the next layer processing is increased or decreased by 5-30% based on the original laser power, and the powder laying speed is increased or decreased by 1-10% based on the original powder laying speed according to the actual situation. The inventors found that the layer thickness deviation or surface defects often originate from the mismatch of energy input (laser power) or material delivery (powder laying speed). By adjusting the laser power, the input energy density can be directly changed, affecting the melting depth and width; by adjusting the powder laying speed, the powder supply rate can be changed, affecting the formation and solidification behavior of the molten pool. For insufficient layer thickness, the laser power can be appropriately increased or the powder laying speed can be reduced to enhance the melting effect; for over-melting or surface unevenness, the power can be reduced or the powder laying speed can be increased. This dynamic adjustment process is the key to realizing the technical effect of "shape-property synergistic regulation", which suppresses defect generation and improves manufacturing precision and part density through real-time compensation.

[0013] Further, in step S2, real-time monitoring of temperature fluctuations is also included to control whether the subtractive process is started.

[0014] Further, in step S2, when the temperature value is detected to remain below 30-50℃, the subtractive process is started.

[0015] In the present application, since ceramic materials are extremely sensitive to thermal stress, if the subtractive process is performed when the temperature is too high, the risk of crack aggravation due to thermal shock may increase; and if the subtractive process is performed after the temperature is reduced to a safe range, it is helpful to uniformly distribute heat and release stress. The temperature range of 30-50℃ set in the present application ensures that the ceramic part has been cooled from the high temperature state of laser additive manufacturing to a relatively stable and safe interval, and at this time, laser subtractive manufacturing is performed, which can maximize the avoidance of thermal stress concentration and material damage caused by the superposition of local high temperature and cold processing.

[0016] Further, in step S1, the ceramic powder includes any one of zirconium oxide, silicon nitride, aluminum oxide, and silicon carbide; the particle size of the ceramic powder is 5-100 μm; the carrier plate is a ceramic carrier plate, which includes any one of a zirconium oxide carrier plate, a silicon nitride carrier plate, an aluminum oxide carrier plate, and a silicon carbide carrier plate, and the thickness is 500 μm-1 mm. In the present application, the selected ceramic powder has characteristics such as high melting point and high hardness, which is suitable for laser additive and subtractive manufacturing; the powder particle size ensures good flowability and uniformity of powder laying, which is beneficial to form a dense powder bed. The carrier plate uses a ceramic material compatible with the powder material, which can reduce the interfacial stress caused by the mismatch of the thermal expansion coefficient; the thickness provides sufficient mechanical support strength and thermal conduction stability, ensuring that the preheating heat can be effectively and uniformly transferred to the powder bed.

[0017] Further, in step S2, the inert gas includes any one of nitrogen and argon.

[0018] Further, the laser preheating module and the laser additive module adopt continuous laser or pulsed laser, the wavelength is 355-1064nm, the power is 300-1000W, the spot diameter is 100-500μm, the scanning speed is 500-2000mm / s, and the scanning path interval is 100μm-1mm.

[0019] In the application, the wavelength covers the range from ultraviolet to near infrared, and the absorption rates of different ceramic materials to different wavelengths of laser are different, and this range provides flexibility. The power and the spot diameter jointly determine the energy density, and it is necessary to ensure that the ceramic powder can be melted. The scanning speed and the path interval affect the processing efficiency and the heat input distribution. The parameters set in the application are related to each other, and need to be optimized and combined according to the characteristics of specific ceramic materials, so as to realize effective preheating and stable molten pool forming.

[0020] Further, the laser subtractive module is a pulsed laser, the wavelength is 355-1064nm, the power is 50-500W, the spot diameter is 20-100μm, the scanning speed is 100-1000mm / s, and the scanning path interval is 20-200μm.

[0021] In the application, the pulsed laser is suitable for precise subtractive machining, can produce high peak power and short pulse effect, realize accurate removal of materials, and reduce the heat affected zone. The application sets a smaller spot diameter, a lower power, a slower scanning speed and a denser path interval, so that high-precision material removal and surface finish can be realized, and the needs of contour finishing and allowance control can be met.

[0022] Further, the online monitoring system includes a coaxial high-resolution camera, a laser displacement sensor and an infrared thermal imager. The coaxial high-resolution camera is used for in-situ monitoring of molten pool morphology, surface spheroidization and crack morphology defects. The laser displacement sensor is used for accurate measurement of the actual layer thickness of each layer, and the deviation is obtained by comparing with the set value. The infrared thermal imager is used for real-time capture of the temperature distribution and fluctuation of the processing area.

[0023] The core innovation point of the technical solution is to construct a complete closed-loop process system for laser additive and subtractive collaborative manufacturing of ceramic materials. First, through the special design of the light path system and process parameters, the compatibility problem of ceramic high melting point, low thermal conductivity and traditional metal additive and subtractive equipment is solved. Secondly, the alternating rhythm of additive and subtractive and real-time monitoring of temperature field are combined, so that the local heat can be redistributed during the intermittent process, effectively inhibiting the accumulation of residual stress and crack risk of ceramic caused by rapid thermal cycle. Finally, the integration of online monitoring system and dynamic compensation realizes the synchronous correction of forming geometric error and machining allowance, improves the density of the part while controlling the manufacturing precision to the micron level, and forms the shape and property collaborative control ability. The invention realizes the integrated manufacturing of ceramic parts from forming to finishing through the in-situ alternation and dynamic coupling of the four links of preheating, additive, subtractive and monitoring.

[0024] The key of the invention is to use the laser preheating module to provide stable thermal initial conditions for high melting point ceramic powder, reduce the thermal stress impact of subsequent processing; then realize the layer-by-layer accumulation of the part body through the additive process, and intermittently introduce the subtractive process for allowance removal and contour finishing. This alternating cycle mechanism not only solves the limitations of traditional single process, but also captures the layer thickness deviation, surface topography defects and temperature fluctuations in real time through the online monitoring system, forming a closed-loop feedback control of process parameters, thereby systematically breaking through the technical bottleneck of ceramic materials in additive and subtractive collaborative manufacturing.

[0025] The beneficial effects of the invention are as follows: 1. Breakthrough of process compatibility bottleneck: develop a laser additive and subtractive integrated device suitable for the characteristics of ceramic materials, control the variable spot diameter laser head and multi-axis motion mechanism cooperatively to solve the processing adaptability problem caused by the high melting point and low thermal conductivity of ceramic; 2. Inhibit thermal stress defects: use additive and subtractive collaborative processing method to redistribute local heat through subtractive process to reduce residual stress caused by previous additive process and reduce the risk of crack defects; 3. Realize shape and property collaborative control: build a dynamic compensation algorithm for additive forming geometric error and subtractive machining allowance, combine online topography detection and closed-loop feedback to simultaneously improve the density and manufacturing precision of ceramic parts; 4. Shorten the manufacturing process: through the in-situ integration of additive and subtractive processes, avoid multiple sintering, debinding and secondary processing links in traditional process, significantly improve the integrated manufacturing efficiency of complex structure ceramic parts. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is an embodiment of the invention ceramic material laser additive and subtractive collaborative manufacturing device schematic diagram; Figure 2Figure 1 is a schematic diagram of the laser additive and subtractive collaborative manufacturing of a single-layer ceramic material according to another embodiment of the present application; Figure 3 Figure 2 is a schematic diagram of the laser additive and subtractive collaborative manufacturing of a multi-layer step structure ceramic material according to another embodiment of the present application; Figure 4 Figure 3 is a schematic diagram of the laser additive and subtractive collaborative manufacturing of a multi-layer array structure ceramic material according to another embodiment of the present application; Figure 1 is a schematic diagram of the laser additive and subtractive collaborative manufacturing of a single-layer ceramic material according to another embodiment of the present application; DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only 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 a person of ordinary skill in the art without creative labor fall within the scope of protection of the present application. Embodiment 1

[0028] A method for manufacturing a ceramic material by using a laser additive and subtractive collaborative process, characterized in that the method comprises the following steps: S1, spreading ceramic powder on a carrier plate, heating the carrier plate by using a laser preheating module, and transferring heat from the carrier plate to the ceramic powder to achieve preheating; S2, alternately performing an additive process and a subtractive process in an inert gas environment until a ceramic part is formed; specifically as follows: The additive process: laser selective melting is used to melt ceramic powder layer by layer by using a laser additive module to achieve part body forming; The subtractive process: after completing a certain number of layers of the additive process, switching to a laser subtractive mode, and removing the excess amount and finishing the profile of the current layer surface by using a laser subtractive module; The surface morphology of the ceramic material and real-time process parameters are monitored in real time by using an online monitoring system; after completing 1 layer of the additive process, 1 layer of the subtractive process is performed, and real-time adjustment is made according to the online detection data. If the layer thickness deviation of the current layer is greater than 10 μm or the surface morphology has obvious defects, the laser power of the next layer of processing is adjusted by ± 5%, and the powder spreading speed is adjusted by ± 1% according to the actual situation.

[0029] Further, in step S2, the layer thickness of the ceramic powder melted layer by layer in the additive process is 30 μm.

[0030] Further, in step S2, when the additive process and the subtractive process are alternately performed, the layer thickness adjustment range of each additive process or subtractive process is ±3 μm.

[0031] Further, in step S2, real-time monitoring of temperature fluctuations is further included to control whether the subtractive process is started.

[0032] Further, in step S2, when the temperature value is detected to be kept below 30℃, the subtractive process is started.

[0033] Further, in step S1, the ceramic powder is zirconia; the particle size of the ceramic powder is 5 μm; the carrier plate is a ceramic carrier plate, which is a zirconia carrier plate with a thickness of 500 μm.

[0034] Further, in step S2, the inert gas is nitrogen.

[0035] Further, the laser preheating module and the laser additive module use continuous laser with a wavelength of 355 nm, a power of 300 W, a spot diameter of 100 μm, a scanning speed of 500 mm / s, and a scanning path interval of 100 μm.

[0036] Further, the laser subtractive module is a pulsed laser with a wavelength of 355 nm, a power of 300 W, a spot diameter of 100 μm, a scanning speed of 500 mm / s, and a scanning path interval of 100 μm.

[0037] Further, the online monitoring system includes a coaxial high-resolution camera, a laser displacement sensor, and an infrared thermal imager.

[0038] The sintered density of the obtained zirconia ceramic is ≥97%, the layer thickness deviation is ≤±8 μm, and the material utilization rate is ≥88%. Example 2

[0039] A method for manufacturing ceramic materials by laser additive and subtractive collaborative process, characterized in that it comprises the following steps: S1, spreading ceramic powder on a carrier plate, heating the carrier plate by a laser preheating module, and transferring heat from the carrier plate to the ceramic powder to achieve preheating; S2, alternately performing additive process and subtractive process in an inert gas environment until the ceramic part is formed; specifically as follows: Additive process: laser selective melting is adopted to melt ceramic powder layer by layer by a laser additive module to realize the formation of the main body of the part; Subtractive process: after completing a certain number of additive processes, switch to laser subtractive mode, and remove the current layer surface by laser subtractive module and profile finishing; Wherein, the surface morphology of the ceramic material and the real-time process parameters are monitored in real time by the online monitoring system; after completing 5 layers of additive process, 5 layers of subtractive process are executed, and real-time adjustment is made according to the online detection data. If the layer thickness deviation of the current layer is greater than 80μm or the surface morphology has obvious defects, the laser power of the next layer processing is adjusted by ±30%, and the powder laying speed is adjusted by ±10% according to the actual situation.

[0040] Further, in step S2, the layer thickness of the ceramic powder melted layer by layer in the additive process is 100μm.

[0041] Further, in step S2, when the additive process and the subtractive process are alternately performed, the layer thickness adjustment range of each additive process or subtractive process is ±10μm.

[0042] Further, in step S2, real-time monitoring of temperature fluctuation is further included to control whether to start the subtractive process.

[0043] Further, in step S2, when the temperature value is detected to be kept below 50℃, the subtractive process is started.

[0044] Further, in step S1, the ceramic powder is silicon carbide; the particle size of the ceramic powder is 100μm; the carrier plate is a ceramic carrier plate, which is a silicon carbide carrier plate with a thickness of 1mm.

[0045] Further, in step S2, the inert gas is argon.

[0046] Further, the laser preheating module and the laser additive module use pulsed laser with a wavelength of 1064nm, a power of 1000W, a spot diameter of 500μm, a scanning speed of 2000mm / s, and a scanning path interval of 1mm.

[0047] Further, the laser subtractive module is a pulsed laser with a wavelength of 1064nm, a power of 500W, a spot diameter of 100μm, a scanning speed of 1000mm / s, and a scanning path interval of 200μm.

[0048] Further, the online monitoring system includes a coaxial high-resolution camera, a laser displacement sensor, and an infrared thermal imager.

[0049] The sintered density of the obtained silicon carbide ceramic is ≥85%, the layer thickness deviation is ≤±7μm, and the material utilization rate is ≥90%. Example 3

[0050] A method for manufacturing ceramic materials by laser additive and subtractive collaborative process, characterized in that it comprises the following steps: S1, spread the ceramic powder on the carrier plate, heat the carrier plate with a laser preheating module, transfer the heat to the ceramic powder through the carrier plate to achieve preheating; S2, in an inert gas environment, alternately perform additive and subtractive processes until the ceramic part is formed; Specifically as follows: Additive process: laser selective melting is used to melt ceramic powder layer by layer through a laser additive module to form the main body of the part; Subtractive process: after completing a certain number of additive processes, switch to laser subtractive mode, and use a laser subtractive module to remove excess material and refine the profile on the current layer surface; Among them, the surface morphology of the ceramic material and the real-time process parameters are monitored in real time by an online monitoring system; After completing 2 layers of additive process, 2 layers of subtractive process are performed, and real-time adjustment is made according to the online detection data. If the layer thickness deviation of the current layer is greater than 20μm or the surface morphology has obvious defects, the laser power of the next layer processing is adjusted by ±10%, and the powder laying speed is adjusted by ±3%.

[0051] Further, in step S2, the layer thickness of the ceramic powder melted layer by layer in the additive process is 40μm.

[0052] Further, in step S2, when alternately performing additive and subtractive processes, the layer thickness adjustment range of each additive or subtractive process is ±4μm.

[0053] Further, in step S2, real-time monitoring of temperature fluctuations is also included to control whether the subtractive process is started.

[0054] Further, in step S2, when the detected temperature value remains below 35℃, the subtractive process is started.

[0055] Further, in step S1, the ceramic powder is silicon nitride; The particle size of the ceramic powder is 10μm; The carrier plate is a ceramic carrier plate, which is a silicon nitride carrier plate with a thickness of 600μm.

[0056] Further, in step S2, the inert gas is argon.

[0057] Further, the laser preheating module and the laser additive module use pulsed laser with a wavelength of 500nm, a power of 400W, a spot diameter of 200μm, a scanning speed of 1000mm / s, and a scanning path interval of 300μm.

[0058] Further, the laser subtractive module is a pulsed laser with a wavelength of 500 nm, a power of 100 W, a spot diameter of 40 μm, a scanning speed of 300 mm / s, and a scanning path interval of 60 μm.

[0059] Further, the online monitoring system comprises a coaxial high-resolution camera, a laser displacement sensor, and an infrared thermal imager.

[0060] The sintered density of the obtained silicon nitride ceramic is greater than or equal to 88%, the layer thickness deviation is less than or equal to ±8 μm, and the material utilization rate is greater than or equal to 87%. Embodiment 4

[0061] A method for manufacturing a ceramic material by using a laser additive and subtractive collaborative process, characterized in that it comprises the following steps: S1, spreading ceramic powder on a carrier plate, heating the carrier plate by using a laser preheating module, and transferring heat from the carrier plate to the ceramic powder to achieve preheating; S2, alternately performing an additive process and a subtractive process in an inert gas environment until a ceramic part is formed; specifically as follows: Additive process: using laser selective melting, melting ceramic powder layer by layer by using a laser additive module to achieve part body forming; Subtractive process: after completing a certain number of layers of additive process, switching to laser subtractive mode, and removing excess material and contour finishing on the surface of the current layer by using a laser subtractive module; Wherein, the surface morphology of the ceramic material and the real-time process parameters are monitored in real time by an online monitoring system; after completing 4 layers of additive process, 4 layers of subtractive process are performed, and real-time adjustment is made according to the online detection data; if the layer thickness deviation of the current layer is greater than 60 μm or the surface morphology has obvious defects, the laser power of the next layer processing is adjusted by ±20%, and the powder laying speed is adjusted by ±7% according to the actual situation.

[0062] Further, in step S2, the layer thickness of the ceramic powder melted layer by layer in the additive process is 90 μm.

[0063] Further, in step S2, when alternately performing the additive process and the subtractive process, the layer thickness adjustment range of each additive process or subtractive process is ±9 μm.

[0064] Further, in step S2, real-time monitoring of temperature fluctuation is further included to control whether to start the subtractive process.

[0065] Further, in step S2, when the detected temperature value is kept below 45℃, the subtractive process is started.

[0066] Further, in step S1, the ceramic powder is alumina; the particle size of the ceramic powder is 90 pm; the carrier plate is a ceramic carrier plate, which is an alumina carrier plate with a thickness of 900 pm.

[0067] Further, in step S2, the inert gas is nitrogen.

[0068] Further, the laser preheating module and the laser additive module use continuous laser with a wavelength of 800 nm, a power of 700 W, a spot diameter of 400 pm, a scanning speed of 1500 mm / s, and a scanning path interval of 600 pm.

[0069] Further, the laser subtractive module is a pulsed laser with a wavelength of 800 nm, a power of 300 W, a spot diameter of 80 pm, a scanning speed of 600 mm / s, and a scanning path interval of 150 pm.

[0070] Further, the online monitoring system includes a coaxial high-resolution camera, a laser displacement sensor, and an infrared thermal imager.

[0071] The sintered density of the obtained alumina ceramic is ≥97%, the layer thickness deviation is ≤±4 pm, and the material utilization rate is ≥94%. Example 5

[0072] A method for manufacturing ceramic materials using a laser additive and subtractive collaborative process, characterized in that it comprises the following steps: S1, spreading ceramic powder on a carrier plate, heating the carrier plate using a laser preheating module, and transferring heat from the carrier plate to the ceramic powder to achieve preheating; S2, in an inert gas environment, alternately performing an additive process and a subtractive process until a ceramic part is formed; specifically as follows: Additive process: using laser selective melting, melting ceramic powder layer by layer through a laser additive module to achieve part body forming; Subtractive process: after completing a certain number of additive processes, switching to laser subtractive mode, and removing excess material and contour finishing the current layer surface through a laser subtractive module; Wherein, the surface morphology of the ceramic material and the real-time process parameters are monitored in real time by an online monitoring system; after completing 2 layers of additive process, 1 layer of subtractive process is performed, and real-time adjustment is made according to the online detection data; if the layer thickness deviation of the current layer is greater than 50 pm or the surface morphology has obvious defects, the laser power of the next layer processing is adjusted by ±17.5%, and the powder laying speed is adjusted by ±5.5% according to the actual situation.

[0073] Further, in step S2, the layer thickness of the ceramic powder melted layer by layer in the additive process is 70 pm.

[0074] Further, in step S2, when the additive process and the subtractive process are alternately performed, the thickness adjustment range of each additive process or subtractive process is ±5 μm.

[0075] Further, in step S2, real-time monitoring of temperature fluctuations is further included to control whether the subtractive process is started.

[0076] Further, in step S2, when the temperature value is detected to be kept below 40℃, the subtractive process is started.

[0077] Further, in step S1, the ceramic powder is zirconia; the particle size of the ceramic powder is 50 μm; the carrier plate is a ceramic carrier plate, which is a zirconia carrier plate with a thickness of 750 μm.

[0078] Further, in step S2, the inert gas is nitrogen.

[0079] Further, the laser preheating module and the laser additive module use continuous laser with a wavelength of 700 nm, a power of 650 W, a spot diameter of 300 μm, a scanning speed of 1250 mm / s, and a scanning path interval of 500 μm.

[0080] Further, the laser subtractive module is a pulsed laser with a wavelength of 700 nm, a power of 275 W, a spot diameter of 60 μm, a scanning speed of 550 mm / s, and a scanning path interval of 110 μm.

[0081] Further, the online monitoring system includes a coaxial high-resolution camera, a laser displacement sensor, and an infrared thermal imager.

[0082] The sintered zirconia ceramic has a sintering density of ≥95%, a layer thickness deviation of ≤±10 μm, and a material utilization rate of ≥86%. Embodiment 6

[0083] A method for manufacturing a ceramic material by using a laser additive and subtractive process, characterized by comprising the following steps: S1, spreading ceramic powder on a carrier plate, and heating the carrier plate by using a laser preheating module to transfer heat from the carrier plate to the ceramic powder to achieve preheating; S2, alternately performing an additive process and a subtractive process in an inert gas environment until a ceramic part is formed; specifically as follows: Additive process: using laser selective melting, and melting ceramic powder layer by layer by using a laser additive module to achieve part body forming; Subtractive process: after completing a certain number of layers of additive process, switching to laser subtractive mode, and removing excess amount and contour finishing on the surface of the current layer by using a laser subtractive module; The surface morphology of the ceramic material and real-time process parameters are monitored in real time by the online monitoring system; after each 3 layers of additive process are completed, 2 layers of subtractive process are performed, and real-time adjustment is performed according to the online detection data; if the layer thickness deviation of the current layer is greater than 60 μm or the surface morphology has obvious defects, the laser power of the next layer processing is ± 19% based on the original laser power, and the powder laying speed is ± 6% based on the original powder laying speed.

[0084] Further, in step S2, the layer thickness of the ceramic powder melted layer by layer in the additive process is 60 μm.

[0085] Further, in step S2, when the additive process and the subtractive process are alternately performed, the layer thickness adjustment range of each additive process or subtractive process is ± 6 μm.

[0086] Further, in step S2, real-time monitoring of temperature fluctuation is further included to control whether to start the subtractive process.

[0087] Further, in step S2, when the temperature value is detected to be kept below 43℃, the subtractive process is started.

[0088] Further, in step S1, the ceramic powder is alumina; the particle size of the ceramic powder is 60 μm; the carrier plate is a ceramic carrier plate, and the ceramic carrier plate is an alumina carrier plate or a silicon carbide carrier plate, and the thickness is 600 μm.

[0089] Further, in step S2, the inert gas is argon.

[0090] Further, the laser preheating module and the laser additive module use pulsed laser, the wavelength is 800 nm, the power is 750 W, the spot diameter is 280 μm, the scanning speed is 1600 mm / s, and the scanning path interval is 600 μm.

[0091] Further, the laser subtractive module is a pulsed laser, the wavelength is 800 nm, the power is 410 W, the spot diameter is 60 μm, the scanning speed is 600 mm / s, and the scanning path interval is 130 μm.

[0092] Further, the online monitoring system includes a coaxial high-resolution camera, a laser displacement sensor, and an infrared thermal imager.

[0093] The sintering density of the obtained alumina ceramic is ≥95%, the layer thickness deviation is ≤±3 μm, and the material utilization rate is ≥92%. Example 7

[0094] The embodiment provides a ceramic material laser additive and subtractive collaborative manufacturing device, which comprises a laser additive module 1, a laser subtractive module 2, a ceramic powder spreading area 3, a laser preheating module 4 and a carrier plate 5, wherein the ceramic powder spreading area is arranged above the carrier plate 5, the laser additive module 1 and the laser subtractive module 2 are symmetrically arranged above the ceramic powder spreading area, and the laser preheating module 4 is correspondingly arranged below the carrier plate 5.

[0095] In actual work, the ceramic powder spreading area 3 is first acted on by the laser additive module 1 to form a laser additive area A9. Then, the laser subtractive module 2 is used to form a laser subtractive array area A13 (which is an array through-hole area). At the same time, powder is spread on the laser additive area A9 to continue forming the ceramic powder spreading area 3. Then, the laser additive module 1 is used to form a laser additive area B11. Then, the laser subtractive module 2 is used to form a laser subtractive array area B14 (which is a suspension column arrangement area).

[0096] Through the method of the embodiment, synchronous processing and closed-loop collaboration of laser additive and laser subtractive are realized, laser additive can be carried out at the same time as laser subtractive, and the manufacturing efficiency of ceramic parts is greatly improved. Through the formation of a plurality of ceramic powder spreading areas layer by layer and the use of additive and subtractive collaborative process, a composite structure such as an array through-hole and a suspension column arrangement can be integrally formed in a single manufacturing cycle, and the integrated manufacturing efficiency of complex ceramic parts is significantly improved. This method is especially suitable for efficient and high-precision manufacturing of high aspect ratio micro-holes, internal flow channels and other features in multi-layer ceramic components, and breaks through the limitations of traditional step-by-step processing in terms of efficiency and structural complexity.

[0097] Comparative Example 1 The comparative example provides a method for manufacturing a ceramic material by using a laser additive and subtractive collaborative process, which is the same as that in Embodiment 5, except that the laser preheating process in step S1 is omitted. The sintering density of the obtained zirconia ceramic is ≥ 87%, the layer thickness deviation is ≤ ± 15 μm, and the material utilization rate is ≥ 78%.

[0098] Comparative Example 2 The comparative example provides a method for manufacturing a ceramic material by using a laser additive and subtractive collaborative process, which is the same as that in Embodiment 5, except that all additive processes are completed first (without intermittent subtractive), and then overall subtractive processing is carried out, and the processing parameters are the same as those in Embodiment 5. The sintering density of the obtained zirconia ceramic is ≥ 90%, the layer thickness deviation is ≤ ± 20 μm, and the material utilization rate is ≥ 83%.

[0099] Comparative Example 3 The comparative example 4 provides a method for manufacturing ceramic material by laser additive and subtractive collaborative process, which is the same as that of the example 5, except that the ceramic particle size is 150 μm. The sintered density of the obtained zirconia ceramic is ≥ 85%, the layer thickness deviation is ≤ ± 15 μm, and the material utilization rate is ≥ 85%.

[0100] Comparative example 4 The comparative example 4 provides a method for manufacturing ceramic material by laser additive and subtractive collaborative process, which is the same as that of the example 5, except that the ceramic particle size is 150 μm. The sintered density of the obtained zirconia ceramic is ≥ 85%, the layer thickness deviation is ≤ ± 15 μm, and the material utilization rate is ≥ 85%.

[0101] In particular, the performance effect tests of the above examples and comparative examples are all based on the test method of the prior art in the art, and are tested by using the same test parameters and evaluation indexes.

[0102] It is apparent for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, but can be implemented in other concrete forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all aspects as illustrative and not restrictive, and the scope of the present application is defined by the appended claims rather than the above description, and it is intended to encompass all changes falling within the meaning and range of equivalents of the claims. Any reference signs in the claims should not be considered as limiting the claims involved.

[0103] In addition, it should be understood that, although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be properly combined to form other embodiments which can be understood by those skilled in the art. It should be noted that the technical features not described in detail in the present application can be realized by any prior art.

Claims

1. A method of manufacturing a ceramic material using a laser additive and subtractive collaborative process, characterized in that, The method comprises the following steps: S1, spreading ceramic powder on a carrier plate, heating the carrier plate by using a laser preheating module, transferring heat from the carrier plate to the ceramic powder to achieve preheating; S2, alternately performing an additive process and a subtractive process in an inert gas environment until the ceramic part is formed; specifically as follows: The additive process: using laser selective melting, melting ceramic powder layer by layer by a laser additive module to realize the forming of the main body of the part; The subtractive process: after completing a certain number of layers of the additive process, switching to a laser subtractive mode, and removing the excess amount and contour finishing on the surface of the current layer by a laser subtractive module; The surface morphology of the ceramic material and the real-time process parameters are monitored in real time by an online monitoring system; after completing 1-5 layers of the additive process, 1-5 layers of the subtractive process are performed, and real-time adjustment is made according to the online detection data; if the layer thickness deviation of the current layer is greater than 10-80 μm or the surface morphology has obvious defects, the next layer of powder spreading speed or laser power is adjusted for compensation.

2. The method of ceramic material according to claim 1, characterized in that, In step S2, the layer thickness of the ceramic powder melted layer by layer in the additive process is 30-100 μm.

3. The method of ceramic material according to claim 2, characterized in that, When the additive process or the subtractive process is alternately performed, the layer thickness adjustment range of each additive process or subtractive process is ±3-10 μm.

4. The method of ceramic material according to claim 3, characterized in that, In step S2, if the layer thickness deviation of the current layer is greater than 10-80 μm or the surface morphology has obvious defects, the laser power of the next layer of processing is increased or decreased by 5-30% based on the original laser power, and the powder spreading speed is increased or decreased by 1-10% based on the original powder spreading speed.

5. The method of ceramic material according to claim 4, characterized in that, In step S2, real-time monitoring of temperature fluctuations is also included to control whether the subtractive process is started.

6. The method of ceramic material according to claim 5, characterized in that, In step S2, when the detected temperature value is kept below 30-50℃, the subtractive process is started.

7. The method of ceramic material according to claim 1, characterized in that, In step S1, the ceramic powder includes any one of zirconia, silicon nitride, alumina, and silicon carbide; the particle size of the ceramic powder is 5-100 μm; the carrier plate is a ceramic carrier plate, which includes any one of a zirconia carrier plate, a silicon nitride carrier plate, an alumina carrier plate, and a silicon carbide carrier plate, and the thickness is 500 μm-1 mm.

8. The method of ceramic material according to claim 7, characterized in that, In step S2, the inert gas includes any one of nitrogen and argon.

9. The method of ceramic material according to claim 1, characterized in that, The laser preheating module and the laser additive module use continuous laser or pulsed laser, the wavelength is 355-1064 nm, the power is 300-1000 W, the spot diameter is 100-500 μm, the scanning speed is 500-2000 mm / s, and the scanning path interval is 100 μm-1 mm.

10. The method of ceramic material according to claim 1, characterized in that, The laser subtractive module is a pulsed laser, the wavelength is 355-1064 nm, the power is 50-500 W, the spot diameter is 20-100 μm, the scanning speed is 100-1000 mm / s, and the scanning path interval is 20-200 μm.

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