Silicon carbide micro-channel heat exchanger formed based on photocuring printing process
By using photopolymerization printing and debinding sintering technology, the problem of fabricating complex microchannel structures using traditional processes has been solved, enabling the fabrication of efficient and low-cost silicon carbide microchannel heat exchangers, thus improving heat transfer efficiency and stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANDONG UNIV OF TECH
- Filing Date
- 2026-01-19
- Publication Date
- 2026-05-01
AI Technical Summary
Traditional manufacturing processes are difficult to use to fabricate silicon carbide heat exchangers with complex microchannel structures, resulting in high processing costs and low efficiency.
A silicon carbide microchannel heat exchanger was fabricated using a photopolymerization printing process combined with degreasing and sintering techniques. The heat exchanger consists of a silicon carbide substrate and interconnected microchannel structures. A high-precision, complex structure is formed through layer-by-layer printing, degreasing, and sintering.
This study has enabled the efficient and low-cost fabrication of silicon carbide heat exchangers with complex microchannel structures, improving heat transfer efficiency and stability, extending service life, and reducing maintenance costs.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of photopolymer 3D printing ceramic materials, specifically relating to the preparation of silicon carbide ceramics and the application of silicon carbide microchannel heat exchanger devices. Background Technology
[0002] Silicon carbide ceramics, due to their high thermal conductivity, high temperature resistance (above 1600 ℃), and strong corrosion resistance, have become ideal materials for heat exchangers in high-temperature and highly corrosive environments. However, traditional manufacturing processes face significant bottlenecks. Machining costs surge due to the high hardness of silicon carbide, exceeding 10 times that of metal processing, and it cannot achieve complex flow channel formation. Casting and mold forming are difficult to manufacture porous, thin-walled, and other intricate structures. Furthermore, the difference in thermal expansion coefficients between metals and ceramics can easily lead to sealing failures. These problems have spurred the exploration of new manufacturing technologies.
[0003] The emergence of photopolymer 3D printing technology has made it possible to overcome the aforementioned bottlenecks. It achieves precise molding of complex structures by curing photosensitive ceramic slurry layer by layer. In terms of material formulation, d50 SiC powder is used to ensure high solids content, and photosensitive resin and photoinitiator are added to improve light penetration depth. Combined with composite sintering aids, the material properties are enhanced. In terms of process, by optimizing parameters such as exposure time and layer thickness, and with the integration of debinding and sintering technology, densification close to the theoretical density is achieved. Furthermore, an innovative thermal expansion compensation structure and biomimetic flow channel are designed, which significantly improves the heat transfer efficiency and stability of the heat exchanger.
[0004] Currently, photopolymer 3D printed silicon carbide heat exchangers have demonstrated significant advantages in fields such as chemical engineering, energy, and environmental protection, with a service life far exceeding that of traditional equipment and a substantial reduction in maintenance costs. However, this technology still faces challenges, such as balancing the stability of slurries with high solids content and low viscosity, controlling sintering defects, and scaling up production. These are key areas that current research needs to address in order to promote its wider industrial application. Summary of the Invention
[0005] The present invention aims to overcome the problems of difficulty in fabricating complex microchannel structures, high processing costs, and low efficiency in the preparation of silicon carbide microchannel heat exchangers using traditional processes in the prior art, and provides a silicon carbide microchannel heat exchanger based on photopolymerization printing process.
[0006] The technical solution adopted in this invention is characterized by a silicon carbide microchannel heat exchanger formed by photopolymerization printing process, comprising a silicon carbide substrate made by photopolymerization printing and subsequent degreasing and sintering processes, wherein the silicon carbide substrate has interconnected microchannels, the microchannels include an inlet section, a heat exchange section and an outlet section, and the silicon carbide substrate has a liquid inlet communicating with the inlet section and a liquid outlet communicating with the outlet section.
[0007] A method for fabricating a silicon carbide microchannel heat exchanger based on photopolymerization printing technology includes the following steps:
[0008] Step 1: Preparation of slurry;
[0009] Silicon carbide powder, photosensitive resin, dispersant, and photoinitiator are mixed in proportion, and after stirring and ball milling, a uniform silicon carbide slurry is obtained.
[0010] Step 2: Printing the raw blank;
[0011] The silicon carbide slurry from step one is placed in a photopolymer printer and printed layer by layer according to the preset microchannel structure model to obtain a silicon carbide microchannel heat exchanger blank.
[0012] Step 3: Degreasing of the unglazed blank;
[0013] The green blank from step two is placed in a degreasing furnace and degreased under an inert atmosphere to remove organic components from the green blank.
[0014] Step 4: Sintering of the green body;
[0015] The degreased green blank from step three is placed in a sintering furnace and sintered under an inert atmosphere to obtain a silicon carbide microchannel heat exchanger substrate.
[0016] Step 5: Grinding and printing the substrate;
[0017] The substrate after sintering in step four is then surface-polished and microchannel-cleaned to obtain the silicon carbide microchannel heat exchanger.
[0018] In step one, the solid content of silicon carbide powder is 70wt%-78wt%, the mass fraction of dispersant KOS163 (a polymeric type containing acidic groups) is 1wt%-1.5wt%, the mass fractions of photosensitive resins HDDA (1,6-hexanediol diacrylate) and TMPTA (propane trimethylol triacrylate) are 33wt%-34wt% and 14wt%-15wt%, respectively, the mass fraction of photoinitiator TPO (diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide) is 1wt%-1.25wt%, and the mass fraction of photoinitiator 819 (phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide) is 0.5wt%-1wt%, which are then mixed to form a slurry.
[0019] In step two, the wavelength of the light source for photopolymerization printing is 350-410 nm, the thickness of the printed layer is 20-100 μm, and the exposure time is 5-30 s / layer.
[0020] In step three, the degreasing temperature is 300-600℃, the heating rate is 0.5-2℃ / min, and the holding time is 2-6 h; the ratio of phenolic resin to anhydrous ethanol is 1:1-1:2, the impregnation time is 30-60 min, and the curing time is 1-2 h; the carbonization temperature is 600-800℃, the heating rate is 1-2℃ / min, and the holding time is 1-3 h.
[0021] In step four, the sintering temperature is 1600-2000℃, the heating rate is 5-10℃ / min, and the holding time is 1-4h.
[0022] The beneficial effects of the method for preparing a silicon carbide microchannel heat exchanger based on photopolymerization printing process of the present invention are:
[0023] This invention relates to the field of microchannel heat exchanger manufacturing technology, specifically a silicon carbide microchannel heat exchanger fabricated using a photopolymerization printing process. The heat exchanger is prepared by photopolymerization printing of a silicon carbide preform, followed by debinding, sintering, and other subsequent processing to form a silicon carbide body with a complex microchannel structure. This invention solves the problems of traditional manufacturing processes, such as difficulty in fabricating complex three-dimensional microchannel structures, significant material damage, and high costs. It offers advantages such as high production efficiency, low cost, and excellent heat exchanger performance. Attached Figure Description
[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific implementation methods.
[0025] Figure 1 This is a process flow diagram of a silicon carbide microchannel heat exchanger based on DLP 3D printing according to the present invention;
[0026] Figure 2 This is a scanning electron microscope image of a silicon carbide microchannel heat exchanger 3D printed by DLP according to the present invention.
[0027] Figure 3 This is an X-ray diffraction pattern of a silicon carbide microchannel heat exchanger printed by DLP 3D according to the present invention;
[0028] Figure 4 This invention relates to the density and porosity of a silicon carbide microchannel heat exchanger produced by DLP 3D printing.
[0029] Figure 5 This is a structural diagram of a silicon carbide microchannel heat exchanger printed by DLP 3D according to the present invention. Figure 6 This is a cross-sectional view of a silicon carbide microchannel heat exchanger printed by DLP 3D according to the present invention; Figure 7 This is a diagram of the internal structure of a silicon carbide microchannel heat exchanger printed by DLP 3D printing according to the present invention. Detailed Implementation
[0030] A method for fabricating a silicon carbide microchannel heat exchanger based on photopolymerization printing technology includes the following steps:
[0031] Step 1: Slurry Preparation: D50 silicon carbide powder is milled in an alcohol medium for 10-20 minutes at a speed of 1000-2100 r / s. A layer of silicon dioxide is then coated onto the silicon carbide surface to obtain SiC@SiO2. Oxidation temperature is 1000-1300℃, and oxidation time is 2-6 hours. The pre-sintered, agglomerated powder is then dispersed. Ball milling is performed for 30-60 minutes at a speed of 500-1500 r / s. The final powder is then mixed with the photosensitive monomer, photoinitiator, and dispersant.
[0032] The powder has a solid content of 70wt%-78wt%, the dispersant KOS163 has a mass fraction of 1wt%-1.5wt%, the photosensitive resins HDDA and TMPTA have mass fractions of 33wt%-34wt% and 14wt%-15wt% respectively, the photoinitiator TPO has a mass fraction of 1wt%-1.25wt%, and the photoinitiator 819 has a mass fraction of 0.5wt%-1wt%, which are mixed to form a slurry.
[0033] Step 2, Printing of the blank: Pour the prepared slurry into the printing tank and print layer by layer according to the preset microchannel structure model to obtain the blank of the silicon carbide microchannel heat exchanger.
[0034] The light source wavelength for photopolymerization printing is 350-410 nm, the printing layer thickness is 20-100 μm, and the exposure time is 5-30 s / layer.
[0035] Step 3: Degreasing of the blank: The printed blank is degreased under a nitrogen atmosphere to remove organic components from the blank.
[0036] The degreasing treatment temperature is 300-600℃, the heating rate is 0.5-2℃ / min, and the holding time is 2-6h; the ratio of phenolic resin to anhydrous ethanol is 1:1-1:2, the impregnation time is 30-60 min, and the curing time is 1-2 h; the carbonization temperature is 600-800℃, the heating rate is 1-2℃ / min, and the holding time is 1-3 h.
[0037] Step 4: Sintering of the green body: The heat exchanger after degreasing is sintered in an inert atmosphere to obtain silicon carbide microchannel heat exchanger ceramic.
[0038] The sintering temperature is 1600-2000℃, the heating rate is 5-10℃ / min, and the holding time is 1-4 h.
[0039] Step 5: After sintering, the heat exchanger ceramic is surface polished and microchannel cleaned to obtain the silicon carbide microchannel heat exchanger.
[0040] Example 1:
[0041] Step 1: The d50 silicon carbide powder was milled in an alcohol medium for 15 minutes at a speed of 1900 r / s. A layer of silicon dioxide was then coated onto the surface of the silicon carbide to obtain SiC@SiO2. The oxidation temperature was 1100℃, and the oxidation time was 6 hours. The pre-sintered agglomerated powder was then dispersed. The powder was ball-milled for 30 minutes at a speed of 1000 r / s. The resulting powder was then mixed with photosensitive monomers, photoinitiators, and dispersants. The solid content of the powder was 70 wt%, the mass fractions of the photosensitive resins HDDA and TMPTA were 33.5 wt% and 14.2 wt%, respectively, the mass fractions of the photoinitiators TPO and 819 were 1 wt% and 0.5 wt%, respectively, and the mass fraction of the dispersant KOS163 was 1 wt%.
[0042] Step 2: Pour the prepared slurry into the printing tank and print layer by layer according to the preset microchannel structure model to obtain a silicon carbide microchannel heat exchanger blank. The wavelength is 410nm, the printing layer thickness is 25μm, and the exposure time is 15s / layer.
[0043] Step 3: The printed blank is placed in a degreasing furnace and degreased under a nitrogen atmosphere. The degreasing temperature is 600℃, the heating rate is 1℃ / min, and the holding time is 2h. The ratio of phenolic resin to anhydrous ethanol is 1:1, the impregnation time is 30min, and the curing time is 1h. The carbonization temperature is 800℃, the heating rate is 1℃ / min, and the holding time is 2h.
[0044] Step 4: The degreased heat exchanger is sintered in an inert atmosphere to obtain silicon carbide microchannel heat exchanger ceramic. The sintering temperature is 1700℃, the heating rate is 5℃ / min, and the holding time is 2h.
[0045] Step 5: After sintering, the heat exchanger ceramic is surface polished and microchannel cleaned to obtain the silicon carbide microchannel heat exchanger.
[0046] The slurry prepared in Example 1 was used for DLP 3D printing, which successfully produced a high-precision, high-strength silicon carbide microchannel heat exchanger. The scanning electron microscope (SEM) image and X-ray diffraction (XRD) pattern of the printed silicon carbide microchannel heat exchanger are shown below. Figure 2 , 3 As shown in the figure. Microchannels of the heat exchanger can be seen from electron microscopy, and the XRD pattern shows the absence of excess impurities and high density.
[0047] Example 2:
[0048] Step 1: The d50 silicon carbide powder was milled in an alcohol medium for 15 minutes at a speed of 1900 r / s. A layer of silicon dioxide was then coated onto the surface of the silicon carbide to obtain SiC@SiO2. The oxidation temperature was 1100℃, and the oxidation time was 6 hours. The pre-sintered agglomerated powder was then dispersed. The powder was ball-milled for 30 minutes at a speed of 1000 r / s. The resulting powder was then mixed with photosensitive monomers, photoinitiators, and dispersants. The solid content of the powder was 70 wt%, the mass fractions of the photosensitive resins HDDA and TMPTA were 33.5 wt% and 14.2 wt%, respectively, the mass fractions of the photoinitiators TPO and 819 were 1 wt% and 0.5 wt%, respectively, and the mass fraction of the dispersant KOS163 was 1.25 wt%.
[0049] Step 2: Pour the prepared slurry into the printing tank and print layer by layer according to the preset microchannel structure model to obtain a silicon carbide microchannel heat exchanger blank. The wavelength is 410nm, the printing layer thickness is 25μm, and the exposure time is 15s / layer.
[0050] Step 3: The printed blank is placed in a degreasing furnace and degreased under a nitrogen atmosphere. The degreasing temperature is 600℃, the heating rate is 1℃ / min, and the holding time is 2h. The ratio of phenolic resin to anhydrous ethanol is 1:1, the impregnation time is 30min, and the curing time is 1h. The carbonization temperature is 800℃, the heating rate is 1℃ / min, and the holding time is 2h.
[0051] Step 4: The degreased heat exchanger is sintered in an inert atmosphere to obtain silicon carbide microchannel heat exchanger ceramic. The sintering temperature is 1700℃, the heating rate is 5℃ / min, and the holding time is 2h.
[0052] Step 5: After sintering, the heat exchanger ceramic is surface polished and microchannel cleaned to obtain the silicon carbide microchannel heat exchanger.
[0053] Comparing the slurry prepared by the formulation in Example 2 with that in Example 1, it was found that the increase in the mass fraction of the dispersant reduced the sedimentation ability of the slurry, and the microchannel heat exchanger printed by the example showed stratification after sintering.
[0054] Example 3:
[0055] Step 1: The d50 silicon carbide powder was milled in an alcohol medium for 15 minutes at a speed of 1900 r / s. A layer of silicon dioxide was then coated onto the surface of the silicon carbide to obtain SiC@SiO2. The oxidation temperature was 1100℃, and the oxidation time was 6 hours. The pre-sintered agglomerated powder was then dispersed. The powder was ball-milled for 30 minutes at a speed of 1000 r / s. The resulting powder was then mixed with photosensitive monomers, photoinitiators, and dispersants. The solid content of the powder was 70 wt%, the mass fractions of the photosensitive resins HDDA and TMPTA were 33.5 wt% and 14.2 wt%, respectively, the mass fractions of the photoinitiators TPO and 819 were 1 wt% and 0.5 wt%, respectively, and the mass fraction of the dispersant KOS163 was 1.5 wt%.
[0056] Step 2: Pour the prepared slurry into the printing tank and print layer by layer according to the preset microchannel structure model to obtain a silicon carbide microchannel heat exchanger blank. The wavelength is 410nm, the printing layer thickness is 25μm, and the exposure time is 15s / layer.
[0057] Step 3: The printed blank is placed in a degreasing furnace and degreased under a nitrogen atmosphere. The degreasing temperature is 600℃, the heating rate is 1℃ / min, and the holding time is 2h. The ratio of phenolic resin to anhydrous ethanol is 1:1, the impregnation time is 30min, and the curing time is 1h. The carbonization temperature is 800℃, the heating rate is 1℃ / min, and the holding time is 2h.
[0058] Step 4: The degreased heat exchanger is sintered in an inert atmosphere to obtain silicon carbide microchannel heat exchanger ceramic. The sintering temperature is 1700℃, the heating rate is 5℃ / min, and the holding time is 2h.
[0059] Step 5: After sintering, the heat exchanger ceramic is surface polished and microchannel cleaned to obtain the silicon carbide microchannel heat exchanger.
[0060] Comparing the slurry prepared by the formulation in Example 3 with that in Example 1, it was found that increasing the mass fraction of the dispersant reduced the sedimentation capacity of the slurry, increased the required exposure time, and caused stratification to occur after sintering of the printed microchannel heat exchanger.
Claims
1. A method for fabricating a silicon carbide microchannel heat exchanger based on a photopolymerization printing process, characterized in that, Includes the following steps: Step 1: Preparation of slurry; Silicon carbide powder, photosensitive resin, dispersant, and photoinitiator are mixed in proportion, and after stirring and ball milling, a uniform silicon carbide slurry is obtained. Step 2: Printing the raw blank; The silicon carbide slurry from step one is placed in a photopolymer printer and printed layer by layer according to the preset microchannel structure model to obtain a silicon carbide microchannel heat exchanger blank. Step 3: Degreasing of the unglazed blank; The green blank from step two is placed in a degreasing furnace and degreased, carbonized, and carbonized under an inert atmosphere to remove organic components from the green blank. Step 4: Sintering of the green body; The degreased green blank from step three is placed in a sintering furnace and sintered under an inert atmosphere to obtain a silicon carbide microchannel heat exchanger substrate. Step 5: Grinding and cleaning the substrate; The substrate after sintering in step four is then surface-polished and microchannel-cleaned to obtain the silicon carbide microchannel heat exchanger.
2. The method for preparing a silicon carbide microchannel heat exchanger based on photopolymerization printing process according to claim 1, characterized in that, In step one, the silicon carbide slurry is prepared by mixing silicon carbide powder with a solid content of 70wt%-78wt%, dispersant KOS163 (a polymeric type containing acidic groups) with a mass fraction of 1%-1.5%, photosensitive resins HDDA (1,6-hexanediol diacrylate) and TMPTA (propane trimethylol triacrylate) with mass fractions of 33wt%-34wt% and 14wt%-15wt%, respectively, photoinitiator TPO (diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide) with a mass fraction of 1wt%-1.25wt%, and photoinitiator 819 (phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide) with a mass fraction of 0.5wt%-1wt%.
3. The method for preparing a silicon carbide microchannel heat exchanger based on photopolymerization printing process according to claim 1, characterized in that, In step two, the light source wavelength for photopolymerization printing is 350-410 nm, the printing layer thickness is 20-100 μm, and the exposure time is 5-30 s / layer.
4. The method for preparing a silicon carbide microchannel heat exchanger based on photopolymerization printing process according to claim 1, characterized in that, The method for degreasing a silicon carbide matrix according to claim 3 is characterized in that the degreasing treatment in step three is carried out at a temperature of 300-600℃, a heating rate of 0.5-2℃ / min, and a holding time of 2-6 h; the ratio of phenolic resin to anhydrous ethanol is 1:1-1:2, the impregnation time is 30-60 min, and the curing time is 1-2 h; the carbonization temperature is 600-800℃, the heating rate is 1-2℃ / min, and the holding time is 1-3 h.
5. The method for preparing a silicon carbide microchannel heat exchanger based on photopolymerization printing process according to claim 1, characterized in that, In step four, the sintering temperature is 1600-2000℃, the heating rate is 5-10℃ / min, and the holding time is 1-4 h.