A photosensitive resin, a photosensitive metal paste and application thereof, a photocured metal component and a preparation method and application thereof

Abstract

The present application relates to the technical field of metal additive manufacturing, and particularly relates to a photosensitive resin, a photosensitive metal slurry and application thereof, a light-cured metal component and a preparation method and application thereof. The photosensitive resin provided by the present application comprises raw materials including a photosensitive resin monomer, a photosensitive resin prepolymer and a photoinitiator; the photosensitive resin monomer comprises a first photosensitive resin monomer, and the first photosensitive resin monomer comprises one or more of 1,6-hexanediol diacrylate, lauryl acrylate, 2-propoxy neopentyl glycol diacrylate and 1,5-ethoxy trimethylolpropane triacrylate. The photosensitive metal slurry prepared by using the photosensitive resin is applied to the preparation of metal parts by light-cured 3D printing, and the problem of residual carbon caused by the debinding treatment in an oxygen-free atmosphere can be solved, and the precipitation of carbide in the microstructure of the light-cured metal material is avoided, so that the mechanical properties of the light-cured metal material are equivalent to those of the commercial forged metal, and the tribological properties are better than those of the commercial forged metal.

Description

Technical Field

[0001] This invention relates to the field of metal additive manufacturing technology, and in particular to a photosensitive resin, a photosensitive metal paste and its application, a photocurable metal component and its preparation method and application. Background Technology

[0002] The continuous innovation and development of metal additive manufacturing technology has provided numerous possibilities for the processing and manufacturing of metal parts with complex shapes, intricate structures, thin walls, or porous structures. Currently, the metal additive manufacturing technologies that have been extensively researched in academia and widely applied in industry mainly include powder bed fusion and direct energy deposition. These technologies utilize high-energy laser beams, electron beams, or other heat sources to directly melt and rapidly solidify metal powder or filaments, printing layer by layer until the entire part is manufactured. The rapid melting and solidification process of the metal raw materials easily yields fine-grained structures or non-equilibrium phases, resulting in materials with higher hardness, tensile strength, and yield strength than forged metals. However, instantaneous cooling leads to high residual stress and a certain degree of porosity within the material, resulting in low elongation at break and a susceptibility to deformation and cracking, posing potential risks when used under conditions requiring high fatigue performance and reliability.

[0003] Photopolymerization technology is another important branch of additive manufacturing, currently mainly used for the molding and preparation of ceramic materials, especially white or light-colored ceramics such as alumina, zirconium oxide, and silicon oxide. The main steps of this technology are, in sequence, preparation of the photosensitive metal paste (composed of powder of the material to be cured, photosensitive resin, photoinitiator, and various additives), 3D printing, debinding (removing organic components such as photosensitive resin), and high-temperature sintering (achieving powder densification). Its working principle is to use ultraviolet light to irradiate the photosensitive paste, causing the liquid paste to solidify rapidly, printing layer by layer until the entire part is formed, followed by debinding and high-temperature sintering to achieve material densification.

[0004] Photopolymerization is an indirect forming technology for metal parts. Compared to the rapid melting and solidification processes involved in powder bed fusion and direct energy deposition (DED) technologies, photopolymerization avoids problems such as stress, deformation, and cracking caused by thermal shrinkage, reduces porosity in the material, and helps minimize the loss of low-melting-point elements. Furthermore, photopolymerization offers high precision and high forming quality; the metal parts produced by photopolymerization exhibit significantly better dimensional accuracy and surface roughness than those produced by powder bed fusion and DED technologies.

[0005] However, achieving mechanical properties (density, tensile strength, and elongation at break) and functionalities (such as electrical conductivity, wear resistance, and corrosion resistance) comparable to forged metals using photopolymerization technology, while simultaneously ensuring high dimensional and surface accuracy, presents numerous technical challenges. Most importantly, to prevent metal powder oxidation, the degreasing process for metal-printed green blanks must be conducted in an oxygen-free atmosphere (such as inert atmospheres like argon or non-reactive atmospheres like nitrogen). This leads to incomplete decomposition of the photosensitive resin, leaving residual carbon on the metal powder surface. This residual carbon is difficult to completely remove during subsequent sintering, which has a destructive impact on the properties of the sintered metal material. For many metals, carbon is the most important alloying element; failing to address the residual carbon problem will significantly reduce the material's plasticity, corrosion resistance, and fatigue performance. Currently, there are no reports on how to solve the residual carbon problem. Summary of the Invention

[0006] The purpose of this invention is to provide a photosensitive resin, a photosensitive metal paste and its application, a photocurable metal component and its preparation method and application. The photosensitive metal paste formulated with the photosensitive resin, when applied to photocurable 3D printing of metal parts, can solve the problem of residual carbon caused by oxygen-free atmosphere degreasing treatment, and avoid the precipitation of carbides in the microstructure of the photocurable metal material. This results in the mechanical properties of the photocurable metal material being comparable to commercially available forged metals, and its tribological properties being superior to those of commercially available forged metals.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0008] This invention provides a photosensitive resin, the raw materials for which include photosensitive resin monomer, photosensitive resin prepolymer and photoinitiator;

[0009] The photosensitive resin monomer includes a first photosensitive resin monomer, which includes one or more of 1,6-hexanediol diacrylate, laurate acrylate, 2-propoxyneopentyl glycol diacrylate, and 1,5-ethoxytrimethylolpropane triacrylate.

[0010] Preferably, the photosensitive resin monomer further includes a second photosensitive resin monomer, and the mass ratio of the first photosensitive resin monomer to the second photosensitive resin monomer is (4~2):(1~3).

[0011] The second photosensitive resin monomer includes one or more of isobornyl acrylate, 4-hydroxybutyl acrylate, 1,9-nonanediol diacrylate and acryloylmorpholine.

[0012] Preferably, the mass ratio of the photosensitive resin monomer to the photosensitive resin prepolymer is (7~5):(3~5);

[0013] The photosensitive resin prepolymer is an aliphatic polyurethane acrylate and / or a modified polyurethane acrylate.

[0014] The present invention also provides a photosensitive metal paste, comprising a photosensitive resin and metal powder in a mass ratio of (25~7):(75~93);

[0015] The photosensitive resin is the photosensitive resin described in the above technical solution.

[0016] Preferably, the particle size distribution of the metal powder is in the range of 0~25μm;

[0017] The metal powder includes iron-based alloy powder, nickel-based alloy powder, titanium-based alloy powder, or copper-based alloy powder.

[0018] The present invention also provides the application of the photosensitive metal paste described in the above technical solution in 3D printing.

[0019] This invention also provides a method for preparing photocurable metal components, comprising the following steps:

[0020] The photosensitive metal paste is sequentially subjected to 3D printing, degreasing, carbon removal and sintering to obtain the photocurable metal component.

[0021] The photosensitive metal paste is the photosensitive metal paste described in the above technical solution;

[0022] The degreasing process is carried out in pure argon or an argon-hydrogen mixture.

[0023] The carbon removal and sintering processes are carried out independently in an argon-hydrogen mixture or pure hydrogen.

[0024] Preferably, the degreasing process is as follows: heating from room temperature to 200-300℃ at a heating rate of 0.2-2℃ / min, holding at this temperature for 30-120 min; heating from 200-300℃ to 400-500℃ at a heating rate of 0.05-0.5℃ / min, holding at this temperature for 60-180 min; finally heating from 400-500℃ to 550-650℃ at a heating rate of 0.2-2℃ / min, holding at this temperature for 30-120 min; and then cooling to room temperature.

[0025] The process for removing residual carbon is as follows: heating from room temperature to 550-650℃ at a heating rate of 5-20℃ / min, and holding at that temperature for 0-30min; heating from 550-650℃ to 950-1050℃ at a heating rate of 0.5-2.5℃ / min, and holding at that temperature for 0-60min.

[0026] The sintering process is as follows: the temperature is increased from 950 to 1050°C to the final sintering temperature at a heating rate of 0.5 to 1°C / min, held at that temperature for 4 to 8 hours, and then cooled to room temperature.

[0027] The present invention also provides photocurable metal components prepared by the preparation method described in the above technical solution.

[0028] The present invention also provides the application of the photocurable metal components described in the above technical solution in the field of friction.

[0029] This invention provides a photosensitive resin, the raw materials of which include a photosensitive resin monomer, a photosensitive resin prepolymer, and a photoinitiator. The photosensitive resin monomer includes a first photosensitive resin monomer, which comprises one or more of 1,6-hexanediol diacrylate, laurate acrylate, 2-propoxyneopentyl glycol diacrylate, and 1,5-ethoxytrimethylolpropane triacrylate. When the photosensitive resin prepared using the specific photosensitive resin monomer of this invention is applied to the preparation of photocurable metal components, it can reduce the residual carbon elements generated on the surface of the metal powder during the debinding process of the photosensitive resin. This results in the prepared photocurable metal material having mechanical properties comparable to commercially available forged metals, and tribological properties superior to commercially available forged metals.

[0030] This invention also provides a photosensitive metal paste, comprising a photosensitive resin and metal powder in a mass ratio of (25~7):(75~93); the photosensitive resin is the photosensitive resin described in the above technical solution. The photosensitive metal paste of this invention has a high paste viscosity (50~200 Pa·s) in a static state, which can slow down the settling speed of the metal powder and ensure that the solid content of the metal powder is maximized while ensuring smooth printing; simultaneously, the photosensitive metal paste exhibits obvious shear thinning characteristics, and has a low paste viscosity during the spreading process (the viscosity range during the spreading process in 3D printing is 1~10 Pa·s), which can ensure smooth spreading of the paste and improve the quality and precision of curing.

[0031] This invention also provides a method for preparing a photocurable metal component, comprising the following steps: sequentially performing 3D printing, degreasing, carbon removal, and sintering on a photosensitive metal slurry to obtain the photocurable metal component; the photosensitive metal slurry is the photosensitive metal slurry described in the above-mentioned technical solution. The preparation method removes most of the photosensitive resin polymer through degreasing, and removes residual carbon through carbon removal and sintering processes, thus avoiding carbide precipitation in the microstructure of the photocurable metal material, achieving densification of the metal powder, and making the mechanical properties of the prepared photocurable metal material comparable to those of commercially available forged metal, while its tribological properties are superior to those of commercially available forged metal.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The mechanical properties of metal materials prepared by photopolymerization technology are comparable to those of commercially available forged metals, and their tribological properties are superior. Compared with the two more mature metal 3D printing technologies, powder bed melting and direct energy deposition, metal parts prepared by photopolymerization technology have higher dimensional accuracy and surface quality. Attached Figure Description

[0034] Figure 1 SEM image (a) and particle size distribution curve (b) of the sieved stainless steel powder described in Example 1.

[0035] Figure 2 The viscosity of the photosensitive metal paste described in Example 1 is shown as a function of shear rate.

[0036] Figure 3 This is a schematic diagram illustrating the printing principle of photopolymer 3D printing as described in this invention;

[0037] Figure 4 The measured dimensions are those of the rectangular photocurable metal component actually prepared in Example 1.

[0038] Figure 5 The images show SEM images, three-dimensional morphology, and surface roughness of the photocurable metal component described in Example 1 on the exposure plane (a) and on the plane perpendicular to the exposure plane (b).

[0039] Figure 6 The engineering stress-strain curves of the photocured AISI 316L stainless steel described in Example 1 and the commercially available forged AISI 316L stainless steel are shown.

[0040] Figure 7 The dynamic polarization curves are those of the photocured AISI 316L stainless steel described in Example 1 and the commercially available forged AISI 316L stainless steel.

[0041] Figure 8 The friction coefficient curves (a) and wear rates (b) of the photocured AISI 316L stainless steel described in Example 1 and commercially available forged AISI 316L stainless steel in a 3.5wt% NaCl aqueous solution are shown.

[0042] Figure 9 This is a photograph of the photocurable AISI 316L stainless steel part described in Example 1;

[0043] Figure 10 The engineering stress-strain curves of the photocurable AISI 316L stainless steel materials described in Examples 1 and 7 are shown.

[0044] Figure 11The engineering stress-strain curves of the photocurable AISI 316L stainless steel materials described in Comparative Example 1 and Example 1 are shown.

[0045] Figure 12 The engineering stress-strain curves of the photocurable AISI 316L stainless steel materials described in Comparative Example 3 and Example 1 are shown.

[0046] Figure 13 Metallurgical microscope images of the photocurable AISI 316L stainless steel material (a) described in Comparative Example 3 and the photocurable AISI 316L stainless steel material (b) described in Example 1. Detailed Implementation

[0047] This invention provides a photosensitive resin, the raw materials for which include photosensitive resin monomer, photosensitive resin prepolymer and photoinitiator;

[0048] The photosensitive resin monomer includes a first photosensitive resin monomer, which includes one or more of 1,6-hexanediol diacrylate, laurate acrylate, 2-propoxyneopentyl glycol diacrylate, and 1,5-ethoxytrimethylolpropane triacrylate.

[0049] In this invention, unless otherwise specified, all raw materials used in the preparation are commercially available products well known to those skilled in the art.

[0050] In this invention, the first photosensitive resin monomer includes one or more of 1,6-hexanediol diacrylate (HDDA), laurate acrylate (LA), 2-propoxyneopentyl glycol diacrylate (2PO-NPGDA), and 15-ethoxytrimethylolpropane triacrylate (15EO-TMPTA). When the first photosensitive resin monomer is two or more of the above-mentioned specific selections, this invention does not impose any special limitation on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio.

[0051] In this invention, the photosensitive resin monomer preferably further includes a second photosensitive resin monomer, which preferably includes one or more of isobornyl acrylate (IBOA), 4-hydroxybutyl acrylate (4-HBA), 1,9-nonanediol diacrylate (NDDA), and acrylmorpholine (ACMO). When the second photosensitive resin monomer is two or more of the above-mentioned specific selections, this invention does not impose any special limitation on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio.

[0052] In this invention, the mass ratio of the first photosensitive resin monomer to the second photosensitive resin monomer is preferably (4~2):(1~3), more preferably (3.5~2.5):(1.5~2.5), and most preferably (3.2~2.8):(1.8~2.2).

[0053] In this invention, the photosensitive resin prepolymer is an aliphatic polyurethane acrylate and / or a modified polyurethane acrylate; the aliphatic polyurethane acrylate is preferably a difunctional aliphatic polyurethane acrylate U600; the modified polyurethane acrylate is preferably a modified difunctional polyurethane acrylate Easepi 864; when the photosensitive resin prepolymer is an aliphatic polyurethane acrylate and a modified polyurethane acrylate, this invention does not impose any special limitation on the ratio of the aliphatic polyurethane acrylate and the modified polyurethane acrylate, and they can be mixed in any ratio.

[0054] In this invention, the preferred mass ratio of the photosensitive resin monomer to the photosensitive resin prepolymer is (7~5):(3~5), more preferably (6.8~5.2):(3.2~4.8), and most preferably (6.5~5.5):(3.5~4.5).

[0055] In this invention, controlling the mass ratio of the photosensitive resin monomer and the photosensitive resin prepolymer within the above-mentioned range is intended to obtain a photosensitive resin with higher viscosity. This results in a metal slurry with higher viscosity after the addition of metal powder, thereby slowing down the settling speed of the metal powder and ensuring the smooth curing and molding of the high-solids-content metal slurry.

[0056] In this invention, the photoinitiator preferably includes trimethylbenzoyl diphenylphosphine oxide; the mass percentage of the photoinitiator in the total mass of the photosensitive resin monomer and the photosensitive resin prepolymer is preferably 0.5-5%, more preferably 1-4.5%, and most preferably 1.5-4%.

[0057] In this invention, the raw materials for preparing the photosensitive resin preferably include dispersants and defoamers.

[0058] In this invention, the dispersant preferably includes one or more of oleic acid, sodium dodecylbenzenesulfonate, polyacrylic acid, polycarboxylic acid, and polyvinyl alcohol. When the dispersant is two or more of the above-mentioned specific selections, this invention does not impose any special limitation on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio. In this invention, the mass percentage of the dispersant relative to the total mass of the photosensitive resin monomer and the photosensitive resin prepolymer is preferably 0.1-3%, more preferably 0.5-2.3%, and most preferably 1.2-1.7%.

[0059] In this invention, the defoamer preferably includes one or more of BYK-052N, ACP-1400, KSZ-108, and BYK-088. When the defoamer is two or more of the above-mentioned specific selections, this invention does not impose any special limitation on the proportion of the above-mentioned specific substances, and they can be mixed in any proportion. In this invention, the mass percentage of the defoamer relative to the total mass of the photosensitive resin monomer and the photosensitive resin prepolymer is preferably 0.1-2%, more preferably 0.2-1.8%, and most preferably 0.4-1.5%.

[0060] In this invention, the method for preparing the photosensitive resin preferably includes the following steps:

[0061] The photosensitive resin is obtained by mixing the photosensitive resin monomer, the photosensitive resin prepolymer and the photoinitiator.

[0062] In this invention, the mixing is preferably performed by first mixing the photosensitive resin monomer and the photosensitive resin prepolymer, then adding the photoinitiator and stirring. The stirring temperature is preferably 30~60℃, more preferably 35~50℃, and most preferably 40℃; the stirring speed is preferably 200~600 r / min, more preferably 300~500 r / min, and most preferably 400 r / min; the stirring time is preferably 0.5~3 h, more preferably 0.8~2 h, and most preferably 1 h.

[0063] After mixing, the present invention preferably includes the sequential addition of a dispersant and an antifoaming agent to the resulting mixture. The present invention does not impose any special limitations on the process of adding the dispersant and antifoaming agent; any process well-known to those skilled in the art can be used. In the present invention, after adding the dispersant and antifoaming agent, stirring is preferably included. The stirring temperature is preferably 30-60°C, more preferably 35-50°C, and most preferably 40°C; the stirring speed is preferably 200-600 r / min, more preferably 300-500 r / min, and most preferably 400 r / min. The stirring time is preferably 0.5-3 h, more preferably 0.8-2 h, and most preferably 1 h.

[0064] In this invention, the photosensitive resin has good photocuring and rheological properties, and high interlayer bonding strength.

[0065] The present invention also provides a photosensitive metal paste, comprising a photosensitive resin and metal powder in a mass ratio of (25~7):(75~93);

[0066] The photosensitive resin is the photosensitive resin described in the above technical solution.

[0067] In this invention, the particle size distribution range of the metal powder is preferably 0~25μm. In an embodiment of this invention, the metal powder is preferably obtained by vibrating and sieving commercially available metal powder with a particle size ≤30μm. The vibrating and sieving is preferably performed using a 1000-mesh sieve.

[0068] In this invention, the metal powder preferably includes iron-based alloy powder, nickel-based alloy powder, titanium-based alloy powder, or copper-based alloy powder. This invention does not impose any particular limitation on the type of iron-based alloy powder, nickel-based alloy powder, titanium-based alloy powder, or copper-based alloy powder; any type well-known to those skilled in the art can be used. In embodiments of this invention, the metal powder can be AISI 316L stainless steel powder, AISI 304L stainless steel powder, 17-4PH martensitic stainless steel powder, Inconel 625 nickel-based alloy powder, Ti6Al4V titanium alloy powder, or pure copper powder.

[0069] In this invention, the preferred mass ratio of the photosensitive resin to the metal powder is (25~7):(75~93), more preferably (23~8):(77~92), and most preferably (21~9):(79~91).

[0070] In this invention, the preparation method of the photosensitive metal paste preferably includes the following steps:

[0071] The photosensitive resin and metal powder are mixed and then homogenized to obtain the photosensitive metal paste.

[0072] The present invention does not impose any special limitations on the mixing process; any process known to those skilled in the art can be used.

[0073] In this invention, the rotational speed of the homogenization process is preferably 300-900 r / min, more preferably 400-800 r / min, and most preferably 500-700 r / min; the homogenization time is preferably 1-10 min, more preferably 2-8 min, and most preferably 3-7 min; the homogenization process is preferably carried out under vacuum conditions, and the vacuum degree is preferably 0-5 kPa, more preferably 0-3 kPa, and most preferably 0-1.3 kPa. In an embodiment of this invention, the homogenization process is specifically carried out in a centrifugal homogenizer.

[0074] In this invention, the homogenization process serves to achieve thorough mixing of the metal powder and the photosensitive resin, and to remove air bubbles from the photosensitive metal slurry.

[0075] The present invention also provides the application of the photosensitive metal paste described in the above technical solution in 3D printing.

[0076] This invention also provides a method for preparing photocurable metal components, comprising the following steps:

[0077] The photosensitive metal paste is sequentially subjected to 3D printing, degreasing, carbon removal and sintering to obtain the photocurable metal component.

[0078] The photosensitive metal paste is the photosensitive metal paste described in the above technical solution.

[0079] The present invention involves sequentially performing 3D printing, degreasing, carbon removal, and sintering on a photosensitive metal paste to obtain the photocurable metal component.

[0080] Before performing the 3D printing, the present invention preferably includes a vacuum degassing process. The vacuum level of the vacuum degassing process is preferably 0-5 kPa, more preferably 0-3 kPa, and most preferably 0-1.3 kPa. The rotation speed of the vacuum degassing process is preferably 300-900 r / min, more preferably 400-800 r / min, and most preferably 500-700 r / min. The duration of the vacuum degassing process is preferably 1-6 min, more preferably 2-5 min, and most preferably 3-4 min. In an embodiment of the present invention, the vacuum degassing process is specifically performed in a centrifugal homogenizer.

[0081] In this invention, the energy density of the light source for 3D printing is preferably 10~90 mW / cm². 2 More preferably 20~80mW / cm 2 The optimal value is 30~60mW / cm. 2 The exposure time is preferably 3-50s, more preferably 5-40s, and most preferably 10-30s; the printing thickness is preferably 15-50μm / layer, more preferably 18-45μm / layer, and most preferably 20-40μm / layer. In this invention, the 3D printing preferably uses a digital light processing photopolymerization 3D printer. Compared with stereolithography photopolymerization 3D printers, digital light processing photopolymerization 3D printers have higher printing efficiency and can reduce the risk of printing failure due to metal powder settling. In this invention, the digital light processing photopolymerization 3D printer is preferably equipped with a real-time slurry stirring and replenishment device. On the one hand, the photosensitive metal slurry is stirred in real time to prevent metal powder settling; on the other hand, the slurry in the slurry tank is replenished in a timely manner. The amount of slurry replenished is controlled by a liquid level sensor installed at the top of the slurry tank. Under the premise of ensuring continuous printing, the amount of slurry replenished at one time should be as small as possible to further improve the problem of metal powder settling in the photosensitive metal slurry (e.g., Figure 3(As shown). In this invention, the unprinted photosensitive metal paste is preferably stirred in real time during the 3D printing process. This invention does not impose any special limitations on the real-time stirring process; any process well-known to those skilled in the art can be used. In this invention, the real-time stirring can further improve the problem of metal powder sedimentation in the photosensitive metal paste.

[0082] After the 3D printing is completed, the present invention preferably includes sequential cleaning and drying. In this invention, isopropanol is preferably used as the cleaning agent. The present invention does not impose any special limitations on the cleaning process; any process well-known to those skilled in the art can be used. Similarly, the present invention does not impose any special limitations on the drying process; any process well-known to those skilled in the art can be used.

[0083] In this invention, the degreasing treatment is preferably carried out in pure argon or an argon-hydrogen mixture, and the carbon removal and sintering treatments are preferably carried out independently in an argon-hydrogen mixture or pure hydrogen. When the degreasing, carbon removal, and sintering treatments are carried out in an argon-hydrogen mixture, the hydrogen content in the argon-hydrogen mixture is preferably 1-99%, more preferably 2-99%, and most preferably 3-99%. In this invention, the gas flow rate of the pure argon, argon-hydrogen mixture, or pure hydrogen is preferably 0.1-2 L / min, more preferably 0.3-1.8 L / min, and most preferably 0.5-1.5 L / min. In this invention, the control of the above gas flow rate can maintain the gas flow in a laminar state, which is conducive to more complete decomposition of the photosensitive resin and less carbon residue.

[0084] In this invention, the degreasing treatment is preferably performed using a stepped heating process. The stepped heating process is preferably as follows: heating from room temperature to 200-300°C at a heating rate of 0.2-2°C / min, holding at this temperature for 30-120 min; heating from 200-300°C to 400-500°C at a heating rate of 0.05-0.5°C / min, holding at this temperature for 60-180 min; and finally heating from 400-500°C to 550-650°C at a heating rate of 0.2-2°C / min, holding at this temperature. 30~120 min; cool to room temperature with the furnace; more preferably, heat from room temperature to 230~270℃ at a heating rate of 0.5~1.5℃ / min and hold for 60~90 min; heat from 230~270℃ to 430~470℃ at a heating rate of 0.05~0.2℃ / min and hold for 90~150 min; finally heat from 430~470℃ to 570~630℃ at a heating rate of 0.5~1.5℃ / min and hold for 60~90 min; cool to room temperature with the furnace.

[0085] In this invention, the carbon removal process is preferably carried out at a heating rate of 5-20°C / min, raising the temperature from room temperature to 550-650°C and holding for 0-30 min; at a heating rate of 0.5-2.5°C / min, raising the temperature from 550-650°C to 950-1050°C and holding for 0-60 min; more preferably, at a heating rate of 10-15°C / min, raising the temperature from room temperature to 560-630°C and holding for 0-20 min; and at a heating rate of 1.0-2.0°C / min, raising the temperature from 560-630°C to 980-1020°C and holding for 20-50 min. In this invention, the above heating rate and holding time allow the residual carbon to fully react with hydrogen (chemical equation: ...). This achieves the purpose of thoroughly removing residual carbon.

[0086] In this invention, the sintering process is preferably carried out at a heating rate of 0.5~1℃ / min, from 950~1050℃ to the final sintering temperature, held at that temperature for 4~8 hours, and then cooled to room temperature; more preferably, the heating rate is 0.6~0.8℃ / min, from 980~1020℃ to the final sintering temperature, held at that temperature for 5~7 hours, and then cooled to room temperature. In this invention, the final sintering temperature is preferably 20~100℃ lower than the melting point of the metal powder in the photosensitive metal paste. In this invention, the cooling is preferably furnace cooling. In this invention, the sintering process can achieve the purpose of metal densification, giving the prepared photocurable metal component high precision and excellent mechanical and tribological properties.

[0087] The present invention also provides photocurable metal components prepared by the preparation method described in the above technical solution.

[0088] This invention also provides the application of the photocurable metal components described above in the field of friction. This invention does not impose any special limitations on the methods for these applications; methods well-known to those skilled in the art can be used.

[0089] The following detailed descriptions, in conjunction with embodiments, illustrate the photosensitive resin, photosensitive metal paste and their applications, as well as the photocurable metal components and their preparation methods and applications provided by the present invention. However, these descriptions should not be construed as limiting the scope of protection of the present invention.

[0090] Example 1

[0091] According to the mass ratio of 2.5:1:2:4.5, the first photosensitive resin monomer LA (25g) and HDDA (10g), the second photosensitive resin monomer IBOA (20g), and the photosensitive resin prepolymer U600 (45g) were mixed. Then, 1g of photoinitiator trimethylbenzoyl diphenylphosphine oxide (1% of the total mass of LA, HDDA, IBOA, and U600) was added. The mixture was stirred for 1 hour at 40℃ and 400r / min using a magnetic stirrer. Then, 1g of dispersant oleic acid (1% of the total mass of LA, HDDA, IBOA, and U600) was added. The mixture was stirred for 1 hour at 40℃ and 400r / min using a magnetic stirrer. Finally, 0.3g of defoamer BYK-052N (0.3% of the total mass of LA, HDDA, IBOA, and U600) was added. The mixture was stirred for 1 hour at 40℃ and 400r / min using a magnetic stirrer to obtain the photosensitive resin.

[0092] Commercially available AISI 316L stainless steel powder with a particle size ≤30μm was sieved through a 1000-mesh sieve using a vibrating sieve to obtain the sieved stainless steel powder (SEM image shown). Figure 1 As shown in 'a', the particle size distribution curve is as follows: Figure 1 As shown in b, by Figure 1 It can be seen that the sieved stainless steel powder has good sphericity, a smooth surface, and almost no satellite particles. The particle size of the sieved stainless steel powder is 3~25μm, and the particle size distribution exhibits a Gaussian distribution characteristic. 10 It is 6.4 μm, d 50 It is 11.3 μm, d 90 (18.8μm)

[0093] The sieved stainless steel powder and the above photosensitive resin were mixed at a mass ratio of 88:12 and then homogenized in a centrifugal homogenizer (rotation speed 560 r / min, time 3 min, vacuum degree 1.3 kPa) to obtain a photosensitive metal slurry.

[0094] The rheological properties of the photosensitive metal paste were tested using a rotational rheometer. The test conditions were as follows: a parallel disk module was used, with a disk diameter of 50 mm, a disk spacing of 0.5 mm, and a shear rate variation range of 0.01–1000 s⁻¹. -1 The temperature is 25℃. Figure 2 This is a curve showing the viscosity of the photosensitive metal paste as a function of shear rate. Figure 2It can be seen that the viscosity of the photosensitive metal paste decreases with increasing shear rate, exhibiting a clear shear-thinning behavior. When the photosensitive metal paste is left to stand (shear rate approaches 0), its viscosity is relatively high, approximately 112 Pa·s, indicating a slow settling rate of the metal powder in the paste, which is related to the high amount of photosensitive resin prepolymer used. When the shear rate is 333 s⁻¹... -1 When the viscosity value is low (approximately 3.4 Pa·s) during the shear rate action of the slurry during the 3D printing process, it is easy to spread the photosensitive metal slurry, which is beneficial to improving the forming quality and accuracy of photopolymer 3D printing.

[0095] The photosensitive metal slurry was vacuum degassed in a centrifugal homogenizer (660 r / min, 3 min, 1.3 kPa vacuum) before photopolymerization 3D printing. A digital light processing photopolymerization 3D printer equipped with a real-time slurry stirring and replenishment device was selected (printing principle as follows). Figure 3 As shown), the parameters for the photopolymerization 3D printing are: light source energy density of 45 mW / cm². 2 The exposure time was 15s, and the printing thickness was 25μm / layer, resulting in a green blank of a metal part.

[0096] After the green blank of the metal part is cleaned with isopropanol to remove residual slurry and dried, it is degreased in a controlled atmosphere box furnace. The degreasing atmosphere is an argon-hydrogen mixture with a hydrogen content of 5% and a gas flow rate of 0.5 L / min to maintain laminar flow. The degreasing process is as follows: the temperature is increased from room temperature to 250°C at a heating rate of 1°C / min and held for 60 min; the temperature is increased from 250°C to 450°C at a heating rate of 0.15°C / min and held for 120 min; finally, the temperature is increased from 450°C to 550°C at a heating rate of 0.5°C / min and held for 60 min; the furnace is then cooled to room temperature to obtain the brown blank of the metal part.

[0097] The metal part blanks were subjected to carbon removal (using an argon-hydrogen mixture with a hydrogen content of 5% and a gas flow rate of 0.5 L / min to maintain laminar flow; the process involved heating from room temperature to 550°C at a rate of 10°C / min, then heating from 550°C to 1000°C at a rate of 1.625°C / min, and holding at that temperature for 30 min) and sintering (using an argon-hydrogen mixture with a hydrogen content of 5% and a gas flow rate of 0.5 L / min to maintain laminar flow; the process involved heating from 1000°C to 1380°C at a rate of 0.67°C / min, holding at that temperature for 6 h, and then cooling to room temperature with the furnace) to obtain high-precision, photocured metal components with excellent mechanical and tribological properties (denoted as AISI 316L stainless steel parts).

[0098] The photocurable metal component was designed as a cuboid according to the preparation method of Example 1. The dimensions of the cuboid in the length, width, and height directions were designed to be 20mm × 15mm × 4mm. The actual photocurable metal component was measured. Figure 4 The actual measured dimensions of the photocured metal components obtained from the fabrication process are given by... Figure 4 It can be seen that the dimensional errors of the photocurable metal components actually prepared are +0.35%, +0.20%, and -0.25% in the length, width, and height directions, respectively, which shows that they have very high dimensional accuracy.

[0099] Figure 5 The images show SEM photographs, three-dimensional morphology, and surface roughness of the photocurable metal component described in Example 1 on the exposure plane (a) and on a plane perpendicular to the exposure plane (b). Figure 5 It can be seen that in the direction of the exposure plane, its surface is smooth and flat with a surface roughness of only 1.7 μm. In the direction perpendicular to the exposure plane, its surface has a small number of pores and a surface roughness of 6.0 μm. This shows that the metal components prepared by photopolymerization technology have high surface quality, whether in the exposure plane or the side.

[0100] The density of the photocured metal component, measured using Archimedes' displacement method, was 7.65 g / cm³. 3 The density reached 95.9%. Room temperature tensile tests (loading rate 0.5 mm / min) were conducted using a general-purpose mechanical testing machine to evaluate the mechanical properties of the photocured metal components and to compare them with commercially available forged AISI 316L stainless steel. Rectangular cross-section tensile specimens were directly printed using photocuring technology. After degreasing, sintering, grinding, and polishing, the cross-sectional dimensions were approximately 3.3 × 2 mm, and the parallel length was approximately 11 mm. Forged AISI 316L stainless steel tensile specimens were machined using an EDM wire cutting machine, with dimensions identical to the above. The engineering stress-strain curves of the two types of specimens are shown below. Figure 6 As shown, by Figure 6 It can be seen that the photocurable AISI 316L stainless steel material described in Example 1 has a tensile strength of 543 MPa, a yield strength of 180 MPa, and an elongation at break of 62%; the commercially available forged AISI 316L stainless steel material has a tensile strength of 564 MPa, a yield strength of 185 MPa, and an elongation at break of 85%, and the mechanical properties of the two materials are comparable.

[0101] AISI 316L stainless steel is widely used in marine engineering equipment, petrochemicals, and other industries due to its excellent corrosion resistance. Therefore, maintaining the excellent corrosion resistance is crucial when using photopolymerization technology to fabricate AISI 316L stainless steel metal components. Corrosion resistance is evaluated using dynamic polarization curves measured with an electrochemical workstation. Ag / AgCl was selected as the reference electrode, a platinum electrode as the auxiliary electrode, and the photopolymerized AISI 316L stainless steel or commercially available forged AISI 316L stainless steel was used as the working electrode. The electrolyte was a 3.5wt% NaCl aqueous solution. Both the photopolymerized AISI 316L and commercially available forged AISI 316L were immersed in the 3.5wt% NaCl aqueous solution for 1 hour to stabilize their surface state. Then, dynamic polarization curve tests were performed. The scanning range of the working electrode relative to the reference electrode was -0.6V to +0.6V, and the scanning speed was 0.5mV / s. The dynamic polarization curves of the two materials are shown below. Figure 7 As shown, the etching potential of the photocurable AISI 316L described in Example 1 is -0.163V, and the etching current density is 1.70×10⁻⁶. -7 A / cm 2 The corrosion potential of commercially available forged AISI 316L is -0.156V and the corrosion current density is 1.08×10⁻⁶. -7 A / cm 2 The similarity indicates that the corrosion resistance of the photocurable AISI 316L material prepared by this invention in a 3.5wt% NaCl aqueous solution is comparable to that of commercially available forged AISI 316L material.

[0102] The photocured AISI 316L stainless steel material or commercially available forged AISI 316L stainless steel material was subjected to corrosion and friction performance testing. The test was conducted on a reciprocating friction testing machine equipped with an electrochemical workstation. The corrosive medium was a 3.5wt% NaCl aqueous solution. Ag / AgCl was selected as the reference electrode, a platinum electrode as the auxiliary electrode, and the photocured AISI 316L stainless steel material or commercially available forged AISI 316L stainless steel material as the working electrode. The photocured AISI 316L stainless steel material or commercially available forged AISI 316L stainless steel material was subjected to reciprocating sliding motion relative to a stationary Si3N4 sphere (6mm in diameter). The sliding stroke was 10mm, the load was 10N, and the reciprocating frequency was 2Hz. Before the test, the photocured AISI 316L stainless steel material or commercially available forged AISI 316L stainless steel material was immersed in a 3.5wt% NaCl aqueous solution for 10min. Then, a triboelectric corrosion test was conducted at open circuit potential (OCP) for 40min, followed by 10min of rest after unloading. The entire test lasted for 1h, and the electrochemical workstation automatically recorded the potential and current throughout the process. Figure 8The friction coefficient curves (a) and wear rate (b) of the aforementioned photocured AISI 316L stainless steel and commercially available forged AISI 316L stainless steel in a 3.5wt% NaCl aqueous solution are provided by [the relevant authority / organization]. Figure 8 It can be seen that the coefficient of friction of both photocured AISI 316L stainless steel and commercially available forged AISI 316L stainless steel is about 0.45. However, the wear rate of photocured AISI 316L stainless steel is reduced by 31.8% compared with that of commercially available forged AISI 316L stainless steel, and its tribological properties are superior to those of commercially available forged AISI 316L stainless steel.

[0103] Figure 9 The image shows a physical photograph of the photocured AISI 316L stainless steel part prepared in Example 1. Figure 9 It is evident that photopolymerization technology produces complex-shaped metal parts with high dimensional accuracy and low surface roughness, free from deformation, warping, delamination, and cracking. It also exhibits four micropores with a diameter of 0.5 mm along the printing direction and two micropores perpendicular to the printing direction, demonstrating high shape accuracy. Compared to traditional metal forming methods such as casting, mold forming, and machining, photopolymerization 3D printing technology has unique advantages in preparing complex-shaped metal parts with internal channels, fine structures, thin walls, or porous structures. It eliminates the need for molds, allows for customization, offers low cost, and has a short production cycle, providing a simple and efficient method for manufacturing complex metal components.

[0104] Example 2

[0105] The first photosensitive resin monomers 2PO-NPGDA (20g) and LA (10g), the second photosensitive resin monomer ACMO (20g), and the photosensitive resin prepolymer Easepi 864 (50g) were mixed in a mass ratio of 2:1:2:5. Then, 1.5g of the photoinitiator trimethylbenzoyl diphenylphosphine oxide (1.5% of the total mass of 2PO-NPGDA, LA, ACMO, and Easepi 864) was added. The mixture was stirred for 1 hour at 40℃ and 400 rpm using a magnetic stirrer. Next, 1g of the dispersant polyacrylic acid (1% of the total mass of 2PO-NPGDA, LA, ACMO, and Easepi 864) was added. The mixture was stirred for 1 hour at 40℃ and 400 rpm using a magnetic stirrer. Finally, 0.5g of the defoamer ACP-1400 (1% of the total mass of 2PO-NPGDA, LA, ACMO, and Easepi 864) was added. The photosensitive resin was obtained by stirring the mixture (0.5% of the total mass of 864) at 40℃ and 400r / min for 1h using a magnetic stirrer.

[0106] Commercially available AISI 304L stainless steel powder with a particle size ≤30μm was sieved through a 1000-mesh sieve using a vibrating sieve to obtain sieved stainless steel powder.

[0107] The sieved stainless steel powder and the above photosensitive resin were mixed at a mass ratio of 87:13 and then homogenized in a centrifugal homogenizer (rotation speed 560 r / min, time 3 min, vacuum degree 1.3 kPa) to obtain a photosensitive metal slurry.

[0108] The photosensitive metal slurry was vacuum degassed in a centrifugal homogenizer (660 r / min, 3 min, 1.3 kPa vacuum) before photopolymerization 3D printing. A digital light processing photopolymerization 3D printer equipped with a real-time slurry stirring and replenishment device was selected. The parameters for the photopolymerization 3D printing were: light source energy density of 45 mW / cm³. 2 The exposure time was 18s, and the printing thickness was 25μm / layer, resulting in a green blank of a metal part.

[0109] After the green blank of the metal part is cleaned with isopropanol to remove residual slurry and dried, it is degreased in a controlled atmosphere box furnace. The degreasing atmosphere is pure argon, and the gas flow rate is 1L / min to maintain the gas flow in a laminar state. The degreasing process is as follows: the temperature is increased from room temperature to 250℃ at a heating rate of 1.5℃ / min and held for 50min; the temperature is increased from 250℃ to 450℃ at a heating rate of 0.2℃ / min and held for 120min; finally, the temperature is increased from 450℃ to 600℃ at a heating rate of 1℃ / min and held for 60min; the furnace is then cooled to room temperature to obtain the brown blank of the metal part.

[0110] The metal part blanks were subjected to carbon removal (using pure hydrogen atmosphere, gas flow rate of 1L / min to maintain laminar flow, process of heating from room temperature to 600℃ at a heating rate of 10℃ / min, then heating from 600℃ to 1000℃ at a heating rate of 2.5℃ / min, and holding at that temperature for 30min) and sintering treatment (using pure hydrogen atmosphere, gas flow rate of 1L / min to maintain laminar flow, process of heating from 1000℃ to 1360℃ at a heating rate of 0.8℃ / min, holding at that temperature for 7h, and then cooling to room temperature with the furnace) in a tube furnace to obtain high-precision, photocured metal components with excellent mechanical and tribological properties (denoted as AISI 304L stainless steel parts).

[0111] Example 3

[0112] According to a mass ratio of 2:1.5:2:4.5, the first photosensitive resin monomer HDDA (20g), 15EO-TMPTA (15g), the second photosensitive resin monomer IBOA (20g), and the photosensitive resin prepolymer U600 (45g) were mixed, and then 1g of photoinitiator trimethylbenzoyl diphenylphosphine oxide (1% of the total mass of HDDA, 15EO-TMPTA, IBOA, and U600) was added. The mixture was then subjected to magnetic induction at 40℃ and 400 r / min. After stirring for 1 hour, 1 g of dispersant oleic acid (1% of the total mass of HDDA, 15EO-TMPTA, IBOA, and U600) was added, and the mixture was stirred for 1 hour at 40°C and 400 r / min using a magnetic stirrer. Then, 0.5 g of defoamer BYK-052N (0.5% of the total mass of HDDA, 15EO-TMPTA, IBOA, and U600) was added, and the mixture was stirred for 1 hour at 40°C and 400 r / min using a magnetic stirrer to obtain the photosensitive resin.

[0113] Commercially available 17-4PH martensitic stainless steel powder with a particle size ≤30μm was sieved through a 1000-mesh sieve using a vibrating sieve to obtain sieved martensitic stainless steel powder.

[0114] The sieved martensitic stainless steel powder and the above photosensitive resin were mixed at a mass ratio of 86:14 and then homogenized in a centrifugal homogenizer (rotation speed 560 r / min, time 3 min, vacuum degree 1.3 kPa) to obtain a photosensitive metal slurry.

[0115] The photosensitive metal slurry was subjected to vacuum degassing in a centrifugal homogenizer (660 r / min, 3 min, 1.3 kPa vacuum) before photopolymerization 3D printing. A digital light processing photopolymerization 3D printer equipped with a real-time slurry stirring and replenishment device was selected. The parameters for the photopolymerization 3D printing were: light source energy density of 50 mW / cm³. 2 The exposure time was 20 seconds, and the printing thickness was 25 μm / layer, resulting in a green blank of a metal part.

[0116] After the green blank of the metal part is cleaned with isopropanol to remove residual slurry and dried, it is degreased in a controlled atmosphere box furnace. The degreasing atmosphere is an argon-hydrogen mixture with a hydrogen content of 5% and a gas flow rate of 0.5 L / min to maintain laminar flow. The degreasing process is as follows: the temperature is increased from room temperature to 250°C at a rate of 1°C / min and held for 60 min; the temperature is increased from 250°C to 470°C at a rate of 0.3°C / min and held for 180 min; finally, the temperature is increased from 470°C to 650°C at a rate of 1.5°C / min and held for 60 min; the furnace is then cooled to room temperature to obtain the brown blank of the metal part.

[0117] The metal part blanks were subjected to carbon removal (using an argon-hydrogen mixture with a hydrogen content of 10% and a gas flow rate of 0.5 L / min to maintain laminar flow; the process involved heating from room temperature to 650°C at a rate of 10°C / min, then heating from 650°C to 950°C at a rate of 1°C / min, and holding at that temperature for 60 min) and sintering (using an argon-hydrogen mixture with a hydrogen content of 10% and a gas flow rate of 0.5 L / min to maintain laminar flow; the process involved heating from 950°C to 1370°C at a rate of 0.75°C / min, holding at that temperature for 6.5 h, and then cooling to room temperature with the furnace) in a tube furnace to obtain high-precision, photocured metal components with excellent mechanical and tribological properties (denoted as 17-4PH martensitic stainless steel parts).

[0118] Example 4

[0119] Following a mass ratio of 2.5:1.5:1.5:4.5, 45g of Easepi 864 (a photosensitive resin prepolymer) containing the first photosensitive resin monomers HDDA (25g), LA (15g), and the second photosensitive resin monomer ACMO (15g) was mixed. Then, 1.5g of the photoinitiator trimethylbenzoyl diphenylphosphine oxide (1.5% of the total mass of HDDA, LA, ACMO, and Easepi 864) was added. The mixture was stirred for 1 hour at 40°C and 400 rpm using a magnetic stirrer. Next, 1g of the dispersant polyacrylic acid (1% of the total mass of HDDA, LA, ACMO, and Easepi 864) was added. The mixture was stirred again for 1 hour at 40°C and 400 rpm using a magnetic stirrer. Finally, 0.5g of the defoamer ACP-1400 (1% of the total mass of HDDA, LA, ACMO, and Easepi 864) was added. The photosensitive resin was obtained by stirring the mixture (0.5% of the total mass of 864) at 40℃ and 400r / min for 1h using a magnetic stirrer.

[0120] Commercially available Inconel 625 nickel-based alloy powder with a particle size ≤30μm was sieved through a 1000-mesh sieve using a vibrating sieve to obtain sieved nickel-based alloy powder.

[0121] The sieved nickel-based alloy powder and the above-mentioned photosensitive resin were mixed at a mass ratio of 91:9 and then homogenized in a centrifugal homogenizer (rotation speed of 560 r / min, time of 3 min, vacuum degree of 1.3 kPa) to obtain a photosensitive metal slurry.

[0122] The photosensitive metal slurry was vacuum degassed in a centrifugal homogenizer (660 r / min, 3 min, 1.3 kPa vacuum) before photopolymerization 3D printing. A digital light processing photopolymerization 3D printer equipped with a real-time slurry stirring and replenishment device was selected. The parameters for the photopolymerization 3D printing were: light source energy density of 55 mW / cm³. 2 The exposure time was 15s, and the printing thickness was 20μm / layer, resulting in a green blank of a metal part.

[0123] After the green blank of the metal part is cleaned with isopropanol to remove residual slurry and dried, it is degreased in a controlled atmosphere box furnace. The degreasing atmosphere is an argon-hydrogen mixture with a hydrogen content of 5% and a gas flow rate of 0.5 L / min to maintain laminar flow. The degreasing process is as follows: the temperature is increased from room temperature to 220°C at a heating rate of 1.5°C / min and held for 45 min; the temperature is increased from 220°C to 450°C at a heating rate of 0.2°C / min and held for 120 min; finally, the temperature is increased from 450°C to 550°C at a heating rate of 1°C / min and held for 60 min; the furnace is then cooled to room temperature to obtain the brown blank of the metal part.

[0124] The metal part blanks were subjected to carbon removal (using pure hydrogen atmosphere, gas flow rate of 1L / min to maintain laminar flow, process of heating from room temperature to 550℃ at a heating rate of 10℃ / min, then heating from 550℃ to 1000℃ at a heating rate of 2℃ / min) and sintering treatment (using pure hydrogen atmosphere, gas flow rate of 0.5L / min to maintain laminar flow, process of heating from 1000℃ to 1260℃ at a heating rate of 0.7℃ / min, holding at that temperature for 6 hours, and then cooling to room temperature with the furnace) in a tube furnace to obtain a high-precision, photocured metal component with excellent mechanical and tribological properties (denoted as Inconel 625 nickel-based alloy part).

[0125] Example 5

[0126] According to a mass ratio of 2:2:1:5, the first photosensitive resin monomers HDDA (20g), 2PO-NPGDA (20g), the second photosensitive resin monomer IBOA (10g), and the photosensitive resin prepolymer Easepi 864 (50g) were mixed. Then, 1g of the photoinitiator trimethylbenzoyl diphenylphosphine oxide (1% of the total mass of HDDA, 2PO-NPGDA, IBOA, and Easepi 864) was added. The mixture was stirred for 1 hour at 40℃ and 400 rpm using a magnetic stirrer. Next, 1g of the dispersant oleic acid (1% of the total mass of HDDA, 2PO-NPGDA, IBOA, and Easepi 864) was added. The mixture was stirred for 1 hour at 40℃ and 400 rpm using a magnetic stirrer. Finally, 0.2g of the defoamer ACP-1400 (1% of the total mass of HDDA, 2PO-NPGDA, IBOA, and Easepi 864) was added. The photosensitive resin was obtained by stirring the mixture (0.2% of the total mass of 864) at 40℃ and 400r / min for 1h with a magnetic stirrer.

[0127] Commercially available Ti6Al4V titanium alloy powder with a particle size ≤30μm was sieved through a 1500-mesh sieve using a vibrating sieve to obtain sieved titanium alloy powder.

[0128] The sieved titanium alloy powder and the above photosensitive resin were mixed at a mass ratio of 79:21 and then homogenized in a centrifugal homogenizer (rotation speed 560 r / min, time 3 min, vacuum degree 1.3 kPa) to obtain a photosensitive metal slurry.

[0129] The photosensitive metal slurry was vacuum degassed in a centrifugal homogenizer (660 r / min, 3 min, 1.3 kPa vacuum) before photopolymerization 3D printing. A digital light processing photopolymerization 3D printer equipped with a real-time slurry stirring and replenishment device was selected. The parameters for the photopolymerization 3D printing were: light source energy density of 45 mW / cm³. 2 The exposure time was 14s, and the printing thickness was 20μm / layer, resulting in a green blank of a metal part.

[0130] After the green blank of the metal part is cleaned with isopropanol to remove residual slurry and dried, it is degreased in a controlled atmosphere box furnace. The degreasing atmosphere is an argon-hydrogen mixture with a hydrogen content of 15% and a gas flow rate of 0.5 L / min to maintain laminar flow. The degreasing process is as follows: the temperature is increased from room temperature to 240°C at a rate of 1°C / min and held for 60 min; the temperature is increased from 240°C to 450°C at a rate of 0.15°C / min and held for 120 min; finally, the temperature is increased from 450°C to 600°C at a rate of 0.5°C / min and held for 60 min; the furnace is then cooled to room temperature to obtain the brown blank of the metal part.

[0131] The metal part blanks were subjected to carbon removal (using an argon-hydrogen mixture with a hydrogen content of 50% and a gas flow rate of 0.5 L / min to maintain laminar flow, with the temperature increased from room temperature to 600°C at a rate of 10°C / min, and then increased from 600°C to 950°C at a rate of 1.5°C / min) and sintering (using an argon-hydrogen mixture with a hydrogen content of 50% and a gas flow rate of 0.5 L / min to maintain laminar flow, with the temperature increased from 950°C to 1600°C at a rate of 1°C / min, held at that temperature for 4 hours, and then cooled to room temperature with the furnace) in a tube furnace to obtain a high-precision, photocured metal component with excellent mechanical and tribological properties (denoted as Ti6Al4V titanium alloy part).

[0132] Example 6

[0133] According to a mass ratio of 2.5:1.5:2.5:3.5, 25g of the first photosensitive resin monomer 15EO-TMPTA and 15g of LA, 25g of the second photosensitive resin monomer ACMO, and 35g of the photosensitive resin prepolymer U600 were mixed, and then 2g of the photoinitiator trimethylbenzoyl diphenylphosphine oxide (2% of the total mass of 15EO-TMPTA, LA, ACMO, and U600) was added. The mixture was then subjected to magnetic induction at 40℃ and 400r / min. After stirring for 1 hour under the specified conditions, 1 g of dispersant polyacrylic acid (1% of the total mass of 15EO-TMPTA, LA, ACMO and U600) was added, and the mixture was stirred for 1 hour at 40℃ and 400 r / min using a magnetic stirrer. Then, 0.4 g of defoamer BYK-088 (0.4% of the total mass of 15EO-TMPTA, LA, ACMO and U600) was added, and the mixture was stirred for 1 hour at 40℃ and 400 r / min using a magnetic stirrer to obtain the photosensitive resin.

[0134] Commercially available pure copper powder with a particle size ≤30μm is sieved through a 1000-mesh sieve using a vibrating sieve to obtain sieved pure copper powder.

[0135] The sieved pure copper powder and the above photosensitive resin were mixed at a mass ratio of 87:13 and then homogenized in a centrifugal homogenizer (rotation speed 560 r / min, time 3 min, vacuum degree 1.3 kPa) to obtain a photosensitive metal slurry.

[0136] The photosensitive metal slurry was subjected to vacuum degassing in a centrifugal homogenizer (660 r / min, 3 min, 1.3 kPa vacuum) before photopolymerization 3D printing. A digital light processing photopolymerization 3D printer equipped with a real-time slurry stirring and replenishment device was selected. The parameters for the photopolymerization 3D printing were: light source energy density of 50 mW / cm³. 2 The exposure time was 18s, and the printing thickness was 25μm / layer, resulting in a green blank of a metal part.

[0137] After the green blank of the metal part is cleaned with isopropanol to remove residual slurry and dried, it is degreased in a controlled atmosphere box furnace. The degreasing atmosphere is an argon-hydrogen mixture with a hydrogen content of 5% and a gas flow rate of 0.5 L / min to maintain laminar flow. The degreasing process is as follows: the temperature is increased from room temperature to 250°C at a heating rate of 1°C / min and held for 60 min; the temperature is increased from 250°C to 430°C at a heating rate of 0.1°C / min and held for 120 min; finally, the temperature is increased from 430°C to 550°C at a heating rate of 0.5°C / min and held for 60 min; the furnace is then cooled to room temperature to obtain the brown blank of the metal part.

[0138] The metal part blanks were subjected to carbon removal (using pure hydrogen atmosphere, gas flow rate of 0.5 L / min to maintain laminar flow, process of heating from room temperature to 550℃ at a heating rate of 10℃ / min, then heating from 550℃ to 950℃ at a heating rate of 2.5℃ / min) and sintering treatment (using pure hydrogen atmosphere, gas flow rate of 0.65 L / min to maintain laminar flow, process of heating from 950℃ to 1050℃ at a heating rate of 1℃ / min, holding at that temperature for 5 hours, and then cooling to room temperature with the furnace) in a tube furnace to obtain a high-precision, photocured metal component (denoted as pure copper part) with excellent mechanical and tribological properties.

[0139] Example 7

[0140] Referring to Example 1, the difference is that the sintering time is 2 hours, resulting in a photocured metal component.

[0141] The density of the photocured metal component was measured using Archimedes' displacement method and found to be 7.20 g / cm³. 3 The density is only 90.2%, which is significantly lower than the density of 95.9% of the photocurable metal component described in Example 1. Figure 10 The engineering stress-strain curves of the photocured AISI 316L stainless steel materials prepared in Examples 1 and 7 were compared. Figure 10It can be seen that the tensile strength, yield strength, and elongation at break of the photocured AISI 316L stainless steel material described in Example 7 are 495 MPa, 149 MPa, and 53%, respectively, which are reduced to 91%, 83%, and 85% of the tensile strength, yield strength, and elongation at break of the photocured AISI 316L stainless steel material described in Example 1. This is because the holding time during sintering is relatively short, resulting in insufficient diffusion between metal powders, leading to higher porosity and lower material density, which in turn reduces the tensile strength, yield strength, and elongation at break of the material.

[0142] Comparative Example 1

[0143] Referring to Example 1, the difference lies in that the raw materials for preparing the photosensitive resin, in addition to containing the first photosensitive resin monomer HDDA, the second photosensitive resin monomer IBOA and the photosensitive resin prepolymer U600, also contain a certain proportion of OPPEA, wherein the mass ratio of HDDA, OPPEA, IBOA and U600 is 1:2.5:2:4.5, and a photocurable metal component is prepared.

[0144] Table 1 lists the residual carbon rates of several commonly used photosensitive resin monomers after thermogravimetric analysis (TGA) following photocuring. The heating temperature range for the TGA test was from room temperature to 800℃, with a heating rate of 10℃ / min, and a nitrogen atmosphere. As shown in Table 1, the residual carbon rates of the four photosensitive resin monomers HDDA, LA, 2PO-NPGDA, and 15EO-TMPTA were relatively low, all below 5%, while the residual carbon rates of ACMO, OPPEA, and TMPTA were relatively high, all around 10%.

[0145] Table 1. Carbon residue of commonly used photosensitive resin monomers after photocuring and thermal weight loss

[0146]

[0147] Figure 11 The engineering stress-strain curves of the photocurable AISI 316L stainless steel materials prepared in Example 1 and Comparative Example 1 were compared. Figure 11 As can be seen, the tensile strength, yield strength, and elongation at break of the photocurable AISI 316L stainless steel material described in Comparative Example 1 all decrease significantly, with a tensile strength of 350 MPa, a yield strength of 133 MPa, and an elongation at break of 40%. This is because the photosensitive resin formulation contains 25 wt% OPPEA. After degreasing, too much carbon remains on the surface of the metal powder. Even with subsequent decarburization and sintering, the carbon cannot be completely removed. This leads to the precipitation of a certain amount of carbides at the grain boundaries of the microstructure of the sintered metal material, causing increased brittleness and decreased plasticity. Therefore, the tensile strength, yield strength, and elongation at break all decrease significantly.

[0148] Comparative Example 2

[0149] Referring to Example 1, the difference is that the second photosensitive resin monomer IBOA is not added. The mass ratio of the first photosensitive resin monomers LA and HDDA to the photosensitive resin prepolymer U600 is 3.1:1.3:5.6. The prepared photosensitive metal paste was used for 3D printing, but printing failure occurred. This is mainly because the molecular formulas of photosensitive resins LA and U600 both contain long linear alkyl groups. The steric hindrance effect of the active acrylate groups between adjacent molecules is large, reducing the contact probability and increasing the difficulty of the photopolymerization reaction. Furthermore, the photosensitive resin components lack IBOA, which leads to weak interfacial bonding between adjacent cured layers, causing printing failure.

[0150] Comparative Example 3

[0151] Referring to Example 1, the difference is that the atmosphere for removing residual carbon and sintering is changed to a vacuum environment to prepare a photocurable metal component;

[0152] Figure 12 The engineering stress-strain curves of the photocurable AISI 316L stainless steel materials described in Example 1 and Comparative Example 3 were compared. Figure 12 It is known that the tensile strength of the photocured AISI 316L stainless steel material prepared under vacuum is only 310 MPa (a significant decrease of 42.9% compared to Example 1), and the elongation at break is only 4% (a significant decrease of 90.6% compared to Example 1), which is insufficient for engineering applications. This is because hydrogen was lacking during the decarburization and sintering processes. The residual carbon elements could not be removed at high temperatures and remained inside the material. As a result, after sintering, the residual carbon elements reacted with the metal elements to form carbides, which precipitated at the grain boundaries to form brittle phases. In addition, the precipitated phases hindered dislocation movement, and the combined effect of these two factors increased the overall brittleness of the material.

[0153] Figure 13 Metallurgical microscope images of the photocurable AISI 316L stainless steel material (a) described in Comparative Example 3 and the photocurable AISI 316L stainless steel material (b) described in Example 1; by Figure 13 (a) It can be seen that when residual carbon cannot be removed, a large amount of brittle carbide phase precipitates at the grain boundaries of AISI 316L austenite grains.

[0154] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for producing a photocured metal member, characterized by, The method comprises the following steps: The photosensitive metal paste is subjected to 3D printing, debinding treatment, residual carbon removal and sintering treatment in sequence to obtain the photocured metal component; The photosensitive metal paste comprises photosensitive resin and metal powder; The raw materials for preparing the photosensitive resin comprise photosensitive resin monomer, photosensitive resin prepolymer and photoinitiator; The photosensitive resin monomer is one or more of 1,6-hexanediol diacrylate, lauryl acrylate, 2-propoxy neopentyl glycol diacrylate and 1,5-ethoxytrimethylolpropane triacrylate; The second photosensitive resin monomer is one or more of isobornyl acrylate, 4-hydroxybutyl acrylate, 1,9-nonanediol diacrylate and acryloyl morpholine; The debinding treatment is performed in pure argon or argon-hydrogen mixed gas; The residual carbon removal and sintering treatment are independently performed in argon-hydrogen mixed gas or pure hydrogen. The mass ratio of the photosensitive resin to the metal powder is (25-7):(75-93).

2. The production method according to claim 1, wherein The mass ratio of the first photosensitive resin monomer to the second photosensitive resin monomer is (4-2):(1-3).

3. The production method according to claim 1, wherein The mass ratio of the photosensitive resin monomer to the photosensitive resin prepolymer is (7-5):(3-5).

4. The production method according to claim 1, wherein The photosensitive resin prepolymer is aliphatic polyurethane acrylate and / or modified polyurethane acrylate. The particle size distribution range of the metal powder is 0-25 μm.

5. The production method according to claim 1, wherein The metal powder comprises iron-based alloy powder, nickel-based alloy powder, titanium-based alloy powder or copper-based alloy powder. The debinding treatment process is as follows: the temperature is raised from room temperature to 200-300 °C at a rate of 0.2-2 °C / min, and then the temperature is kept for 30-120 min; the temperature is raised from 200-300 °C to 400-500 °C at a rate of 0.05-0.5 °C / min, and then the temperature is kept for 60-180 min; finally, the temperature is raised from 400-500 °C to 550-650 °C at a rate of 0.2-2 °C / min, and then the temperature is kept for 30-120 min; and then the temperature is cooled to room temperature.

6. The production method according to claim 1, wherein The residual carbon removal process is as follows: the temperature is raised from room temperature to 550-650 °C at a rate of 5-20 °C / min, and then the temperature is kept for 0-30 min; the temperature is raised from 550-650 °C to 950-1050 °C at a rate of 0.5-2.5 °C / min, and then the temperature is kept for 0-60 min. The sintering treatment process is as follows: the temperature is raised from 950-1050 °C to the final sintering temperature at a rate of 0.5-1 °C / min, and then the temperature is kept for 4-8 h, and then the temperature is cooled to room temperature.

7. The photocured metal component prepared by the method of any one of claims 1-6.

8. The photocured metal component of claim 7 for use in the field of friction. ​

Images