Light-cured metal component and method for producing same

Abstract

This invention belongs to the field of additive manufacturing of metal materials, specifically relating to a photocurable metal component and its preparation method. The method for preparing the photocurable metal component includes the following steps: (1) photocuring and 3D printing a stainless steel slurry to obtain a metal blank; (2) thermally degreasing the metal blank to obtain a thermally degreased metal blank; (3) vacuum sintering the thermally degreased metal blank to obtain the photocurable metal component. In step (1), the stainless steel slurry comprises a stainless steel alloy, a photosensitive resin, a photoinitiator, and a dispersant; the photosensitive resin comprises 3-hydroxy-2,2-dimethylpropyl-3-hydroxy-2,2-dimethylpropyl diacrylate, 2-hydroxyethyl methacrylate phosphate, and trimethylolpropane triacrylate. This invention combines photocurable molding technology with powder metallurgy technology, which can maintain the mechanical properties and density of the material, and also maintain high surface precision when forming complex parts.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing of metal materials, and specifically relates to a photocurable metal component and its preparation method. Background Technology

[0002] Austenitic 316L stainless steel possesses excellent corrosion resistance, high toughness, and plasticity, making it widely used in biomedical, marine engineering, and energy and chemical industries. Traditional methods for manufacturing 316L stainless steel, such as rolling followed by machining, suffer from poor ability to create complex structures, low surface finish, and long production cycles. While powder metallurgy injection molding can improve surface quality and provides some forming capability for more complex parts, its structural design is not flexible enough, making it difficult to mass-produce products with complex internal cavities and porous structures.

[0003] In recent years, 3D printing technology has been widely used in the field of metal materials due to its advantages of being able to prepare complex structural parts, flexible design, on-demand manufacturing and high material utilization. The relatively mature additive manufacturing process for 316L is selective laser melting (SLM), but this technology has high equipment costs, parts may have anisotropy, and the surface accuracy of the product is poor. Meanwhile, binder jetting (BJP) technology for preparing 316L stainless steel is still in the experimental research stage.

[0004] Therefore, there is an urgent need to develop a method for preparing metal components that is flexible in design, low in cost, and has high surface precision. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a photocurable metal component and its preparation method. This invention combines photocurable molding technology and powder metallurgy technology, which can maintain the mechanical properties and density of the material, while also maintaining high surface precision when molding complex parts. It also offers advantages in printing accuracy and speed, shortens the process cycle, is suitable for mass production, and reduces costs.

[0006] Specifically, the present invention provides a method for preparing photocurable metal components, the method comprising the following steps: (1) The stainless steel slurry was subjected to photopolymerization 3D printing to obtain a metal blank; (2) The metal billet sample is subjected to hot degreasing treatment to obtain a hot degreased metal billet sample; (3) Vacuum sintering is performed on the hot-degreased metal blank to obtain a photocurable metal component; In step (1), the stainless steel slurry comprises a stainless steel alloy, a photosensitive resin, a photoinitiator, and a dispersant; the photosensitive resin comprises 3-hydroxy-2,2-dimethylpropyl-3-hydroxy-2,2-dimethylpropyl diacrylate, 2-hydroxyethyl methacrylate phosphate, and trimethylolpropane triacrylate.

[0007] In one or more embodiments, in step (1), the light source intensity of the photopolymerization 3D printing is 20000-40000 μm / cm. 2 .

[0008] In one or more embodiments, in step (1), the wavelength of the light source for the photopolymerization 3D printing is 380-405nm.

[0009] In one or more embodiments, in step (1), the thickness of the printed layer of the photopolymer 3D printing is 10-30 μm.

[0010] In one or more embodiments, in step (1), the exposure time of the photopolymer 3D printing is 1-20s.

[0011] In one or more embodiments, in step (2), the metal billet is subjected to thermal degreasing in an argon atmosphere.

[0012] In one or more embodiments, in step (2), the heating rate of the thermal degreasing treatment is ≤5℃ / min.

[0013] In one or more embodiments, in step (2), the thermal degreasing process includes the following stages: in the first stage, the temperature is raised to 200-300°C at a constant heating rate of 1-5°C / min and held at a constant temperature for 1-6 hours; in the second stage, the temperature is raised to 400-500°C at a constant heating rate of 0.5-3°C / min and held at a constant temperature for 2-6 hours, and then cooled with the furnace.

[0014] In one or more embodiments, step (3) of the vacuum sintering includes the following stages: a first stage where the temperature is raised to 900-1100°C at a constant heating rate of 0.5-6°C / min and held at a constant temperature for 1-6 hours; and a second stage where the temperature is raised to 1200-1450°C at a constant heating rate of 0.5-4°C / min and held at a constant temperature for 1-6 hours.

[0015] In one or more embodiments, in step (3), the vacuum level is 10. -1 -10 -5 Pa.

[0016] In one or more embodiments, the stainless steel alloy in the stainless steel slurry has a mass fraction of 70wt%-88wt%. In one or more embodiments, the photosensitive resin in the stainless steel slurry has a mass fraction of 10wt%-25wt%. In one or more embodiments, the photoinitiator in the stainless steel slurry has a mass fraction of 0.4 wt%-3 wt%. In one or more embodiments, the dispersant in the stainless steel slurry has a mass fraction of 1wt%-4wt%; In one or more embodiments, the particle size D50 of the stainless steel alloy is 10-30 μm.

[0017] In one or more embodiments, the stainless steel alloy is a 316L stainless steel alloy.

[0018] In one or more embodiments, the photoinitiator is selected from one or more of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl 2,4,6-trimethylbenzoylphosphonate, and 1-hydroxycyclohexylphenyl ketone; In one or more embodiments, the dispersant is selected from one or more of BYK-102, BYK-180, BYK-9076, BYK-109, BYK-108, BYK-110 and BYK-333.

[0019] In one or more embodiments, the method further includes: (1') Mix the photosensitive resin, photoinitiator and dispersant evenly to obtain a premixed solution; (2') Add the premixed liquid to the stainless steel alloy and ball mill it to obtain the ball milling intermediate; (3') Vacuum degassing treatment is performed on the ball mill intermediate to obtain stainless steel slurry.

[0020] In one or more embodiments, the ball milling speed is 200-1000 r / min.

[0021] In one or more embodiments, the sum of the masses of the premixed liquid and the stainless steel alloy is in a mass ratio of (1-10):1 to the mass of the grinding balls used in the ball mill.

[0022] In one or more embodiments, the ball milling time is 0.1-10 hours.

[0023] In one or more embodiments, the vacuum degassing rotation speed is 200-2000 r / min.

[0024] In one or more embodiments, the vacuum degassing time is 0.1-1 h.

[0025] Photocurable metal components prepared by any of the methods described in this invention.

[0026] Compared with existing technologies, this invention has the following beneficial technical effects: This invention combines photopolymerization 3D printing technology with powder metallurgy processes. Compared with the traditional manufacturing process of 316L stainless steel, this technology has the ability to manufacture on demand and form complex structural parts, and does not require subsequent processing, shortening the process cycle and eliminating the need for separate mold making. Compared with other 3D printing technologies, the density and mechanical properties are effectively improved, further enhancing the surface accuracy of the parts. It has advantages in printing accuracy and speed, reduces residual stress in the formed parts, is suitable for mass production, and reduces costs. Attached Figure Description

[0027] Figure 1 This is a magnified microscopic image of the honeycomb sample obtained in Example 2 of the present invention after degreasing and sintering. Detailed Implementation

[0028] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0029] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0030] In this document, the terms “contains,” “includes,” “containing,” and similar terms encompass the meanings of “basically composed of” and “composed of.” For example, when this document discloses “A contains B and C,” “A is basically composed of B and C” and “A is composed of B and C” should be considered as having been disclosed in this document.

[0031] In this document, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0032] Unless otherwise specified, percentages refer to mass percentages and proportions refer to mass ratios in this article.

[0033] In this document, when describing embodiments or examples, it should be understood that it is not intended to limit the invention to those embodiments or examples. Rather, all alternatives, modifications, and equivalents of the methods and materials described herein are covered within the scope defined by the claims.

[0034] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0035] The method for preparing photocurable metal components provided by this invention includes the following steps: (1) The stainless steel slurry was subjected to photopolymerization 3D printing to obtain a metal blank; (2) The metal billet sample is subjected to hot degreasing treatment to obtain a hot degreased metal billet sample; (3) Vacuum sintering is performed on the hot degreased metal blank to obtain a photocurable metal component.

[0036] This invention combines photopolymer 3D printing with powder metallurgy technology, effectively maintaining density and mechanical properties. It improves the forming capability of complex and precision structural parts, enhances the surface accuracy of formed parts, reduces subsequent grinding and polishing processes, significantly reduces energy consumption costs, and improves production efficiency, thus helping to achieve the goal of low-cost mass production of complex metal parts.

[0037] In step (1), the stainless steel slurry may contain a stainless steel alloy, a photosensitive resin, a photoinitiator, and a dispersant; the photosensitive resin may contain 3-hydroxy-2,2-dimethylpropyl-3-hydroxy-2,2-dimethylpropyl diacrylate, 2-hydroxyethyl methacrylate phosphate, and trimethylolpropane triacrylate. In this invention, the photosensitive resin encapsulates the stainless steel alloy for effective dispersion, and rapid molding is achieved through photopolymerization. This invention has found that the above three photosensitive resins have a synergistic effect in improving the curing thickness of the stainless steel slurry and enhancing printing efficiency. The stainless steel slurry containing the above photosensitive resins can achieve 3D printing with micro-nano level precision, and the printed products have good integrity and molding performance.

[0038] In this invention, the mass ratio of 3-hydroxy-2,2-dimethylpropyl-3-hydroxy-2,2-dimethylpropyl diacrylate to 2-hydroxyethyl methacrylate phosphate can be 1:(0.6-1.2), for example 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1.0, 1:1.1, 1:1.2. The mass ratio of 3-hydroxy-2,2-dimethylpropyl-3-hydroxy-2,2-dimethylpropyl diacrylate to trimethylolpropane triacrylate can be 1:(0.8-1.4), for example 1:0.8, 1:0.9, 1:1.0, 1:1.1, 1:1.2, 1:1.3, 1:1.4. In this invention, the mass ratio of 3-hydroxy-2,2-dimethylpropyl-3-hydroxy-2,2-dimethylpropyl diacrylate, 2-hydroxyethyl methacrylate phosphate, and trimethylolpropane triacrylate is controlled at 1:(0.6-1.2):(0.8-1.4), which is beneficial to improving the curing thickness, printing efficiency, and printing accuracy of stainless steel slurry, and the printed products have good integrity and molding performance.

[0039] In the stainless steel slurry of this invention, the mass fraction of stainless steel alloy can be 70wt%-88wt%, for example 70wt%, 72wt%, 74wt%, 76wt%, 78wt%, 80wt%, 82wt%, 84wt%, 86wt%, and 88wt%. In the stainless steel slurry of this invention, the mass fraction of photosensitive resin can be 10wt%-25wt%, preferably 12.75wt%-23wt%, for example 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, and 20wt%. In the stainless steel slurry of this invention, the mass fraction of photoinitiator can be 0.4wt%-3wt%, for example 1.0wt%, 1.5wt%, 2.0wt%, 2.5wt%, and 3.0wt%. In the stainless steel slurry of this invention, the mass fraction of dispersant can be 1wt%-4wt%, for example 1.0wt%, 1.5wt%, 2.0wt%, 2.5wt%, 3.0wt%, 3.5wt%, and 4.0wt%.

[0040] In the stainless steel slurry of this invention, the stainless steel alloy is in powder form. In this invention, the particle size D50 of the stainless steel alloy can be 10-30 μm, preferably 10-20 μm, for example 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, or 20 μm. Controlling the particle size D50 of the stainless steel alloy within the above-mentioned preferred range in this invention is beneficial for obtaining products with good mechanical properties, high surface precision, and good appearance. In this invention, the stainless steel alloy can be 316L stainless steel alloy. In some embodiments, the composition of commercial 316L stainless steel alloy, by mass percentage, satisfies: Cr: 16-18%, Ni: 10-14%, Mo: 2-3%, C≤0.03%, O≤0.06%, Si≤1.0%, Mn≤2.0%, with the balance being Fe and unavoidable impurities. In some embodiments, the balance is Fe and unavoidable impurities.

[0041] In this invention, the photoinitiator can be one or more selected from phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl 2,4,6-trimethylbenzoylphosphonate, and 1-hydroxycyclohexylphenyl ketone. In this invention, the above-mentioned photoinitiator rapidly generates free radicals in a localized area by absorbing ultraviolet light energy, initiating cross-linking and curing of the photosensitive monomer or resin. In this invention, the dispersant can be one or more selected from BYK-102, BYK-180, BYK-9076, BYK-109, BYK-108, BYK-110, and BYK-333. In this invention, the above-mentioned dispersant can ensure the stability and rheological properties of the slurry and prevent particle sedimentation or agglomeration.

[0042] In step (1), the light source intensity for photopolymer 3D printing can be 20000-40000 μm / cm. 2 For example, 20000μm / cm 2 25000μm / cm 2 30000μm / cm 2 35000μm / cm 2 40000μm / cm 2 In step (1), the wavelength of the light source for photopolymer 3D printing can be 380-405nm, such as 380nm, 385nm, 390nm, 395nm, 400nm, and 405nm. In step (1), the thickness of the printed layer for photopolymer 3D printing can be 10-30μm, such as 10μm, 15μm, 20μm, 25μm, and 30μm. In step (1), the exposure time for photopolymer 3D printing can be 1-20s, such as 2s, 4s, 6s, 8s, 10s, 12s, 14s, 16s, 18s, and 20s.

[0043] In step (2), the metal billet sample can undergo thermal degreasing in an argon atmosphere. This invention improves the degreasing rate of the sample by controlling the degreasing atmosphere, and finally obtains a high-precision alloy sample by high-temperature sintering. In step (2), the heating rate of the thermal degreasing treatment can be ≤5℃ / min. In step (2), the thermal degreasing treatment may include the following stages: The first stage is to raise the temperature to 200-300℃ at a constant heating rate of 1-5℃ / min, for example, 1℃ / min, 2℃ / min, 3℃ / min, 4℃ / min, 5℃ / min, for example, 200℃, 220℃, 240℃, 260℃, 280℃, 300℃, and maintain the temperature for 1-6h, for example, 1h, 2h, 3h, 4h, 5h, 6h; The second stage is to raise the temperature to 400-500℃ at a constant heating rate of 0.5-3℃ / min, for example, 0.5℃ / min, 1℃ / min, 1.5℃ / min, 2℃ / min, 2.5℃ / min, for example, 400℃, 420℃, 440℃, 460℃, 480℃, 500℃, and maintain the temperature for 3-6h, for example, 3h, 4h, 5h, 6h, and then cool it with the furnace. In the hot degreasing process of this invention, controlling the heating rate, holding temperature and holding time within the range of this invention can avoid structural cracking and deformation, improve the degreasing rate of the sample, and finally obtain an alloy sample with good precision and excellent mechanical properties by sintering at high temperature.

[0044] In some embodiments of the present invention, the hot degreasing is carried out in two stages, and the heating rate of the first stage of hot degreasing is greater than that of the second stage. The present invention controls the heating rate of the first stage of hot degreasing to be greater than that of the second stage, which is beneficial to obtaining alloy samples with good precision and excellent mechanical properties.

[0045] In this invention, thermal degreasing is first performed in an atmospheric environment, followed by sintering in a vacuum environment. Compared to thermal degreasing and sintering in an atmospheric environment, this method is more conducive to obtaining photocurable metal components with good precision and excellent mechanical properties. In this invention, cooling is not required after thermal degreasing; vacuum sintering can be performed directly, which is beneficial for obtaining photocurable metal components with good precision and excellent mechanical properties.

[0046] In step (3), vacuum sintering includes the following stages: The first stage is to raise the temperature to 900-1100℃ at a constant heating rate of 0.5-6℃ / min, for example 1℃ / min, 2℃ / min, 3℃ / min, 4℃ / min, 5℃ / min, 6℃ / min, for example 900℃, 950℃, 1000℃, 1050℃, 1100℃, and hold it at a constant temperature for 1-6h, for example 1h, 2h, 3h, 4h, 5h, 6h; The second stage is to raise the temperature to 1200-1450℃ at a constant heating rate of 0.5-4℃ / min, for example 1℃ / min, 2℃ / min, 3℃ / min, 4℃ / min, for example 1200℃, 1250℃, 1300℃, 1350℃, 1400℃, and hold it at a constant temperature for 1-6h, for example 1h, 2h, 3h, 4h, 5h, 6h. By controlling the heating rate, holding temperature, and holding time within the range specified in this invention during the vacuum sintering process, photocurable metal components with good precision and excellent mechanical properties can be obtained.

[0047] In some embodiments of the present invention, vacuum sintering employs a two-stage thermal vacuum sintering process, wherein the heating rate of the first stage of vacuum sintering is greater than that of the second stage. The present invention controls the heating rate of the first stage of vacuum sintering, which is beneficial for obtaining photocurable metal components with good precision and excellent mechanical properties.

[0048] In some embodiments of the present invention, thermal degreasing employs a two-stage thermal degreasing process, wherein the heating rate of the first stage of thermal degreasing is greater than that of the second stage; vacuum sintering employs a two-stage thermal vacuum sintering process, wherein the heating rate of the first stage of vacuum sintering is greater than that of the second stage. Simultaneously controlling the heating rate of the first stage of thermal degreasing to be greater than that of the second stage and the heating rate of the first stage of vacuum sintering to be greater than that of the second stage is beneficial for obtaining photocurable metal components with good precision and excellent mechanical properties.

[0049] In step (3), the vacuum level is preferably 10. -1 -10 -5 Pa, for example, 10 -5 Pa, 10 -4 Pa, 10 -3 Pa, 10 -2 Pa, 10 -1 Pa. By controlling the vacuum degree within the range specified in this invention during the vacuum sintering process, photocured metal components with good precision and excellent mechanical properties can be obtained.

[0050] The method for preparing photocurable metal components of the present invention further includes: (1') mixing photosensitive resin, photoinitiator and dispersant evenly to obtain a premix; (2') adding the premix to a stainless steel alloy and ball milling to obtain a ball milling intermediate; (3') performing vacuum degassing treatment on the ball milling intermediate to obtain a stainless steel slurry.

[0051] In this invention, the ball milling speed can be 200-1000 r / min, for example, 200 r / min, 300 r / min, 400 r / min, 500 r / min, 600 r / min, 700 r / min, or 800 r / min. In this invention, the ratio of the sum of the mass of the premixed liquid and the stainless steel alloy to the mass of the grinding balls used in the ball mill can be (1-10):1. In this invention, the ball-to-material ratio refers to the ratio of the sum of the mass of the premixed liquid and the stainless steel alloy to the mass of the grinding balls used in the ball mill. In this invention, the ball milling time can be 0.1-10 h, for example, 0.5 h, 1 h, 2 h, 4 h, 6 h, 8 h, or 10 h, for example, a ratio of 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1. In this invention, the rotation speed of vacuum degassing can be 200-2000 r / min, for example, 200 r / min, 400 r / min, 600 r / min, 800 r / min, 1000 r / min, 1200 r / min, 1400 r / min, 1600 r / min, 1800 r / min, and 2000 r / min. In this invention, the vacuum degassing time can be 0.1-1 h, for example, 0.1 h, 0.2 h, 0.3 h, 0.4 h, 0.5 h, 0.6 h, 0.7 h, 0.8 h, 0.9 h, and 1.0 h.

[0052] This invention provides photocurable metal components prepared by the method described herein.

[0053] The present invention will be described below by way of specific embodiments. It should be understood that these embodiments are merely illustrative and are not intended to limit the scope of the invention. The methods, reagents, and materials used in the embodiments are conventional methods, reagents, and materials in the art, unless otherwise stated. The raw material compounds in the embodiments are all commercially available.

[0054] Example 1

[0055] The specific steps for preparing the photocurable metal component in this embodiment are as follows: (1) Weigh 85wt% of photosensitive resin (a mixture of 30wt% 3-hydroxy-2,2-dimethylpropyl-3-hydroxy-2,2-dimethylpropyl diacrylate, 30wt% 2-hydroxyethyl methacrylate phosphate and 40wt% trimethylolpropane triacrylate), 10wt% of dispersant BYK-333, and 5wt% of photoinitiator diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, and put it into a vacuum jar. Place the vacuum jar in a homogenizer and mix for 10min at 800rpm under vacuum to obtain a premixed solution; weigh 75wt% of 316L stainless steel alloy powder (D50 of 30μm) was loaded into a ball mill jar, and 25wt% premixed liquid was gradually and slowly added to the 316L stainless steel alloy powder to mix and obtain a ball milling intermediate. The ball milling speed was 600 r / min, the ball milling time was 6 h, and the ball-to-powder ratio (the sum of the mass of the premixed liquid and the stainless steel alloy powder to the mass of the grinding balls used in the ball mill) was 3.5:1. The ball milling intermediate was then removed and transferred to a vacuum jar for degassing treatment to obtain a stainless steel slurry. The homogenization vacuum degassing speed was 1500 r / min, and the vacuum degassing time was 15 min. (2) The stainless steel slurry was subjected to photopolymerization 3D printing treatment, and the light source was exposed and cured layer by layer with an intensity of 30000μm / cm. 2 The light source wavelength was 380nm, the printing layer thickness was 30μm, and the exposure time was 16s to obtain a metal billet sample. (3) The metal billet sample was placed in an argon atmosphere for hot degreasing treatment to obtain a hot degreased metal billet sample. The specific hot degreasing treatment is as follows: In the first stage, the temperature was raised from room temperature to 300℃ at a constant heating rate of 5℃ / min and kept at a constant temperature for 2h; In the second stage, the temperature was raised to 450℃ at a constant heating rate of 2℃ / min and kept at a constant temperature for 2h to completely decompose the photosensitive resin inside the metal billet sample, and then cooled with the furnace. (4) The hot-degreased metal billet is placed in a vacuum sintering furnace for vacuum sintering to achieve densification of the alloy and obtain a photocurable metal component; the specific vacuum sintering is as follows: the first stage heats the metal billet to 1000℃ at a constant heating rate of 6℃ / min and holds it at that temperature for 4h; the second stage continues to heat to 1400℃ at a constant heating rate of 2℃ / min and holds it at that temperature for 4h, wherein the vacuum degree is 10 -3 Pa.

[0056] Example 2

[0057] The specific steps for preparing the photocurable metal component in this embodiment are as follows: (1) Weigh 87wt% of photosensitive resin (a mixture of 30wt% 3-hydroxy-2,2-dimethylpropyl-3-hydroxy-2,2-dimethylpropyl diacrylate, 30wt% 2-hydroxyethyl methacrylate phosphate and 40wt% trimethylolpropane triacrylate), 9wt% of dispersant BYK-333, and 4wt% of photoinitiator diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, and put it into a vacuum jar. Place the vacuum jar in a homogenizer and mix for 10 min at 800 rpm under vacuum to obtain a premixed solution; weigh 80wt% of 316L stainless steel alloy powder (D50 of 20μm) was loaded into a ball mill jar, and 20wt% premixed liquid was gradually and slowly added to the 316L stainless steel alloy powder to mix and obtain a ball milling intermediate. The ball milling speed was 600 r / min, the ball milling time was 6 h, and the ball-to-powder ratio (the ratio of the sum of the mass of the premixed liquid and the stainless steel alloy to the mass of the grinding balls used in the ball mill) was 3.5:1. The ball milling intermediate was then removed and transferred to a vacuum jar for degassing treatment to obtain a stainless steel slurry. The homogenization vacuum degassing speed was 1500 r / min, and the vacuum degassing time was 15 min. (2) The stainless steel slurry was subjected to photopolymerization 3D printing treatment, and the light source was exposed and cured layer by layer with an intensity of 30000μm / cm. 2 The light source wavelength was 380nm, the printing layer thickness was 20μm, and the exposure time was 10s to obtain a metal billet sample. (3) The metal billet sample was placed in an argon atmosphere for hot degreasing treatment to obtain a hot degreased metal billet sample. The specific hot degreasing treatment is as follows: In the first stage, the temperature was raised from room temperature to 200℃ at a constant heating rate of 4℃ / min and kept at a constant temperature for 4h; In the second stage, the temperature was raised to 500℃ at a constant heating rate of 3℃ / min and kept at a constant temperature for 3h to completely decompose the photosensitive resin inside the metal billet sample, and then cooled with the furnace. (4) The hot-degreased metal billet is placed in a vacuum sintering furnace for vacuum sintering to achieve densification of the alloy and obtain a photocurable metal component; the specific vacuum sintering is as follows: In the first stage, the metal billet is heated to 1000℃ at a constant heating rate of 4℃ / min and held at the temperature for 2h; in the second stage, the temperature is further increased to 1350℃ at a constant heating rate of 2℃ / min and held at the temperature for 3h, wherein the vacuum degree is 10 -3 Pa.

[0058] Example 3

[0059] The specific steps for preparing the photocurable metal component in this embodiment are as follows: (1) Weigh 89wt% of photosensitive resin (a mixture of 30wt% 3-hydroxy-2,2-dimethylpropyl-3-hydroxy-2,2-dimethylpropyl diacrylate, 30wt% 2-hydroxyethyl methacrylate phosphate and 40wt% trimethylolpropane triacrylate), 8wt% of dispersant BYK-333, and 3wt% of photoinitiator diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, and put it into a vacuum jar. Place the vacuum jar in a homogenizer and mix for 15min at 800rpm under vacuum to obtain a premixed solution; weigh 85wt% of 316L stainless steel alloy powder (D50 of 10μm) was loaded into a ball mill jar, and 15wt% premixed liquid was gradually and slowly added to the 316L stainless steel alloy powder to mix and obtain a ball milling intermediate. The ball milling speed was 600 r / min, the ball milling time was 6 h, and the ball-to-powder ratio (the sum of the mass of the premixed liquid and the stainless steel alloy powder to the mass of the grinding balls used in the ball mill) was 3.5:1. The ball milling intermediate was then removed and transferred to a vacuum jar for degassing treatment to obtain a stainless steel slurry. The homogenization vacuum degassing speed was 1500 r / min, and the vacuum degassing time was 15 min. (2) The stainless steel slurry was subjected to photocuring 3D printing, and the light source was exposed and cured layer by layer with an intensity of 25000μm / cm. 2 The light source wavelength was 405nm, the printing layer thickness was 10μm, and the exposure time was 6s to obtain a metal billet sample. (3) The metal billet sample was placed in an argon atmosphere for hot degreasing treatment to obtain a hot degreased metal billet sample. The specific hot degreasing treatment is as follows: In the first stage, the temperature was raised from room temperature to 300℃ at a constant heating rate of 2℃ / min and kept at a constant temperature for 6h; in the second stage, the temperature was raised to 500℃ at a constant heating rate of 1℃ / min and kept at a constant temperature for 6h to completely decompose the photosensitive resin inside the metal billet sample, and then cooled with the furnace. (4) The hot-degreased metal billet is placed in a vacuum sintering furnace for vacuum sintering to achieve densification of the alloy and obtain a photocurable metal component; the specific vacuum sintering is as follows: In the first stage, the metal billet is heated to 1000℃ at a constant heating rate of 2℃ / min and held at that temperature for 1h; in the second stage, the temperature is further increased to 1300℃ at a constant heating rate of 1℃ / min and held at that temperature for 1h, wherein the vacuum degree is 10 -5 Pa.

[0060] Comparative Example 1

[0061] The conditions for this comparative example are the same as those for Example 1, except that the particle size D50 of the 316L stainless steel alloy powder is 50 μm, the printing layer thickness is 50 μm, and the exposure time is 25 s.

[0062] Comparative Example 2

[0063] The conditions for this comparative example are the same as those for Example 2, except that the vacuum degree of vacuum sintering in this comparative example is 10 Pa.

[0064] Test case

[0065] Mechanical property testing: The mechanical properties of the photocurable metal components prepared in Examples 1-3 and Comparative Examples 1-2 were tested according to GB / T 1220 standard. The test results are shown in Table 1.

[0066] Surface morphology: The surface morphology of the photocurable metal components prepared in Examples 1-3 and Comparative Examples 1-2 was observed, and the test results are shown in Table 1.

[0067] Table 1: Mechanical properties and surface morphology of photocurable metal components prepared in Examples 1-3 and Comparative Examples 1-2

[0068] The mechanical properties of 316L stainless steel are tensile strength ≥470MPa, yield strength ≥170MPa, and elongation ≥40%. As can be seen from Table 1, the photocurable metal components prepared by the method of this application meet the mechanical property requirements of 316L stainless steel.

[0069] Although the typical mechanical properties of stainless steel materials prepared by SLM (tensile strength of 500 MPa and yield strength of 300 MPa) meet the usage standards, the products produced by the SLM printing process have high surface roughness, requiring post-processing such as cutting or polishing. This process is complex, lengthy, and costly. Compared to the SLM process, the surface precision and quality of the photocured metal components produced by this invention are significantly improved, eliminating the need for post-processing such as cutting or polishing.

[0070] Compared with traditional processes (such as rolling and machining, powder metallurgy injection molding), the photocurable metal components produced by this invention have superior tensile strength and yield strength, and effectively solve the problem that traditional processes are difficult to form for micro-nano parts, suspended structures and internal cavity structures.

[0071] Table 1 also shows that in Comparative Example 1, due to the larger particle size D50 used, a higher sintering driving force was required. Under the same sintering temperature, the sample surface was gray, and due to the large particle diameter and wide distribution, the sintered sample surface was relatively rough. In Comparative Example 2, due to the vacuum degree of only 10 Pa, oxidation occurred. Although the mechanical properties met the requirements, oxidation affected the surface quality of the product's performance and had a significant impact on subsequent practical applications.

[0072] In addition, the preparation process of the present invention is short, suitable for large-scale mass production, and reduces subsequent processing, which greatly reduces production costs.

Claims

1. A method of making a photocured metal component, characterized by, The method includes the following steps: (1) The stainless steel slurry was subjected to photopolymerization 3D printing to obtain a metal blank; (2) The metal billet sample is subjected to hot degreasing treatment to obtain a hot degreased metal billet sample; (3) Vacuum sintering is performed on the hot-degreased metal blank to obtain a photocurable metal component; In step (1), the stainless steel slurry comprises a stainless steel alloy, a photosensitive resin, a photoinitiator, and a dispersant; the photosensitive resin comprises 3-hydroxy-2,2-dimethylpropyl-3-hydroxy-2,2-dimethylpropyl diacrylate, 2-hydroxyethyl methacrylate phosphate, and trimethylolpropane triacrylate.

2. The method of claim 1, wherein, The method has one or more of the following characteristics: In step (1), the light source intensity of the light-cured 3D printing is 20000-40000 μm / cm 2 ; In step (1), the wavelength of the light source for the photopolymerization 3D printing is 380-405nm; In step (1), the thickness of the printed layer in the photopolymer 3D printing is 10-30 μm; In step (1), the exposure time for the photopolymerization 3D printing is 1-20s.

3. The method according to claim 1, characterized in that, In step (2), the metal billet sample undergoes thermal degreasing treatment under an argon atmosphere; and / or In step (2), the heating rate of the thermal degreasing treatment is ≤5℃ / min.

4. The method of claim 1, wherein, In step (2), the hot degreasing treatment includes the following stages: in the first stage, the temperature is raised to 200-300℃ at a constant heating rate of 1-5℃ / min and kept at a constant temperature for 1-6h; in the second stage, the temperature is raised to 400-500℃ at a constant heating rate of 0.5-3℃ / min and kept at a constant temperature for 2-6h, and then cooled with the furnace.

5. The method of claim 1, wherein, In step (3), the vacuum sintering includes the following stages: the first stage is to heat up to 900-1100℃ at a constant heating rate of 0.5-6℃ / min and hold at a constant temperature for 1-6h; the second stage is to heat up to 1200-1450℃ at a constant heating rate of 0.5-4℃ / min and hold at a constant temperature for 1-6h.

6. The method of claim 1, wherein, In step (3), the vacuum degree is 10 -1 -10 -5 Pa.

7. The method of claim 1, wherein, The method has one or more of the following characteristics: In the stainless steel slurry, the mass fraction of the stainless steel alloy is 70wt%-88wt%. In the stainless steel slurry, the mass fraction of the photosensitive resin is 10wt%-25wt%; In the stainless steel slurry, the mass fraction of the photoinitiator is 0.4wt%-3wt%; In the stainless steel slurry, the mass fraction of the dispersant is 1wt%-4wt%; The particle size D50 of the stainless steel alloy is 10-30 μm; The stainless steel alloy is 316L stainless steel alloy; The photoinitiator is selected from one or more of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl 2,4,6-trimethylbenzoylphosphonate, and 1-hydroxycyclohexylphenyl ketone; The dispersant is selected from one or more of BYK-102, BYK-180, BYK-9076, BYK-109, BYK-108, BYK-110 and BYK-333.

8. The method according to claim 1, characterized in that, The method further includes: (1') Mix the photosensitive resin, photoinitiator and dispersant evenly to obtain a premixed solution; (2') Add the premixed liquid to the stainless steel alloy and ball mill it to obtain the ball milling intermediate; (3') Vacuum degassing treatment is performed on the ball mill intermediate to obtain stainless steel slurry.

9. The method according to claim 8, characterized in that, The method has one or more of the following characteristics: The ball milling speed is 200-1000 r / min; The mass ratio of the sum of the premixed liquid and the stainless steel alloy to the mass of the grinding balls used in the ball mill is (1-10):1; The ball milling time is 0.1-10 hours; The rotation speed of the vacuum degassing is 200-2000 r / min; The vacuum degassing time is 0.1-1h.

10. A photocurable metal component, characterized in that, The photocurable metal component is prepared by any one of claims 1-9.

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