WO2019241911A1 - Prototype formulation of resin mold for photocuring rapid molding and investment casting process thereof - Google Patents

Abstract

Disclosed is a resin mold for photocuring rapid molding, comprising, in weight percentages: a photosensitive resin: 60-95 wt%, and an inert low molecular weight substance: 5-40 wt%, wherein the photosensitive resin comprises: 10-70 wt% of an active oligomer, 20-70 wt% of an active diluent, 0.2-6 wt% of a photoinitiator, and the balance of a functional auxiliary agent. Also disclosed are a method for preparing a photocuring system, a photocuring molding process and a method for baking a mold. A casting method using the resin mold has the advantages of a low cost, a high efficiency, being not prone to deform, and being able to produce a thinner casting.

Description

Prototype formulation of resin mold for light curing rapid prototyping and investment casting process thereof Technical field

 The invention belongs to the field of photo-curing, and particularly relates to a prototype of a resin mold used for photo-curing rapid molding and an investment casting process thereof.

Background technique

Investment casting or "lost wax" casting is a precision casting process in which wax patterns are transformed into solid metal parts after multiple steps of processing. Investment casting makes it possible to economically produce near-net-shape metal parts with complex geometries and features, including alloys that are difficult to machine or are not machined. In order to produce precision parts, near-net-shape forming of castings can reduce processing time and costs and bring parts to specifications. Although traditional investment casting is popular, the low-volume production of investment casting is very expensive in prototype, maintenance, custom or special component production due to the high cost of molds for wax patterns and the long manufacturing and shaping cycles. of.

Rapid prototyping (RP) technology is rapidly becoming the standard tool for product design and manufacturing. With its disruptive capabilities, it can quickly manufacture 3D parts for design verification or as a functional prototype and production tool, and is an indispensable tool for shortening product design and development time cycles. The advantages of RP technology in reducing mold cost and shortening production cycle have promoted its application in investment casting.

Combining rapid prototyping and investment casting technology produces a new type of investment casting technology, which not only retains the advantages of rapid prototyping, but also shows its unique aspect in the field of casting, which has a cost compared to traditional wax casting Low, high efficiency, not easy to deform, and can produce thinner castings, etc. When the product is updated, only the CAD geometric model needs to be changed to obtain the casting mold very conveniently, which can greatly save the time of making the mold.

The basic principles of rapid prototyping technology can be summarized as stacked manufacturing, which can be divided into the following types: stereolithography (SLA), digital light processing (DLP), selective laser sintering (SLS), fused deposition / fuse deposition ( FDM), layered solid manufacturing (LOM), electron beam fuse deposition (EBFF) and other forming processes. Based on various conditions, different technologies have their own advantages and disadvantages.

Rapid prototyping is the most direct casting model for precision casting. The dimensional accuracy of castings mainly depends on the accuracy of the prototype. Among the above-mentioned rapid prototyping processes, SLA and DLP are made by photo-curing using photosensitive resin as the material. Due to the characteristics of good surface quality, high dimensional accuracy, and the ability to achieve relatively fine dimensional molding, SLA and DLP have been widely used. .

Light curing rapid prototyping investment casting technology is to replace the wax pattern in investment casting with a prototype of liquid photosensitive resin, that is, the resin prototype is first printed layer by layer on the light curing rapid prototyping machine, and then the refractory material is poured multiple times, such as Fused silica, alumina and magnesia ceramic pastes are used to form investment casting shells. After drying until the shells are solidified, the resin is fired to remove the resin. The resulting refractory ceramic shell is used as the casting shell. Cool to obtain metal parts.

At present, such as CN 101955625A and CN 104109328A, the photosensitive resin system composed of reactive diluent, unsaturated acrylate and epoxy oligomer, and ultraviolet photoinitiator is used for laser rapid molding. For example, in CN 105802257A, traditional rosin and paraffin are used as the matrix, and a small amount of additives are added to obtain a solid resin at room temperature. The mixture system is heated and liquefied and spray-cooled and solidified by a 3D printing nozzle.

The resin used for photo-curing rapid molding is a thermosetting resin after the photo-curing reaction. It cannot melt and flow after being heated. It can only be softened first, and then gasified and disappeared as the temperature continues to rise. In the initial stage of the mold baking and removal of the resin mold prototype, the mold may expand and crack due to the thermal expansion of the prototype; in addition, if the initial thermal decomposition temperature of the resin is high, or the thermal decomposition process is concentrated in a local temperature range, it is easy to produce too much The gas cracked the shell.

After the baking is completed, if the resin mold prototype has a large amount of ash residue or tar-like residue that is not easy to remove, it will cause defects such as inclusions in the casting.

The disadvantages of the above-mentioned CN 105802257A are that the molding is limited by the viscosity of the mixture after heating in the nozzle, and the viscosity of the resin after heating and melting is too large, resulting in low molding accuracy. In addition, the patent does not study the firing performance of the resin model.

In the above-listed CN 101955625A and CN 104109328A, the system formula is a conventional photo-curing photosensitive resin. During the photo-curing process, the double bonds are cross-linked into a three-dimensional network structure under the initiation of a photoinitiator, and are cured layer by layer until the desired Model. Then, a ceramic slurry is poured on the mold, and then baked. However, after the photo-curing reaction is a thermosetting resin material, it cannot melt and flow after being heated, so that in the subsequent firing process, the initial decomposition temperature of the resin is high, and the thermal decomposition temperature is concentrated in a local temperature range, which will cause more The gas cracks the shell; in addition, the thermal expansion coefficient of the resin is greater than that of the refractory shell material, which will also cause the shell to expand and crack.

technical problem

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Technical solutions

In order to solve the above technical problems, the present invention provides a resin mold for photo-curing rapid molding, which includes, by weight percentage, a photosensitive resin: 60-95 wt%, and an inert low-molecular weight substance: 5-40 wt%.

The photosensitive resin includes, by weight percentage, 10-70 wt% of an active oligomer, 20-70 wt% of a reactive diluent, 0.2-6 wt% of a photoinitiator, and the balance is a functional auxiliary.

Preferably, the active oligomer is at least one of acrylate, acrylamide and silane acrylate.

Preferably, the acrylate is selected from at least one of pure acrylate, epoxy acrylate, urethane acrylate, and polyester acrylate.

Preferably, the reactive diluent uses at least one of a bifunctional or polyfunctional alkyl acrylate, an alkoxy acrylate, and an ethylene glycol acrylate.

The photoinitiator uses a free-radical type and a cationic type photoinitiator which can absorb under 250-440 nm ultraviolet light. The free radical type photoinitiator uses phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide, ethyl 2,4,6-trimethylbenzoylphosphonic acid, and diphenyl (2, 4,6-trimethylbenzoyl) phosphine oxide, bis 2,6-difluoro-3-pyrrolephenylferrocene, 2-isopropylthioanthrone, 4-phenylbenzophenone, At least one of 2-phenylbenzyl-2-dimethylamine-1- (4-morpholine benzylphenyl) butanone; the cationic photoinitiator uses an aryldiazonium salt, a diaryl iodonium salt, At least one of a triarylsulfonium salt and an aromatic ferrocene salt.

The functional additive uses at least one of a defoaming agent, a leveling agent, and an adhesion promoter, and the additive amount of each additive is 0.5-4% of the total weight of the resin mold. The defoamer uses at least one of aliphatic amide, polyethylene glycol, modified polydimethylsiloxane, and polymer solution without silicone; the leveling agent uses polyacrylate compound, polyether / At least one of a polyester / aralkyl-modified dimethylsiloxane solution and a fluorocarbon-modified polyacrylate copolymer solution; the adhesion promoter uses amine silane, phosphate polymer, and epoxy silane At least one of oligomers.

Inert low-molecular-weight substances use suitable moderate-boiling substances, and their boiling points are preferably in the range of 120-250 ° C; and their molecular weights are in the range of 50-5000, preferably 200-1000; inert low-molecular-weight substances use inert oligomers and inert small molecules At least one of the diluents. When it is a mixture of the two, its weight ratio is 1: 0.2 to 1: 5, and the inert oligomer may be at least one of polycaprolactone polyol, polypropylene glycol, ethylene polymer, and polyvinylpyrrolidone. One type; the inert small molecule diluent may be at least one of ethylene glycol, glycerol, propylene carbonate, butoxymethacrylamide, and diethylene glycol dimethyl ether.

The inert low-molecular-weight substances do not participate in the photo-curing polymerization reaction, do not react with the functional groups in the components in the photosensitive system, have better solubility in the photosensitive resin system, and have a lower solubility during the firing process. Softening and gasifying / decomposing at the temperature, leaving a void in the three-dimensional model, and expanding the model to the void in the process of further increasing the temperature, can prevent the shell from cracking.

A method for preparing a photo-curing system: the active oligomer, a reactive diluent, a photoinitiator, a functional auxiliary, and an inert low-molecular-weight substance are stirred at a medium speed for 5-15h at a certain ratio to obtain a uniform photo-curing system.

Among them, the viscosity range of the system is 100-3000 cp, and the preferred viscosity is 100-1500 cp.

Investment casting or "lost wax" casting is a precision casting process in which a resin mold is transformed into solid metal parts after multiple steps of processing. The invention combines the rapid prototyping technology and the investment casting technology, and uses a rapid prototype to prepare a direct casting model. Compared with traditional wax mold casting, this method has the advantages of low cost, high efficiency, non-deformation, and can produce more precise castings. It only needs to change the CAD geometric model to obtain the casting mold very conveniently, which can greatly save the production. The time of the mold can achieve efficient and high-precision rapid casting in the art casting, jewelry and other industries, and has a wide application prospect in the industrial fields such as aviation and civil parts.

The present invention adopts the above technical solution, and has the advantages that: Adding an inert low-molecular-weight substance to the photo-curing system, the inert substance does not participate in the photo-curing polymerization reaction, does not react with the functional groups in the components of the photosensitive system, has good solubility in the photosensitive resin system, and During the firing process, gasification or decomposition at a lower temperature leaves a void in the three-dimensional model, and in the process of further increasing the temperature, the model expands to the void to prevent cracking of the shell. After the calcination was completed, the resin mold prototype was completely consumed, and no tar-like residue or obvious ash was found in the mold shell.

Preparation method of light curing system: the oligomer, reactive diluent, photoinitiator, functional assistant and inert low molecular weight substance are stirred at a medium speed for 5-15h at a certain ratio to obtain a uniform light curing system. The viscosity range of this system is 100-3000 cp, and the preferred viscosity is 100-1500 cp.

A light curing molding process method includes the following steps:

Step A: Design a three-dimensional solid model by modeling software, slice the model according to the designed solidified layer thickness using the slicing software, and import the sliced file into the light curing rapid prototyping machine (SLA or DLP) control software;

Step B: The above-mentioned photo-curing system is placed under SLA or DLP to perform point-by-point / layer-by-layer exposure curing, and when a layer is processed, a section of the part is generated;

Step C: The forming platform rises or falls by a distance of a solidified layer thickness, and the thickness of each layer ranges from 20 to 100 μm;

Step D: Repeat the above steps, and build up the layer by layer to obtain a three-dimensional solid model.

Preferably, in the step C, the layer thickness is 20, 50, 75, or 100 μm.

Preferably, the wavelength of the photo-curing rapid prototyping machine is preferably 355 nm, 365 nm, 385 nm, 405 nm, and 420 nm.

A model baking method includes the following steps:

Step (1): The above-mentioned photo-cured three-dimensional prototype is coated with a refractory slurry to form an investment casting mold shell. After the first layer of the coated slurry is dried, it is coated again. This step is repeated 10- 20 times;

Step (2) It is immersed in a metal container containing refractory paste, and then put together in a sintering furnace to bake off the resin mold prototype, so that the cavity corresponding to the final three-dimensional part is left in the refractory shell. Structure; Finally, the molten metal or alloy is injected into the liquid, and the refractory shell is removed after cooling to obtain the final three-dimensional metal or alloy component.

The refractory slurry is made of ceramic slurry such as fused silica, alumina, and magnesia.

Among them, the resin prototype in the firing process in step (2) due to thermal expansion and weightless gas can easily cause the mold shell to swell and fail, so the thermal weightlessness of the light-curing resin plays a decisive role in the complete production of the ceramic mold shell. . For this reason, thermogravimetric analysis tests were performed on the solidified model. The results show that the moderate heat of the system is mainly divided into two stages. The first stage is at 120-250 ° C. The thermal decomposition in this stage is mainly the gas of inert low molecular weight substances. The decomposition or decomposition leaves a void in the three-dimensional model, and the model expands to the void in the process of further increasing the temperature, which can prevent the cracking of the shell; the second stage is at 300-500 ° C, mainly the molecular chain breaks. The opening of the chemical bonds between the atoms changes the large molecules into small molecules. This thermal weight loss characteristic can provide guidance for the process of the roasting process.

Preferably, the roasting process includes: slowly heating up to 80-120 ° C at a rate of 2-10 ° C / h and holding for 4-12 hours; and then heating up to 120-250 ° C at a rate of 1-5 ° C / min, Incubate for 2-8 h; finally heat up to 700-1000 ° C at a rate of 1-5 ° C / min, and incubate for 2-8 hours to ensure that the resin does not have any residue. After the prototype was roasted, no tar-like residue or obvious ash was found in the shell, and the ash content was less than 0.5%.

In the present invention, an inert low-molecular-weight substance is added to the photo-curing system. The inert substance does not participate in the photo-curing polymerization reaction, does not react with the functional groups in the components in the photosensitive system, and has good solubility in the photosensitive resin system. In addition, during the firing process, gasification or decomposition at a lower temperature leaves a void in the three-dimensional model, and the model expands to the void in the process of further increasing the temperature, thereby preventing the shell from cracking. In addition, a thermal weight loss analysis test is performed on the cured resin to provide guidance for subsequent firing processes. After the calcination was completed, the resin mold prototype was completely consumed, and no tar-like residue or obvious ash was found in the mold shell. Compared with traditional wax pattern casting, this method has the advantages of low cost, high efficiency, non-deformation, and can produce thinner castings. When the product is upgraded, only the CAD geometric model needs to be changed, and the casting can be obtained very conveniently. The mold can greatly save the time for making the mold. It can achieve high-efficiency and high-precision rapid casting in the art casting, jewelry and other industries, and has a wide application prospect in the industrial fields such as aviation and civil parts.

Beneficial effect

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BRIEF DESCRIPTION OF THE DRAWINGS

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Best Mode of the Invention

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Embodiments of the invention

The preferred embodiments of the present invention are described in further detail below:

Example 1

54g of reactive oligomer acrylate, 33.25g of reactive diluent alkyl acrylate, 4.75g of photoinitiator phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide, 1g of defoamer aliphatic Amide, 1g leveling agent polyacrylate compound, 1g adhesion promoter amine silane, and 5g inert low-molecular-weight polycaprolactone polyol. After mixing, stir at medium speed for 15h to make the viscosity range of 1000 cp. Light curing system.

A three-dimensional solid model is designed by the modeling software, and the model is sliced according to the designed solidified layer thickness using the slicing software. The sliced file is imported into the 405nm light curing rapid prototyping machine (SLA or DLP) control software. The system is placed under SLA or DLP for point-by-point / layer-by-layer exposure curing. When one layer is processed, a section of the part is generated, and the molding platform is raised or lowered by a distance of the solidified layer thickness. The layer thickness is 20 μm, and the above steps are repeated. 3D layer-by-layer accumulation and accumulation to obtain a three-dimensional solid model.

The three-dimensional prototype is coated with refractory slurry fused silica to form an investment casting mold shell. After the first layer of the coated slurry is dried, it is coated again. This step is repeated 10 times, and it is immersed in a refractory container. Put the slurry in the metal container and put it together in a sintering furnace to bake the prototype of the resin mold. The baking process includes: slowly heating to 80 ° C at a rate of 2 ° C / h and holding for 4 hours; then at 1 ° C / min heats up to 150 ° C for 2 h; finally heats up to 700 ° C at a rate of 1 ° C / min for 2 h, leaving the cavity structure corresponding to the final three-dimensional part in the refractory shell; finally The liquid molten alloy is injected, and the refractory shell is removed after cooling to obtain the final three-dimensional alloy part.

Example 2

42g of active oligomer acrylamide, 12g of reactive diluent alkoxyacrylate, 3g of photoinitiator 2,4,6-trimethylbenzoylphosphonic acid ethyl ester, 1g of defoamer polyethylene glycol, 1g Leveling agent polyether-modified dimethylsiloxane solution, 1g adhesion promoter phosphate polymer, and 40g inert low-molecular polypropylene glycol. After mixing, stir at medium speed for 5h to make the viscosity range 1500 cp. Uniform light curing system.

A three-dimensional solid model is designed by the modeling software. The model is used to slice the model according to the designed solidified layer thickness. The sliced file is imported into the 365nm light curing rapid prototyping machine (SLA or DLP) control software. The system is placed under SLA or DLP for point-by-point / layer-by-layer exposure curing. When one layer is processed, a section of the part is generated, and the molding platform is raised or lowered by a distance of the solidified layer thickness. The layer thickness is 50 μm. Repeat the above steps. 3D layer-by-layer accumulation and accumulation to obtain a three-dimensional solid model.

The three-dimensional prototype is coated with alumina slurry of refractory slurry to form an investment casting shell. After the first layer of slurry to be coated is dried, it is coated again. This step is repeated 20 times, and it is immersed in the refractory container. Put the slurry in the metal container and put it together in a sintering furnace to bake the resin mold prototype. The baking process includes: slowly heating to 120 ° C at a rate of 10 ° C / h, holding for 12 hours; and then at 5 ° C. / min heats up to 250 ° C for 8 h; finally heats up to 1000 ° C at 5 ° C / min for 8 h, leaving the cavity structure corresponding to the final three-dimensional part in the refractory shell; Finally, the liquid molten alloy is injected, and the refractory shell is removed after cooling to obtain the final three-dimensional alloy part.

Example 3

52.4 g of active oligomer silane acrylate, 24 g of reactive diluent ethylene glycol acrylate, 1.6 g of photoinitiator diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, and 1 g of defoaming Agent modified polydimethylsiloxane, 1g leveling agent fluorocarbon modified polyacrylate copolymer solution, 1g adhesion promoter epoxy silane oligomer, and 20g inert low molecular weight ethylene polymer, after mixing Stir at medium speed for 10 h to make the viscosity 2000cp, and obtain a uniform photo-curing system.

A three-dimensional solid model is designed by the modeling software. The slice software is used to slice the model according to the designed solidified layer thickness. The sliced file is imported into the 385nm light curing rapid prototyping machine (SLA or DLP) control software. The light is cured. The system is placed under SLA or DLP for point-by-point / layer-by-layer exposure curing. When one layer is processed, a section of the part is generated, and the molding platform is raised or lowered by a distance of the solidified layer thickness. The layer thickness range is 75 μm. Repeat the above. In the step, layer-by-layer accumulation is formed to obtain a three-dimensional solid model.

The three-dimensional prototype is coated with refractory slurry magnesia to form an investment casting mold shell. After the first layer of the coated slurry is dried, it is coated again. This step is repeated 15 times, and it is immersed in the refractory container. Put the slurry in a metal container and put it together in a sintering furnace to bake the prototype of the resin mold. The baking process includes: slowly heating to 100 ° C at a rate of 6 ° C / h and holding for 8 hours; then at 3 ° C The heating rate is increased to 180 ° C / min for 5 hours, and the temperature is raised to 800 ° C at the rate of 3 ° C / min for 5 hours, so that the cavity structure corresponding to the final three-dimensional component is left in the refractory shell; Finally, the liquid molten metal is injected, and the refractory shell is removed after cooling to obtain the final three-dimensional metal part.

Example 4

49.5 g of active oligomer epoxy acrylate, 18 g of reactive diluent alkyl acrylate, 4.5 g of photoinitiator diaryl iodonium salt, 0.5 g of defoamer-free polymer solution containing silicone, 1.2 g of stream Leveling agent polyester-based modified dimethylsiloxane solution, 0.3 g of adhesion promoter epoxy silane oligomer, and 5 g of inert low-molecular-weight glycerol. After mixing, stir at medium speed for 8 h to make the viscosity 1500 cp. A uniform photo-curing system was obtained.

A three-dimensional solid model is designed by the modeling software. The model is used to slice the model according to the designed solidified layer thickness. The sliced file is imported into the 365nm light curing rapid prototyping machine (SLA or DLP) control software. The system is placed under SLA or DLP for point-by-point / layer-by-layer exposure curing. When one layer is processed, a section of the part is generated, and the molding platform rises or falls by a distance of the solidified layer thickness. The layer thickness range is 100 μm. Repeat the above. In the step, layer-by-layer accumulation is formed to obtain a three-dimensional solid model.

The three-dimensional prototype is coated with refractory slurry fused silica to form an investment casting mold shell. After the first layer of the coated slurry is dried, it is coated again. This step is repeated 18 times, and it is immersed in a refractory container. Put the slurry in a metal container, and then put it together in a sintering furnace to bake the prototype of the wax mold. The baking process includes: slowly heating to 110 ° C at a rate of 8 ° C / h, and holding it for 10h; then at 2 ° C / Heating at a rate of min to 200 ° C for 6 h; finally heating to 900 ° C at a rate of 4 ° C / min for 6 h, leaving the cavity structure corresponding to the final three-dimensional component in the refractory shell; finally The molten metal is injected and the refractory shell is removed after cooling to obtain the final three-dimensional metal part.

Table 1

project	this invention	Foreign company products on the market	Domestic company products on the market
Tensile strength at break (MPa)	18-24	14-16	12-15
Young's modulus (MPa)	180-240	150-220	150-200
Elongation at break (%)	10-15%	8-15%	7-9%
Temperature at 2% weight loss (℃)	120	195	240
Roasting residue (%)	Less than 0.5%	Less than 0.7%	Less than 5%
cost	30-45% of foreign products	-	40-50% of foreign products
Minimum resolution (μm)	20	Around 50	50-100

The invention can obtain a three-dimensional prototype with a fine structure, a certain mechanical property and an elongation at break by a light-curing rapid forming method; and the initial temperature of thermal weight loss is low during the firing process, the thermal weight loss curve is smooth, and the shell will not appear Cracking phenomenon; no tar-like residue or obvious ash was found in the mold shell after the roasting of the prototype, and the ash content was less than 0.5%. The method has the advantages of low cost, high efficiency, non-deformation, and can produce thinner and more precise castings. When the product is updated, it is only necessary to change the CAD geometric model to obtain the casting mold very conveniently, which can greatly save the production of molds. In time, it can achieve efficient and high-precision rapid casting in the art casting, jewelry and other industries, and has a wide application prospect in the industrial fields such as aviation and civil parts.

The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be considered that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field to which the present invention pertains, without deviating from the concept of the present invention, several simple deductions or replacements can be made, which should all be regarded as belonging to the protection scope of the present invention.

Industrial applicability

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Sequence Listing Free Content

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Claims (10)

1. A resin mold for photo-curing rapid molding, characterized in that, by weight percentage, it includes: photosensitive resin: 60-95 wt%, inert low molecular weight substance: 5-40 wt%; the photosensitive resin includes: low activity The polymer is 10-70 wt%, the reactive diluent is 20-70 wt%, the photoinitiator is 0.2-6 wt%, and the balance is a functional auxiliary.
2. The resin mold for light-curing rapid molding according to claim 1, wherein the reactive oligomer uses at least one of acrylate, acrylamide, and silane acrylate; and the reactive diluent uses double At least one of a functional or polyfunctional alkyl acrylate, alkoxy acrylate, and ethylene glycol acrylate; the photoinitiator is Radical and cationic photoinitiators with absorption under nm UV light; the functional auxiliary uses at least one of a defoamer, a leveling agent, and an adhesion promoter, and the amount of each auxiliary is 0.5-4% .
3. The resin mold for light-curing rapid molding according to claim 2, wherein the acrylate is at least one of pure acrylate, epoxy acrylate, polyurethane acrylate, and polyester acrylate; radical type Photoinitiator uses phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide, ethyl 2,4,6-trimethylbenzoylphosphonic acid, and diphenyl (2,4,6 -Trimethylbenzoyl) phosphine oxide, bis 2,6-difluoro-3-pyrrolephenylferrocene, 2-isopropylthioanthone, 4-phenylbenzophenone, 2-benzene At least one of benzyl-2-dimethylamine-1- (4-morpholine benzylphenyl) butanone; a cationic photoinitiator uses an aryldiazonium salt, a diaryl iodonium salt, and a triaryl sulfur At least one of an onium salt and an aromatic ferrocene salt.
4. The resin mold for light-curing rapid molding according to claim 2, wherein the defoaming agent comprises an aliphatic amide, polyethylene glycol, modified polydimethylsiloxane, and a polymer containing no silicone. Material solution; leveling agent using at least one of polyacrylate compound, polyether / polyester / aralkyl modified dimethylsiloxane solution, and fluorocarbon modified polyacrylate copolymer solution; adhesion The accelerator uses at least one of an aminosilane, a phosphate polymer, and an epoxysilane oligomer.
5. The resin mold for light-curing rapid molding according to claim 1, wherein at least one of an inert oligomer and an inert small molecule diluent is used as the inert low molecular weight substance. When it is a mixture of the two, the weight ratio is 1: 0.2 to 1: 5, and the molecular weight is 50-5000. The inert oligomer uses polycaprolactone polyol, polypropylene glycol, ethylene polymer, polyethylene At least one of the pyrrolidone; the inert small molecule diluent may be at least one of ethylene glycol, glycerol, propylene carbonate, butoxymethacrylamide, and diethylene glycol dimethyl ether.
6. A method for preparing a photo-curing system, characterized in that the active oligomer, active diluent, photoinitiator, functional auxiliary and inert low molecular weight substance are stirred for 5-15h according to the compounding ratio of claim 1, A uniform photo-curing system was obtained.
7. The preparation method according to claim 6, wherein the viscosity of the photo-curing system is in the range of 100-3000 cp.

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8. A light curing molding process includes the following steps:

   Step A: Design a three-dimensional solid model by modeling software, slice the model according to the designed solidified layer thickness using the slicing software, and import the sliced file into the light curing rapid prototyping machine (SLA or DLP) control software;

   Step B: The above-mentioned photo-curing system is placed under SLA or DLP to perform point-by-point / layer-by-layer exposure curing, and when a layer is processed, a section of the part is generated;

   Step C: The forming platform rises or falls by a distance of a solidified layer thickness, and each layer thickness ranges from 20 to 100 μm;

   Step D: Repeat the above steps, and build up the layer by layer to obtain a three-dimensional solid model.
9. A model firing method is characterized in that it includes the following steps:

   Step (1): The refractory slurry is applied to the photo-cured three-dimensional prototype obtained in claim 8 to form an investment casting shell. After the first layer of the slurry is dried, the coating is applied again. , This step is repeated 10-20 times;

   Step (2): immerse it in a metal container containing refractory paste, and then place it together in a sintering furnace to fire and remove the three-dimensional prototype of the resin mold, so that the corresponding three-dimensional part of the final part is left in the refractory shell. Cavity structure; finally, the molten metal or alloy is injected into the liquid, and the refractory shell is removed after cooling to obtain the final three-dimensional metal or alloy component.
10. The method according to claim 9, wherein the refractory slurry uses at least one of fused silica, alumina, and magnesia.

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