TWI395662B - Method of forming shell mold and high strength ceramic or metal-ceramic composite prototype using such shell mold - Google Patents

Description

Method for molding shell mold and method for molding high strength ceramic or cermet composite using the shell mold

The present invention relates to a forming method for forming a shell mold, and a method for forming a prototype of a high-strength ceramic or cermet composite using the shell mold, or by using the shell mold to make a silicone rubber The molding method of the mold.

Rapid prototyping (RP) forming technology uses layered processing technology to automatically create 3D solid objects in accordance with the solid geometry of computer-aided design (CAD). The rapid prototyping technology overcomes the geometric dead angles that cannot be completed by tool machining, and automates solid freeform fabrication (SFF), and the molded prototype has no shape limitations. Therefore, rapid prototyping technology is particularly suitable for forming workpieces with complex contours.

The materials that can be used for rapid prototyping are divided into photosensitive resin, wax, metal, ceramic and composite materials. However, ceramic materials have advantages such as high strength, high melting point, corrosion resistance, and low cost, so they are particularly worthy of development.

So far, the rapid prototyping technologies that can be used to make ceramic products are: (1) stereolithography apparatus (SLA), (2) selective laser sintering (SLS), and (3) stack manufacturing. (Laminated object manufacturing, LOM), (4) three-dimensional printing (3DP), (5) fused deposition modeling (FDM), etc., the above methods are directly laminated to produce ceramic workpieces. However, it is not easy to manufacture a high-density, high-strength, complex-shaped ceramic product.

Because ceramics have high hardness and brittleness so that they are not easy to process, conventional ceramic products are not easy to produce workpieces with complex internal shapes. If a rapid prototyping technique is used to directly fabricate a ceramic workpiece, it is often necessary to additionally design and fabricate a support structure to produce a ceramic workpiece of complex internal shape, especially when the article has an overhanging structure.

Accordingly, one aspect of the present invention provides a molding method for forming a shell mold, which is then used to form a high strength ceramic or cermet composite prototype. Therefore, after the shell mold is manufactured by the rapid prototyping technology of the present invention, the ceramic slurry can be pressed into the cavity of the shell mold, and the mold can be fully filled with the high fluidity of the slurry. With the space and the gap, it is possible to manufacture ceramic workpieces with complex internal shapes without the need to make a support structure. In addition, the general model is a solid structure. The model used in the present invention is a shell mold which is formed into a thin shell by rapid prototyping technology. Therefore, the mold manufacturing time can be greatly reduced, and the ceramic prototype can be quickly produced.

In addition, another scope of the present invention is to provide a shell mold manufactured by rapid prototyping technology, which is followed by techniques of vibration, vacuuming, heat equalizing, heat treatment, etc. to fabricate a ceramic product. Thereby, a ceramic workpiece having high strength (300 MPa or more), high density (95% or more), and high precision (feature size: 25 μm or less) can be obtained.

Further, another aspect of the present invention is to provide a method of molding a high strength cermet composite prototype using a shell mold manufactured by a rapid prototyping technique.

Further, another aspect of the present invention is to provide a molding method for turning a silicone mold by using a shell mold manufactured by a rapid prototyping technique. Thereby, the ceramic slurry or the cermet composite slurry is pressurized and injected into the cavity of the silicone mold, and after drying, the ceramic green workpiece or the cermet composite green workpiece can be obtained. In addition, chocolate, juice, syrup or formable dishes can be pressurized into the cavity of the silicone mold, thereby obtaining a food shape with a high complexity or a multi-layered shape.

According to a molding method of a first preferred embodiment of the present invention, the molding method is used to form a shell mold. The shell mold is composed of a thin layer of a continuously solidified N-layer molding material, wherein N is a natural number. The molding method first prepares a molding material. Next, the molding method first coats the first layer of molding material on a work table. Then, the molding method is to irradiate a part of the molding material of the first layer molding material with a radiation beam according to a cross-sectional pattern of the molding layer corresponding to the curing of the first layer to cure the irradiated molding material, thereby forming the first A thin layer of layered cured molding material. Next, the molding method applies an i-th layer molding material to the ( i -1)-layer molding material, wherein the i- system ranges from an integer index of one of 2 to N. Next, the method of forming the thin layer system according to one of the molding material to be cured layer i-sectional pattern to the radiation beam of the i-th layer of the molding material the molding material to solidify the molding material to be irradiated, thereby forming the i A thin layer of layered cured molding material. Next, the molding method is a step of repeatedly coating the i-th layer molding material and irradiating the i-th layer molding material with the radiation beam until the N-layer cured material-forming thin layer is completed. Finally, the molding method removes the residual molding material attached to the thin layer of the N-layer cured molding material to obtain the shell mold.

A molding method according to a second preferred embodiment of the present invention for molding a ceramic green body by using a shell mold formed by the molding method of the present invention. The molding method firstly uniformly mixes a ceramic powder, a binder and a suspending agent in a ratio and stirs them into a slurry. Next, the molding method pours the slurry into the cavity of the shell mold and fills the cavity of the shell mold. Next, the molding method performs an ultrasonic vibration process on the shell mold filled with the slurry to make the ceramic powder in the slurry more dense. Next, the molding method performs a vacuuming process on the shell mold filling the slurry to remove bubbles in the slurry. Next, the molding method performs a heating process corresponding to the shell mold filling the slurry, so that the binder of the slurry is heated to generate the chemical gel reaction. Finally, the molding process removes the shell mold to obtain the ceramic green body. The ceramic green body formed by the molding method of the present invention is further sintered into a high strength ceramic prototype.

A molding method according to a third preferred embodiment of the present invention for molding a metal-ceramic composite green body by using a shell mold formed by the molding method of the present invention. The molding method firstly uniformly mixes a metal powder, a binder and a suspending agent in a ratio and stirs them into a slurry. Next, the molding method pours the slurry into the cavity of the shell mold and fills the cavity of the shell mold. Next, the molding method performs an ultrasonic vibration process on the shell mold filled with the slurry to make the composite material powder in the slurry more dense. Next, the molding method performs a vacuuming process on the shell mold filling the slurry to remove bubbles in the slurry. Next, the molding method performs a heating process on the shell mold filling the slurry, so that the binder of the slurry is heated to generate the chemical gel reaction. Finally, the molding process removes the shell mold to obtain the metal-ceramic composite green body.

A molding method according to a fourth preferred embodiment of the present invention for molding a die mold by using a shell mold formed by the molding method of the present invention. The molding method firstly produces a male mold and a female mold by using a silicone material by a rewinding technique. Finally, the molding method completes the silicone mold by clamping the male mold with the master mold, and the silicone mold has a cavity.

The advantages and spirit of the present invention will be further understood from the following detailed description of the invention.

Referring to FIG. 1 and FIG. 2A to FIG. 2D, FIG. 1 is a flow chart showing a molding method 1 according to a first preferred embodiment of the present invention. The molding method 1 according to the present invention is used to form a shell mold 28. In particular, the shell mold 28 is composed of a thin layer of N-layer continuously solidified molding material, where N is a natural number. 2A to 2D are schematic views showing the molding of the shell mold 28 by using a rapid prototyping apparatus 2.

As shown in Fig. 1, the molding method 1 according to the present invention first performs step S10 to prepare a molding material.

In one embodiment, the molding material is an ultraviolet light photosensitive resin, and the radiation beam is an ultraviolet light laser, and the ultraviolet light photosensitive resin irradiated by the ultraviolet light laser is hardened. The ultraviolet light photosensitive resin is used as a molding material for the shell mold, and the shell mold must have a thickness greater than or equal to 0.5 mm to prevent deformation of the shell mold during subsequent casting.

In another embodiment, the molding material is a wax powder, and the radiation beam is a laser, and the laser powder irradiated by the laser is sintered together. The ultraviolet light photosensitive resin is used as a molding material of the shell mold, and the shell mold must have a thickness greater than or equal to 1 mm. The wax shell mold can be directly heated and burned after the ceramic green body or the cermet green body is obtained by subsequent casting.

Next, as shown in FIG. 1 and FIG. 2A, the molding method 1 according to the present invention performs step S12 to apply a first layer of molding material onto a table 24 by a coating device 22. The table 24 has a plane and is actuated to move up and down along one of the axes perpendicular to the plane (i.e., parallel to one of the Z axes in Fig. 2A). According to the present invention, the coating device 22 may include a funnel 222 containing the slurry SL and a squeegee 224 (or cylindrical roller) that allows the molding material SL to be evenly distributed on the table 24. The funnel 222 pushes a suitable molding material SL' onto the table 24. The squeegee 224 coats the aforementioned molding material SL' into a uniform thin layer molding material SL'. The thickness of each layer of molding material SL' can be controlled to be about 0.1 mm. However, the invention is not limited thereto, and the required coating thickness may be determined according to the curvature of the section curve of the product and the characteristics of the molding material, that is, the coating thickness is variable. For example, as the curvature of the cross-section curve of the article is larger, the thickness of the coating becomes smaller. Moreover, the present invention is not limited to coating the molding material in a horizontal or equal thickness.

Next, as shown in FIG. 1 and FIG. 2B, the molding method 1 according to the present invention performs step S14 to form a curing thin layer forming device 26 according to a cross-sectional pattern of the formed thin layer SL which corresponds to the curing of the first layer. One of the emitted radiation beams illuminates a portion of the molding material SL' of the first layer of molding material SL', wherein the first layer molding material SL' is cured by the molding material SL' irradiated by the radiation beam, thereby forming the first layer of curing A thin layer of molding material SL" (dark part in Figure 2B). That is, and stick together.

As shown in FIG. 2B, the cured thin layer forming device 26 includes a laser beam generating device 262, a light guiding mechanism 264, and a focusing mirror 266. The laser beam generating device 262 is configured to generate a laser beam, such as a CO ₂ laser, a Nd:YAG laser, a He-Cd laser, an Ar laser or a UV laser. In a specific embodiment, the laser beam generating device 262 can be equipped with a temperature sensor. When the temperature sensor detects that the temperature of the cooling water used to cool the laser beam generating device 262 exceeds 25 ° C, the temperature sensor The laser beam generating means 262 stops the excitation of the laser light. The light guiding mechanism 264 and the focusing mirror 266 are actuated in parallel according to the cross-sectional pattern of each layer of the cured forming material thin layer SL" to move in the XY plane as shown in FIG. 2B. The light guiding mechanism 264 is used to guide the light guiding mechanism 264. The laser beam is directed to the focusing mirror 266. The focusing mirror 266 is used to focus the laser beam to each layer of the forming material SL'. In one embodiment, the scanning rate of the laser beam is 85 mm/s and the scanning pitch is 0.1. Mm, the laser power is 10 W. In one embodiment, a jet tube can be added to the focusing mirror 266. The jet tube is used to introduce low-pressure air and is quickly ejected through its nozzle, which prevents molding during laser beam scanning. The material is spattered and attached to the focusing lens, which affects the accuracy of the scanning of the laser beam.

Also shown in Figure 2B, the light directing mechanism 264 in accordance with the present invention includes a plurality of fixed mirrors and mirrors that can be actuated in parallel with the X-Y plane as shown in Figure 2B. For example, reference numerals 264a and 264b in FIG. 2B denote fixed mirrors, and reference numeral 264c denotes a mirror that can be actuated to move along an axis of the X-axis shown in parallel with FIG. 2B, and numeral 264d denotes a follow-up mirror. 264c is actuated and is movable along a mirror that is parallel to one of the Y axes shown in Figure 2B. The focusing mirror 266 moves along with the mirror 264d.

In a specific embodiment, the cured thin layer forming apparatus 26 according to the present invention has a laser beam scanning operation range of 450 mm × 250 mm, a maximum speed of 3000 mm/min or more, and an X-Y axis repeatability of ± 0.02 mm.

Alternatively, the present invention can also utilize galvanometric scanning to focus the laser beam onto each layer of molding material SL'.

Next, as shown in FIG. 1 and FIG. 2C, the molding method 1 according to the present invention performs step S16, and the table 24 is actuated to be lowered by a distance (thickness of a thin layer) along an axis of the Z axis in parallel with FIG. Therefore, it is not necessary to re-adjust the focus reference of the cured thin layer forming device 26 after the subsequent application of a new layer of the molding material. In addition, it should be emphasized that in practical applications, it is necessary to have a thin layer of each layer of molding material not to have the same thickness.

Next, as shown in FIG. 1, the molding method 1 according to the present invention performs step S18, and the coating device 22 coats the i-th layer molding material on the ( i -1) layer molding material, and the i- system ranges from 2 An integer indicator to one of N. Subsequently, the molding method 1 according to the present invention performs step S20 of illuminating the laser beam emitted by the solidified thin layer forming device 26 according to a cross-sectional pattern of the thin layer SL of the molding material corresponding to the ith layer curing. a part of the molding material SL' of the i- layer molding material SL'. Similarly, the part of the molding material SL' irradiated by the laser beam by the i-th layer molding material SL' is heated to cause a hardening reaction or sintering, thereby forming the ith Thin layer SL" of layer cured molding material. In practice, via the CAM technology, the computer can be connected to the molding device 2, and the cured thin layer forming device 26 is controlled to heat each layer of the molding material SL' according to the specific sectional patterns (possibly generated by CAD), and further Achieve automated manufacturing.

Next, according to the molding method 1 of the present invention, step S22 is performed to determine whether all of the specific sectional patterns have been scanned to cure the molding material layer SL' coated on or above the table 24. If the result of the determination in step S22 is negative, the molding method 1 according to the present invention executes step S16, and the table 24 is actuated to be lowered by a distance (thickness of a thin layer), and steps S18 and S20 are successively performed.

If the result of the determination in step S22 is affirmative, the molding method 1 according to the present invention performs step S24, and removes the N layer by a removing device (not shown in FIG. 2A, FIG. 2B and FIG. 2C). The cured molding material thin layer SL" of the residual molding material SL' is obtained to obtain a shell mold 28 as shown in Fig. 2D. In a specific embodiment, the removal device is capable of spraying a liquid (for example, water) to remove the adhesion. The N-layer cured molding material thin layer SL" of the residual molding material SL'.

Referring to FIG. 3 and FIG. 4, FIG. 3 is a flow chart showing a molding method 3 according to a second preferred embodiment of the present invention. The molding method 3 according to the second preferred embodiment of the present invention is for molding a ceramic green body using the shell mold 28 formed by the molding method of the present invention. FIG. 4 is a schematic view showing the molding of the ceramic green body by using the shell mold 28.

As shown in FIG. 3, the molding method 3 according to the present invention first performs step S30, uniformly mixing a ceramic powder, a binder, and a suspending agent in a ratio and stirring into a slurry.

In one embodiment, the ceramic powder may be tantalum carbide (SiC), titanium carbide (TiC), tantalum nitride (Si3N4), titanium oxide (TiO2), aluminum oxide (Al2O3), sodium carbonate, calcium carbonate, zirconium. Lead titanate (PZT), graphite, cerium oxide powder, titanium oxide powder, zirconia, barium carbonate, barium titanate, mica powder, lead oxide, iron oxide, potassium oxide, zinc oxide powder, tricalcium phosphate, hydrogen A powder of oxyapatite, chitin, Na ₂ O, CaO, P ₂ O ₅ , SiO ₂ , MgO, or the like, or a mixed combination of the above materials.

In one embodiment, the binder may be silica sol, titania sol, alumina sol, zirconia sol, polyvinyl alcohol (PVA), Or a mixed combination of the above ceramic sols.

In one embodiment, the suspending agent may be particulate mica powder, polyacrylic acid (PAA), polymethacrylic acid (PMAA), polyethyleneimine (PEI), and polymethacrylate (PMAA-Na, PMAA-). NH4), cerium oxide, titanium oxide, zirconium oxide, sodium citrate or clay, and the like.

In one embodiment, the composition of the slurry is 65 to 55 wt% ceramic powder, 40 to 30 wt% binder, and 3 to 5 wt% suspension. The ceramic powder, the binder and the suspending agent are mixed in proportion, and the homogenizer is used to stir into a uniformly micronized ceramic slurry. The viscosity of the slurry is about 1500~6000mPa‧s with proper fluidity and high proportion of ceramic components.

Next, as shown in FIG. 3 and FIG. 4, the molding method 3 according to the present invention performs step S32, and the slurry 30 is poured into the cavity of the shell mold 28 and fills the cavity of the shell mold 28. As shown in Fig. 4, the slurry 30 is contained in a container 29 and poured into the cavity of the shell mold 28. The shell mold 28 also has an auxiliary sprue 282. Also shown in Fig. 4, the outside of the shell mold 28 is reinforced with a filler material 32 (e.g., a foamed resin) to keep the shell mold from deforming.

Next, as shown in FIG. 3, the molding method 3 according to the present invention performs step S34 to perform an ultrasonic vibration process on the shell mold filled with the slurry to make the ceramic powder in the slurry more dense, ceramic. The density of the slurry can be increased to 95%.

Next, as shown in FIG. 3, the molding method 3 according to the present invention performs step S36 to perform a vacuuming process on the shell mold filling the slurry to remove bubbles in the slurry.

Next, as shown in FIG. 3, the molding method 3 according to the present invention performs step S38, and performs a heating process on the shell mold filling the slurry, so that the binder of the slurry is heated to produce the chemical gel. reaction. The binder added to the ceramic slurry is an oxide sol. The principle of bonding is a gel reaction. After the oxide sol is heated, the atoms formed by evaporation of the water molecules are bonded, so that the oxide sol monomer will be The ceramic particles are glued together. Therefore, the slurry is slowly heated (heating rate 1 ° C / min) to evaporate water molecules, so that the ceramic slurry can be solidified. The faster heating rate causes the slurry to rapidly solidify into a ceramic green body, which causes the moisture in the slurry to not completely evaporate. The poor solidification effect will result in a decrease in the strength of the sintered ceramic product. In addition, the heating temperature cannot be directly raised to 100 ° C to facilitate evaporation of water. Since the model made of the photosensitive resin starts to deform at 50 ° C or higher, the heating temperature should be kept below 50 ° C to gradually solidify into a ceramic green body.

Finally, as shown in FIG. 3, the molding method 3 according to the present invention performs step S39 to remove the shell mold to obtain the ceramic green body. After the slurry is completely solidified, the filler reinforcing material on the outside of the mold is removed and the resin model is removed to obtain a high-density ceramic green body. The ceramic green body may also be subjected to thermal pressure equalization treatment before heat treatment to increase the density of the green body, and the strength of the ceramic workpiece may be improved after sintering.

In a specific embodiment, in order to prevent the ceramic green body from being sintered together with the heat-resistant brick of the high-temperature furnace during sintering, the ceramic green body may be placed on the surface of the alumina thin plate, and a graphite bottom plate is placed under the alumina plate (it may also be oxidized) The aluminum base plate is then placed in a high temperature furnace and heated to 110 ° C (heating rate 5 ° C / min) to remove residual moisture in the ceramic green body. Then, the temperature is raised to 1600 ° C or higher at a heating rate of 10 ° C / min for 2 hours to cause solid sintering between the ceramic particles, followed by cooling to room temperature in the furnace to obtain a high strength, high density ceramic product (strength is achieved) 300MPa or more).

In one embodiment, the ceramic green body has a minute feature size, and the shell mold has a fine exhaust slit corresponding to one of the minute feature sizes to discharge the minute feature size of the ceramic green body. gas. In practical applications, if a resin shell mold is used, the minimum thin layer thickness can be up to 10 μm, and the “fine structure exhaust design” can eliminate the residual gas at the fine size in the cavity. Therefore, when the ceramic slurry (the fine ceramic powder in the slurry has a particle size of less than 1 μm) is solidified, the ceramic green body has a minute feature size of 20 μm or less.

In one embodiment, the binder is an epoxy powder. The ceramic green body is continuously bonded at a temperature of 200 to 300 ° C, and then heated to 1000 ° C for sintering and removing the epoxy resin, and then heated to 1500 ° C or higher to be sintered into a ceramic finished product, and then The liquid helium is infiltrated into the pores left by the epoxy resin in the finished ceramic product to enhance the hardness and strength of the ceramic finished product.

If a wax shell mold is used, the ceramic green body formed by the molding method 3 of the present invention can be formed to have an internal complex shape or an internal communicating pore structure after sintering.

In a specific embodiment, the slurry may be added with carbon fiber filaments, tungsten fiber filaments or boron fiber filaments to impart a fiber strengthening effect to the toughness of the ceramic.

Referring to FIG. 5, FIG. 5 is a flow chart showing a molding method 5 according to a third preferred embodiment of the present invention. The molding method 5 according to the third preferred embodiment of the present invention is for molding a metal-ceramic composite green body by using a shell mold formed by the molding method of the present invention.

As shown in FIG. 5, the molding method 5 according to the present invention first performs step S50, uniformly mixing a metal powder, a binder, and a suspending agent in a ratio and stirring into a slurry.

In one embodiment, the composition of the slurry is 87 to 75 wt% metal powder, 20 to 10 wt% binder, and 3 to 5 wt% suspension.

In another embodiment, the composition of the slurry is 85 wt% 10 μm stainless steel powder, 10 wt% cerium oxide gel binder, and 5 wt% particulate mica powder suspension. After the slurry is prepared into a green body, it is placed in a sintering furnace and heated to a high temperature of 1200 ° C or higher for sintering treatment, and the tensile strength after polishing is up to 700 MPa or more.

Next, as shown in FIG. 5, the molding method 5 according to the present invention performs step S52, pouring the slurry into the cavity of the shell mold and filling the cavity of the shell mold.

Next, as shown in FIG. 5, the molding method 5 according to the present invention performs step S54 to perform an ultrasonic vibration program on the shell mold filled with the slurry to make the composite material powder in the slurry more dense.

Next, as shown in FIG. 5, the molding method 5 according to the present invention performs step S56 to perform a vacuuming process on the shell mold filling the slurry to remove bubbles in the slurry.

Next, as shown in FIG. 5, the molding method 5 according to the present invention performs step S58, and performs a heating process on the shell mold filling the slurry, so that the binder of the slurry is heated to produce the chemical gel. reaction.

Finally, as shown in FIG. 5, the molding method 5 according to the present invention performs step S59 to remove the shell mold to obtain the metal-ceramic composite green body. After the slurry is completely solidified, the shell mold is removed to obtain a high-density metal-ceramic composite green body. The metal-ceramic composite green body can also be subjected to thermal pressure equalization treatment before heat treatment to increase the density of the green body, and the strength of the metal-ceramic composite workpiece can be improved after sintering. The metal-ceramic composite green body can also be sintered in a vacuum furnace or a protective gas (for example, nitrogen) environment to prevent oxidation reaction of the metal and improve mechanical properties of the product.

According to another preferred embodiment of the present invention, the metal powder is coated with a layer of a polymer material (e.g., PE, PP) in place of the binder. After the shell mold is formed according to the present invention, the polymer material is removed by preheating and adding a quenching agent, and is heated in a vacuum sintering furnace to a high temperature of 1200 ° C or higher for sintering treatment, thereby obtaining a cermet composite product.

Referring to FIG. 6, FIG. 6 is a flow chart showing a molding method 6 according to a fourth preferred embodiment of the present invention. The molding method 6 according to the fourth preferred embodiment of the present invention is for molding a silicone mold using a shell mold formed by the molding method according to the present invention.

As shown in FIG. 6, the molding method 6 according to the present invention first performs step S60 by making a male mold and a female mold using a silicone material by a rewinding technique. Finally, as shown in FIG. 6, the molding method 6 according to the present invention performs step S62, and the male mold is closed with the master mold to complete the silicone mold, and the silicone mold has a cavity. Thereby, the ceramic slurry or the cermet composite slurry is pressurized and injected into the cavity of the silicone mold, and after drying, the ceramic green workpiece or the cermet composite green workpiece can be obtained. In addition, chocolate, juice, syrup or formable dishes can be pressurized into the cavity of the silicone mold, thereby obtaining a food shape with a high complexity or a multi-layered shape.

In summary, the ceramic slurry and the cermet composite slurry used in the present invention have good fluidity and can flow to various parts of the shell mold model (including complex shapes and minute feature sizes). After the ceramic slurry and the cermet composite slurry are solidified, the ceramic green body or the cermet composite green body having the same shape as the cavity can be reproduced and the same surface roughness as that of the mold surface can be achieved. It can be mass produced at room temperature. In addition, the general model is a solid structure. The model used in the present invention is made into a thin shell shape by rapid prototyping technology, so that the mold manufacturing time can be greatly reduced and the ceramic prototype can be quickly produced.

The features and spirit of the present invention will be more apparent from the detailed description of the preferred embodiments. On the contrary, the intention is to cover various modifications and equivalents within the scope of the invention as claimed. Therefore, the scope of the patented scope of the invention should be construed as broadly construed in the

1, 3, 5, 6. . . Molding method

S10~S24. . . Method step

2. . . Molding equipment

twenty two. . . Coating device

222. . . funnel

224. . . Scraper

twenty four. . . Workbench

26. . . Curing thin layer forming device

262. . . Laser beam generating device

264. . . Light guiding mechanism

264a, 264b, 264c, 264d. . . Reflector

266. . . Focusing mirror

SL. . . Molding material

SL'. . . Molding material layer

SL"...a thin layer of cured molding material

28. . . Shell mold

282. . . Auxiliary sprue

29. . . container

30. . . Ceramic slurry

32. . . Filler

S30~S39. . . Method step

S50~S59. . . Method step

S60~S62. . . Method step

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a flow chart of a molding method in accordance with a first preferred embodiment of the present invention.

Figure 2A is a schematic diagram of the process of forming a shell mold using a rapid prototyping apparatus in the process of coating a molding material.

Figure 2B is a schematic diagram of the formation of a shell mold using a rapid prototyping apparatus in a radiation beam scanning curing process.

Figure 2C is a schematic diagram of the use of a rapid prototyping apparatus to form a shell mold after stacking a plurality of layers of a cured layer of the formed material.

Figure 2D is a schematic view of a shell mold completed in accordance with a molding method of a first preferred embodiment of the present invention.

Figure 3 is a flow chart of a molding method in accordance with a second preferred embodiment of the present invention.

Figure 4 is a schematic view showing the molding of a ceramic green body by using a shell mold according to the present invention.

Figure 5 is a flow chart of a molding method in accordance with a third preferred embodiment of the present invention.

Figure 6 is a flow chart of a molding method in accordance with a fourth preferred embodiment of the present invention.

3. . . Molding method

S30~S39. . . Method step

Claims (20)

A molding method for molding a shell mold, which is composed of a thin layer of a N-layer continuously solidified molding material, N is a natural number, and the molding method comprises the following steps: (a) coating a first layer molding The material is on a work surface; (b) irradiating a portion of the molding material of the first layer molding material with a radiation beam to cure the irradiated molding material according to a cross-sectional pattern of the molding layer corresponding to the curing of the first layer, thereby Forming a thin layer of the first layer of the cured molding material; (c) coating the i-th layer molding material on the ( i -1) layer molding material, wherein the i series ranges from an integer index of 2 to N; (d) the sheet of one of the molding material to be cured layer i-sectional pattern to the beam of radiation of the i-th layer of the molding material the molding material to solidify the molding material is irradiated, thereby forming a thin layer of molding material of the i-th cured (e) repeating steps (d) and (e) until the N-layer cured material layer is completed; and (f) removing the residual molding material attached to the N-layer cured molding material thin layer, To obtain the shell mold. The molding method of claim 1, wherein the molding material is an ultraviolet photosensitive resin, and the radiation beam is an ultraviolet laser. The molding method of claim 2, wherein the shell mold has a thickness greater than or equal to 0.5 mm. The molding method of claim 1, wherein the molding material is a wax powder, and the radiation beam is a laser. The molding method of claim 4, wherein the shell mold has a thickness greater than or equal to 1 mm. A molding method for molding a ceramic green body by using a shell mold formed by the molding method according to claim 1 of the patent application, the molding method comprising the steps of: arranging a ceramic powder, a binder, and a suspending agent Mixing uniformly and stirring into a slurry; pouring the slurry into the cavity of the shell mold and filling the cavity of the shell mold; performing an ultrasonic vibration program on the shell mold filling the slurry The ceramic powder in the slurry is more dense; a vacuum process is performed on the shell mold filling the slurry to remove bubbles in the slurry; and heating is performed corresponding to the shell mold filling the slurry. a procedure of heating the binder of the slurry to produce the chemical gel reaction; and removing the shell mold to obtain the ceramic green body. The molding method according to claim 6, wherein the ceramic powder is selected from the group consisting of niobium carbide (SiC), titanium carbide (TiC), tantalum nitride (Si3N4), titanium oxide (TiO2), and aluminum oxide (Al2O3). , sodium carbonate, calcium carbonate, lead zirconate titanate (PZT), graphite, cerium oxide powder, titanium oxide powder, zirconia, barium carbonate, barium titanate, mica powder, lead oxide, iron oxide, potassium oxide, zinc oxide One of a group consisting of powder, tricalcium phosphate, hydroxyapatite, chitin, Na ₂ O, CaO, P ₂ O ₅ , SiO ₂ , MgO, and a mixture thereof. The molding method according to claim 6, wherein the binder is selected from the group consisting of silica sol, titania sol, alumina sol, zirconia sol, polyethylene One of a group consisting of a polyvinyl alcohol (PVA) and a mixed combination of binders. The molding method of claim 6, wherein the suspending agent is selected from the group consisting of particulate mica powder, polyacrylic acid (PAA), polymethacrylic acid (PMAA), polyethyleneimine (PEI), and polymethacrylic acid. One of a group consisting of salt (PMAA-Na, PMAA-NH4), cerium oxide, titanium oxide, zirconium oxide, sodium fulvate salt, and clay. The molding method according to claim 6, wherein the composition of the slurry is 65 to 55 wt% ceramic powder, 40 to 30 wt% of a binder, and 3 to 5 wt% of a suspending agent. The molding method according to claim 6, wherein the bonding agent is an epoxy powder, and the ceramic green body is continuously bonded at a temperature of 200 to 300 ° C, and then heated to 1000. The crucible is sintered at °C and the epoxy resin is removed, and then heated to 1500 ° C or higher to be sintered into a ceramic finished product, and then the liquid crucible is infiltrated into the pores left by the epoxy resin in the finished ceramic product to enhance the finished ceramic product. Hardness and strength. The molding method according to claim 6, wherein the slurry is further provided with a carbon fiber yarn, a tungsten fiber yarn or a boron fiber yarn. The molding method according to claim 6, wherein the ceramic green body has a minute feature size, and the shell mold has a fine exhaust gap for a part of the minute feature size to discharge the ceramic green body. The gas at the tiny feature size. The molding method of claim 6, wherein the outer side of the shell mold is reinforced with a filler material. A molding method for molding a metal-ceramic composite green body by using a shell mold formed by the molding method according to claim 1 of the patent application, the molding method comprising the steps of: disposing a metal powder, a binder, and a The suspending agent is uniformly mixed in a ratio and stirred into a slurry; the slurry is poured into the cavity of the shell mold and filled with the cavity of the shell mold; an ultrasonic wave is applied to the shell mold filling the slurry a vibration process to make the composite powder in the slurry more dense; a vacuuming process is performed on the shell mold filling the slurry to remove bubbles in the slurry; corresponding to filling the slurry The shell mold is subjected to a heating process such that the binder of the slurry is heated to produce the chemical gel reaction; and the shell mold is removed to obtain the metal-ceramic composite green body. The molding method according to claim 15, wherein the composition of the slurry is 87 to 75 wt% of metal powder, 20 to 10 wt% of a binder, and 3 to 5 wt% of a suspending agent. The molding method according to claim 15, wherein the composition of the slurry is 85 wt% of a 10 μm stainless steel powder, a 10 wt% cerium oxide gel binder, and a suspension of 5 wt% of the particulate mica powder. A molding method for molding a metal-ceramic composite green body by using a shell mold formed by the molding method according to claim 1 of the patent application, the molding method comprising the steps of: coating an outer layer with a polymer material The metal powder is uniformly mixed with a suspending agent in a ratio and stirred into a slurry; the slurry is poured into a cavity of the shell mold and filled with a cavity of the shell mold; and the shell mold is filled with the slurry. Performing an ultrasonic vibration program to make the composite powder in the slurry more dense; performing a vacuuming process on the shell mold filling the slurry to remove bubbles in the slurry; The shell mold of the slurry is subjected to a heating process to solidify the slurry; and the shell mold is removed to obtain the metal-ceramic composite green body. The molding method according to claim 18, wherein the polymer material coated with the metal powder is polyethylene (PE) or polypropylene (PP). A molding method for molding a plastic mold by using a shell mold formed by the molding method according to claim 1 of the patent application, the molding method comprising the steps of: forming a male mold by using a rubber material by a rewinding technique; a master mold; and the mold is assembled with the master mold to complete the mold, the mold has a cavity.