Hybrid reinforcing agent and binder jet 3d printing method

Abstract

The application relates to a mixed reinforcing agent characterized by comprising a mixture of alkali carbonate and one or more of zirconium oxide, zirconite powder, white corundum and silicon oxide, and the solute particle size of the mixture is 10 nm-50 mu m. The application also relates to a binder jet 3D printing method. The scheme can solve the problem of low strength of the binder jet 3D printing ceramic product in the prior art.

Description

Technical Field

[0001] This invention relates to the field of printing method technology, and in particular to a 3D printing method for jetting a mixture of reinforcing agent and binder. Background Technology

[0002] Casting cores are crucial materials in the investment casting process, used to pour molten metal into the casting to form a specific shape. Commonly used core materials include core sand, metals, and ceramics. Among these, ceramic cores have become the primary core material for high-melting-point metal casting due to their advantages such as high melting point, corrosion resistance, and chemical stability. Currently, ceramic cores are mainly classified as silica-based, alumina-based, and calcium oxide-based. Traditional forming methods for ceramic cores include compression molding, hot die casting, gel casting, and injection molding. These traditional methods cannot form cores with complex shapes, limiting the development of ceramic cores in fields such as aerospace. 3D printing technology provides an innovative approach to forming complex, irregularly shaped ceramic cores. 3D printing, also known as additive manufacturing, is a technology that uses digital models as a basis to form materials in three-dimensional space through layer-by-layer deposition.

[0003] 3D printing manufacturing methods can greatly simplify the manufacturing process and shorten the development cycle. It also offers advantages such as high precision, low cost, minimal material waste, and strong design flexibility, thus gradually becoming one of the most promising key technologies for forming complex and irregularly shaped ceramic materials. Among the many 3D printing technologies, binder jetting 3D printing technology has been widely researched and applied in numerous fields. However, currently, binder jetting 3D printed shells / cores suffer from low strength and poor surface quality when casting high-melting-point metals (such as titanium alloys). Furthermore, precision casting of ceramic shells / cores generally requires not only high strength but also controlled porosity, two factors that have always been difficult to achieve simultaneously. Summary of the Invention

[0004] Therefore, it is necessary to provide a method for 3D printing ceramic products with mixed reinforcing agents and binders to address the problem of low strength in existing binder jet 3D printing technologies.

[0005] To solve the above problems, the present invention adopts the following technical solution:

[0006] In a first aspect, embodiments of the present invention disclose a mixed reinforcing agent comprising a mixture of basic carbonate with one or more of zirconium oxide, zircon powder, white corundum and silicon oxide, wherein the solute particle size of the mixture is 10 nm-50 μm.

[0007] In one embodiment, the mixture further includes one or more of an alcohol-based solvent or a water-based solvent, a dispersant, a binder, a defoamer, and a penetrant.

[0008] In one embodiment, the basic carbonate includes basic calcium carbonate and basic zirconium carbonate.

[0009] Secondly, embodiments of the present invention disclose a binder jetting 3D printing method, applied to the aforementioned mixed reinforcing agent, comprising:

[0010] For powder preparation, ceramic powder with a particle size of 10-100μm is selected, wherein the ceramic powder includes one of alumina, zirconium oxide, silicon oxide, and calcium oxide;

[0011] Before sintering, ceramic powder is used to prepare ceramic green bodies using binder jet 3D printing technology, and the mixed reinforcing agent is impregnated on the surface of the ceramic green body. After waiting for 1 to 20 minutes, it is allowed to penetrate into the interior of the green body, and then it is dried.

[0012] After sintering and drying, the material is placed in a sintering furnace for sintering strengthening. The sintering temperature is 1000 to 1800℃ and the sintering time is 1 to 10 hours.

[0013] In one embodiment, the drying process includes: first letting it stand, and then placing it in an oven for heating at a temperature of 50 to 200°C for 1 to 5 hours.

[0014] In one embodiment, when the mixed reinforcing agent includes an alcohol-based solvent, drying is achieved by burning the alcohol-based solvent using an ignition method.

[0015] In one embodiment, the powder preparation includes: selecting ceramic powder with a particle size of 10-100μm, wherein the ceramic powder includes one of alumina, zirconium oxide, silicon oxide, and calcium oxide, and mixing the ceramic powder with basic carbonate to form printing powder.

[0016] In one embodiment, the particle size of the basic carbonate is 50 nm to 100 μm.

[0017] The technical solution adopted in this invention can achieve the following beneficial effects:

[0018] The mixed reinforcing agent disclosed in this invention includes basic carbonates. During the printing process, the printed part containing the mixed reinforcing agent decomposes at high temperatures to form submicron-sized oxides such as zirconium oxide and calcium oxide. In previous studies, zirconium oxide and calcium oxide were typically added to the matrix powder as sintering aids before printing. However, this method of adding oxides as sintering aids can lead to uneven mixing, uneven microstructure after sintering, and lower density and strength. However, the zirconium oxide and calcium oxide formed through the above method have submicron-sized particles and can exist in situ within the sintered part, resulting in a more uniform distribution and improved product density, surface quality, and mechanical properties. Detailed Implementation

[0019] This invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this invention.

[0020] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," "top," "bottom," "end," "top," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] This invention discloses a mixed reinforcing agent, which includes a mixture of basic carbonate with one or more of zirconium oxide, zircon powder, white corundum and silicon oxide, wherein the solute particle size of the mixture is 10 nm-50 μm.

[0023] As described above, the mixed reinforcing agent disclosed in this invention includes basic carbonates. Therefore, during the printing process, the printed part containing the mixed reinforcing agent decomposes at high temperatures to form submicron-sized oxides such as zirconium oxide and calcium oxide. In previous studies, zirconium oxide and calcium oxide were typically added to the matrix powder as sintering aids before printing. However, this method of adding oxides as sintering aids can lead to uneven mixing, uneven microstructure after sintering, and lower density and strength. However, the zirconium oxide and calcium oxide formed through the above method have submicron-sized particles and can exist in situ within the sintered part, resulting in a more uniform distribution and improved density, surface quality, and mechanical properties of the product.

[0024] In an optional embodiment, the mixture may further include one or more of an alcohol-based solvent or a water-based solvent, a dispersant, a binder, a defoamer, and a penetrant to ensure that the formed zirconium oxide, calcium oxide, etc., can exist in the sintered part in a better in-situ manner, with a more uniform distribution, and can further improve the density, surface quality, and mechanical properties of the product.

[0025] In one optional embodiment, the basic carbonate may include basic calcium carbonate, basic zirconium carbonate, or other carbonates, and the embodiments of the present invention do not limit this.

[0026] Based on the hybrid reinforcing agent disclosed in the embodiments of the present invention, the embodiments of the present invention also disclose a binder jetting 3D printing method, applied to the hybrid reinforcing agent described in any of the above embodiments, the disclosed binder jetting 3D printing method comprising:

[0027] For powder preparation, ceramic powder with a particle size of 10-100μm is selected, wherein the ceramic powder includes one of alumina, zirconium oxide, silicon oxide, and calcium oxide;

[0028] Before sintering, ceramic powder is used to prepare ceramic green bodies using binder jet 3D printing technology, and the mixed reinforcing agent is impregnated on the surface of the ceramic green body. After waiting for 1 to 20 minutes, it is allowed to penetrate into the interior of the green body, and then it is dried.

[0029] After sintering and drying, the material is placed in a sintering furnace for sintering strengthening. The sintering temperature is 1000 to 1800℃ and the sintering time is 1 to 10 hours.

[0030] As described above, in the binder jetting 3D printing method disclosed in this invention, a mixed reinforcing agent is added during the printing process. This causes the mixed reinforcing agent on the printed part to decompose at high temperatures, forming submicron-sized oxides such as zirconium oxide and calcium oxide. In previous studies, zirconium oxide and calcium oxide were typically added to the matrix powder as sintering aids before printing. However, this method, where oxides are added as sintering aids, may result in uneven mixing, uneven microstructure after sintering, and lower density and strength. However, the zirconium oxide and calcium oxide formed through the above method have submicron-sized particles and can exist in situ within the sintered part, resulting in a more uniform distribution and improved density, surface quality, and mechanical properties of the product.

[0031] Meanwhile, the calcium oxide formed from the decomposition of basic calcium carbonate reacts with ZrO2 at high temperatures to form CaZrO3. CaZrO3 refractory material is a high-melting-point refractory compound with a melting point exceeding 2300℃. CaZrO3 materials are characterized by a low coefficient of thermal expansion, high strength, good chemical stability, and strong resistance to alkaline slag erosion. Therefore, for systems containing both zirconium oxide and basic calcium carbonate, the strength can be significantly improved.

[0032] Furthermore, the carbon dioxide formed by the decomposition of basic carbonates is conducive to the generation of more pores in the ceramic shell. Previous studies often failed to balance porosity and mechanical properties. This approach can improve strength while giving the ceramic shell a porosity that meets the requirements for casting.

[0033] In one alternative embodiment, the drying process may include: first letting it stand, and then placing it in an oven for heating at a temperature of 50 to 200°C for 1 to 5 hours, thereby ensuring the drying effect.

[0034] In an optional embodiment, when the mixed reinforcing agent includes an alcohol-based solvent, the alcohol-based solvent is burned by ignition to achieve drying, thereby ensuring a better drying effect.

[0035] In one optional embodiment, powder preparation may specifically include: selecting ceramic powder with a particle size of 10-100 μm, wherein the ceramic powder includes one of alumina, zirconium oxide, silicon oxide, and calcium oxide, and mixing the ceramic powder with basic carbonate to form printing powder. In this case, basic carbonate is added during the ceramic powder preparation process to ensure better achievement of the beneficial effects described above.

[0036] In one alternative embodiment, the particle size of the basic carbonate can be from 50 nm to 100 μm.

[0037] The following are specific implementation examples:

[0038] Example 1

[0039] (1) Preparation of the mixed reinforcing agent: The main components of the mixed reinforcing agent include 50% basic calcium carbonate (10nm) + 40% zircon powder + 10% other components. In addition to the above components, it also includes water-based solvents, dispersants, binders, defoamers, penetrants, etc.

[0040] (2) Preparation of powder: The binder spray 3D printing powder used is alumina powder with a median particle size of 10μm.

[0041] (3) Before sintering: Ceramic products are prepared by binder jetting 3D printing technology, and then the mixed reinforcing agent prepared in (1) is impregnated on the surface of the ceramic product. After waiting for 10 minutes, it is allowed to penetrate into the interior of the green body, and then left to stand for 24 hours to dry.

[0042] (4) Sintering: After drying, the ceramic product with mixed reinforcing agent is placed in a sintering furnace for sintering and strengthening. The sintering temperature is 1700℃ and the sintering time is 2h.

[0043] (5) Performance Comparison

[0044]

[0045] Example 2

[0046] (1) Preparation of powder: The binder sprayed 3D printing powder is 80% calcium oxide powder of 30μm + 10% basic calcium carbonate of 50nm + 10% basic zirconium carbonate of 80nm.

[0047] (2) Pre-sintering treatment: Ceramic products are prepared using the powder in (2) through binder jet 3D printing technology.

[0048] (3) Sintering treatment: direct sintering, sintering temperature is 1600℃, sintering time is 3h.

[0049] (4) Performance Comparison

[0050]

[0051] Example 3

[0052] (1) Preparation of the mixed reinforcing agent: The main components of the mixed reinforcing agent include 60% basic zirconium carbonate (20nm) + 30% zircon powder + 10% other components. In addition to the above components, it also includes alcohol-based solvents, dispersants, binders, defoamers, penetrants and other components.

[0053] (2) Preparation of powder: The binder sprayed 3D printing powder used is 80% 30μm zirconium oxide powder + 20% 10μm basic calcium carbonate.

[0054] (3) Before sintering: Ceramic products are prepared by binder jetting 3D printing technology. Then, the mixed reinforcing agent prepared in (1) is impregnated on the surface of the ceramic product. After waiting for 1 minute, it is allowed to penetrate into the interior of the green body. Then, the alcohol-based solvent is burned by ignition to dry the surface.

[0055] (4) Sintering: After drying, the ceramic product with mixed reinforcing agent is placed in a sintering furnace for post-treatment strengthening. The sintering temperature is 1500℃ and the sintering time is 5h.

[0056] (5) Performance Comparison

[0057]

[0058] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for 3D printing with adhesive jetting, characterized in that, include: For powder preparation, ceramic powder with a particle size of 10-100μm is selected, and the ceramic powder includes zirconium oxide; For pre-sintering treatment, the ceramic powder is used to prepare ceramic green bodies using binder jet 3D printing technology, and a mixed reinforcing agent is impregnated on the surface of the ceramic green body. After waiting for 1 to 20 minutes to allow it to penetrate into the interior of the green body, it is then dried. The mixed reinforcing agent comprises a mixture of basic carbonates and one or more of zirconium oxide, zircon powder, white corundum, and silicon dioxide, and the solute particle size of the mixture is 10 nm-50 μm. The basic carbonates include basic calcium carbonate. After sintering and drying, the material is placed in a sintering furnace for sintering strengthening. The sintering temperature is 1000 to 1800℃ and the sintering time is 1 to 10 hours.

2. The binder jetting 3D printing method according to claim 1, characterized in that, The drying process includes: first, letting it stand, and then placing it in an oven for heating at a temperature of 50 to 200°C for 1 to 5 hours.

3. The binder jetting 3D printing method according to claim 1, characterized in that, The mixture also includes one or more of the following: alcohol-based solvents or water-based solvents, dispersants, binders, defoamers, and penetrants.

4. The binder jetting 3D printing method according to claim 3, characterized in that, When the mixed reinforcing agent includes an alcohol-based solvent, drying is achieved by burning the alcohol-based solvent using an ignition method.

5. The binder jetting 3D printing method according to claim 1, characterized in that, The powder preparation includes: mixing the ceramic powder with basic carbonate to form printing powder.

6. The binder jetting 3D printing method according to claim 5, characterized in that, The particle size of the basic carbonate is 50 nm to 100 μm.

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