A 3D printing method of a cermet composite article

Abstract

A 3D printing method of cermet composite product, comprising the following steps: S1, printing a ceramic framework, printing the ceramic framework by using a binder jetting 3D printing method; S2, printing a sand mold, designing a matching sand mold three-dimensional model by using a three-dimensional modeling software, and printing the sand mold by using a binder jetting 3D printing method according to the three-dimensional model; S3, interface treatment of the ceramic framework, pre-coating a metal activator layer on the surface of the ceramic framework; S4, nesting and assembling the ceramic framework and the sand mold, nesting the interface-treated ceramic framework in the sand mold; S5, infiltration pouring, slowly pouring a metal liquid into a cavity formed by the sand mold and the ceramic framework. The 3D method of the cermet composite product utilizes a metal melt-ceramic skeleton interface reaction control technology, forms a gradient transition layer to improve the bonding strength, and thus prepares a cermet composite material with excellent performance.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and more specifically, to a method for manufacturing metal-ceramic composite products using binder jet 3D printing technology. Background Technology

[0002] Metal-ceramic composites combine the high hardness, wear resistance, and high-temperature resistance of ceramics with the toughness, conductivity, and machinability of metals, making them key materials in aerospace, semiconductors, and engineering machinery. While binder jet 3D printing technology can be used to directly print metal-ceramic mixed powders to prepare metal-ceramic composites, the differences in physical properties can easily lead to poor interlayer bonding and uneven performance. Recent research on metal-ceramic composite powder 3D printing, although improving surface quality through a porous ceramic gasket-melt infiltration process, still cannot solve the core problem of insufficient interfacial bonding strength between the complex ceramic framework and the gold melt. Summary of the Invention

[0003] Therefore, it is necessary to provide a 3D printing method for metal-ceramic composite products to address the problem of insufficient bonding strength in existing technologies. This method utilizes the metal melt-ceramic skeleton interface reaction control technology to form a gradient transition layer to improve bonding strength, thereby preparing high-performance metal-ceramic composite materials.

[0004] A 3D printing method for metal-ceramic composite products, the method comprising the following steps: S1, Printing ceramic frame, using adhesive jet 3D printing method to print ceramic frame; S2, Printing sand mold: Design a matching 3D model of the sand mold using 3D modeling software, and print the sand mold using the adhesive jetting 3D printing method based on the 3D model; S3, ceramic frame interface treatment, pre-coating the surface of the ceramic frame with a metal activator layer; S4, nest the ceramic frame and the sand mold, and nest the interface-treated ceramic frame in the sand mold; S5, Melting and pouring: The molten metal is slowly poured into the cavity formed by the sand mold and the ceramic frame.

[0005] Furthermore, the powder used to form the ceramic framework comprises a mixture of ceramic powder and a small amount of nano-yttrium oxide.

[0006] Furthermore, the nano-yttrium oxide accounts for 0.5%–2% of the mass of the ceramic powder.

[0007] Furthermore, in step S1, a three-dimensional model of the ceramic frame is designed before printing the ceramic frame. The three-dimensional model of the ceramic frame includes a pure ceramic structure area and a metal-ceramic composite area. The metal-ceramic composite zone determines the spatial location and volume of subsequent metal material filling through negative design or cavity pre-reservation.

[0008] Furthermore, in step S1, when printing the ceramic frame, an interlocking interface feature is designed at the location where the ceramic frame and the metal are combined. The interlocking interface feature includes a dovetail groove, an inverted conical hole, or a three-dimensional mesh interlocking structure.

[0009] Furthermore, in step S2, the sand mold is offset by 0.1-0.3mm at equal distances based on the shape of the ceramic frame.

[0010] Furthermore, the sand mold is provided with a tapered positioning groove, and the ceramic frame is provided with a tapered protrusion that matches the tapered positioning groove.

[0011] Furthermore, in step S3, the metal activator layer is titanium powder or chromium powder, and the solvent is ethanol.

[0012] Furthermore, the particle size of the titanium powder or chromium powder is 0.01-0.02 mm.

[0013] Furthermore, the coating thickness of the metal activation layer is 0.02-0.1 mm.

[0014] This invention provides a 3D printing method for metal-ceramic composite products. It employs binder jet 3D printing to form a complex ceramic frame, which is then combined with high-precision metal infiltration technology. A metal activator is applied to the bonding area between the ceramic frame and the metal substrate, ensuring a strong bond and improving the bonding strength, wear resistance, and thermal stability of the metal-ceramic composite product. In the metal infiltration technology, a sand mold matching the ceramic frame is printed using 3D printing. The ceramic frame is nested within the sand mold, and molten metal is poured in, filling the forming cavity between the ceramic frame and the sand mold, thus completing the molding of the ceramic-metal composite product. This invention utilizes 3D printing technology to rapidly manufacture ceramic frames and sand molds, significantly shortening the product design-to-manufacturing cycle and improving production efficiency. Detailed Implementation

[0015] To facilitate understanding of the present invention, a more comprehensive description will be provided below. However, the present 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 the present invention.

[0016] 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.

[0017] 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.

[0018] The present invention provides a 3D printing method for metal composite products, comprising the following steps: S1, Printing ceramic frame, using adhesive jet 3D printing method to print ceramic frame; S2, Printing sand mold: Design a three-dimensional model of the matching sand mold using three-dimensional modeling software, and print the sand mold using the adhesive jet 3D printing method based on the three-dimensional model; S3, ceramic frame interface treatment, pre-coating the surface of the ceramic frame with a metal activator layer; S4, nest the ceramic frame and the sand mold, and nest the interface-treated ceramic frame in the sand mold; S5, Melting and pouring: The molten metal is slowly poured into the cavity formed by the sand mold and the ceramic frame.

[0019] This invention provides a 3D printing method for metal-ceramic composite products. A complex ceramic frame is formed using binder jet 3D printing. The formed ceramic frame is then combined with high-precision metal infiltration technology. A metal activator is applied to the areas where the ceramic frame bonds to the metal substrate, ensuring a good bond between the two. In the metal infiltration technology, a sand mold matching the ceramic frame is printed using 3D printing. The ceramic frame is nested within the sand mold, and molten metal is poured in, filling the forming cavities of both the ceramic frame and the sand mold, thus completing the forming of the ceramic frame and the metal-ceramic composite product.

[0020] The following describes the 3D printing method for metal-ceramic composite products with specific embodiments to further understand the inventive concept of the 3D printing method for metal-ceramic composite products.

[0021] In one embodiment, the 3D printing method for the metal-ceramic composite article includes the following steps: S1, Printing the ceramic frame. The ceramic frame is printed using a binder jet 3D printing method. The specific steps include: S11. A 3D model of the ceramic frame was designed using 3D software. Based on the design requirements of the composite product, the ceramic frame model was divided into a pure ceramic structure area and a metal-ceramic composite area. In the metal-ceramic composite area, the spatial location and volume of the subsequent filling of the metal material were determined through negative design or cavity pre-reservation. In the areas where composite metal materials are required, interlocking interface features were designed, including but not limited to dovetail grooves, inverted conical holes, and 3D mesh interlocking structures, to enhance the mechanical bonding force of the metal-ceramic interface.

[0022] S12, Ceramic Frame Printing. The three-dimensional model of the ceramic frame is imported into the 3D printing equipment, and the 3D printing equipment is started for printing. Specifically, the mixed ceramic composite powder is placed in the powder spreader. The powder spreader first spreads a layer of ceramic powder, and then the print head selectively sprays ink according to the layered cross-sectional characteristics of the three-dimensional model of the ceramic frame. Then, the powder bed descends by one layer, the powder spreader continues to spread powder, and the print head sprays ink again. The above steps are repeated until the ceramic frame is printed. The ceramic composite powder used to form the ceramic frame is a mixture of ceramic powder and a small amount of nano-yttrium oxide. The nano-yttrium oxide accounts for 0.5%-2% of the mass ratio of the ceramic powder. The ceramic powder is silicon carbide or alumina.

[0023] S13, Ceramic Frame Curing. The powder bed workpiece printed in step S12 is transferred to a curing oven for drying and curing. The curing temperature is 160℃ and the curing time is 240 min.

[0024] S14, Powder Cleaning. The cured powder bed is transferred to the powder cleaning station to remove all powder from the surface and interior of the ceramic frame green body, obtaining a 3D printed ceramic frame green body.

[0025] S15, Sintering. The ceramic frame green body is transferred to a sintering furnace for sintering treatment to obtain a 3D printed ceramic frame.

[0026] S2, printing sand mold.

[0027] The sand mold is printed using a specific method. Specifically, based on the three-dimensional model of the ceramic frame, a sand mold is generated by offsetting the ceramic frame's outline by 0.1-0.3mm at equal intervals. This 0.1-0.3mm gap allows space for the ceramic frame's thermal expansion during subsequent molten metal pouring and prevents the sand mold from sticking to the ceramic frame, facilitating easy demolding after pouring.

[0028] S3, Ceramic frame interface treatment: A metal activator layer is pre-coated onto the surface of the ceramic frame. The metal activator is carbon powder or chromium powder with a particle size of 0.01-0.02 mm, the solvent is ethanol, and the metal activator coating thickness is 0.05-0.1 mm. By applying the metal activator layer, the ceramic frame and the metal substrate achieve good bonding, improving the bonding strength of the metal-ceramic composite product.

[0029] S4, nest the ceramic frame and the sand mold, nest the ceramic frame after the interface treatment in step S3 in the sand mold, wherein the space between the metal-ceramic composite area in S1 and the internal boundary of the sand mold is the forming cavity; S5, Melting and Casting: Molten metal is slowly poured into the cavity formed by the sand mold and the ceramic frame. The forming cavity is the space formed by the metal-ceramic composite area reserved in step S1 and the inner boundary of the sand mold. The molten metal is slowly poured into this cavity to ensure it is fully filled. After pouring, the molten metal is allowed to cool and solidify naturally. After the casting cools, the sand mold is removed by vibration, sandblasting, or cutting to obtain the metal-ceramic composite product. The composite product then undergoes post-processing steps such as cleaning, grinding, heat treatment, and machining to meet the final product quality requirements. In this step, because dovetail grooves, inverted conical holes, or three-dimensional mesh interlocking structures are pre-reserved at the composite location of the ceramic frame and the metal material in step S1, the molten metal fills these pre-reserved dovetail grooves, inverted conical holes, or three-dimensional mesh interlocking structures on the ceramic frame during pouring. After the molten metal cools, these interlocking features form an interlocking structure between the metal material and the ceramic frame, thereby enhancing the mechanical bonding force of the metal-ceramic interface.

[0030] In another embodiment, the sand mold is provided with a tapered positioning groove, and the ceramic frame is provided with a tapered protrusion that matches the tapered positioning groove. The tapered positioning groove and the tapered protrusion facilitate positioning when the ceramic frame and the sand mold are nested together. Example

[0031] This embodiment uses the above method to manufacture a metal-ceramic composite piston for automotive engines.

[0032] Includes the following steps: S1, Print the ceramic frame of the metal-ceramic composite piston using a binder jet 3D printing method. Specifically, this includes the following steps: S11 uses 3D software to design a 3D model of the composite piston ceramic frame. Based on the design requirements of automotive engine pistons, the composite piston ceramic frame model is divided into a pure ceramic structure area and a metal-ceramic composite area. In the metal-ceramic composite area, the spatial position and volume of subsequent metal material filling are determined through negative design or cavity pre-reservation. In areas where composite metal materials are required, interlocking interface features are designed, including but not limited to dovetail grooves, inverted conical holes, and 3D mesh interlocking structures, to enhance the mechanical bonding force of the metal-ceramic interface.

[0033] S12, Composite piston ceramic frame printing. The three-dimensional model of the composite piston ceramic frame is imported into the 3D printing equipment, and the 3D printing equipment is started for printing. Specifically, the mixed powder of silicon carbide powder and nano-yttrium oxide (wherein the nano-yttrium oxide accounts for 0.8% of the mass ratio of silicon carbide powder, and the particle size of nano-yttrium oxide is 20nm) is placed in the powder spreader. The powder spreader first spreads a layer of ceramic powder, and then the printing nozzle selectively sprays ink according to the layered cross-sectional characteristics of the three-dimensional model of the ceramic frame. Then the printing powder bed drops one layer, the powder spreader continues to spread powder, and the printing head sprays ink again. The above steps are repeated until the ceramic frame is printed.

[0034] S13, Curing of the composite piston ceramic frame. The powder bed workbox printed in step S12 is transferred to a curing oven for drying and curing. The curing temperature is 160℃ and the curing time is 240 min.

[0035] S14, Powder Removal. The cured powder bed is transferred to the powder removal station to remove all powder from the surface and interior of the composite piston ceramic frame green body, thus obtaining the 3D printed composite piston ceramic frame green body.

[0036] S15, Sintering. The composite piston ceramic frame green body is transferred to a sintering furnace for sintering treatment to obtain a 3D printed composite piston ceramic frame.

[0037] S2, Printing sand mold: Design a three-dimensional model of the matching sand mold using three-dimensional modeling software, and print the sand mold using the adhesive jet 3D printing method based on the three-dimensional model.

[0038] The three-dimensional model of the matching piston sand mold is designed using 3D modeling software such as SolidWorks or UG. The cavity of the sand mold is generated by offsetting the shape of the composite ceramic frame by 0.2mm at equal distances, and a tapered positioning groove is set.

[0039] S3, Composite piston ceramic frame interface treatment, wherein a metal activator layer is pre-coated on the surface of the composite piston ceramic frame; wherein the metal activator tank is a titanium powder activator layer, the particle size of the titanium powder is 0.02 mm, the solvent is ethanol, and the coating thickness is 0.08 mm.

[0040] S4, nest the ceramic frame of the composite piston and the sand mold, and nest the interface-treated composite piston ceramic frame in the sand mold; S5, Melting and Casting: The molten aluminum alloy is slowly poured into the cavity formed by the sand mold and the composite piston ceramic frame. The forming cavity is the space formed by the metal-ceramic composite area reserved in step S1 and the inner boundary of the sand mold. The molten aluminum is slowly poured into this forming cavity, ensuring that the molten metal fully fills the cavity. After pouring, the molten metal is allowed to cool and solidify naturally. After the casting has cooled, the sand mold is removed by vibration, sandblasting, cutting, etc., to obtain the metal-ceramic composite piston product. The metal-ceramic composite piston product is then machined, including turning and grinding, followed by surface treatment to improve the piston surface quality and corrosion resistance. Testing shows that this metal-ceramic composite piston exhibits good performance during engine operation, with significantly improved wear resistance and thermal stability.

[0041] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0042] 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 3D printing method for metal-ceramic composite products, characterized in that, The 3D printing method for the metal-ceramic composite product includes the following steps: S1, Printing ceramic frame, using adhesive jet 3D printing method to print ceramic frame; S2, Printing sand mold: Design a matching 3D model of the sand mold using 3D modeling software, and print the sand mold using the adhesive jetting 3D printing method based on the 3D model; S3, ceramic frame interface treatment, pre-coating the surface of the ceramic frame with a metal activator layer; S4, nest the ceramic frame and the sand mold, and nest the interface-treated ceramic frame in the sand mold; S5, Melting and pouring: The molten metal is slowly poured into the cavity formed by the sand mold and the ceramic frame.

2. The 3D printing method for a metal-ceramic composite product according to claim 1, characterized in that, In step S1, the powder used to form the ceramic framework includes a mixture of ceramic powder and a small amount of nano-yttrium oxide powder.

3. The 3D printing method for a metal-ceramic composite product according to claim 2, characterized in that, The nano-yttrium oxide accounts for 0.5%–2% of the mass of the ceramic powder.

4. The 3D printing method for a metal-ceramic composite product according to claim 1, characterized in that, In step S1, a three-dimensional model of the ceramic frame is designed before printing the ceramic frame. The three-dimensional model of the ceramic frame includes a pure ceramic structure area and a metal-ceramic composite area. The metal-ceramic composite zone determines the spatial location and volume of subsequent metal material filling through negative design or cavity pre-reservation.

5. The 3D printing method for a metal-ceramic composite product according to claim 1, characterized in that, In step S1, when printing the ceramic frame, an interlocking interface feature is designed at the location where the ceramic frame and the metal are combined. The interlocking interface feature includes a dovetail groove, an inverted conical hole, or a three-dimensional mesh interlocking structure.

6. The 3D printing method for a metal-ceramic composite product according to claim 1, characterized in that, In step S2, the sand mold is offset by 0.1-0.3mm at equal distances based on the shape of the ceramic frame.

7. The 3D printing method for a metal-ceramic composite product according to claim 6, characterized in that, The sand mold is provided with a tapered positioning groove, and the ceramic frame is provided with a tapered protrusion that matches the tapered positioning groove.

8. The 3D printing method for a metal-ceramic composite product according to claim 1, characterized in that, In step S3, the metal activator layer is titanium powder or chromium powder, and the solvent is ethanol.

9. The 3D printing method for a metal-ceramic composite product according to claim 8, characterized in that, The particle size of the titanium powder or chromium powder is 0.01-0.02 mm.

10. The 3D printing method for a metal-ceramic composite product according to claim 8, characterized in that, The coating thickness of the metal activation layer is 0.02-0.1 mm.