Rapid sintering method for metal ceramic and composite material

Abstract

The invention relates to the technical field of multidisciplinary cross fusion of powder metallurgy, composite materials, additive manufacturing, high-temperature sintering and the like, a shell and a core of a high-precision complex mold are rapidly prepared through the 3D printing technology, materials are filled or injected into the mold, high-temperature sintering manufacturing is carried out, the mold can be demolded through high-temperature thermal decomposition, and the mold is formed. The method can be used for manufacturing composite materials such as metal ceramic, nano materials, fiber materials and carbides, has the characteristics of low cost, high precision, high quality, high efficiency, flexible design, normal-temperature forming, wide application range, large size, multiple materials and the like, and can be directly filled with powder or combined with nano sol to realize rapid sintering.

Description

Technical Field

[0001] The present invention belongs to the field of advanced manufacturing technology, and relates to the technical scope of multi-disciplinary cross-integration such as powder metallurgy, composite materials, additive manufacturing (3D printing), and high-temperature sintering. In terms of powder metallurgy, it focuses on achieving high-performance forming of powder materials such as metals and ceramics through new processes. Specifically, it relates to a method and system for rapidly preparing high-precision complex molds based on 3D printing technology, and manufacturing various composite material products through this mold combined with specific processes, which can achieve efficient demolding, accelerate or eliminate the debinding link, and provide key technical support for fields such as high-end manufacturing, aerospace, and the automotive industry. Background Art

[0002] In the field of traditional composite material manufacturing, especially in the manufacturing of high-performance composite materials such as metal ceramics, nano materials, fiber materials, and carbides, the preparation of molds often faces many challenges. Traditional mold manufacturing methods (such as machining, casting, etc.) have problems such as long processing cycles, high costs, and poor design flexibility for molds with complex shapes and high-precision requirements. For example, machining is difficult to achieve precise forming of complex internal cavity structures, and the casting process may have problems such as insufficient mold accuracy and internal defects.

[0003] In addition, in the process of composite material forming, the demolding link is also a major problem. Traditional demolding methods (such as mechanical demolding, chemical demolding, etc.) may cause damage to composite material products, affecting the quality and performance of the products. Moreover, traditional manufacturing processes also have obvious limitations in realizing multi-material composite, large-size product manufacturing, and room-temperature forming, and it is difficult to meet the diverse and personalized needs of modern industry for high-performance composite material products.

[0004] With the development of additive manufacturing (3D printing) technology, it has shown great potential in the field of mold manufacturing. However, at present, there are still many technical gaps in combining 3D printing technology with the high-temperature sintering manufacturing of composite materials to achieve efficient, high-quality, and multi-material composite manufacturing methods. There is an urgent need to develop an innovative manufacturing technology to solve the above problems. Summary of the Invention

[0005] (I) Object of the Invention

[0006] The object of the present invention is to provide a method and system for rapidly preparing high-precision complex molds based on 3D printing technology, and manufacturing various composite material products through this mold combined with specific processes, so as to overcome the deficiencies of traditional manufacturing methods in mold preparation, demolding, and composite material forming, and realize the manufacturing of composite material products with low cost, high precision, high quality, high efficiency, flexible design, room-temperature forming, wide application range, large size, and multi-material composite.

[0007] (II) Technical Solution

[0008] Preparation of Mold Shells and Cores by 3D Printing

[0009] Using a 3D printing device, according to a preset three-dimensional model of a complex mold, a specific 3D printing material (such as photosensitive resin, ceramic slurry, etc., selected according to subsequent sintering processes and mold performance requirements) is used to rapidly prepare high-precision mold shells and cores. During the printing process, by optimizing printing parameters (such as layer thickness, printing speed, laser power, etc.), ensure that the dimensional accuracy and surface quality of the mold shells and cores meet the requirements. For example, for molds with high-precision requirements, the layer thickness can be controlled within the range of 0.01 - 0.1 mm, and the printing speed is adjusted to an appropriate value according to the material characteristics to ensure printing quality.

[0010] 3D printing technology allows designers to freely design the internal structure and external shape of the mold, enabling rapid prototyping of complex structures and greatly improving the flexibility of mold design. Whether it is a mold with complex runner and cavity structures or a mold with a special-shaped appearance, it can be accurately manufactured by 3D printing technology.

[0011] Mold Assembly and Material Filling or Injection

[0012] Precisely assemble the printed mold shells and cores to form a complete mold. During the assembly process, specific positioning structures and sealing measures can be adopted to ensure the sealing performance and dimensional accuracy of the mold. For example, set tiny positioning protrusions and grooves on the contact surface between the mold shell and the core, and achieve precise assembly through mechanical cooperation. At the same time, use sealant or sealing gaskets to ensure that the mold does not leak during subsequent filling or injection processes.

[0013] Fill or inject composite material raw materials into the assembled mold. According to the type of composite material products to be manufactured, select appropriate raw materials, such as metal ceramic powder, nanomaterials, fiber materials, carbide particles, etc. The filling or injection process can be carried out by means of pressure injection, vacuum adsorption, etc., to ensure that the raw materials fully fill all parts of the mold and avoid defects such as voids and bubbles.

[0014] The nano-sol can be mixed with the composite material raw materials to form a uniform mixed system. The nano-sol can play roles such as filling, strengthening, and dispersing in the mixed system, improving the performance of the composite material. Chemical reactions or physical bonding occur between the nano-particles and the composite material matrix, promoting the sintering densification of the material.

[0015] High-Temperature Sintering Manufacturing

[0016] Put the mold filled or injected with raw materials into a high-temperature sintering furnace for sintering. During the sintering process, precisely control process parameters such as sintering temperature, heating rate, holding time, and cooling rate according to the composition and performance requirements of the composite material raw materials.

[0017] At high temperatures, the photosensitive resin undergoes thermal cracking reactions to generate small molecule gases (such as carbon dioxide, carbon monoxide, methane, etc.). These gases are discharged from the mold to complete the demolding process. This high-temperature thermal decomposition demolding method avoids the possible damage to the product caused by traditional demolding methods and ensures the integrity and surface quality of the product.

[0018] During the high-temperature sintering process, a series of physical and chemical changes occur in the composite material raw materials, such as the volatilization of the binder, the formation and growth of sintering necks between particles, and the densification of the material. Eventually, a composite material product with certain strength and performance is formed.

[0019] (III) Beneficial effects

[0020] Low cost: 3D printing technology reduces the mechanical processing, casting and other processes in the traditional mold manufacturing process, reducing the mold preparation cost. At the same time, since the mold can be demolded by high-temperature thermal decomposition, complex demolding equipment and processes are not required, further reducing the production cost.

[0021] High precision: 3D printing technology can achieve high-precision mold manufacturing, and the dimensional accuracy can be controlled at the micron level, thus ensuring the high-precision molding of composite material products.

[0022] High quality: The densification of material condensation is enhanced by the nano sol, ensuring the internal quality and structural integrity of the product. In addition, by precisely controlling the sintering process parameters, composite material products with excellent performance can be obtained.

[0023] High efficiency: From mold preparation to the molding of composite material products, the entire manufacturing process has a short cycle. 3D printing technology quickly prepares the mold, the high-temperature sintering process is relatively efficient, and the debinding step can be omitted, greatly improving the production efficiency.

[0024] Flexible design: 3D printing technology allows designers to freely design the mold structure, and can easily realize the manufacturing of composite material products with complex shapes and personalized designs, meeting the needs of different customers.

[0025] Room temperature molding: During the material filling or injection process, it can be carried out at room temperature without special heating or cooling equipment, reducing the requirements for the production environment.

[0026] Wide application range: Widely used in many fields such as aerospace, automotive manufacturing, electronic information, biomedicine, etc., and can also be used for manual manufacturing of traditional processes.

[0027] Large size: 3D printing equipment is constantly developing and improving, and can manufacture molds with larger sizes, and then realize the manufacturing of large-size products, breaking through the limitations of traditional manufacturing methods in terms of size.

[0028] Multi-materials: Suitable for a wide range of materials. By reasonably selecting and mixing different composite material raw materials, the combination of multiple materials can be achieved, giving full play to the advantages of various materials and improving the comprehensive performance of the products. Specific implementation methods

[0030] Preparing molds by 3D printing

[0031] Using photosensitive resin as the 3D printing material, through a stereolithography 3D printing device, according to the three-dimensional models of metal and ceramic molds, setting parameters such as layer thickness of 0.05 mm, scanning speed of 1500 mm / s, and laser power of 100 mW, etc., to print high-precision metal and ceramic mold shells and cores.

[0032] After printing, post-process the molds, such as removing the support structure, cleaning the residual photosensitive resin on the surface, etc., to ensure the smooth surface and accurate dimensions of the molds.

[0033] Mold assembly and material filling

[0034] Precisely assemble the mold shell and core through positioning protrusions and grooves, and apply sealant on the contact surface to ensure the sealing of the mold.

[0035] Mix metal and ceramic powders with nano-sol evenly in precise proportion to make metal-ceramic feedstock. Fill the assembled mold with the feedstock by pressure injection to ensure that the feedstock fully fills all parts of the mold.

[0036] Manufacturing by high-temperature sintering

[0037] Put the mold filled with feedstock into a sintering furnace and set appropriate sintering temperature and time. The photosensitive resin mold material undergoes a thermal decomposition reaction at high temperature, and the generated gas is discharged from the exhaust port to achieve the separation of the mold from the metal and ceramic products.

[0038] Post-processing

[0039] After sintering, wait for the mold to cool naturally to room temperature. Take out the formed product and have it post-processed by experienced workers, such as grinding and polishing, and finally conduct strict quality inspections.

Claims

1. A method for manufacturing metal, ceramic and composite products based on 3D printing technology, characterized in that, It includes the following steps: Shell and core preparation: Using 3D printing technology, rapidly manufacture mold shells and cores with high precision and complex structures. The precision of the shell and core can meet the requirements of high-precision forming and can adapt to forming of various complex shapes; Material filling: Fill or inject metal powder, ceramic powder, composite material raw materials into the mold space formed by the prepared shell and core; High-temperature sintering: Place the mold filled with materials in a high-temperature environment for sintering to make the materials tightly combined; Finished product obtaining: After sintering is completed, take out the sintered body to obtain the finished product made of the required materials.

2. A rapid prototyping method based on 3D printing technology for the material according to claim 1, characterized in that, The 3D printing material is one or more of photosensitive resin and PLA, which is selected according to the subsequent sintering process and mold performance requirements.

3. A rapid prototyping method based on 3D printing technology for the material according to claim 1, characterized in that, The composite material raw material is one or more of metal, ceramic powder and nanomaterial, fiber material and carbide mixture.

4. A rapid prototyping method based on 3D printing technology for the material according to claim 1, characterized in that, It also includes mixing nano sol and composite material raw materials to form a uniform mixing system to achieve rapid sintering during the subsequent sintering process.

5. A rapid prototyping method based on 3D printing technology for the material according to claim 1, characterized in that, When filling or injecting composite material raw materials, one or more of vibration filling, mechanical feeding, gas fluidization, electrostatic spraying, vacuum adsorption, cold isostatic pressing, etc. are adopted.

6. A rapid prototyping method based on 3D printing technology for the material according to claim 1, characterized in that, The mold material is decomposed or vaporized by high-temperature thermal decomposition to realize the separation of the mold and the product.

7. A rapid prototyping method based on 3D printing technology for the material according to claim 1, characterized in that, The sintered body is subjected to hot isostatic pressing treatment to improve the density and performance of the sintered body.

8. A rapid prototyping method based on 3D printing technology for the material according to claim 1, characterized in that, During the sintering process, a specific atmosphere, such as inert gas or reducing gas, is introduced into the sintering environment to control the oxidation-reduction reaction during sintering and improve the performance of the finished product.