Composite materials, preparation methods and electronic devices

Abstract

This application provides a composite material, a manufacturing method, and an electronic device. The composite material includes a matrix layer, a hardened layer, and a transition layer. The transition layer is disposed between the matrix layer and the hardened layer. The melting point of the transition layer material is lower than that of the matrix layer material and the hardened layer material. The composite material provided by this application, by introducing a transition layer, can improve the elemental distribution at the interface between the matrix layer and the hardened layer, which is beneficial for improving the interfacial bonding strength. It also broadens the selection space for the matrix layer and hardened layer materials. The transition layer enables reliable bonding between two materials with significant differences, improving the interfacial bonding strength to above 400 MPa.

Description

Technical Field

[0001] This application relates to the field of composite materials technology, and more specifically to a composite material, a manufacturing method, and an electronic device. Background Technology

[0002] For layered composite materials, the compositions of the two layers need to be relatively similar to ensure the bonding strength; otherwise, cracking and deformation are likely to occur. Therefore, in existing layered composite materials, high interfacial bonding strength cannot be achieved between material layers with significant compositional differences, and the selection of the composition of each material layer is quite limited. Summary of the Invention

[0003] In view of this, this application provides a composite material, a preparation method, and an electronic device to achieve high interfacial bonding strength between material layers with large compositional differences.

[0004] In a first aspect, embodiments of this application provide a composite material, comprising a matrix layer, a hardened layer, and a transition layer, wherein the transition layer is disposed between the matrix layer and the hardened layer, and the melting point of the transition layer material is lower than the melting point of the matrix layer material and the melting point of the hardened layer material.

[0005] The composite material provided in this application, by introducing a transition layer, can improve the elemental distribution at the interface between the matrix layer and the hardened layer, which is beneficial to improving the interfacial bonding strength. At the same time, it also broadens the selection space of matrix layer and hardened layer materials. The transition layer can realize the reliability of bonding between two materials with large differences, improve the interfacial bonding strength, and enable the interfacial bonding strength to reach more than 400 MPa.

[0006] In one possible design, the transition layer is made of one of cobalt, copper, or nickel-iron alloys. These materials can melt upon reaching the sintering temperature, transforming from a solid phase to a liquid phase. This allows them to flow and permeate between the solid matrix layer and the hardened layer material particles. The capillary force of the liquid phase can agglomerate the powder particles, enhancing the bonding strength.

[0007] In one possible design, the thickness of the transition layer is 10% to 20% of the thickness of the composite material. By keeping the thickness of the transition layer within this range, appropriate liquid phase interaction can be ensured, thereby improving the density of the composite material.

[0008] In one possible design, the substrate layer is made of stainless steel. The stainless steel used in the substrate layer has a melting point greater than the sintering temperature. That is, when the sintering temperature reaches 1000℃~1200℃, the stainless steel substrate layer will not melt, allowing the material particles of the substrate layer to remain in the solid phase. The solid phase particles are sintered and bonded through mechanisms such as diffusion, local evaporation and condensation, and gradually become denser.

[0009] In one possible design, the thickness of the matrix layer is 50% to 70% of the thickness of the composite material. By keeping the thickness of the matrix layer within this range, it is possible to ensure that the composite material has suitable toughness, while also ensuring that the composite material has high structural strength and structural stability, thus enabling the composite material to have a long service life.

[0010] In one possible design, the hardening layer is made of one of FeCoNiCrAl, FeCoNiCuAl, or FeCoNiCuMo. Hardening layers made of these materials can have high hardness, reaching 45 HRC or higher.

[0011] In one possible design, the thickness of the hardened layer is 20% to 40% of the thickness of the composite material. By keeping the thickness of the hardened layer within this range, the surface hardness of the hardened layer can be guaranteed while ensuring the bonding strength, thus ensuring a stable shape when the composite material is used in a product.

[0012] In one possible design, the thickness of the composite material is between 4 mm and 8 mm, thereby enabling the composite material to be made thinner while ensuring that different materials have high interfacial bonding strength.

[0013] Secondly, this application also provides a method for preparing the composite material provided in the first aspect of this application, comprising the following steps:

[0014] The matrix layer powder, transition layer powder, and hardened layer powder are respectively mixed with binder through a mixing and granulation process to obtain matrix layer feed, transition layer feed, and hardened layer feed;

[0015] The base layer feed, transition layer feed, and hardening layer feed are sequentially injected into the mold cavity to obtain a green body;

[0016] The green blank is subjected to cold isostatic pressing;

[0017] The binder in the green body is removed by a degreasing process to obtain a degreased green body;

[0018] The degreased blank is subjected to sintering densification treatment;

[0019] Deep cryogenic treatment is performed on the degreased blank that has undergone sintering and densification to obtain the composite material.

[0020] The composite material prepared using this process has the same technical effects as the composite material described above, and will not be elaborated further here.

[0021] In one possible design, the average particle size of the transition layer powder is between 10 μm and 20 μm. By simultaneously optimizing the thickness and particle size of the transition layer powder, better wettability can be achieved between the liquid phase material of the transition layer and the solid phase particles of the matrix layer and the hardened layer. This facilitates the capillary attraction of the liquid phase material to bring the two solid phase particles closer together, thereby increasing the density.

[0022] In one possible design, the average particle size of the matrix layer powder is between 5 μm and 10 μm, which is beneficial for achieving high density of the composite material while reducing the preparation cost of various material powders.

[0023] In one possible design, the average particle size of the hardened layer powder is between 5 μm and 15 μm, which is beneficial for achieving high density of the composite material while reducing the preparation cost of various material powders.

[0024] In one possible design, the cold isostatic pressing molding pressure is between 50MPa and 200MPa, and the holding time is between 0.5h and 1h, which can ensure that the green body has a high density while saving production costs.

[0025] In one possible design, the sintering densification process employs hot isostatic pressing (HIP) sintering, with a sintering temperature between 1000℃ and 1200℃, a holding time between 1h and 4h, and a holding pressure between 100MPa and 300MPa, thereby ensuring that the sintered material has high density and ideal material properties.

[0026] In one possible design, the binder comprises, by weight percentage: 75%–85% polyoxymethylene, 5%–15% polyethylene, and 5%–15% stearic acid. A binder with this material ratio allows the aforementioned feedstocks to have ideal flowability, which is beneficial for improving the forming effect of the green body in subsequent processes.

[0027] In one possible design, in the matrix layer feed, the volume ratio of the matrix layer powder to the binder is between (55%–60%): (45%–40%); the volume ratio of the transition layer powder to the binder is between (50%–55%): (50%–45%); and the volume ratio of the hardened layer powder to the binder is between (60%–65%): (40%–35%). This ensures the performance of various feed materials while reducing production costs.

[0028] In one possible design, the removal of the binder from the green body via a degreasing process specifically includes:

[0029] Heat to 300℃~400℃ at a rate of 3℃ / min~8℃ / min, and hold for 1h~4h;

[0030] Heat to 700℃~800℃ at a rate of 5℃ / min~10℃ / min, and hold for 3h~6h;

[0031] Cool to room temperature.

[0032] The process of removing the binder by adopting a two-stage heating step to reach the target degreasing temperature, and controlling the corresponding heating rate and holding time, can effectively control the degreasing rate, so that the binder is almost completely removed, and avoid defects such as uneven carbon content distribution, deformation, and cracks in the green body during the degreasing process.

[0033] In one possible design, the process temperature of the mixing and granulation process is between 140℃ and 190℃, the mixing and granulation time is between 1h and 6h, and the rotation speed of the mixing and granulation equipment is between 70r / min and 130r / min. This ensures feeding performance and helps reduce costs.

[0034] In one possible design, during the step of sequentially injecting the base layer, transition layer, and hardening layer into the mold cavity, the injection temperature is between 150°C and 185°C, the injection pressure is between 60MPa and 120MPa, and the mold cavity temperature is between 40°C and 110°C. This can result in a relatively stable green body and prevent uneven green body density caused by injection.

[0035] Thirdly, this application also provides an electronic device, which includes the composite material provided in the first aspect of this application. The electronic device including the aforementioned composite material has similar technical effects to the aforementioned composite material, and will not be described in detail here.

[0036] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the structure of the composite material provided in the embodiments of this application;

[0039] Figure 2 A flowchart illustrating the preparation method provided in the embodiments of this application.

[0040] Explanation of reference numerals in the attached figures:

[0041] 1-Matrix layer;

[0042] 2- Hardened layer;

[0043] 3-Transition layer. Detailed Implementation

[0044] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0045] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0046] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0047] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0048] In the description of this application, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; unless otherwise specified or explained, the term "multiple" refers to two or more; the terms "connected," "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0049] For layered composite materials, to ensure the bonding strength between adjacent layers, the compositions of the two layers need to be relatively similar; otherwise, cracking and deformation are likely to occur. For example, one layer of the composite material may use a WC-Co based cemented carbide as the matrix material, while the other layer may use a WC-Co based cemented carbide with added TiN, TiC, and Al2O3, or a multi-element alloy with added TiC and TiN as the coating material. Since the main material in both layers is WC-Co based cemented carbide, the bonding strength between the two layers can be guaranteed. However, if one layer uses a material with a significantly different composition than WC-Co based cemented carbide, the bonding strength between the two layers will decrease significantly, making cracking and deformation more likely. Therefore, in existing layered composite materials, high interfacial bonding strength cannot be achieved between material layers with significant compositional differences, which greatly limits the selection of the composition of each material layer.

[0050] Figure 1 This is a schematic diagram of the structure of the composite material provided in the embodiments of this application, with reference to... Figure 1 This application provides a composite material that can be used to manufacture electronic devices, such as mobile phones, tablets, and automotive products. This embodiment does not limit the type of electronic device. Furthermore, this composite material can also be used to manufacture parts within electronic devices, such as hinge components, that require surface wear resistance.

[0051] The composite material comprises a matrix layer, a hardened layer, and a transition layer, with the transition layer positioned between the matrix layer and the hardened layer. The melting point of the transition layer material is lower than that of both the matrix layer and the hardened layer materials. In the preparation of this composite material, powders for preparing the matrix layer, hardened layer, and transition layer are first prepared, namely, matrix layer powder, hardened layer powder, and transition layer powder. These powders are then mixed with appropriate amounts of binder, and respectively processed through a compounding and granulation process to obtain the corresponding matrix layer feedstock, hardened layer feedstock, and transition layer feedstock. Then, using co-injection molding technology, the matrix layer feedstock, hardened layer feedstock, and transition layer feedstock are sequentially injected into the mold cavity to obtain a green compact. The green compact is then subjected to cold isostatic pressing. Next, a debinding process is used to remove the binder from the green compact, and finally, sintering and densification followed by cryogenic treatment yield the composite structural part.

[0052] In the sintering densification step, when heated to the sintering temperature, the melting point of the transition layer material is lower than that of the matrix layer material and the hardened layer material. The transition layer material melts before the matrix layer material and the hardened layer material, transforming from a solid phase to a liquid phase, while the matrix layer material and the hardened layer material remain solid. The liquid-phase transition layer material flows and permeates between the solid particles of the matrix layer material and the hardened layer material. There is good wettability between the liquid-phase particles and the solid particles. As the liquid-phase transition layer material flows, the liquid surface between the two solid particles bends towards the liquid phase side, generating a capillary suction force. Under this suction force, the two solid particles can be brought closer together, ultimately achieving densification of the sintered body. The resulting composite material can achieve a density of over 98%. By introducing a transition layer, a bridge can be built between the matrix layer and the hardened layer interface. This can improve the element distribution at the matrix layer and the hardened layer interface, which is beneficial to improving the interfacial bonding strength. It also broadens the selection space for matrix layer and hardened layer materials. The transition layer can improve the reliability of bonding between two materials with large differences, and enhance the interfacial bonding strength, enabling the interfacial bonding strength to reach more than 400 MPa.

[0053] In one embodiment, the transition layer material can be one of cobalt (Co), copper (Cu), or nickel-iron alloy (Ni-Fe). In the aforementioned sintering step, the sintering temperature can be 1000℃~1200℃. These materials used in the transition layer can melt when the sintering temperature is reached, changing from a solid phase to a liquid phase. This allows them to flow and permeate between the solid matrix layer and the hardened layer material particles. The capillary force of the liquid phase can agglomerate the powder particles and improve the bonding strength.

[0054] In one embodiment, the substrate layer can be made of stainless steel. Optionally, the stainless steel grade used in the substrate layer can be one of 304L, 316L, or HK30. The stainless steel used in the substrate layer has a melting point higher than the sintering temperature. That is, when the sintering temperature reaches 1000℃~1200℃, the stainless steel substrate layer will not melt, allowing the material particles of the substrate layer to remain in a solid phase. The solid phase particles are sintered and bonded through mechanisms such as diffusion, local evaporation, and condensation, and gradually become denser.

[0055] In one embodiment, the hardening layer material can be one of FeCoNiCrAl, FeCoNiCuAl, and FeCoNiCuMo. The hardening layer material powder is composed of five metal powders mixed in an equimolar ratio, and the purity of each of the five metal element powders is not less than 99.9%. For example, when the hardening layer material is FeCoNiCrAl, the hardening layer material powder is composed of iron (Fe), cobalt (Co), nickel (Ni), chromium (Cr), and aluminum (Al). For example, when the hardening layer material is FeCoNiCuAl, the hardening layer material powder is composed of iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), and aluminum (Al). For example, when the hardening layer material is FeCoNiCuMo, the hardening layer material powder is composed of iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), and molybdenum (Mo). Hardening layers composed of such materials can have high hardness, reaching 45 HRC or higher.

[0056] In one embodiment, the thickness of the transition layer is 10% to 20% of the thickness of the composite material. By keeping the thickness of the transition layer within this range, appropriate liquid phase interaction can be ensured, thereby improving the density of the composite material.

[0057] In one embodiment, the thickness of the matrix layer is 50% to 70% of the thickness of the composite material. By keeping the thickness of the matrix layer within this range, the composite material can be guaranteed to have suitable toughness, while also ensuring high structural strength and structural stability, thus enabling the composite material to have a long service life.

[0058] In one embodiment, the thickness of the hardened layer is 20% to 40% of the thickness of the composite material. By keeping the thickness of the hardened layer within this range, the surface hardness of the hardened layer can be guaranteed while ensuring the bonding strength, thus ensuring a stable shape when the composite material is used in the product.

[0059] In one embodiment, the thickness of the composite material is between 4 mm and 8 mm, which allows for a thinner composite material while ensuring high interfacial bonding strength between different materials. In another embodiment, the thickness of the transition layer is between 0.4 mm and 1.6 mm.

[0060] Figure 2 The flowchart of the preparation method provided in the embodiments of this application is shown below. Figure 2 This application also provides a method for preparing the aforementioned composite material, wherein the preparation method includes the following steps:

[0061] Step S1: The matrix layer powder, transition layer powder and hardening layer powder are mixed with the binder through a mixing and granulation process to obtain the matrix layer feed, transition layer feed and hardening layer feed respectively.

[0062] Prior to step S1, matrix layer powder, transition layer powder, and hardening layer powder can be prepared separately. Then, the matrix layer powder, transition layer powder, and hardening layer powder can be mixed with the corresponding amount of binder, and matrix layer feed, transition layer feed, and hardening layer feed can be prepared separately through a mixing and granulation process.

[0063] The average particle size of the transition layer powder is between 10 μm and 20 μm, and the thickness of the transition layer can be controlled to be 10% to 20% of the composite material thickness. Therefore, by simultaneously optimizing the thickness and particle size of the transition layer powder, good wettability can be achieved between the liquid phase material of the transition layer and the solid particles of the matrix and hardened layers. This facilitates the capillary attraction of the liquid phase material to bring the two solid particles closer together, improving density. Furthermore, the average particle size of the matrix layer powder is between 5 μm and 10 μm, and the average particle size of the hardened layer powder is between 5 μm and 15 μm. This also contributes to achieving high density in the composite material while reducing the preparation cost of various material powders.

[0064] In one embodiment, the mixing and granulation process can be carried out by mixing and granulation equipment, the process temperature can be between 140°C and 190°C, the mixing and granulation time can be between 1 hour and 6 hours, and the rotation speed of the mixing and granulation equipment can be between 70 r / min and 130 r / min, thereby ensuring feeding performance and helping to reduce costs.

[0065] In one embodiment, the binder comprises, by weight percentage: 75%–85% polyoxymethylene, 5%–15% polyethylene, and 5%–15% stearic acid. The ranges for each material include endpoints. A binder with this material ratio allows the aforementioned feedstocks to have ideal flowability, which is beneficial for improving the forming effect of the green body in subsequent processes.

[0066] In one embodiment, the adhesive comprises, by weight percentage: 80% polyoxymethylene, 10% polyethylene, and 10% stearic acid.

[0067] In one embodiment, the adhesive comprises, by weight percentage: 78% polyoxymethylene, 13% polyethylene, and 9% stearic acid.

[0068] In one embodiment, the adhesive comprises, by weight percentage: 82% polyoxymethylene, 7% polyethylene, and 11% stearic acid.

[0069] In the above embodiments, the material ratio of the binder can make the aforementioned feedstocks have ideal fluidity, which is beneficial to improving the forming effect of the green body in subsequent processes.

[0070] In one embodiment, as described above, the matrix layer powder in step S1 is mixed with a corresponding amount of binder to prepare the matrix layer feedstock, the transition layer powder is mixed with a corresponding amount of binder to prepare the transition layer feedstock, and the hardening layer powder is mixed with a corresponding amount of binder to prepare the hardening layer feedstock. To ensure the performance of each feedstock while reducing production costs, the volume ratio of matrix layer powder to binder is between (55%–60%):(45%–40%), the volume ratio of transition layer powder to binder is between (50%–55%):(50%–45%), and the volume ratio of hardening layer powder to binder is between (60%–65%):(40%–35%). All of the above volume ratio ranges include endpoint values.

[0071] In one embodiment, the volume ratio of the matrix layer powder to the binder is 56%:44%, the volume ratio of the hardened layer powder to the binder is 62%:38%, and the volume ratio of the transition layer powder to the binder is 52%:48%.

[0072] In one embodiment, the volume ratio of the matrix layer powder to the binder is 58%:42%, the volume ratio of the hardened layer powder to the binder is 64%:36%, and the volume ratio of the transition layer powder to the binder is 53%:47%.

[0073] Step S2: The base layer feed, transition layer feed, and hardening layer feed are injected into the mold cavity in sequence to obtain the green body.

[0074] In this process, co-injection molding technology can be used to sequentially inject the base layer, transition layer, and hardening layer into the mold cavity. During this process, the injection temperature is between 150℃ and 185℃, the injection pressure is between 60MPa and 120MPa, and the mold cavity temperature is between 40℃ and 110℃. This results in a relatively stable green body and prevents uneven density caused by injection. The base layer, transition layer, and hardening layer in the green body can be arranged sequentially.

[0075] Step S3: Perform cold isostatic pressing on the green billet.

[0076] By applying cold isostatic pressing to the green blank, the density of the green blank can be increased and the porosity reduced, laying the foundation for achieving high density through subsequent sintering processes. In one embodiment, the forming pressure of cold isostatic pressing is between 50 MPa and 200 MPa, and the holding time is between 0.5 h and 1 h, thereby ensuring that the green blank has a high density while saving production costs.

[0077] Step S4: Remove the binder from the green body through a degreasing process to obtain a degreased green body.

[0078] The green blank obtained after cold isostatic pressing has a certain interfacial bonding strength. After the binder is removed, it can still maintain stable structural characteristics and can be degreased blank containing only base layer material, transition layer material and hardening layer material.

[0079] In one embodiment, the degreasing process can specifically employ a thermal degreasing process. The following steps can be specifically used in the process of removing the binder from the green body through the degreasing process:

[0080] Step S41: First, heat to 300℃~400℃ at a rate of 3℃ / min~8℃ / min, and keep warm for 1h~4h.

[0081] Step S42: Heat to 700℃~800℃ at a rate of 5℃ / min~10℃ / min and keep warm for 3h~6h.

[0082] Step S43: Cool to room temperature. In one embodiment, the furnace can be allowed to cool naturally to room temperature.

[0083] In this process, thermal degreasing is used to remove the binder by employing a two-stage heating process in steps S41 and S42 to reach the target degreasing temperature. The heating rate and holding time are controlled to effectively control the degreasing rate, ensuring that the binder is almost completely removed and avoiding defects such as uneven carbon content distribution, deformation, and cracks in the green body during the degreasing process.

[0084] Step S5: Sinter and densify the degreased blank.

[0085] The densification treatment can be achieved using hot isostatic pressing (HIP). During this process, the degreased blank is placed in a sealed container, which is then evacuated, with the vacuum level controlled to be less than or equal to 5 × 10⁻⁶. -3 The process involves injecting high-pressure argon gas into a container via a compressor, simultaneously heating the degreased blank under high temperature and pressure. This densification process ensures uniform pressure applied to the surface of the degreased blank from all directions, resulting in a homogeneous internal structure. This sintering method leverages a strong driving force to rapidly densify the powder, while the short holding time effectively prevents grain growth, thus significantly improving the performance of products formed from the composite material. Furthermore, the hot isostatic pressing (HIP) process offers advantages such as uniform heating, low sintering temperature, short sintering time, and fine, uniform grain size, greatly enhancing production efficiency and facilitating mass production.

[0086] In one embodiment, the sintering densification process adopts hot isostatic pressing (HIP) sintering, with a sintering temperature between 1000°C and 1200°C, a holding time between 1 hour and 4 hours, and a holding pressure between 100 MPa and 300 MPa, thereby ensuring that the sintered material has high density and ideal material properties.

[0087] Step S6: Deep cryogenic treatment is performed on the degreased blank that has undergone sintering densification to obtain the composite material.

[0088] One method involves using liquid nitrogen or similar media to perform cryogenic treatment on the degreased blanks after sintering and densification. The holding time for cryogenic treatment ranges from 5 to 10 hours. Cryogenic treatment reduces residual thermal stress in the composite material. This thermal stress refers to the stress generated during the sintering process due to temperature differences, with sources including the temperature difference between the furnace cavity and the environment during heating and cooling. Excessive accumulation of thermal stress can affect the bonding strength between materials and even lead to cracking and deformation. By utilizing the cryogenic treatment process, the significant drop in ambient temperature causes the material to shrink in volume, reducing the compressive stress on its surroundings and significantly lowering residual stress, thereby improving product performance.

[0089] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A composite material, characterized in that, include: The substrate layer is made of stainless steel. Hardened layer; A transition layer is provided between the substrate layer and the hardened layer, wherein the melting point of the transition layer material is lower than the melting point of the substrate layer material and the melting point of the hardened layer material; The thickness of the transition layer is 10% to 20% of the thickness of the composite material, the thickness of the matrix layer is 50% to 70% of the thickness of the composite material, and the thickness of the hardening layer is 20% to 40% of the thickness of the composite material. The material of the hardened layer is one of FeCoNiCrAl, FeCoNiCuAl, and FeCoNiCuMo; The thickness of the composite material is between 4 mm and 8 mm.

2. The composite material according to claim 1, characterized in that, The transition layer is made of either copper or nickel-iron alloy.

3. A method for preparing the composite material according to any one of claims 1-2, characterized in that, Includes the following steps: The matrix layer powder, transition layer powder, and hardened layer powder are respectively mixed with a binder through a granulation process to obtain matrix layer feed, transition layer feed, and hardened layer feed; the average particle size of the transition layer powder is between 10 μm and 20 μm. The base layer feed, transition layer feed, and hardening layer feed are sequentially injected into the mold cavity to obtain a green body; The green blank is subjected to cold isostatic pressing; The binder in the green body is removed by a degreasing process to obtain a degreased green body; The degreased blank is subjected to sintering densification treatment; Deep cryogenic treatment is performed on the degreased blank that has undergone sintering and densification to obtain the composite material.

4. The preparation method according to claim 3, characterized in that, The average particle size of the matrix layer powder is between 5 μm and 10 μm.

5. The preparation method according to any one of claims 3-4, characterized in that, The average particle size of the hardened layer powder is between 5 μm and 15 μm.

6. The preparation method according to any one of claims 3-5, characterized in that, The forming pressure of the cold isostatic pressing is between 50MPa and 200MPa, and the holding time is between 0.5h and 1h.

7. The preparation method according to any one of claims 3-6, characterized in that, The sintering densification process adopts hot isostatic pressing sintering process, with sintering temperature between 1000℃ and 1200℃, holding time between 1h and 4h, and holding pressure between 100MPa and 300MPa.

8. The preparation method according to any one of claims 3-7, characterized in that, The adhesive comprises, by weight percentage: 75%~85% polyoxymethylene, 5%~15% polyethylene, and 5%~15% stearic acid.

9. The preparation method according to any one of claims 3-8, characterized in that, In the substrate layer feeding process, the volume ratio of the substrate layer powder to the binder is between (55%~60%) and (45%~40%). The volume ratio of the transition layer powder to the binder is between (50%~55%) and (50%~45%). The volume ratio of the hardened layer powder to the adhesive is between (60%~65%) and (40%~35%).

10. The preparation method according to any one of claims 3-9, characterized in that, The removal of binder from the green body through a degreasing process specifically includes: Heat to 300℃~400℃ at a rate of 3℃ / min~8℃ / min, and hold for 1h~4h; Heat to 700℃~800℃ at a rate of 5℃ / min~10℃ / min, and hold for 3h~6h; Cool to room temperature.

11. The preparation method according to any one of claims 3-10, characterized in that, The process temperature of the mixing and granulation process is between 140℃ and 190℃, the mixing and granulation time is between 1h and 6h, and the rotation speed of the mixing and granulation equipment is between 70r / min and 130r / min.

12. The preparation method according to any one of claims 3-11, characterized in that, In the step of sequentially injecting the substrate layer feed, transition layer feed, and hardening layer feed into the mold cavity, the injection temperature is between 150℃ and 185℃, the injection pressure is between 60 MPa and 120 MPa, and the mold cavity temperature is between 40℃ and 110℃.

13. An electronic device, characterized in that, Includes the composite material described in any one of claims 1-2.

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