Al-aln-sic composite material and method for manufacturing the same

Abstract

The application discloses an Al-AlN-SiC composite material and a preparation method thereof. The Al-AlN-SiC composite material is prepared through ball milling and discharge plasma hot-press sintering of aluminum powder and silicon carbide powder, nitrogen is introduced during the sintering process, and the Al-AlN-SiC composite material is in-situ synthesized, so that the Al-AlN-SiC composite material is prepared in a high-efficiency and low-cost manner. The Al-AlN-SiC composite material has excellent thermal performance and meets the requirements of electronic packaging materials.

Description

Technical Field

[0001] This invention belongs to the field of metal matrix composite technology, and relates to an Al-AlN-SiC composite material and its preparation method. Background Technology

[0002] Al-SiC materials, with their low cost, high mechanical properties, and good thermal properties, have broad application prospects in the automotive, aerospace, and electronic packaging fields. Aluminum nitride, with its low coefficient of thermal expansion and high thermal conductivity, is another attractive thermal management material. However, in traditional Al-SiC materials, SiC exists as a rough, angular, isolated phase, significantly reducing the material's mechanical and thermal properties. Furthermore, pure AlN materials exhibit brittleness due to their inherent defects, limiting their application in many fields.

[0003] Adding the AlN phase to the Al-SiC matrix is ​​a promising approach to improve the mechanical and thermal properties of Al-SiC materials. For example, AlN has a thermal expansion coefficient that is close to that of SiC, but its thermal conductivity is higher. Therefore, in some fields, Al-AlN-SiC materials can replace traditional Al-SiC materials.

[0004] Based on this, the in-situ synthesis of AlN-reinforced Al-AlN-SiC composite materials, which combine the excellent properties of Al-SiC and AlN materials, has potential application value in the field of electronic packaging.

[0005] Traditional methods for preparing Al-AlN-Si materials generally include: (1) using Al-infiltrated porous Si3N4 preform process, obtaining Al-AlN-Si materials with AlN-Si interconnect structure through in-situ reaction of Si3N4 and Al. However, since molten Al is difficult to completely infiltrate into the Si3N4 preform, some closed pores cannot be completely filled, and the cost of Si3N4 preform is relatively high. (2) using powder metallurgy technology (Al, AlN, SiC) to prepare Al-AlN-Si materials with uniform structure, which can effectively optimize phase size and morphology. Patent document CN103160716B discloses a low thermal expansion and high strength AlN-Si-Al hybrid composite material and its preparation method, which uses powder metallurgy technology. The AlN-Si-Al hybrid composite material obtained has excellent density. However, this method has certain drawbacks. In particular, during the preparation process, the wettability between molten Al and AlN powder is relatively low, resulting in poor connectivity between AlN and Al. It is not easy to form an AlN-Si interconnect structure in the Al matrix. At the same time, the AlN powder required by this method is expensive, which is not conducive to large-scale industrial production.

[0006] For the reasons mentioned above, there is an urgent need to study a novel Al-AlN-SiC composite material that is simple to prepare and has excellent performance. Summary of the Invention

[0007] To overcome the aforementioned problems, the inventors conducted intensive research and invented an Al-AlN-SiC composite material and its preparation method. The material is obtained by ball milling aluminum powder and silicon carbide powder followed by spark plasma hot pressing sintering. Nitrogen gas is introduced during the sintering process, allowing for in-situ synthesis of the Al-AlN-SiC composite material. This method provides an efficient and low-cost way to prepare Al-AlN-SiC composite materials. The Al-AlN-SiC composite material exhibits excellent thermal properties, meeting the requirements of electronic packaging materials, thus completing this invention.

[0008] Specifically, the object of the present invention is to provide the following aspects:

[0009] In a first aspect, an Al-AlN-SiC composite material is provided, wherein, by mass, the percentage content of SiC is 10-70%, the percentage content of Al is 20-60%, and the percentage content of AlN is 10-30%.

[0010] Optionally, the composite material has a density of 98–99.5% and a coefficient of thermal expansion of 6–13 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 80–160 W·m. -1 ·K -1 .

[0011] Optionally, the composite material is prepared by ball milling and sintering aluminum powder and silicon carbide powder, wherein nitrogen gas is introduced during the sintering process.

[0012] Secondly, a method for preparing Al-AlN-SiC composite materials is provided, the method comprising:

[0013] Step 1: Ball mill aluminum powder and silicon carbide powder to obtain composite powder;

[0014] Step 2: Sinter the composite powder to obtain the Al-AlN-SiC composite material.

[0015] Optionally, in step 1, the ball milling speed is 100-700 r / min and the ball milling time is 0.5-12 h.

[0016] Optionally, in step 1, a milling medium is added during ball milling, wherein the milling medium is an alcohol solvent.

[0017] Optionally, in step 2, the sintering includes: heating from room temperature to 600-1200°C at a heating rate of 20-60°C / min, and holding at that temperature for 0.5-3 hours.

[0018] Optionally, in step 2, nitrogen gas is introduced at a rate of 10 to 30 L / h.

[0019] Optionally, in step 2, pressure is applied to the composite powder during the sintering process, and the pressure used is 30 to 100 MPa.

[0020] Thirdly, an electronic packaging material is provided, wherein the electronic packaging material is an Al-AlN-SiC composite material prepared by the method described in the second aspect.

[0021] The beneficial effects of this invention include:

[0022] (1) The thermal expansion coefficient of the Al-AlN-SiC composite material provided by this invention is 5 to 12 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 80–160 W·m. -1 ·K -1 .

[0023] (2) The method for preparing Al-AlN-SiC composite material provided by the present invention is to obtain aluminum powder and silicon carbide powder by ball milling and spark plasma hot pressing sintering. Nitrogen gas is introduced during the sintering process as a nitrogen source to promote the in-situ reaction of AlN. It is an efficient and low-cost method for preparing Al-AlN-SiC composite material.

[0024] (3) The method for preparing Al-AlN-SiC composite material provided by the present invention uses aluminum powder and silicon carbide powder, combined with spark plasma sintering technology, to synthesize Al-AlN-SiC composite material in situ, which effectively solves the problem that the rough isolated SiC phase in Al-SiC leads to a decrease in the mechanical and thermal properties of Al-AlN-SiC composite material. Attached Figure Description

[0025] Various other advantages and benefits of the present invention will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0026] In the attached diagram:

[0027] Figure 1 The image shows a SEM image of the Al-AlN-SiC composite material in Example 1 of the present invention. Detailed Implementation

[0028] Specific embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While specific embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0029] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in function. The terms "comprising" or "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The following descriptions are preferred embodiments for carrying out the invention; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of the invention. The scope of protection of this invention is determined by the appended claims.

[0030] To facilitate understanding of the embodiments of the present invention, further explanations and descriptions will be provided below with reference to the accompanying drawings and specific embodiments. The accompanying drawings do not constitute a limitation on the embodiments of the present invention.

[0031] In a first aspect, according to the present invention, an Al-AlN-SiC composite material is provided, wherein, by mass, the percentage content of SiC is 10-70%, the percentage content of Al is 20-60%, and the percentage content of AlN is 10-30%.

[0032] Furthermore, the composite material has a density of 98–99.5% and a coefficient of thermal expansion of 6–13 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 80–160 W·m. -1 ·K -1 .

[0033] According to the present invention, in the composite material, Al and N2 react in situ to synthesize AlN, the AlN is attached to the Al interface, and a composite skeleton structure of AlN and SiC is formed in the composite material.

[0034] Secondly, according to the present invention, a method for preparing an Al-AlN-SiC composite material includes:

[0035] Step 1: Ball mill aluminum powder and silicon carbide powder to obtain composite powder;

[0036] Step 2: Sinter the composite powder under a nitrogen atmosphere to obtain the Al-AlN-SiC composite material.

[0037] Specifically:

[0038] Step 1: Ball mill aluminum powder and silicon carbide powder to obtain composite powder.

[0039] In step 1, the ball-milled composite powder was used as a precursor to pre-shape the microstructure of the Al-AlN-SiC sample. On the one hand, during the ball milling process, some SiC powder was embedded into the tough Al particles, forming some special composite powders containing many defects. On the other hand, the atoms of both the ball-milled SiC and Al particles were in a high-energy state, which increased the chemical potential gradient at the interface, causing the tiny SiC particles to form interconnected structures. This induced the SiC and Al particles to form a framework structure after sintering, which prolonged the residence time of N2 in the Al matrix.

[0040] In step 1, the higher the purity of the aluminum powder and silicon carbide powder, the higher the purity of Al, AlN, and SiC in the resulting Al-AlN-SiC composite material. The purity of the aluminum powder is above 99.9%, and the purity of the silicon carbide powder is above 99.9%.

[0041] In step 1, the inventors discovered that when no silicon carbide powder was added to the reaction system, AlN was not detected in the resulting Al-AlN-SiC composite material. As the content of silicon carbide powder increased, the AlN content in the Al-AlN-SiC composite material showed a trend of first increasing and then decreasing. Preferably, the mass percentage of silicon carbide powder in the composite powder is 10–60 wt%, more preferably, the mass percentage of silicon carbide powder in the composite powder is 40–55 wt%, for example, 50 wt%, with the balance being aluminum powder.

[0042] In step 1, the ball milling effect is related to the ball milling rate, ball milling time, ball size, ball-to-material ratio, and solid-liquid ratio.

[0043] The ball milling speed is 100-700 r / min, preferably 400-600 r / min, for example 500 r / min.

[0044] According to the present invention, as the ball milling speed increases, the powder particles of aluminum powder and silicon carbide powder become finer and more uniformly distributed, which can, to some extent, increase the AlN content in the Al-AlN-SiC composite material and improve the thermal expansion coefficient and thermal conductivity of the Al-AlN-SiC composite material; however, excessively fast ball milling speeds can lead to cold welding of aluminum powder and silicon carbide powder. A ball milling speed of 100–700 r / min is more suitable.

[0045] In step 1, the ball milling time is 0.5 to 12 hours, preferably 2 to 6 hours, for example 6 hours.

[0046] The inventors discovered that excessively short ball milling times result in no detectable AlN in the final sintered Al-AlN-SiC composite material. While the AlN content increases with increasing ball milling time, excessively long times do not lead to a sustained increase in AlN content. Furthermore, a higher AlN content in the Al-AlN-SiC composite material is not necessarily better; excessive AlN can reduce the density of the composite. Therefore, this invention aims to achieve a balance between ball milling time, AlN content, and the density of the Al-AlN-SiC composite, or to determine the ball milling time based on actual needs.

[0047] In step 1, the ball milling media protects the aluminum powder and silicon carbide powder during the ball milling process and prevents the aluminum powder from oxidizing during the ball milling process. The ball milling media is an alcohol solvent with a low boiling point, easy volatility, and easy removal in the subsequent sintering process. It also has low surface tension and will not cause the composite powder to clump together. Preferably, it is non-toxic and safe to operate anhydrous ethanol.

[0048] If there is too little grinding media, it will not be able to fully protect the composite powder; if there is too much grinding media, it will reduce the grinding efficiency. The weight ratio of the grinding media to the composite powder is 1:(4-15), preferably 1:(5-10), and more preferably 1:(6-7).

[0049] In step 1, the grinding balls used in the ball mill are zirconia balls with a size of Φ6 to 16 mm, preferably zirconia balls with a size of Φ7 to 12 mm, and more preferably zirconia balls with a size of Φ8 to 12 mm. For example, they can be 8 mm, 9 mm, 10 mm, 11 mm or 12 mm, but are not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0050] According to the present invention, the ball loading is determined based on the required ball milling efficiency to achieve optimal impact and grinding conditions, while simultaneously improving the AlN content in the Al-AlN-SiC composite material. The weight ratio of the composite powder to the grinding balls is 5–30:1, preferably 10–20:1, for example, 10:1.

[0051] In step 1, the finer the powder after ball milling, the more continuous the AlN skeleton is formed. The average particle size of the aluminum powder and silicon carbide powder after ball milling is 10-25 μm, preferably 12-16 μm, and more preferably 14-15 μm.

[0052] Step 2: Sinter the composite powder under a nitrogen atmosphere to obtain the Al-AlN-SiC composite material.

[0053] In step 2, N2 reacts with molten Al to increase the efficiency of in-situ AlN synthesis in the material. When N2 continuously flows into the Al matrix and the sintering temperature exceeds the melting point of Al, the high chemical potential gradient at the interface leads to the flow reaction of Al with N2 and the in-situ synthesis of AlN / AlN-SiC. Furthermore, the AlN synthesized in-situ by the reaction of Al with N2 can adhere to the Al interface through a nitrogen diffusion reaction, forming an Al-AlN-SiC composite material with an AlN-SiC composite framework structure within the Al matrix.

[0054] In step 3, the sintering includes: heating from room temperature to 600-1200℃ at a heating rate of 20-60℃ / min, and holding at that temperature for 0.5-3 hours.

[0055] In step 3, a slow heating rate will prolong the sintering time and easily form an AlN passivation film at the Al interface to inhibit the reaction, resulting in a decrease in the AlN content in the Al-AlN-SiC composite material. A too fast heating rate will also prolong the sintering time. An excessively fast heating rate will lead to an incomplete liquid phase sintering reaction process, failing to allow sufficient AlN to form, resulting in a low AlN content in the Al-AlN-SiC composite material. At the same time, an excessively fast heating rate will lead to stress concentration and crack propagation within the material, thereby affecting its mechanical properties.

[0056] Furthermore, if the sintering temperature is too low, the AlN content in the Al-AlN-SiC composite material is extremely low, resulting in a low density of the Al-AlN-SiC composite material; if the sintering temperature is too high, significant Al segregation will occur.

[0057] Furthermore, if the sintering holding time is too short, the AlN content in the Al-AlN-SiC composite material will be low, resulting in insufficient density and uneven structure. This leads to a weak bond between AlN and the Al matrix, affecting the strength and wear resistance of the Al-AlN-SiC composite material. If the sintering holding time is too long, the AlN grains in the Al-AlN-SiC composite material will grow, reducing the density of the Al-AlN-SiC composite material and affecting its mechanical and thermal conductivity.

[0058] In a further preferred embodiment, the sintering includes: heating from room temperature to 800-1100°C at a heating rate of 30-50°C / min, and holding at that temperature for 1-3 hours.

[0059] In a further preferred embodiment, the sintering includes: heating from room temperature to 1020°C at a heating rate of 40°C / min and holding at that temperature for 2 hours.

[0060] The ambient temperature is the operating temperature, which is usually 0 to 40°C, preferably 10 to 30°C, for example 25°C.

[0061] In step 2, during the sintering process, in order to ensure a complete reaction and save costs, nitrogen gas is introduced at a rate of 10-30 L / h to provide a nitrogen source for the preparation of Al-AlN-SiC composite materials.

[0062] The higher the nitrogen flow rate and the more nitrogen flow in the same time period, the higher the AlN content in the Al-AlN-SiC composite material. Considering the density and other properties of the Al-AlN-SiC composite material, the Al-AlN-SiC composite material with the best performance is obtained when the nitrogen flow rate is 10-30 L / h.

[0063] According to the preferred embodiment, pressure is applied to the composite powder during the sintering process. The pressure used is 30-100 MPa, preferably 40-90 MPa, more preferably 40-80 MPa, and can be 40 MPa, 60 MPa, 80 MPa, with 80 MPa being the most preferred.

[0064] According to the present invention, the sintering is performed using spark plasma hot pressing sintering, which heats up to a high temperature in a very short time, greatly shortening the production cycle. High-density Al-AlN-SiC composite materials can be formed at relatively low temperatures. Furthermore, due to the unique processing method of spark plasma hot pressing sintering, the composition, microstructure, and morphology of Al and SiC can be effectively controlled, resulting in high-quality, high-performance Al-AlN-SiC composite materials.

[0065] In a preferred embodiment, step 2 is performed in a spark plasma sintering furnace.

[0066] According to the present invention, a method for preparing an Al-AlN-SiC composite material is provided. The heat of SiC is conducted through AlN, and AlN promotes the formation of an AlN-SiC interconnect structure in the Al matrix, thereby improving the thermal diffusivity of the Al-AlN-SiC composite material. The AlN-SiC composite structure effectively suppresses the thermal expansion of Al, improving the thermal expansion stability of the material. The interaction between SiC, AlN, Al, and AlN-SiC effectively solves the problem of reduced mechanical and thermal properties of the Al-AlN-SiC composite material caused by the rough, isolated SiC phase in Al-SiC.

[0067] Thirdly, an electronic packaging material, said electronic packaging material being an Al-AlN-SiC composite material prepared by the method described in the second aspect.

[0068] Example

[0069] The present invention is further described below through specific examples; however, these examples are merely exemplary and do not constitute any limitation on the scope of protection of the present invention.

[0070] Example 1

[0071] Aluminum powder (99.9% purity) and silicon carbide powder (99.9% purity) were mixed with anhydrous ethanol at a mass ratio of 1:1, and the weight ratio of the mixture of aluminum powder and silicon carbide powder to anhydrous ethanol was 100:15. The mixture was then added to a high-energy ball mill, and 8mm zirconia grinding balls were added at a weight ratio of 10:1 (the mixture of aluminum powder and silicon carbide powder to grinding balls). The mixture was ball-milled at 500r / min for 6h to obtain a composite powder. The average particle size of both aluminum powder and silicon carbide powder in the composite powder was 14μm.

[0072] The composite powder was added into a Φ40mm graphite mold, which was then placed in a spark plasma sintering furnace. Nitrogen gas was introduced into the furnace at a rate of 20 L / h, and the temperature was increased from 25℃ to 1020℃ at a rate of 40℃ / min, and held at that temperature for 2 hours for sintering. During sintering, a sintering pressure of 80 MPa was applied to the composite powder. After sintering, the powder was cooled to room temperature in the spark plasma sintering furnace and removed to obtain the Al-AlN-SiC composite material. Its SEM characterization is as follows: Figure 1 As shown, the dark gray background represents the Al phase enrichment region, while the light gray region represents the SiC and AlN phase enrichment region. It can be seen that SiC and AlN form a composite framework structure in the Al matrix.

[0073] The final Al-AlN-SiC composite material contained 50% SiC, 31.2% Al, and 18.8% AlN. The density of the Al-AlN-SiC composite material was measured to be 99.2%, and the coefficient of thermal expansion was 7.8 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 134 W·m -1 ·K -1 .

[0074] Example 2

[0075] Al-AlN-SiC composite materials were prepared in a manner similar to that in Example 1, except that the ball milling time was 2 hours.

[0076] The final Al-AlN-SiC composite material contained 50% SiC, 34.8% Al, and 15.2% AlN, with a density of 98.3% and a coefficient of thermal expansion of 9.6 × 10⁻⁶.-6 ·K -1 The thermal conductivity is 145 W·m -1 ·K -1 .

[0077] Example 3

[0078] Al-AlN-SiC composite materials were prepared in a manner similar to that in Example 1, except that the ball milling time was 12 h.

[0079] The final Al-AlN-SiC composite material contained 50% SiC, 29.8% Al, and 20.2% AlN, with a density of 98.8% and a coefficient of thermal expansion of 7.1 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 117 W·m -1 ·K -1 .

[0080] Example 4

[0081] Al-AlN-SiC composite materials were prepared in a manner similar to that in Example 1, except that the sintering temperature was 660°C.

[0082] The final Al-AlN-SiC composite material contained 50% SiC, 45.8% Al, and 4.2% AlN, with a density of 97.5% and a coefficient of thermal expansion of 14.3 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 83 W·m -1 ·K -1 .

[0083] Example 5

[0084] Al-AlN-SiC composite materials were prepared in a manner similar to that in Example 1, except that the sintering temperature was 800°C.

[0085] The final Al-AlN-SiC composite material contained 50% SiC, 34.4% Al, and 15.6% AlN, with a density of 98.1% and a coefficient of thermal expansion of 12.8 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 102 W·m -1 ·K -1 .

[0086] Example 6

[0087] The Al-AlN-SiC composite material was prepared in a manner similar to that in Example 1, except that nitrogen gas was introduced at a rate of 10 L / h.

[0088] The final Al-AlN-SiC composite material contained 50% SiC, 33.1% Al, and 16.9% AlN, with a density of 99.3% and a coefficient of thermal expansion of 8.6 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 122 W·m -1 ·K -1 .

[0089] Example 7

[0090] The Al-AlN-SiC composite material was prepared in a manner similar to that in Example 1, except that nitrogen gas was introduced at a rate of 30 L / h.

[0091] The final Al-AlN-SiC composite material contained 50% SiC, 31.0% Al, and 19.0% AlN, with a density of 99.0% and a coefficient of thermal expansion of 7.6 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 139 W·m -1 ·K -1 .

[0092] Example 8

[0093] The Al-AlN-SiC composite material was prepared in a manner similar to that in Example 1, except that the mass ratio of aluminum powder to silicon carbide powder was 9:1.

[0094] The final Al-AlN-SiC composite material contained 10% SiC, 83.7% Al, and 6.3% AlN, with a density of 99.5% and a coefficient of thermal expansion of 18.6 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 210 W·m -1 ·K -1 .

[0095] Example 9

[0096] The Al-AlN-SiC composite material was prepared in a manner similar to that in Example 1, except that the mass ratio of aluminum powder to silicon carbide powder was 4:6.

[0097] The final Al-AlN-SiC composite material contained 60% SiC, 26.4% Al, and 13.6% AlN, with a density of 98.3% and a coefficient of thermal expansion of 6.2 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 114 W·m -1 ·K -1 .

[0098] Example 10

[0099] Al-AlN-SiC composite materials were prepared in a manner similar to that in Example 1, except that the ball milling rate was 100 r / min.

[0100] The final Al-AlN-SiC composite material contained 50% SiC, 34.3% Al, and 15.7% AlN, with a density of 99.0% and a coefficient of thermal expansion of 8.9 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 123 W·m -1 ·K -1 .

[0101] Example 11

[0102] Al-AlN-SiC composite materials were prepared in a manner similar to that in Example 1, except that the ball milling rate was 700 r / min.

[0103] The final Al-AlN-SiC composite material contained 50% SiC, 30.8% Al, and 19.2% AlN, with a density of 98.7% and a coefficient of thermal expansion of 7.5 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 127 W·m -1 ·K -1 .

[0104] Example 12

[0105] The Al-AlN-SiC composite material was prepared in a manner similar to that in Example 1, except that the weight ratio of the mixture of aluminum powder and silicon carbide powder to the grinding ball was 5:1.

[0106] The final Al-AlN-SiC composite material contained 50% SiC, 33.3% Al, and 16.7% AlN, with a density of 99.3% and a coefficient of thermal expansion of 8.2 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 133 W·m.-1 ·K -1 .

[0107] Example 13

[0108] The Al-AlN-SiC composite material was prepared in a manner similar to that in Example 1, except that the weight ratio of the mixture of aluminum powder and silicon carbide powder to the grinding balls was 30:1.

[0109] The final Al-AlN-SiC composite material contained 50% SiC, 31.0% Al, and 19.0% AlN, with a density of 99.0% and a coefficient of thermal expansion of 7.6 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 129 W·m -1 ·K -1 .

[0110] Example 14

[0111] Al-AlN-SiC composite materials were prepared in a manner similar to that in Example 1, except that the sintering holding time was 0.5 h.

[0112] The final Al-AlN-SiC composite material contained 50% SiC, 39.5% Al, and 10.5% AlN, with a density of 96.8% and a coefficient of thermal expansion of 10.2 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 86 W·m -1 ·K -1 .

[0113] Example 15

[0114] Al-AlN-SiC composite material was prepared in a manner similar to that in Example 1, except that the sintering holding time was 3 hours.

[0115] The final Al-AlN-SiC composite material contained 50% SiC, 31.0% Al, and 19.0% AlN, with a density of 99.1% and a coefficient of thermal expansion of 7.7 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 130 W·m -1 ·K -1 .

[0116] Example 16

[0117] Al-AlN-SiC composite materials were prepared in a manner similar to that in Example 1, except that the heating rate during sintering was 20 °C / min.

[0118] The final Al-AlN-SiC composite material contained 50% SiC, 31.2% Al, and 18.8% AlN, with a density of 98.5% and a coefficient of thermal expansion of 8.1 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 137 W·m -1 ·K -1 .

[0119] Example 17

[0120] Al-AlN-SiC composite materials were prepared in a manner similar to that in Example 1, except that the heating rate during sintering was 60 °C / min.

[0121] The final Al-AlN-SiC composite material contained 50% SiC, 32.4% Al, and 17.6% AlN, with a density of 98.9% and a coefficient of thermal expansion of 8.5 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 126 W·m -1 ·K -1 .

[0122] Comparative Example

[0123] Comparative Example 1

[0124] Al-AlN-SiC composite materials were prepared in a manner similar to that in Example 1, except that ball milling was not performed.

[0125] The final Al-AlN-SiC composite material contained 50% SiC, 46.2% Al, and 3.8% AlN, with a density of 98.7% and a coefficient of thermal expansion of 10.3 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 128 W·m -1 ·K -1 .

[0126] Comparative Example 2

[0127] The Al-AlN-SiC composite material was prepared in a manner similar to that in Example 1, except that nitrogen gas was not introduced.

[0128] The final Al-AlN-SiC composite material contained no detected AlN, with a SiC content of 50%, an Al content of 50%, a density of 99.3%, and a coefficient of thermal expansion of 9.6 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 122 W·m -1 ·K -1 .

[0129] Comparative Example 3

[0130] Al-AlN-SiC composite materials were prepared in a manner similar to that in Example 1, except that silicon carbide powder was not added.

[0131] The final composite material contained no SiC, had an Al content of 96.9%, an AlN content of 3.1%, a density of 99.5%, and a coefficient of thermal expansion of 19.8 × 10⁻⁶. -6 ·K -1 The thermal conductivity is 218 W·m. -1 ·K -1 .

[0132] The present invention has been described in detail above with reference to preferred embodiments and exemplary examples. However, it should be noted that these specific embodiments are merely illustrative explanations of the invention and do not constitute any limitation on the scope of protection of the invention. Various improvements, equivalent substitutions, or modifications can be made to the technical content and embodiments of the present invention without departing from the spirit and scope of protection of the invention, and all such modifications fall within the scope of protection of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. An Al-AlN-SiC composite material, characterized by, The percentage content of SiC is 10-70% by mass, the percentage content of Al is 20-60%, and the percentage content of AlN is 10-30% in the composite material; The composite material is prepared by ball milling and sintering of aluminum powder and silicon carbide powder; The ball milling speed is 100-700 r / min, the ball milling time is 0.5-12 h, and the average particle size of the aluminum powder and the silicon carbide powder after ball milling is 10-25 µm; The sintering is performed by spark plasma sintering, and the sintering includes: heating from room temperature to 600-1200 °C at a heating rate of 20-60 °C / min, holding for 0.5-3 h, and introducing nitrogen at a rate of 10-30 L / h during the sintering process.

2. The composite material of claim 1, wherein, The composite material has a density of 98-99.5% and a coefficient of thermal expansion of 6-13×10⁻⁶. -6 ·K -1 The thermal conductivity is 80~160 W·m -1 ·K -1 .

3. A method of producing the Al-AlN-SiC composite material according to claim 1 or 2, characterized by, The method comprises: Step 1: ball milling of aluminum powder and silicon carbide powder to obtain a composite powder; Step 2: sintering of the composite powder in a nitrogen atmosphere to obtain the Al-AlN-SiC composite material.

4. The method of claim 3, wherein, In step 1, a ball milling medium is added during the ball milling, and the ball milling medium is an alcohol solvent.

5. The method of claim 4, wherein, In step 2, a pressure is applied to the composite powder during the sintering process, and the pressure used is 30-100 MPa.

6. An electronic encapsulant material, characterized by, The electronic packaging material is the Al-AlN-SiC composite material prepared by the method of any one of claims 3-5.

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