Method for enhancing bonding strength between diamond particles and copper matrix

Abstract

The invention provides a method for enhancing bonding strength between diamond particles and a copper matrix, and relates to the technical field of preparation of diamond-copper composite materials. According to the method, laser perforation, acid pickling treatment, ultrasonic cleaning treatment, activating treatment, ultrasonic mixing and drying and ultrasonic mixing and drying final heat treatment are carried out on diamond particles, so that the diamond-copper composite material capable of being tightly combined with copper is obtained. The metal organic matter and the surfaces of the diamond particles are compositely connected, and the bonding strength between the diamond particles and a copper matrix is improved. The diamond-copper composite material prepared by the method disclosed by the invention can be synergistically improved in heat-conducting property and mechanical property, and is simple, convenient and easy to operate, low in cost, low in energy consumption, high in efficiency and beneficial to industrial large-scale production and popularization.

Description

Technical Field

[0001] This invention relates to the technical field of diamond-copper composite material preparation, and in particular to a method for enhancing the bonding strength between diamond particles and a copper matrix. Background Technology

[0002] The miniaturization and integration of electronic devices increase the heat flux density of power devices, thus affecting heat dissipation. This necessitates higher thermal conductivity to improve heat dissipation and stabilize device performance. Diamond, due to its unique and excellent properties, is widely used in electronic devices. It is the hardest natural material and also has the highest thermal conductivity. Copper, due to its excellent properties, is widely used in electronic packaging. Diamond possesses excellent thermal conductivity potential, exhibiting high thermal conductivity and a low coefficient of thermal expansion. Diamond-copper composite materials can effectively solve the heat dissipation problem of power devices.

[0003] However, the interfacial bonding between diamond and copper is weak, and the wettability between diamond and copper is too poor, making it difficult to wet. Therefore, surface treatment of diamond is necessary to reduce the wetting angle between diamond and copper and form a good interfacial bond, thereby improving thermal conductivity.

[0004] To address the interface problem between diamond and copper, two main methods are commonly used: diamond surface metallization and matrix alloying. Of these two methods, diamond surface metallization is more effective than matrix alloying. Common methods for diamond surface metallization include vacuum deposition and magnetron sputtering, but these methods have drawbacks, such as uneven coating and high cost.

[0005] Chinese patent CN115821211A discloses a method for preparing diamond / copper composite materials under low temperature and high pressure. The method uses PVD to deposit a nano-titanium layer on the surface of diamond single crystal particles, then mixes it with copper powder by wet method, and obtains the product by low temperature, low pressure, high vacuum degassing sintering and low temperature, high pressure densification sintering. Obviously, this method has defects such as being unable to be industrialized and having serious deficiencies in thermal management performance.

[0006] Chinese patent CN104625077A discloses a high thermal conductivity diamond / copper composite material and its preparation method. The method uses magnetron sputtering to plate titanium or chromium onto the surface of diamond particles of different sizes, assembles copper sheets on the diamond particles, performs vacuum heat treatment, and then inserts them into a pyrophyllite mold. Finally, it performs ultra-high pressure melt infiltration sintering under different sintering process conditions to prepare a high thermal conductivity diamond-copper composite material. Obviously, the preparation cost is much higher, high temperature and high pressure sintering is required, the operation process is complex, and it is not conducive to industrial production.

[0007] Chinese patent CN113462924A discloses a titanium-plated diamond-copper composite material and its preparation method. This method involves depositing a titanium layer onto the surface of diamond particles using a vacuum evaporation coating method, and then vacuum hot-pressing and sintering copper powder and titanium-plated diamond powder to produce a titanium-plated diamond-copper alloy. The alloy is then pulverized, ball-milled, and dried to obtain powder for SLM (Surface Mount Technology) production of the titanium-plated diamond-copper composite material. However, the preparation process suffers from several drawbacks. Step four presents difficulties in pulverizing the diamond-copper composite material; step five requires a specially designed high-Britt hardness ball mill jar, which is expensive; and step seven results in samples with insufficient performance from photopolymerization printing of the composite material using additive manufacturing methods. Although complex shapes can be prepared, the overall performance is currently inferior to diamond-copper composite materials prepared using traditional methods and equipment. Summary of the Invention

[0008] The main objective of this invention is to address the technical problems in existing technologies, such as weak interfacial bonding between diamond and copper, poor wettability of diamond and copper, and the inability to comprehensively improve the thermal conductivity, electrical conductivity, and mechanical properties of diamond-copper composite materials. Therefore, a method for enhancing the bonding strength between diamond particles and a copper matrix is ​​proposed to solve the aforementioned problems. This method involves laser-perforating the diamond particles and using a metal-organic compound to composite-bond the diamond particles, achieving uniform coating and enhanced interfacial bonding.

[0009] The technical solution is as follows:

[0010] A method for enhancing the bonding strength between diamond particles and a copper matrix, the method comprising the following steps:

[0011] S1. Laser perforation: Diamond particles are uniformly filled into a porous array mold, and then a modulated pulsed laser array is used to perform batch perforation to obtain perforated diamond particles.

[0012] S2, pickling treatment: The perforated diamond particles of S1 are placed in the pickling solution for pickling treatment to obtain perforated diamond particles with clean surface.

[0013] S3. Ultrasonic cleaning treatment: The surface-cleaned perforated diamond particles from S2 are placed in an acetone solution for ultrasonic cleaning to obtain pure perforated diamond particles.

[0014] S4. Activation treatment: Place the pure perforated diamond particles from S3 into a tube furnace and introduce hydrogen gas for activation treatment to obtain activated perforated diamond particles.

[0015] S5. Ultrasonic mixing + drying: The activated perforated diamond particles from S4 are placed in an acetone solution containing titanium isopropoxide, ultrasonically mixed, and dried in a drying oven to obtain a mixture in which titanium isopropoxide is uniformly attached to the surface of the diamond particles.

[0016] S6. Final heat treatment: The mixture of S5 titanium isopropoxide uniformly attached to the surface of diamond particles is placed in a tube furnace and argon gas is introduced for final heat treatment to obtain diamond particles with surface coated with metallic titanium.

[0017] S7, Preparation of diamond-copper composite material: Diamond particles coated with titanium metal on the surface of S6 are mixed with copper powder and then sintered by spark plasma to obtain diamond-copper composite material.

[0018] Optionally, the perforated diamond particles in S1 have a particle size of 50-600 μm, and the perforation diameter is 1 / 5-1 / 3 of the diamond particle size.

[0019] Optionally, the pickling solution in S2 is obtained by mixing 98% concentrated sulfuric acid and 99.7% concentrated nitric acid in a 3:1 ratio, and the pickling time is 0.5-2 hours.

[0020] Optionally, the acetone concentration in S3 needs to reach 99.6% or higher, the ultrasonic cleaning frequency is 40-100kHz, and the cleaning time is 0.5-3h.

[0021] Optionally, the vacuum degree in S4 is 1-30 Pa, the hydrogenation temperature is 750-950℃, the heating rate is 10-20℃ / min, the hydrogen flow rate is 5-30 sccm, and the processing time is 30-120 min.

[0022] Optionally, the content of isopropoxide in the acetone solution of isopropoxide in S5 is 50-75 wt%, and the purity of isopropoxide is not less than 98%; the ultrasonic frequency of ultrasonic mixing is 30-50 kHz, the ultrasonic time is 60-180 min; the drying temperature is 30-50℃, and the drying time is 30-120 min.

[0023] Optionally, S5 is a mixture of titanium isopropoxide uniformly attached to the surface of diamond particles, with a particle size of 51-602 μm and an attachment thickness of 1000-2000 nm.

[0024] Optionally, the argon flow rate in S6 is 5-30 sccm, the heating rate is 10-20℃ / min, the final heat treatment temperature is 500-700℃ / min, and the final heat treatment time is 30-90 min.

[0025] Optionally, the overall particle size of the diamond particles coated with titanium in S6 is 50-600 μm, and the thickness of the titanium layer is 100-500 nm.

[0026] Optionally, in S7, the volume ratio of diamond particles coated with titanium metal to copper powder is 5:5-7:3, the temperature of spark plasma sintering is 850-1000℃, and the holding time is 5-30min.

[0027] Optionally, in S7, the volume ratio of diamond particles coated with titanium metal to copper powder is 6:4. When the diamond-copper composite material is plate-shaped with a size of 10×10mm, its thermal conductivity is 526-573W / m·K, its relative density is 88-97%, its Brinell hardness is 85.3-89.7, and its flexural strength is 479-513MPa. When the diamond-copper composite material is cylindrical with a size of φ12.5×2mm, its thermal conductivity is 501-568W / m·K, its relative density is 87-95%, its Brinell hardness is 85.8-89.2, and its flexural strength is 468-525MPa.

[0028] Optionally, in S7, the volume ratio of diamond particles coated with titanium to copper powder is 7:3. When the diamond-copper composite material is plate-shaped with a size of 10×10mm, its thermal conductivity is 497-534W / m·K, its relative density is 85-93%, its Brinell hardness is 85.8-89.7, and its flexural strength is 461-502MPa. When the diamond-copper composite material is cylindrical with a size of φ12.5×2mm, its thermal conductivity is 488-539W / m·K, its relative density is 84-93%, its Brinell hardness is 85.8-89.7, and its flexural strength is 459-498MPa.

[0029] Optionally, in S7, the volume ratio of diamond particles coated with titanium metal to copper powder is 5:5. When the diamond-copper composite material is plate-shaped with a size of 10×10mm, its thermal conductivity is 469-523W / m·K, its relative density is 87-94%, its Brinell hardness is 84.9-88.7, and its flexural strength is 488-522MPa. When the diamond-copper composite material is cylindrical with a size of φ12.5×2mm, its thermal conductivity is 482-519W / m·K, its relative density is 88-94%, its Brinell hardness is 84.7-88.7, and its flexural strength is 479-511MPa.

[0030] Technical principle of the invention:

[0031] This invention increases the surface area of ​​diamond by perforating it, which activates hydrogen functional groups on the diamond surface, facilitating bonding with titanium isopropoxide. The titanium bonds more tightly to the diamond surface. During sintering, molten copper flows into the diamond channels, forming a "beaded" structure. This structure not only bonds tightly to the titanium on the diamond surface and provides good wettability, but also prevents copper from completely detaching even if it falls off the diamond, as the copper particles are connected through the micropores. Compared to other preparation methods, this method results in a tighter bond between the diamond particles and the copper matrix, thereby improving interfacial bonding and increasing the thermal conductivity of the diamond-reinforced copper-based composite material.

[0032] The above technical solution has at least the following advantages compared with the existing technology:

[0033] The above-mentioned solution proposes a method to enhance the bonding strength between diamond particles and copper matrix, which can solve the technical problems in the prior art, such as weak interfacial bonding between diamond and copper, poor wettability between diamond and copper, difficulty in wetting, and inability to comprehensively improve the thermal conductivity, electrical conductivity, and mechanical properties of diamond-copper composite materials.

[0034] This invention uses titanium isopropoxide as a titanium source, which benefits from its highly reactive alkoxy group, which can link with the activated functional group hydrogen on the diamond surface, undergo hydrolysis and condensation, and achieve chemical bonding of titanium species; at the same time, its good volatility and solution processability facilitate subsequent acetone solution mixing, drying and heat treatment.

[0035] The method of this invention increases the contact area between diamond particles and copper matrix by laser perforation of diamond particles, providing microchannels and enabling copper and diamond to bond tightly. This results in higher thermal conductivity between the diamond thermally conductive reinforcing phase and the copper matrix, which is beneficial to improving the overall thermal conductivity of the composite material.

[0036] The method of this invention overcomes the unevenness problem of existing coating technology by activating diamond. By activating the diamond surface, it forms a bond with the metal-organic material, which is conducive to uniform coating, thereby enhancing the interfacial bonding and improving the thermal conductivity.

[0037] In summary, compared with traditional methods, the method of this invention obtains a diamond-copper composite material that can bond tightly with copper by performing laser perforation, acid washing, ultrasonic cleaning, activation, ultrasonic mixing and drying, and final heat treatment of ultrasonic mixing and drying on diamond particles. The diamond-copper composite material prepared by this method can achieve synergistic improvement in thermal conductivity and mechanical properties. It is simple to operate, low in cost, low in energy consumption, and high in efficiency, which is conducive to large-scale industrial production and promotion. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a flowchart of key steps in diamond surface coating, a method for enhancing the bonding strength between diamond particles and a copper substrate according to the present invention. Detailed Implementation

[0040] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0041] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0042] In the embodiments of the present invention, the terms "image" and "picture" may sometimes be used interchangeably. It should be noted that when the distinction is not emphasized, their intended meanings are consistent.

[0043] In this embodiment of the invention, sometimes a subscript such as W1 may be written in a non-subscript form such as W1. When the difference is not emphasized, the meaning they express is the same.

[0044] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0045] A method for enhancing the bonding strength between diamond particles and a copper matrix, wherein the method for enhancing the bonding strength between diamond particles and a copper matrix combines... Figure 1 Includes the following steps:

[0046] S1. Laser perforation: Diamond particles are uniformly filled into a porous array mold, and then a modulated pulsed laser array is used to perform batch perforation to obtain perforated diamond particles.

[0047] S2, pickling treatment: The perforated diamond particles of S1 are placed in the pickling solution for pickling treatment to obtain perforated diamond particles with clean surface.

[0048] S3. Ultrasonic cleaning treatment: The surface-cleaned perforated diamond particles from S2 are placed in an acetone solution for ultrasonic cleaning to obtain pure perforated diamond particles.

[0049] S4. Activation treatment: Place the pure perforated diamond particles from S3 into a tube furnace and introduce hydrogen gas for activation treatment to obtain activated perforated diamond particles.

[0050] S5. Ultrasonic mixing + drying: The activated perforated diamond particles from S4 are placed in an acetone solution containing titanium isopropoxide, ultrasonically mixed, and dried in a drying oven to obtain a mixture in which titanium isopropoxide is uniformly attached to the surface of the diamond particles.

[0051] S6. Final heat treatment: The mixture of S5 titanium isopropoxide uniformly attached to the surface of diamond particles is placed in a tube furnace and argon gas is introduced for final heat treatment to obtain diamond particles with surface coated with metallic titanium.

[0052] S7, Preparation of diamond-copper composite material: Diamond particles coated with titanium metal on the surface of S6 are mixed with copper powder and then sintered by spark plasma to obtain diamond-copper composite material.

[0053] Specifically, the perforated diamond particles in S1 have a diameter of 50-600 μm, and the perforation diameter is 1 / 5-1 / 3 of the diamond particle diameter.

[0054] Specifically, the pickling solution in S2 is obtained by mixing 98% concentrated sulfuric acid and 99.7% concentrated nitric acid in a 3:1 ratio, and the pickling time is 0.5-2 hours.

[0055] Specifically, the acetone concentration in S3 needs to reach 99.6% or higher, the ultrasonic cleaning frequency is 40-100kHz, and the cleaning time is 0.5-3h.

[0056] Specifically, in S4, the vacuum level is 1-30 Pa, the hydrogenation temperature is 750-950℃, the heating rate is 10-20℃ / min, the hydrogen flow rate is 5-30 sccm, and the processing time is 30-120 min.

[0057] Specifically, the content of isopropoxide in the acetone solution of isopropoxide in S5 is 50-75 wt%, and the purity of isopropoxide is not less than 98%; the ultrasonic frequency for ultrasonic mixing is 30-50 kHz, and the ultrasonic time is 60-180 min; the drying temperature is 30-50℃, and the drying time is 30-120 min.

[0058] Specifically, S5 is a mixture in which titanium isopropoxide is uniformly adhered to the surface of diamond particles, with a particle size of 51-602 μm and an adhesion thickness of 1000-2000 nm.

[0059] Specifically, in S6, the argon flow rate is 5-30 sccm, the heating rate is 10-20℃ / min, the final heat treatment temperature is 500-700℃ / min, and the final heat treatment time is 30-90 min.

[0060] Specifically, the overall particle size of the diamond particles coated with titanium in S6 is 50-600 μm, and the thickness of the titanium layer is 100-500 nm.

[0061] Specifically, in S7, the volume ratio of diamond particles coated with titanium metal to copper powder is 5:5-7:3, the temperature of spark plasma sintering is 850-1000℃, and the holding time is 5-30min.

[0062] Specifically, in S7, the volume ratio of diamond particles coated with titanium to copper powder is 6:4. When the diamond-copper composite material is plate-shaped with a size of 10×10mm, its thermal conductivity is 526-573W / m·K, its relative density is 88-97%, its Brinell hardness is 85.3-89.7, and its flexural strength is 479-513MPa. When the diamond-copper composite material is cylindrical with a size of φ12.5×2mm, its thermal conductivity is 501-568W / m·K, its relative density is 87-95%, its Brinell hardness is 85.8-89.2, and its flexural strength is 468-525MPa.

[0063] Specifically, in S7, the volume ratio of diamond particles coated with titanium metal to copper powder is 7:3. When the diamond-copper composite material is plate-shaped with a size of 10×10mm, its thermal conductivity is 497-534W / m·K, its relative density is 85-93%, its Brinell hardness is 85.8-89.7, and its flexural strength is 461-502MPa. When the diamond-copper composite material is cylindrical with a size of φ12.5×2mm, its thermal conductivity is 488-539W / m·K, its relative density is 84-93%, its Brinell hardness is 85.8-89.7, and its flexural strength is 459-498MPa.

[0064] Specifically, in S7, the volume ratio of diamond particles coated with titanium metal to copper powder is 5:5. When the diamond-copper composite material is plate-shaped with a size of 10×10mm, its thermal conductivity is 469-523W / m·K, its relative density is 87-94%, its Brinell hardness is 84.9-88.7, and its flexural strength is 488-522MPa. When the diamond-copper composite material is cylindrical with a size of φ12.5×2mm, its thermal conductivity is 482-519W / m·K, its relative density is 88-94%, its Brinell hardness is 84.7-88.7, and its flexural strength is 479-511MPa.

[0065] Example 1

[0066] This embodiment provides a method for enhancing the bonding strength between diamond particles and a copper matrix, wherein the method for enhancing the bonding strength between diamond particles and a copper matrix is ​​combined with... Figure 1 Includes the following steps:

[0067] S1. Laser perforation: Diamond particles with an average particle size of 200μm are uniformly filled on a porous array mold. The laser beam is modulated to form an array pulsed laser. The modulated pulsed laser array is used to perform batch perforation processing with a perforation diameter of 50μm. The diamond particles are perforated through the micropores to obtain perforated diamond particles.

[0068] S2, pickling treatment: The perforated diamond particles from S1 are placed in an pickling solution for pickling treatment. The pickling solution is a mixture of 98% concentrated sulfuric acid and 99.7% concentrated nitric acid in a 3:1 ratio. The pickling treatment time is 0.5 hours, resulting in perforated diamond particles with clean surfaces.

[0069] S3. Ultrasonic cleaning treatment: Weigh 50g of the surface-cleaned perforated diamond particles from S2 and place them in an acetone solution with a concentration of 99.6% or higher for ultrasonic cleaning at a frequency of 50kHz for 0.5h to obtain pure perforated diamond particles.

[0070] S4. Activation treatment: Place the pure perforated diamond particles from S3 into a tube furnace and introduce hydrogen gas for activation treatment. The vacuum degree is 20 Pa, the hydrogenation temperature is 800 ℃, the heating rate is 15 ℃ / min, the hydrogen flow rate is 10 sccm, and the treatment time is 30 min to obtain activated perforated diamond particles.

[0071] S5. Ultrasonic mixing + drying: The activated perforated diamond particles from S4 are placed in an acetone solution containing titanium isopropoxide, the content of which is 75 wt% and the purity of which is not less than 98%; ultrasonic mixing is performed and the mixture is dried in a drying oven at a frequency of 40 kHz for 30 min; the drying temperature is 40℃ and the drying time is 30 min, resulting in a mixture in which titanium isopropoxide is uniformly adhered to the surface of the diamond particles.

[0072] The mixture of titanium isopropoxide uniformly adhered to the surface of diamond particles has a particle size of 201 μm and an adhesion thickness of 1000 nm.

[0073] S6. Final heat treatment: The mixture of S5 titanium isopropoxide uniformly attached to the surface of diamond particles is placed in a tube furnace and argon gas is introduced for final heat treatment; the argon gas flow rate is 10 sccm, the heating rate is 15℃ / min, the final heat treatment temperature is 600℃ / min, and the final heat treatment time is 30min, to obtain diamond particles with surface coated with metallic titanium.

[0074] The overall particle size of the diamond particles coated with titanium metal is 200 μm, and the thickness of the titanium metal layer is 100 nm.

[0075] S7. Preparation of diamond-copper composite material: Diamond particles coated with titanium metal from S6 are mixed with copper powder and then sintered by spark plasma to obtain diamond-copper composite material; the volume ratio of diamond particles coated with titanium metal to copper powder is 3:2, the spark plasma sintering temperature is 900℃, and the holding time is 15min.

[0076] In this embodiment, the volume ratio of diamond particles coated with titanium to copper powder is 3:2. When the diamond-copper composite material is plate-shaped with a size of 10×10mm, its thermal conductivity is 502W / m·K, its relative density is 92%, its Brinell hardness is 86.3, and its flexural strength is 497MPa. When the diamond-copper composite material is cylindrical with a size of φ12.5×2mm, its thermal conductivity is 498W / m·K, its relative density is 91%, its Brinell hardness is 86.8, and its flexural strength is 488MPa.

[0077] Example 2

[0078] This embodiment provides a method for enhancing the bonding strength between diamond particles and a copper matrix, wherein the method for enhancing the bonding strength between diamond particles and a copper matrix is ​​combined with... Figure 1 Includes the following steps:

[0079] S1. Laser perforation: Diamond particles with an average particle size of 400μm are uniformly filled on a porous array mold. The laser beam is modulated to form an array pulsed laser. The modulated pulsed laser array is used to perform batch perforation processing with a perforation diameter of 100μm, thus perforating the diamond particles through the micropores to obtain perforated diamond particles.

[0080] S2, pickling treatment: The perforated diamond particles from S1 are placed in an pickling solution for pickling treatment. The pickling solution is a mixture of 98% concentrated sulfuric acid and 99.7% concentrated nitric acid in a 3:1 ratio. The pickling treatment time is 0.5 hours, resulting in perforated diamond particles with clean surfaces.

[0081] S3. Ultrasonic cleaning treatment: Weigh 50g of the surface-cleaned perforated diamond particles from S2 and place them in an acetone solution with a concentration of 99.6% or higher for ultrasonic cleaning at a frequency of 50kHz for 0.5h to obtain pure perforated diamond particles.

[0082] S4. Activation treatment: Place the pure perforated diamond particles from S3 into a tube furnace and introduce hydrogen gas for activation treatment. The vacuum degree is 20 Pa, the hydrogenation temperature is 800 ℃, the heating rate is 15 ℃ / min, the hydrogen flow rate is 10 sccm, and the treatment time is 30 min to obtain activated perforated diamond particles.

[0083] S5. Ultrasonic mixing + drying: The activated perforated diamond particles from S4 are placed in an acetone solution containing titanium isopropoxide, the content of which is 75 wt% and the purity of which is not less than 98%; ultrasonic mixing is performed and the mixture is dried in a drying oven at a frequency of 40 kHz for 30 min; the drying temperature is 50 ℃ and the drying time is 50 min, resulting in a mixture in which titanium isopropoxide is uniformly adhered to the surface of the diamond particles.

[0084] The mixture of titanium isopropoxide uniformly adhered to the surface of diamond particles has a particle size of 401 μm and an adhesion thickness of 1000 nm.

[0085] S6. Final heat treatment: The mixture of S5 titanium isopropoxide uniformly attached to the surface of diamond particles is placed in a tube furnace and argon gas is introduced for final heat treatment; the argon gas flow rate is 10 sccm, the heating rate is 15℃ / min, the final heat treatment temperature is 600℃ / min, and the final heat treatment time is 40min, to obtain diamond particles with titanium metal coating on the surface.

[0086] The overall particle size of the diamond particles coated with titanium metal is 400 μm, and the thickness of the titanium metal layer is 100 nm.

[0087] S7. Preparation of diamond-copper composite material: Diamond particles coated with titanium metal from S6 are mixed with copper powder and then sintered by spark plasma to obtain diamond-copper composite material; the volume ratio of diamond particles coated with titanium metal to copper powder is 3:2, the spark plasma sintering temperature is 900℃, and the holding time is 15min.

[0088] In this embodiment, the volume ratio of diamond particles coated with titanium to copper powder is 3:2. When the diamond-copper composite material is plate-shaped with a size of 10×10mm, its thermal conductivity is 519W / m·K, its relative density is 92%, its Brinell hardness is 88.7, and its flexural strength is 485MPa. When the diamond-copper composite material is cylindrical with a size of φ12.5×2mm, its thermal conductivity is 509W / m·K, its relative density is 90%, its Brinell hardness is 88.7, and its flexural strength is 490MPa.

[0089] Example 3

[0090] This embodiment provides a method for enhancing the bonding strength between diamond particles and a copper matrix, wherein the method for enhancing the bonding strength between diamond particles and a copper matrix is ​​combined with... Figure 1 Includes the following steps:

[0091] S1. Laser perforation: Diamond particles with an average particle size of 600μm are uniformly filled on a porous array mold. The laser beam is modulated to form an array pulsed laser. The modulated pulsed laser array is used to perform batch perforation, with a perforation diameter of 200μm. The diamond particles are perforated through the micropores to obtain perforated diamond particles.

[0092] S2, pickling treatment: The perforated diamond particles from S1 are placed in an acid pickling solution for pickling treatment. The acid pickling solution is a mixture of 98% concentrated sulfuric acid and 99.7% concentrated nitric acid in a 3:1 ratio. The pickling treatment time is 1 hour, resulting in perforated diamond particles with a clean surface.

[0093] S3. Ultrasonic cleaning treatment: Weigh 50g of the surface-cleaned perforated diamond particles from S2 and place them in an acetone solution with a concentration of 99.6% or higher for ultrasonic cleaning at a frequency of 50kHz for 0.5h to obtain pure perforated diamond particles.

[0094] S4. Activation treatment: Place the pure perforated diamond particles from S3 into a tube furnace and introduce hydrogen gas for activation treatment. The vacuum degree is 20 Pa, the hydrogenation temperature is 800 ℃, the heating rate is 15 ℃ / min, the hydrogen flow rate is 10 sccm, and the treatment time is 60 min to obtain activated perforated diamond particles.

[0095] S5. Ultrasonic mixing + drying: The activated perforated diamond particles from S4 are placed in an acetone solution containing titanium isopropoxide, the content of which is 75 wt% and the purity of which is not less than 98%; ultrasonic mixing and drying are performed in a drying oven at a frequency of 40 kHz for 30 min; the drying temperature is 50 ℃ and the drying time is 60 min, resulting in a mixture in which titanium isopropoxide is uniformly adhered to the surface of the diamond particles.

[0096] The mixture of titanium isopropoxide uniformly adhered to the surface of diamond particles has a particle size of 601 μm and an adhesion thickness of 1000 nm.

[0097] S6. Final heat treatment: The mixture of S5 titanium isopropoxide uniformly attached to the surface of diamond particles is placed in a tube furnace and argon gas is introduced for final heat treatment; the argon gas flow rate is 10 sccm, the heating rate is 15℃ / min, the final heat treatment temperature is 650℃ / min, and the final heat treatment time is 40min, to obtain diamond particles with titanium metal coating on the surface.

[0098] The overall particle size of the diamond particles coated with titanium is 600 μm, and the thickness of the titanium layer is 150 nm.

[0099] S7. Preparation of diamond-copper composite material: Diamond particles coated with titanium metal from S6 are mixed with copper powder and then sintered by spark plasma to obtain diamond-copper composite material; the volume ratio of diamond particles coated with titanium metal to copper powder is 3:2, the spark plasma sintering temperature is 900℃, and the holding time is 15min.

[0100] In this embodiment, the volume ratio of diamond particles coated with titanium to copper powder is 3:2. When the diamond-copper composite material is plate-shaped with a size of 10×10mm, its thermal conductivity is 519W / m·K, its relative density is 95%, its Brinell hardness is 86.8, and its flexural strength is 497MPa. When the diamond-copper composite material is cylindrical with a size of φ12.5×2mm, its thermal conductivity is 506W / m·K, its relative density is 93%, its Brinell hardness is 86.7, and its flexural strength is 501MPa.

[0101] Example 4

[0102] This embodiment provides a method for enhancing the bonding strength between diamond particles and a copper matrix, wherein the method for enhancing the bonding strength between diamond particles and a copper matrix is ​​combined with... Figure 1 Includes the following steps:

[0103] S1. Laser perforation: Diamond particles with an average particle size of 400μm are uniformly filled on a porous array mold. The laser beam is modulated to form an array pulsed laser. The modulated pulsed laser array is used to perform batch perforation processing with a perforation diameter of 100μm, thus perforating the diamond particles through the micropores to obtain perforated diamond particles.

[0104] S2, pickling treatment: The perforated diamond particles from S1 are placed in an acid pickling solution for pickling treatment. The acid pickling solution is a mixture of 98% concentrated sulfuric acid and 99.7% concentrated nitric acid in a 3:1 ratio. The pickling treatment time is 1 hour, resulting in perforated diamond particles with a clean surface.

[0105] S3. Ultrasonic cleaning treatment: Weigh 50g of the surface-cleaned perforated diamond particles from S2 and place them in an acetone solution with a concentration of 99.6% or higher for ultrasonic cleaning at a frequency of 50kHz for 0.5h to obtain pure perforated diamond particles.

[0106] S4. Activation treatment: Place the pure perforated diamond particles from S3 into a tube furnace and introduce hydrogen gas for activation treatment. The vacuum degree is 20 Pa, the hydrogenation temperature is 800 ℃, the heating rate is 15 ℃ / min, the hydrogen flow rate is 10 sccm, and the treatment time is 30 min to obtain activated perforated diamond particles.

[0107] S5. Ultrasonic mixing + drying: The activated perforated diamond particles from S4 are placed in an acetone solution containing titanium isopropoxide, the content of which is 75 wt% and the purity of which is not less than 98%; ultrasonic mixing and drying are performed in a drying oven at a frequency of 40 kHz for 30 min; the drying temperature is 50 ℃ and the drying time is 60 min, resulting in a mixture in which titanium isopropoxide is uniformly adhered to the surface of the diamond particles.

[0108] The mixture of titanium isopropoxide uniformly adhered to the surface of diamond particles has a particle size of 401 μm and an adhesion thickness of 1000 nm.

[0109] S6. Final heat treatment: The mixture of S5 titanium isopropoxide uniformly attached to the surface of diamond particles is placed in a tube furnace and argon gas is introduced for final heat treatment; the argon gas flow rate is 10 sccm, the heating rate is 15℃ / min, the final heat treatment temperature is 600℃ / min, and the final heat treatment time is 30min, to obtain diamond particles with surface coated with metallic titanium.

[0110] The overall particle size of the diamond particles coated with titanium metal is 400 μm, and the thickness of the titanium metal layer is 300 nm.

[0111] S7. Preparation of diamond-copper composite material: Diamond particles coated with titanium metal from S6 are mixed with copper powder and then sintered by spark plasma to obtain diamond-copper composite material; the volume ratio of diamond particles coated with titanium metal to copper powder is 3:2, the spark plasma sintering temperature is 950℃, and the holding time is 20min.

[0112] In this embodiment, the volume ratio of diamond particles coated with titanium to copper powder is 3:2. When the diamond-copper composite material is plate-shaped with a size of 10×10mm, its thermal conductivity is 551W / m·K, its relative density is 94%, its Brinell hardness is 88.2, and its flexural strength is 490MPa. When the diamond-copper composite material is cylindrical with a size of φ12.5×2mm, its thermal conductivity is 539W / m·K, its relative density is 93%, its Brinell hardness is 88.2, and its flexural strength is 495MPa.

[0113] Example 5

[0114] This embodiment provides a method for enhancing the bonding strength between diamond particles and a copper matrix, wherein the method for enhancing the bonding strength between diamond particles and a copper matrix is ​​combined with... Figure 1 Includes the following steps:

[0115] S1. Laser perforation: Diamond particles with an average particle size of 200μm are uniformly filled on a porous array mold. The laser beam is modulated to form an array pulsed laser. The modulated pulsed laser array is used to perform batch perforation processing with a perforation diameter of 50μm. The diamond particles are perforated through the micropores to obtain perforated diamond particles.

[0116] S2, pickling treatment: The perforated diamond particles from S1 are placed in an acid pickling solution for pickling treatment. The acid pickling solution is a mixture of 98% concentrated sulfuric acid and 99.7% concentrated nitric acid in a 3:1 ratio. The pickling treatment time is 1 hour, resulting in perforated diamond particles with a clean surface.

[0117] S3. Ultrasonic cleaning treatment: Weigh 50g of the surface-cleaned perforated diamond particles from S2 and place them in an acetone solution with a concentration of 99.6% or higher for ultrasonic cleaning at a frequency of 50kHz for 0.5h to obtain pure perforated diamond particles.

[0118] S4. Activation treatment: Place the pure perforated diamond particles from S3 into a tube furnace and introduce hydrogen gas for activation treatment. The vacuum degree is 20 Pa, the hydrogenation temperature is 800 ℃, the heating rate is 15 ℃ / min, the hydrogen flow rate is 10 sccm, and the treatment time is 30 min to obtain activated perforated diamond particles.

[0119] S5. Ultrasonic mixing + drying: The activated perforated diamond particles from S4 are placed in an acetone solution containing titanium isopropoxide, the content of which is 75 wt% and the purity of which is not less than 98%; ultrasonic mixing is performed and the mixture is dried in a drying oven at a frequency of 40 kHz for 30 min; the drying temperature is 50 ℃ and the drying time is 50 min, resulting in a mixture in which titanium isopropoxide is uniformly adhered to the surface of the diamond particles.

[0120] The mixture of titanium isopropoxide uniformly adhered to the surface of diamond particles has a particle size of 201 μm and an adhesion thickness of 1000 nm.

[0121] S6. Final heat treatment: The mixture of S5 titanium isopropoxide uniformly attached to the surface of diamond particles is placed in a tube furnace and argon gas is introduced for final heat treatment; the argon gas flow rate is 10 sccm, the heating rate is 15℃ / min, the final heat treatment temperature is 600℃ / min, and the final heat treatment time is 40min, to obtain diamond particles with titanium metal coating on the surface.

[0122] The overall particle size of the diamond particles coated with titanium metal is 200 μm, and the thickness of the titanium metal layer is 100 nm.

[0123] S7. Preparation of diamond-copper composite material: Diamond particles coated with titanium metal from S6 are mixed with copper powder and then sintered by spark plasma to obtain diamond-copper composite material; the volume ratio of diamond particles coated with titanium metal to copper powder is 3:2, the spark plasma sintering temperature is 900℃, and the holding time is 15min.

[0124] In this embodiment, the volume ratio of diamond particles coated with titanium to copper powder is 3:2. When the diamond-copper composite material is plate-shaped with a size of 10×10mm, its thermal conductivity is 498W / m·K, its relative density is 88%, its Brinell hardness is 86.3, and its flexural strength is 489MPa. When the diamond-copper composite material is cylindrical with a size of φ12.5×2mm, its thermal conductivity is 522W / m·K, its relative density is 90%, its Brinell hardness is 87.2, and its flexural strength is 499MPa.

[0125] Example 6

[0126] This embodiment provides a method for enhancing the bonding strength between diamond particles and a copper matrix, wherein the method for enhancing the bonding strength between diamond particles and a copper matrix is ​​combined with... Figure 1 Includes the following steps:

[0127] S1. Laser perforation: Diamond particles with an average particle size of 400μm are uniformly filled on a porous array mold. The laser beam is modulated to form an array pulsed laser. The modulated pulsed laser array is used to perform batch perforation processing with a perforation diameter of 100μm, thus perforating the diamond particles through the micropores to obtain perforated diamond particles.

[0128] S2, pickling treatment: The perforated diamond particles from S1 are placed in an acid pickling solution for pickling treatment. The acid pickling solution is a mixture of 98% concentrated sulfuric acid and 99.7% concentrated nitric acid in a 3:1 ratio. The pickling treatment time is 1 hour, resulting in perforated diamond particles with a clean surface.

[0129] S3. Ultrasonic cleaning treatment: Weigh 50g of the surface-cleaned perforated diamond particles from S2 and place them in an acetone solution with a concentration of 99.6% or higher for ultrasonic cleaning at a frequency of 50kHz for 1 hour to obtain pure perforated diamond particles.

[0130] S4. Activation treatment: The pure perforated diamond particles from S3 are placed in a tube furnace and hydrogen is introduced for activation treatment. The vacuum degree is 16 Pa, the hydrogenation temperature is 800℃, the heating rate is 15℃ / min, the hydrogen flow rate is 30 sccm, and the treatment time is 90 min to obtain activated perforated diamond particles.

[0131] S5. Ultrasonic mixing + drying: The activated perforated diamond particles from S4 are placed in an acetone solution containing titanium isopropoxide, the content of which is 75 wt% and the purity of which is not less than 98%; ultrasonic mixing and drying are performed in a drying oven at a frequency of 40 kHz for 60 min; the drying temperature is 50 ℃ and the drying time is 90 min, resulting in a mixture in which titanium isopropoxide is uniformly adhered to the surface of the diamond particles.

[0132] The mixture of titanium isopropoxide uniformly adhered to the surface of diamond particles has a particle size of 401 μm and an adhesion thickness of 1500 nm.

[0133] S6. Final heat treatment: The mixture of S5 titanium isopropoxide uniformly attached to the surface of diamond particles is placed in a tube furnace and argon gas is introduced for final heat treatment; the argon gas flow rate is 10 sccm, the heating rate is 15℃ / min, the final heat treatment temperature is 700℃ / min, and the final heat treatment time is 60min, to obtain diamond particles with titanium metal coating on the surface.

[0134] The overall particle size of the diamond particles coated with titanium metal is 400 μm, and the thickness of the titanium metal layer is 400 nm.

[0135] S7. Preparation of diamond-copper composite material: Diamond particles coated with titanium metal from S6 are mixed with copper powder and then sintered by spark plasma to obtain diamond-copper composite material; the volume ratio of diamond particles coated with titanium metal to copper powder is 3:2, the spark plasma sintering temperature is 950℃, and the holding time is 15min.

[0136] In this embodiment, the volume ratio of diamond particles coated with titanium to copper powder is 3:2. When the diamond-copper composite material is plate-shaped with a size of 10x10mm, it has a thermal conductivity of 553W / m·K, a relative density of 94%, a Brinell hardness of 88.7, and a flexural strength of 510MPa. When the diamond-copper composite material is cylindrical with a size of φ12.5×2mm, it has a thermal conductivity of 567W / m·K, a relative density of 95%, a Brinell hardness of 89.2, and a flexural strength of 505MPa.

[0137] The above-mentioned solution proposes a method to enhance the bonding strength between diamond particles and a copper matrix, which can solve the technical problems in the prior art, such as weak interfacial bonding between diamond and copper, poor wettability of diamond and copper, difficulty in wetting, and the inability to comprehensively improve the thermal conductivity, electrical conductivity, and mechanical properties of diamond-copper composite materials.

[0138] This invention uses titanium isopropoxide as a titanium source, which benefits from its highly reactive alkoxy group, which can link with the activated functional group hydrogen on the diamond surface, undergo hydrolysis and condensation, and achieve chemical bonding of titanium species; at the same time, its good volatility and solution processability facilitate subsequent acetone solution mixing, drying and heat treatment.

[0139] The method of this invention increases the contact area between diamond particles and copper matrix by laser perforation of diamond particles, providing microchannels and enabling copper and diamond to bond tightly. This results in higher thermal conductivity between the diamond thermally conductive reinforcing phase and the copper matrix, which is beneficial to improving the overall thermal conductivity of the composite material.

[0140] The method of this invention overcomes the unevenness problem of existing coating technology by activating diamond. By activating the diamond surface, it forms a bond with the metal-organic material, which is conducive to uniform coating, thereby enhancing the interfacial bonding and improving the thermal conductivity.

[0141] In summary, compared with traditional methods, the method of this invention obtains a diamond-copper composite material that can bond tightly with copper by performing laser perforation, acid washing, ultrasonic cleaning, activation, ultrasonic mixing and drying, and final heat treatment of ultrasonic mixing and drying on diamond particles. The diamond-copper composite material prepared by this method can achieve synergistic improvement in thermal conductivity and mechanical properties. It is simple to operate, low in cost, low in energy consumption, and high in efficiency, which is conducive to large-scale industrial production and promotion.

[0142] It should be understood that the term "and / or" 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. A and B can be singular or plural. Additionally, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship. Please refer to the context for a more accurate understanding.

[0143] In this invention, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be a single item or multiple items.

[0144] It should be understood that, in various embodiments of the present invention, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0145] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for enhancing the bonding strength between diamond particles and a copper matrix, characterized in that, The method for enhancing the bonding strength between diamond particles and a copper matrix includes the following steps: S1. Laser perforation: Diamond particles are uniformly filled into a porous array mold, and then a modulated pulsed laser array is used to perform batch perforation to obtain perforated diamond particles. S2, pickling treatment: The perforated diamond particles of S1 are placed in the pickling solution for pickling treatment to obtain perforated diamond particles with clean surface. S3. Ultrasonic cleaning treatment: The surface-cleaned perforated diamond particles from S2 are placed in an acetone solution for ultrasonic cleaning to obtain pure perforated diamond particles. S4. Activation treatment: Place the pure perforated diamond particles from S3 into a tube furnace and introduce hydrogen gas for activation treatment to obtain activated perforated diamond particles. S5. Ultrasonic mixing + drying: The activated perforated diamond particles from S4 are placed in an acetone solution containing titanium isopropoxide, ultrasonically mixed, and dried in a drying oven to obtain a mixture in which titanium isopropoxide is uniformly attached to the surface of the diamond particles. S6. Final heat treatment: The mixture of S5 titanium isopropoxide uniformly attached to the surface of diamond particles is placed in a tube furnace and argon gas is introduced for final heat treatment to obtain diamond particles with surface coated with metallic titanium. S7, Preparation of diamond-copper composite material: Diamond particles coated with titanium metal on the surface of S6 are mixed with copper powder and then sintered by spark plasma to obtain diamond-copper composite material.

2. The method for enhancing the bonding strength between diamond particles and a copper matrix according to claim 1, characterized in that, The perforated diamond particles in S1 have a diameter of 50-600 μm, and the perforation diameter is 1 / 5-1 / 3 of the diamond particle diameter.

3. The method for enhancing the bonding strength between diamond particles and a copper matrix according to claim 1, characterized in that, The pickling solution in S2 is a mixture of 98% concentrated sulfuric acid and 99.7% concentrated nitric acid in a 3:1 ratio, and the pickling time is 0.5-2 hours.

4. The method for enhancing the bonding strength between diamond particles and a copper matrix according to claim 1, characterized in that, The acetone concentration in S3 needs to reach 99.6% or higher, the ultrasonic cleaning frequency is 40-100kHz, and the cleaning time is 0.5-3h.

5. The method for enhancing the bonding strength between diamond particles and a copper matrix according to claim 1, characterized in that, In S4, the vacuum level is 1-30 Pa, the hydrogenation temperature is 750-950℃, the heating rate is 10-20℃ / min, the hydrogen flow rate is 5-30 sccm, and the processing time is 30-120 min.

6. The method for enhancing the bonding strength between diamond particles and a copper matrix according to claim 1, characterized in that, The content of isopropoxide in the acetone solution of isopropoxide-titanium metal organic matter in S5 is 50-75wt%, and the purity of isopropoxide-titanium metal organic matter is not less than 98%; the ultrasonic mixing frequency is 30-50kHz, the ultrasonic time is 60-180min; the drying temperature is 30-50℃, and the drying time is 30-120min.

7. The method for enhancing the bonding strength between diamond particles and a copper matrix according to claim 1, characterized in that, S5 is a mixture in which titanium isopropoxide is uniformly adhered to the surface of diamond particles, with a particle size of 51-602 μm and an adhesion thickness of 1000-2000 nm.

8. The method for enhancing the bonding strength between diamond particles and a copper matrix according to claim 1, characterized in that, In S6, the argon flow rate is 5-30 sccm, the heating rate is 10-20℃ / min, the final heat treatment temperature is 500-700℃ / min, and the final heat treatment time is 30-90min.

9. The method for enhancing the bonding strength between diamond particles and a copper matrix according to claim 1, characterized in that, The overall particle size of the diamond particles coated with titanium in S6 is 50-600 μm, and the thickness of the titanium layer is 100-500 nm.

10. The method for enhancing the bonding strength between diamond particles and a copper matrix according to claim 1, characterized in that, In S7, the volume ratio of diamond particles coated with titanium metal to copper powder is 5:5-7:3, the temperature of spark plasma sintering is 850-1000℃, and the holding time is 5-30min.

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