Method for evaluating hydrolysis resistance of diamond / aluminum composite material
By simulating the use environment of diamond/aluminum composite materials, detecting changes in methane concentration and thermal conductivity, the problem of difficulty in accurately evaluating the hydrolysis resistance of composite materials in the prior art is solved, and efficient and accurate performance evaluation is achieved.
Patent Information
- Application Number
- CN202510243877.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-03
- Publication Date
- 2025-06-20
AI Technical Summary
The prior art is difficult to accurately evaluate the Al4C3 content and its hydrolysis resistance in diamond/aluminum composites, resulting in the inability to effectively evaluate its service performance in practical applications.
By placing the diamond/aluminum composite in sealed bottles with different humidity, temperature and hydrolyzed corrosion liquid, simulate its use environment, use a pump-suction gas detector to detect methane concentration, and measure the thermal conductivity changes in combination with a laser thermal conductivity meter to quantitatively evaluate its hydrolysis resistance.
A high-efficiency quantitative evaluation of the Al4C3 content of diamond/aluminum composite material is achieved, and its hydrolysis resistance is accurately evaluated, providing a fast and accurate testing method.
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Figure CN120177333A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of composite materials, and particularly relates to a method for evaluating the hydrolysis resistance of diamond / aluminum composites. Background Art
[0002] With the rapid development of information technology, electronic devices are gradually miniaturized and highly integrated to achieve faster information processing and computing speeds. However, the power density of electronic devices is also increasing continuously, and a large amount of heat accumulates in the core areas such as chips. Failure caused by heat accumulation has become one of the main reasons for the failure of electronic devices.
[0003] Diamond / aluminum composites have low density, high thermal conductivity, and low coefficient of thermal expansion, and have become candidate materials for the next-generation electronic packaging heat dissipation materials. During the preparation of diamond / aluminum composites, an in-situ reaction occurs between diamond and aluminum to generate Al4C3 at the interface. Although Al4C3 can improve the interfacial bonding force between diamond and aluminum and further improve the thermophysical properties of the composites, the hydrolysis characteristics of Al4C3 will cause the failure of the diamond / aluminum interface, thereby reducing the performance and service life of the composites.
[0004] Currently, the generation of Al4C3 is mainly restricted by adding alloy elements such as Si to the aluminum matrix or coating the diamond particles with a metal coating. However, different contents of Al4C3 still exist at the interface of the diamond / aluminum composites prepared by the above methods (P. Zhu, et al., Nanomaterials , 13(2023): 307; C. Y. Guo, et al., Journal of Alloys and Compounds , 664(2016): 777). Therefore, an efficient method is needed to evaluate the Al4C3 content of diamond / aluminum composites, and further evaluate their hydrolysis resistance and service performance in practical applications.
[0005] Currently, related research evaluates the Al4C3 content by electrolytic extraction of diamond / aluminum composites and observing the surface of the diamond after extraction. However, during the electrolytic extraction process, some Al4C3 will be lost, so the Al4C3 content cannot be accurately measured (I. E. Monje, et al., Scripta Materialia, 66(2012): 789). There are also studies using focused ion beam-assisted scanning transmission electron microscopy to observe the Al4C3 content at the diamond / aluminum interface, but this method can only obtain information within a narrow area of 100 square micrometers (P. Zhu, et al., Composites Part A, 162(2022): 10716). Another study places the diamond / aluminum composite in a humid environment (W. Yang et al., Diamond & Related Materials, 46(2014): 35) to evaluate the changes in properties such as the thermal conductivity of the diamond / aluminum composite. However, this method can only qualitatively analyze the service performance of the diamond / aluminum composite, and cannot quantitatively and efficiently evaluate the Al4C3 content and its anti-hydrolysis performance in the composite material. Summary of the Invention
[0006] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for evaluating the anti-hydrolysis performance of diamond / aluminum composites. By utilizing the characteristic that Al4C3 hydrolyzes to produce methane, the diamond / aluminum composite is placed in a sealed bottle with different humidity, different temperatures, and different hydrolysis corrosion liquids to simulate the usage environment of the composite material. A pump suction type gas detector is used to detect the methane concentration to obtain the Al4C3 content, and combined with a laser thermal conductivity meter to measure the change in thermal conductivity, the anti-hydrolysis performance of the diamond / aluminum composite is quantitatively and efficiently evaluated.
[0007] To achieve the above purpose, the technical solution of the present invention is as follows:
[0008] A method for evaluating the anti-hydrolysis performance of diamond / aluminum composites, comprising the following steps:
[0009] 1) Prepare diamond / aluminum composites;
[0010] 2) Use a laser thermal conductivity meter to measure the thermal conductivity of the diamond / aluminum composite before hydrolysis;
[0011] 3) Configure different hydrolysis corrosion liquids, and fill a certain volume of the corrosion liquid into a sealed bottle with scales and valves;
[0012] 4) Put the diamond / aluminum composite after measuring the thermal conductivity in step 2) into the sealed bottle in step 3), seal the sealed bottle well and place it in a temperature control box, and set the temperature of the temperature control box to simulate the cold and hot alternating environment during the actual application of the composite material;
[0013] 5) After reacting for a certain period of time, use a pump suction gas detector to detect the concentration of methane gas in the sealed bottle, and then calculate the methane content based on the volume of the sealed bottle.
[0014] 6) Use a laser thermal conductivity meter to measure the thermal conductivity of the diamond / aluminum composite material after hydrolysis.
[0015] 7) Quantitatively evaluate the hydrolysis resistance of the diamond / aluminum composite material based on the change in methane content and thermal conductivity before and after hydrolysis.
[0016] Preferably, the diamond / aluminum composite material in step 1) can be prepared by surface modification of diamond or by alloying of the aluminum matrix. Preferably, a coating is prepared on the surface of the diamond / aluminum composite material, which can reduce the hydrolysis rate of the composite material. In the example, a nickel-phosphorus alloy coating is prepared on the surface of the diamond / aluminum composite material by electroless plating.
[0017] Preferably, the diamond / aluminum composite material in step 1) is a cuboid or a cylinder. The cuboid has a length of 6 - 25 mm, a width of 6 - 25 mm, and a thickness of 0.5 - 6 mm; the cylinder has a diameter of 6 - 25 mm and a thickness of 0.5 - 6 mm.
[0018] Preferably, there is a certain amount of interfacial product Al4C3 at the interface of the diamond / aluminum composite material in step 1). The presence of Al4C3 can improve the thermal conductivity of the composite material on the one hand, but on the other hand, it is prone to hydrolysis reaction with water, reducing the service life of the composite material. The specific reaction equation is: Al4C3(s) + H2O(l) → Al(OH)3(s) + CH4↑, and the production amount of methane is positively correlated with the degree of hydrolysis reaction.
[0019] Preferably, the hydrolysis corrosion solution in step 3) is selected from one of deionized water, distilled water, NaCl solution, acidic solution or alkaline solution. The acid is hydrochloric acid or acetic acid, the base is sodium hydroxide or potassium hydroxide, the mass concentration of the NaCl solution is 3 - 4 wt%, and the volume of the hydrolysis corrosion solution is 50 - 300 mL.
[0020] Preferably, the capacity of the sealed bottle in step 3) is 200 - 1000 mL. The sealed bottle is equipped with a scale and a sealing valve, and has good sealing performance.
[0021] Preferably, the operating temperature range of the temperature control box in step 4) is -50 - 300°C.
[0022] Preferably, the hydrolysis time in step 5) is 1 - 1000 hours, preferably 100 - 700 hours.
[0023] Preferably, the pump suction type gas detector described in step 5) is selected from a methane gas detector and a four-in-one gas detector, and the purpose is to detect the methane concentration.
[0024] The present invention also provides a test device for implementing the above method, including a temperature control box, a sealed bottle, a gas detector and a computer. Among them,
[0025] The temperature control box is used to accommodate the sealed bottle and provide a constant temperature;
[0026] The sealed bottle is used to accommodate the sample to be tested and the hydrolysis corrosion liquid, and the sample to be tested is located below the liquid level of the hydrolysis corrosion liquid; a valve is provided above the sealed bottle, and the valve is connected to the gas detector through a hose;
[0027] The gas detector is used to detect the methane concentration in the sealed bottle after the sample is hydrolyzed;
[0028] The computer is electrically connected to the gas detector and the temperature control box respectively, and is used to record the detected methane concentration and the temperature in the temperature control box in real time.
[0029] Compared with other technologies, the prominent advantages of the present invention are:
[0030] 1) The sample preparation is simple and convenient, and the sample sizes are diverse. Specifically, sealed bottles and gas detectors with different volumes can be selected according to the size of the sample.
[0031] 2) The hydrolysis corrosion liquid can be selected according to the use environment of the diamond / aluminum composite material.
[0032] 3) The humidity and temperature of the sealed bottle can be adjusted according to the use environment of the diamond / aluminum composite material.
[0033] 4) When using a pump suction type gas detector to detect the methane concentration, it is not necessary to transfer the gas in the bottle, and the content of the generated methane gas can be detected conveniently, quickly and accurately.
[0034] 5) By combining with a laser thermal conductivity meter to test the thermal conductivity, the hydrolysis resistance of the sample can be analyzed more accurately. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0036] Figure 1 It is a schematic structural diagram of the test device for implementing the above method of the present invention. DETAILED DESCRIPTION OF THE INVENTION
[0037] To make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments.
[0038] Example 1
[0039] A method for evaluating the hydrolysis resistance of a diamond / aluminum composite material includes the following steps:
[0040] 1) Select 60 / 70 mesh diamond particles and pure aluminum as raw materials, and use the gas pressure infiltration method to prepare a diamond / aluminum composite material. Further, use the laser cutting method to process the size of the diamond / aluminum composite material into a small round piece sample of diamond / aluminum composite material with a diameter of 10 mm, a thickness of 3 mm, and a mass of 0.78 g;
[0041] 2) Polish the surface of the small round piece sample of diamond / aluminum composite material with 2000-mesh sandpaper, and ultrasonically clean it with acetone for 3 min to remove the laser cutting residue. Use a laser thermal conductivity meter to measure the thermal conductivity of the sample before hydrolysis corrosion as 696 W m -1 K -1 ;
[0042] 3) Prepare a sodium chloride solution with a mass fraction of 3.5 wt%. Clean and dry a 250 mL sealed bottle with a scale and a sealed valve. Add 100 mL of the sodium chloride solution with a mass fraction of 3.5 wt% to the sealed bottle;
[0043] 4) Put the diamond / aluminum composite material after measuring the thermal conductivity in step 2) into the sealed bottle in step 3), so that the sample is completely immersed in the sodium chloride solution, simulating the use of the sample in the sodium chloride solution environment. Cover the bottle cap, close the sealed valve, and wrap the positions of the bottle cap and the sealed valve with a film to ensure airtightness. Put the sealed bottle into a temperature control box with a set temperature of 25 °C;
[0044] 5) After 1 week (168 h) of hydrolysis corrosion, remove the film, use a gas detector to detect that the concentration of methane in the sealed bottle is 0.2 vol%. According to the volume occupied by the 100 mL sodium chloride solution removed from the sealed bottle, the remaining 150 mL is the volume of methane gas, and calculate that the amount of methane gas generated is 0.3 mL;
[0045] 6) Take out the sample, ultrasonically clean it with deionized water for 2 min to remove the sodium chloride residue on the surface, and use a laser thermal conductivity meter to measure the thermal conductivity of the sample after hydrolysis corrosion as 610 W m -1 K -1 ;
[0046] 7) The thermal conductivity of the sample before hydrolysis corrosion is 696 W m -1 K -1, the thermal conductivity of the sample after hydrolysis corrosion is 610 Wm -1 K -1 . After hydrolysis corrosion, the thermal conductivity decreased by 12.4%, and the amount of methane produced by hydrolysis corrosion was 0.3 mL.
[0047] Example 2
[0048] A method for evaluating the hydrolysis resistance of a diamond / aluminum composite material, comprising the following steps:
[0049] 1) Select 60 / 70 mesh diamond particles and pure aluminum as raw materials, and use the gas pressure infiltration method to prepare a diamond / aluminum composite material. Further, use a laser cutting method to process the size of the diamond / aluminum composite material into a small round piece sample of diamond / aluminum composite material with a diameter of 10 mm, a thickness of 3 mm, and a mass of 0.78 g. The surface of the sample is polished with 2000-mesh sandpaper and ultrasonically cleaned with acetone for 3 min to remove the laser cutting residue. The thermal conductivity of the sample before electroless plating is measured by a laser thermal conductivity meter to be 684 W m -1 K -1 ; Electrolessly deposit a nickel-phosphorus alloy coating with a thickness of about 20 μm on the surface of the sample;
[0050] 2) Polish the surface of the electroless plated diamond / aluminum composite material small round piece sample with 2000-mesh sandpaper and ultrasonically clean it with acetone for 3 min. Use a laser thermal conductivity meter to measure the thermal conductivity of the sample before hydrolysis corrosion to be 667 W m -1 K -1 ;
[0051] 3) Prepare a sodium chloride solution with a mass fraction of 3.5 wt%. Clean and dry a 250 mL sealed bottle with a scale and a sealed valve. Add 100 mL of the sodium chloride solution with a mass fraction of 3.5 wt% to the sealed bottle;
[0052] 4) Put the diamond / aluminum composite material after measuring the thermal conductivity in step 2) into the sealed bottle in step 3) so that the sample is completely immersed in the sodium chloride solution to simulate the use of the sample in the sodium chloride solution environment. Cover the bottle cap, close the sealed valve, and wrap the positions of the bottle cap and the sealed valve with a film to ensure airtightness. Put the sealed bottle into a temperature control box with a set temperature of 25°C;
[0053] 5) After 1 week (168 h) of hydrolysis corrosion, remove the film, and use a gas detector to detect that the concentration of methane in the sealed bottle is 0 vol%. According to the volume occupied by removing 100 mL of sodium chloride solution in the sealed bottle, the remaining 150 mL is the volume of methane gas, and the amount of methane gas produced is calculated to be 0 mL;
[0054] 6) Take out the specimen, ultrasonically clean it with deionized water for 2 min to remove the residual sodium chloride on the surface, and use a laser thermal conductivity meter to measure the thermal conductivity of the specimen after hydrolysis corrosion, which is 693 W m -1 K -1 ;
[0055] 7) The thermal conductivity of the specimen before hydrolysis corrosion is 667 W m -1 K -1 , and the thermal conductivity of the specimen after hydrolysis corrosion is 693 Wm -1 K -1 , the thermal conductivity after hydrolysis corrosion decreases by -3.90%, and the amount of methane generated by hydrolysis corrosion is 0 mL.
[0056] Example 3
[0057] A method for evaluating the hydrolysis resistance of diamond / aluminum composites, comprising the following steps:
[0058] 1) Select 60 / 70 mesh diamond particles and pure aluminum as raw materials, and use the gas pressure infiltration method to prepare diamond / aluminum composites. Further, use the laser cutting method to process the size of the diamond / aluminum composites into small round specimens of diamond / aluminum composites with a diameter of 10 mm, a thickness of 3 mm, and a mass of 0.78 g. The surface of the specimen is polished with 2000-mesh sandpaper and ultrasonically cleaned with acetone for 3 min to remove the laser cutting residue. The thermal conductivity of the specimen before electroless plating is measured by a laser thermal conductivity meter to be 699 W m -1 K -1 ; Electrolessly deposit a nickel-phosphorus alloy coating with a thickness of about 30 μm on the surface of the specimen;
[0059] 2) Polish the surface of the electroless plated diamond / aluminum composite small round specimen with 2000-mesh sandpaper and ultrasonically clean it with acetone for 3 min. Use a laser thermal conductivity meter to measure the thermal conductivity of the specimen before hydrolysis corrosion to be 679 W m -1 K -1 ;
[0060] 3) Prepare a sodium chloride solution with a mass fraction of 3.5 wt%. Clean and dry a 250 mL sealed bottle with a scale and a sealed valve, and add 100 mL of the sodium chloride solution with a mass fraction of 3.5 wt% to the sealed bottle;
[0061] 4) Put the diamond / aluminum composite material after measuring the thermal conductivity in step 2) into the sealed bottle in step 3) so that the specimen is completely immersed in the sodium chloride solution to simulate the use of the specimen in the sodium chloride solution environment. Cover the bottle cap, close the sealed valve, and wrap the positions of the bottle cap and the sealed valve with a film to ensure airtightness. Put the sealed bottle into a temperature control box with a set temperature of 25 °C;
[0062] 5) After 1 week (168 h) of hydrolysis corrosion, remove the film, and use a gas detector to detect that the methane concentration in the sealed bottle is 0 vol%. According to the volume occupied by 100 mL of sodium chloride solution removed from the sealed bottle, the remaining 150 mL is the volume of methane gas. Calculate that the amount of methane gas generated is 0 mL;
[0063] 6) Take out the specimen, ultrasonically clean it with deionized water for 2 min to remove the sodium chloride residue on the surface, and use a laser thermal conductivity meter to measure the thermal conductivity of the specimen after hydrolysis corrosion as 679 W m -1 K -1 ;
[0064] 7) The thermal conductivity of the specimen before hydrolysis corrosion is 679 W m -1 K -1 , the thermal conductivity of the specimen after hydrolysis corrosion is 679 Wm -1 K -1 , the thermal conductivity decreases by 0 after hydrolysis corrosion, and the amount of methane generated by hydrolysis corrosion is 0 mL.
[0065] Example 4
[0066] A method for evaluating the hydrolysis resistance of diamond / aluminum composite materials, comprising the following steps:
[0067] 1) Select 60 / 70 mesh diamond particles and pure aluminum as raw materials, and use the gas pressure infiltration method to prepare diamond / aluminum composite materials. Further, use the laser cutting method to process the size of the diamond / aluminum composite materials into small round specimens of diamond / aluminum composite materials with a diameter of 10 mm, a thickness of 3 mm, and a mass of 0.78 g;
[0068] 2) Polish the surface of the small round specimen of diamond / aluminum composite material with 2000-mesh sandpaper, ultrasonically clean it with acetone for 3 min, and use a laser thermal conductivity meter to measure the thermal conductivity of the specimen before hydrolysis corrosion as 658 W m -1 K -1 ;
[0069] 3) Prepare a sodium chloride solution with a mass fraction of 3.5 wt%. Clean and dry a 250 mL sealed bottle with a scale and a sealing valve, and add 100 mL of sodium chloride solution with a mass fraction of 3.5 wt% to the sealed bottle;
[0070] 4) Put the diamond / aluminum composite material after measuring the thermal conductivity in step 2) into the sealed bottle in step 3) so that the specimen is completely immersed in the sodium chloride solution to simulate the use of the specimen in the sodium chloride solution environment. Cover the bottle cap, close the sealing valve, and wrap the bottle cap and the sealing valve with a film to ensure airtightness. Put the sealed bottle into a temperature control box with a set temperature of 25 °C;
[0071] 5) After 4 weeks (672 h) of hydrolytic corrosion, the film was removed, and the methane concentration in the sealed bottle was detected by a gas detector to be 0.4 vol%. According to the volume occupied by 100 mL of sodium chloride solution removed from the sealed bottle, the remaining 150 mL was the volume of methane gas. The amount of methane gas generated was calculated to be 0.6 mL;
[0072] 6) The specimen was taken out, ultrasonically cleaned with deionized water for 2 min to remove the residual sodium chloride on the surface, and the thermal conductivity of the specimen after hydrolytic corrosion was measured by a laser thermal conductivity meter to be 532 W m -1 K -1 ;
[0073] 7) The thermal conductivity of the specimen before hydrolytic corrosion was 658 W m -1 K -1 , and the thermal conductivity of the specimen after hydrolytic corrosion was 532 Wm -1 K -1 , the thermal conductivity decreased by 19.15% after hydrolytic corrosion, and the amount of methane generated by hydrolytic corrosion was 0.6 mL.
[0074] Example 5
[0075] A method for evaluating the hydrolysis resistance of a diamond / aluminum composite material, comprising the following steps:
[0076] 1) 60 / 70 mesh diamond particles and pure aluminum were selected as raw materials, and a diamond / aluminum composite material was prepared by air pressure infiltration method. Further, the diamond / aluminum composite material was processed into a small round piece specimen with a diameter of 10 mm, a thickness of 3 mm, and a mass of 0.78 g by laser cutting method. The surface of the specimen was polished with 2000-mesh sandpaper and ultrasonically cleaned with acetone for 3 min to remove the laser cutting residue. The thermal conductivity of the specimen before electroless plating was measured by a laser thermal conductivity meter to be 646 W m -1 K -1 ; An electroless nickel-phosphorus alloy coating with a thickness of about 20 μm was deposited on the surface of the specimen by electroless plating;
[0077] 2) The surface of the electroless plated diamond / aluminum composite material small round piece specimen was polished with 2000-mesh sandpaper and ultrasonically cleaned with acetone for 3 min. The thermal conductivity of the specimen before hydrolytic corrosion was measured by a laser thermal conductivity meter to be 632 W m -1 K -1 ;
[0078] 3) A sodium chloride solution with a mass fraction of 3.5 wt% was prepared. A 250 mL sealed bottle with a scale and a sealing valve was cleaned and dried, and 100 mL of the sodium chloride solution with a mass fraction of 3.5 wt% was added to the sealed bottle;
[0079] 4) Place the diamond / aluminum composite after measuring the thermal conductivity in step 2) into the sealed bottle in step 3) so that the specimen is completely immersed in the sodium chloride solution, simulating the usage of the specimen in the sodium chloride solution environment. Cover the bottle cap, close the sealing valve, and wrap the positions of the bottle cap and the sealing valve with a film to ensure airtightness. Then place the sealed bottle into a temperature control box with the temperature set at 25 °C;
[0080] 5) After hydrolysis corrosion for 4 weeks (672 h), remove the film. Use a gas detector to detect that the concentration of methane in the sealed bottle is 0.07 vol%. According to the volume occupied by removing 100 mL of sodium chloride solution in the sealed bottle, the remaining 150 mL is the volume of methane gas. Calculate that the amount of methane gas generated is 0.105 mL;
[0081] 6) Take out the specimen, ultrasonically clean it with deionized water for 2 min to remove the residual sodium chloride on the surface. Use a laser thermal conductivity meter to measure the thermal conductivity of the specimen after hydrolysis corrosion as 570 W m -1 K -1 ;
[0082] 7) The thermal conductivity of the specimen before hydrolysis corrosion is 632 W m -1 K -1 , and the thermal conductivity of the specimen after hydrolysis corrosion is 570 W m -1 K -1 , the thermal conductivity decreases by 9.81% after hydrolysis corrosion, and the amount of methane generated by hydrolysis corrosion is 0.105 mL.
[0083] Example 6
[0084] A method for evaluating the hydrolysis resistance of a diamond / aluminum composite, comprising the following steps:
[0085] 1) Select 60 / 70 mesh diamond particles and pure aluminum as raw materials, and use the gas pressure infiltration method to prepare a diamond / aluminum composite. Further, use a laser cutting method to process the size of the diamond / aluminum composite into a small round piece specimen with a diameter of 10 mm, a thickness of 3 mm, and a mass of 0.78 g. The surface of the specimen is polished with 2000-mesh sandpaper and ultrasonically cleaned with acetone for 3 min to remove the laser cutting residue. The thermal conductivity of the specimen before electroless plating is measured by a laser thermal conductivity meter as 732 W m -1 K -1 ; Electrolessly plate a nickel-phosphorus alloy coating with a thickness of about 30 μm on the surface of the specimen;
[0086] 2) Polish the surface of the electrolessly plated diamond / aluminum composite small round piece specimen with 2000-mesh sandpaper and ultrasonically clean it with acetone for 3 min. Use a laser thermal conductivity meter to measure the thermal conductivity of the specimen before hydrolysis corrosion as 711 W m -1 K-1 ;
[0087] 3) Prepare a sodium chloride solution with a mass fraction of 3.5 wt%. Clean and dry a 250 mL sealed bottle with scale and sealed valve. Add 100 mL of the sodium chloride solution with a mass fraction of 3.5 wt% into the sealed bottle.
[0088] 4) Put the diamond / aluminum composite material after measuring the thermal conductivity in step 2) into the sealed bottle in step 3), so that the specimen is completely immersed in the sodium chloride solution to simulate the usage of the specimen in the sodium chloride solution environment. Cover the bottle cap, close the sealed valve, and wrap the positions of the bottle cap and the sealed valve with a film to ensure airtightness. Put the sealed bottle into a temperature control box with the temperature set at 25 °C.
[0089] 5) After 4 weeks (672 h) of hydrolysis corrosion, remove the film. Use a gas detector to detect that the concentration of methane in the sealed bottle is 0.05 vol%. According to the volume occupied by removing 100 mL of sodium chloride solution in the sealed bottle, the remaining 150 mL is the volume of methane gas. Calculate that the amount of methane gas generated is 0.075 mL.
[0090] 6) Take out the specimen, ultrasonically clean it with deionized water for 2 min to remove the sodium chloride residue on the surface. Use a laser thermal conductivity meter to measure the thermal conductivity of the specimen after hydrolysis corrosion as 644 W m -1 K -1 ;
[0091] 7) The thermal conductivity of the specimen before hydrolysis corrosion is 711 W m -1 K -1 , and the thermal conductivity of the specimen after hydrolysis corrosion is 644 Wm -1 K -1 , the thermal conductivity decreases by 9.42% after hydrolysis corrosion, and the amount of methane generated by hydrolysis corrosion is 0.075 mL.
[0092] Summarize the test results of the above examples as follows:
[0093] Examples 1, 2, and 3 are unplated diamond / aluminum composite materials, diamond / aluminum composite materials with a 20 μm nickel-phosphorus alloy coating on the surface, and diamond / aluminum composite materials with a 30 μm nickel-phosphorus alloy coating on the surface, respectively. For these three types of composite materials, the thermal conductivity decreased to varying degrees after 1 week (168 h) of hydrolysis corrosion in a 25 °C deionized water environment, and methane gas was generated during the reaction.
[0094] After hydrolysis corrosion of the samples of Examples 1, 2, and 3, the percentage decreases in their thermal conductivities were 12.4%, -3.90%, and 0% respectively; the volumes of methane gas generated were 0.3 mL, 0 mL, and 0 mL respectively. According to the percentage decreases in thermal conductivity and the amount of methane gas generated, the anti-hydrolysis properties of the samples of Examples 1, 2, and 3 were quantitatively evaluated. It shows that after electroless nickel-phosphorus alloy plating on the surface of the diamond / aluminum composite material, the anti-hydrolysis property of the sample is improved.
[0095] Examples 4, 5, and 6 were respectively an unplated diamond / aluminum composite material, a diamond / aluminum composite material with a 20-μm thick electroless nickel-phosphorus alloy coating on its surface, and a diamond / aluminum composite material with a 30-μm thick electroless nickel-phosphorus alloy coating on its surface. After 4 weeks (672 h) of hydrolysis corrosion in a deionized water environment at 25°C, the thermal conductivities of these three types of composite materials decreased to varying degrees, and methane gas was generated during the reaction. The composite material sample of Example 4 was different from that of Example 1 in terms of thermal conductivity and hydrolysis corrosion time.
[0096] After hydrolysis corrosion of the samples of Examples 4, 5, and 6, the percentage decreases in their thermal conductivities were 19.15%, 9.81%, and 9.42% respectively; the volumes of methane gas generated were 0.6 mL, 0.105 mL, and 0.075 mL respectively. According to the percentage decreases in thermal conductivity and the amount of methane gas generated, the anti-hydrolysis properties of the samples of Examples 4, 5, and 6 were quantitatively evaluated. Example 6, that is, the sample of the diamond / aluminum composite material with a 30-μm thick electroless nickel-phosphorus alloy coating on its surface, had the best anti-hydrolysis property.
[0097] Compared with Examples 1-3, the hydrolysis corrosion time in Examples 4-6 was extended from 1 week to 4 weeks. It shows that when the hydrolysis corrosion time was 1 week, a 20-μm thick nickel-phosphorus alloy coating could block the hydrolysis reaction of the diamond / aluminum composite material. However, when the hydrolysis corrosion time was extended to 4 weeks, appropriately increasing the thickness of the nickel-phosphorus alloy coating could further reduce the hydrolysis reaction of the diamond / aluminum composite material.
[0098] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.
Claims
1. A method for evaluating the hydrolysis resistance of a diamond / aluminum composite material, characterized in that: The following steps are involved: 1) Preparation of diamond / aluminum composite materials; 2) using a laser thermal conductivity meter to test the thermal conductivity of the diamond / aluminum composite material before hydrolysis; 3) Prepare different hydrolysis corrosion solutions and put them into sealed bottles with scales and valves; 4) placing the diamond / aluminum composite material after the thermal conductivity is measured in step 2) into the sealed bottle in step 3), sealing the sealed bottle and placing it in a temperature control box, and setting the temperature of the temperature control box to simulate the hot and cold alternating environment of the composite material in actual application; 5) After a certain reaction time, use a pump-suction gas detector to detect the concentration of methane gas in the sealed bottle, and then calculate the methane content based on the volume of the sealed bottle; 6) Use laser thermal conductivity meter to test the thermal conductivity of diamond / aluminum composite materials after hydrolysis; 7) The hydrolysis resistance of diamond / aluminum composites was quantitatively evaluated based on the changes in methane content and thermal conductivity before and after hydrolysis.
2. The method for evaluating the hydrolysis resistance of diamond / aluminum composite materials according to claim 1, characterized in that: Step 1) The diamond / aluminum composite material is prepared by surface modification of diamond, or by alloying an aluminum matrix.
3. The method for evaluating the hydrolysis resistance of diamond / aluminum composite materials according to claim 2, characterized in that: A coating is prepared on the surface of the diamond / aluminum composite material, preferably a nickel-phosphorus alloy coating.
4. The method for evaluating the hydrolysis resistance of diamond / aluminum composite materials according to claim 1, characterized in that: Step 1) The diamond / aluminum composite material is a cuboid or a cylinder. The length of the cuboid is 6-25 mm, the width is 6-25 mm, and the thickness is 0.5-6 mm; the diameter of the cylinder is 6-25 mm, and the thickness is 0.5-6 mm.
5. The method for evaluating the hydrolysis resistance of diamond / aluminum composite materials according to claim 1, characterized in that: Step 3) The hydrolysis corrosion solution is selected from one of deionized water, distilled water, NaCl solution, acidic solution or alkaline solution, the acid is hydrochloric acid or acetic acid, the alkali is sodium hydroxide or potassium hydroxide, the mass concentration of the NaCl solution is 3-4 wt%, and the volume of the hydrolysis corrosion solution is 50-300 mL.
6. The method for evaluating the hydrolysis resistance of diamond / aluminum composite materials according to claim 1, characterized in that: Step 3) The sealed bottle has a capacity of 200-1000 mL, is provided with a scale and a sealing valve, and has good sealing performance.
7. The method for evaluating the hydrolysis resistance of diamond / aluminum composite materials according to claim 1, characterized in that: Step 4) The operating temperature range of the temperature control box is -50~300℃.
8. The method for evaluating the hydrolysis resistance of diamond / aluminum composite materials according to claim 1, characterized in that: The hydrolysis time in step 5) is 1 to 1000 hours, preferably 100 to 700 hours.
9. The method for evaluating the hydrolysis resistance of diamond / aluminum composite materials according to claim 1, characterized in that: The pump-suction gas detector described in step 5) is selected from a methane gas detector and a four-in-one gas detector.
10. A testing device for implementing the method according to any one of claims 1 to 9, characterized in that: Including temperature control box, sealed bottle, gas detector and computer, among which, The temperature control box is used to accommodate the sealed bottles and provide constant temperature; The sealed bottle is used to contain the sample to be tested and the hydrolytic corrosive liquid, and the sample to be tested is located below the liquid level of the hydrolytic corrosive liquid; a valve is provided above the sealed bottle, and the valve is connected to the gas detector through a hose; The gas detector is used to detect the methane concentration in the sealed bottle after the sample is hydrolyzed; The computer is electrically connected to the gas detector and the temperature control box respectively, and is used to record the detected methane concentration and the temperature in the temperature control box in real time.