Preparation method of nano graphene oxide in-situ reinforced copper-chromium electrical contact material

Abstract

The invention discloses a preparation method of a nano graphene oxide in-situ reinforced copper-chromium electrical contact material, which comprises the following steps: preparing graphene oxide nanosheets by using an improved Hummers method, uniformly mixing copper powder and chromium powder, and carrying out ultrasonic dispersion on the graphene oxide nanosheets, transferring the mixed metal powder into the ultrasonically dispersed graphene oxide suspension, mechanically stirring, uniformly mixing, carrying out vacuum freeze drying, and finally, carrying out vacuum hot-pressing sintering. The self-made graphene oxide nanosheets are added into the copper-chromium mixed metal powder for vacuum hot-pressing sintering, and graphene oxide is converted into reduced graphene oxide at high temperature, so that the problems of poor affinity between graphene and a copper matrix, poor interface bonding force and poor conductivity of graphene oxide are solved; in addition, nano carbide is formed in situ at a graphene / metal interface in the sintering process, so that the comprehensive performance of the electrical contact material is improved. The method is simple in process, low in energy consumption and remarkable in performance improvement.

Description

technical field

[0001] The invention belongs to the technical field of preparation of electrical materials, in particular to a method for preparing a nanometer graphene oxide in-situ reinforced copper chromium electrical contact material. Background technique

[0002] Copper-based composite materials are widely used as electrical contact materials due to their excellent properties such as high strength, high conductivity, and thermal stability. The copper-based composite material prepared by vacuum hot-pressing sintering method can comprehensively exert the excellent properties of copper and other materials, and improve the comprehensive performance of electrical contacts. Chromium has the characteristics of high melting point, high hardness and low cut-off value, and has a great affinity for oxygen, which ensures the good air suction capacity of the vacuum switch contact. Therefore, the copper-chromium contact material has a strong breaking capacity and is suitable for med...

Examples

preparation example Construction

[0035] A preparation method of nanometer graphene oxide in-situ strengthened copper chromium electrical contact material, the electrical contact material is prepared by improving the Hummers method to prepare graphene oxide, and then mixing the metal mixed powder with the graphene oxide suspension after ultrasonic dispersion , Freeze-dried and then vacuum-pressed and sintered. The preparation process specifically includes the following steps:

[0036] Step 1, preparation of graphene oxide nanosheets

[0037] ① According to the dosage ratio of 1-1.5g: 25-30ml: 0.5-1g: 6-9g, weigh high-purity graphite powder, concentrated sulfuric acid, sodium nitrate and potassium permanganate respectively, and set aside;

[0038] ②Add the concentrated sulfuric acid, sodium nitrate and graphite weighed in step ① into the three-necked flask in sequence, and keep the temperature of the reaction system at 0-5°C under constant stirring to carry out the first-stage reaction for 30-60min. At this stag...

Embodiment 1

[0055] A 0.1GO / Cu30Cr electrical contact material with a size of Φ50 mm×15 mm doped with 0.1% self-made graphene oxide was prepared.

[0056] The specific preparation method is:

[0057] Step 1, preparation of graphene oxide nanosheets

[0058] ①According to the dosage ratio of 1g:25ml:0.5g:6g, weigh high-purity graphite powder, concentrated sulfuric acid, sodium nitrate and potassium permanganate respectively, and set aside;

[0059] ②Add the concentrated sulfuric acid, sodium nitrate and graphite weighed in step ① into the three-necked flask in sequence, and keep the temperature of the reaction system at 3°C ​​for 30 minutes in the first stage of reaction under constant stirring, during which the graphite edge is gradually oxidized; Then, divide the potassium permanganate weighed in step ① into three parts, and add one part at intervals of 10 minutes. Under continuous stirring conditions, keep the temperature of the reaction system at 20 ° C for 2 hours. At this stage, the ...

Embodiment 2

[0075] A 0.3GO / Cu30Cr electrical contact material with a size of Φ50 mm×15 mm and doped with 0.3% graphene oxide was prepared.

[0076] The specific preparation method is:

[0077] Step 1, preparation of graphene oxide nanosheets

[0078] ① According to the dosage ratio of 1.5g: 30ml: 0.8g: 7g, weigh high-purity graphite powder, concentrated sulfuric acid, sodium nitrate and potassium permanganate respectively, and set aside;

[0079] ②Add the concentrated sulfuric acid, sodium nitrate and graphite weighed in step ① into the three-necked flask in turn, and keep the temperature of the reaction system at 0°C under constant stirring to carry out the first stage reaction for 50 minutes, during which the graphite edge is gradually oxidized; Then, divide the potassium permanganate weighed in step ① into three parts, and add one part at intervals of 12 minutes. Under continuous stirring conditions, keep the temperature of the reaction system at 20 ° C for 1.5 hours. At this stage, t...

technical field

[0001] The invention belongs to the technical field of preparation of electrical materials, in particular to a method for preparing a nanometer graphene oxide in-situ reinforced copper chromium electrical contact material. Background technique

[0002] Copper-based composite materials are widely used as electrical contact materials due to their excellent properties such as high strength, high conductivity, and thermal stability. The copper-based composite material prepared by vacuum hot-pressing sintering method can comprehensively exert the excellent properties of copper and other materials, and improve the comprehensive performance of electrical contacts. Chromium has the characteristics of high melting point, high hardness and low cut-off value, and has a great affinity for oxygen, which ensures the good air suction capacity of the vacuum switch contact. Therefore, the copper-chromium contact material has a strong breaking capacity and is suitable for med...

Examples

preparation example Construction

[0035] A preparation method of nanometer graphene oxide in-situ strengthened copper chromium electrical contact material, the electrical contact material is prepared by improving the Hummers method to prepare graphene oxide, and then mixing the metal mixed powder with the graphene oxide suspension after ultrasonic dispersion , Freeze-dried and then vacuum-pressed and sintered. The preparation process specifically includes the following steps:

[0036] Step 1, preparation of graphene oxide nanosheets

[0037] ① According to the dosage ratio of 1-1.5g: 25-30ml: 0.5-1g: 6-9g, weigh high-purity graphite powder, concentrated sulfuric acid, sodium nitrate and potassium permanganate respectively, and set aside;

[0038] ②Add the concentrated sulfuric acid, sodium nitrate and graphite weighed in step ① into the three-necked flask in sequence, and keep the temperature of the reaction system at 0-5°C under constant stirring to carry out the first-stage reaction for 30-60min. At this stag...

Embodiment 1

[0055] A 0.1GO / Cu30Cr electrical contact material with a size of Φ50 mm×15 mm doped with 0.1% self-made graphene oxide was prepared.

[0056] The specific preparation method is:

[0057] Step 1, preparation of graphene oxide nanosheets

[0058] ①According to the dosage ratio of 1g:25ml:0.5g:6g, weigh high-purity graphite powder, concentrated sulfuric acid, sodium nitrate and potassium permanganate respectively, and set aside;

[0059] ②Add the concentrated sulfuric acid, sodium nitrate and graphite weighed in step ① into the three-necked flask in sequence, and keep the temperature of the reaction system at 3°C ​​for 30 minutes in the first stage of reaction under constant stirring, during which the graphite edge is gradually oxidized; Then, divide the potassium permanganate weighed in step ① into three parts, and add one part at intervals of 10 minutes. Under continuous stirring conditions, keep the temperature of the reaction system at 20 ° C for 2 hours. At this stage, the ...

Embodiment 2

[0075] A 0.3GO / Cu30Cr electrical contact material with a size of Φ50 mm×15 mm and doped with 0.3% graphene oxide was prepared.

[0076] The specific preparation method is:

[0077] Step 1, preparation of graphene oxide nanosheets

[0078] ① According to the dosage ratio of 1.5g: 30ml: 0.8g: 7g, weigh high-purity graphite powder, concentrated sulfuric acid, sodium nitrate and potassium permanganate respectively, and set aside;

[0079] ②Add the concentrated sulfuric acid, sodium nitrate and graphite weighed in step ① into the three-necked flask in turn, and keep the temperature of the reaction system at 0°C under constant stirring to carry out the first stage reaction for 50 minutes, during which the graphite edge is gradually oxidized; Then, divide the potassium permanganate weighed in step ① into three parts, and add one part at intervals of 12 minutes. Under continuous stirring conditions, keep the temperature of the reaction system at 20 ° C for 1.5 hours. At this stage, t...

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