Process method for improving pressure resistance of copper-chromium contact prepared from vacuum casting base material

Abstract

The invention belongs to the technical field of electrical materials, and discloses a process method for improving the pressure resistance of a copper-chromium contact prepared from a vacuum casting base material, which comprises the following steps: preparing a copper-chromium contact part and carrying out a pressure resistance test, recording a pressure resistance result, carrying out solid solution and aging treatment on the copper-chromium contact part, and obtaining the pressure resistance of the copper-chromium contact part. The copper-chromium contact part subjected to solid solution and aging treatment is subjected to accurate grinding treatment, the surface of the copper-chromium contact part subjected to ultrasonic treatment is covered with industrial alcohol, ultrasonic treatment is carried out, the copper-chromium contact part subjected to ultrasonic treatment is put into a temperature constant-temperature box to be dried, then a voltage withstanding test is carried out, and a voltage withstanding test result is recorded. Through solid solution aging, accurate grinding, ultrasonic treatment and drying treatment, the internal grain structure of the copper-chromium contact is homogenized, the surface roughness of the contact is obviously reduced, the surface quality of the contact is improved, the voltage withstanding level of a part is improved, the surface roughness is kept to be smaller than or equal to Ra2, and therefore the breakdown voltage of the part is improved.

Description

Technical Field

[0001] This invention belongs to the field of electrical materials technology, specifically relating to a process method for improving the voltage resistance of copper-chromium contacts prepared from vacuum-cast substrates. Background Technology

[0002] Vacuum circuit breakers rely on their copper-chromium moving and stationary contacts to connect and interrupt current. The breakdown performance of their gaps is closely related to the material composition, microstructure, component structure, shape, surface roughness, and cleanliness of the electrodes. Currently, most vacuum circuit breaker copper-chromium moving and stationary contacts are made from raw materials through vacuum casting and then machined. Their internal structure is relatively coarse and their surface is relatively rough. When interrupting the circuit, the arc is easy to start in the copper phase. The coarse internal structure results in relatively few arc-starting positions, and the local arc-starting current is large, which can easily cause burn-out. The rough surface may have protruding tips, which can easily cause discharge, resulting in a relatively low breakdown voltage during the interruption process. Summary of the Invention

[0003] The purpose of this invention is to provide a process method for improving the pressure resistance of copper-chromium contacts prepared from vacuum-cast substrates, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a process method for improving the pressure resistance of copper-chromium contacts prepared from vacuum-cast substrates, comprising the following steps:

[0005] S1: Manufacturing copper-chromium contact components;

[0006] S2: Perform a withstand voltage test on the copper-chromium contact components prepared in S1 under preset conditions and record the withstand voltage results;

[0007] S3: Under conditions exceeding the preset vacuum level, within the range of the first preset temperature, the copper-chromium contact components are subjected to solution treatment and aging for the first preset duration to homogenize the grain structure and improve their hardness and conductivity.

[0008] S4: Select the abrasive particle size and perform fine grinding on the copper-chromium contact parts after solution treatment and aging to reduce the surface roughness of the copper-chromium contact parts;

[0009] S5: Apply industrial alcohol to the surface of the ultrasonically treated copper-chromium contact parts to a depth of 10mm. Perform ultrasonic treatment on the finely ground copper-chromium contact parts for 10 minutes to remove foreign matter from the surface of the copper-chromium contact parts. After ultrasonic treatment, remove the copper-chromium contact parts using a wooden frame.

[0010] S6: After the copper-chromium contact components are removed, they are placed in a constant temperature oven at the second preset temperature and dried for the second preset time.

[0011] S7: Perform a pressure test under preset conditions and record the pressure test results.

[0012] Preferably, the copper-chromium contact components include CuCr25 contact components, CuCr30 contact components, CuCr35 contact components, CuCr40 contact components, CuCr45 contact components, and CuCr50 contact components.

[0013] Preferably, the preset vacuum degree includes 6×10 -3 Pa.

[0014] Preferably, the preset temperature includes 850℃ to 980℃.

[0015] Preferably, the first preset duration includes 4 hours.

[0016] Preferably, the second preset temperature includes 30±0.5℃.

[0017] Preferably, the second preset duration is 30 minutes.

[0018] Preferably, the foreign matter includes metal particle foreign matter and abrasive foreign matter.

[0019] Preferably, the preset conditions are a 4mm opening distance and a 1min test duration.

[0020] Preferably, the abrasive particle size is Ra2.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] This invention processes copper-chromium contacts through solution aging, fine grinding, ultrasonication, and drying to homogenize the internal grain structure of the copper-chromium contacts, significantly reduce the surface roughness of the contacts, improve their surface quality, and enhance the withstand voltage level of the components, maintaining a surface roughness ≤ Ra2, thereby increasing their breakdown voltage. Attached Figure Description

[0023] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Please see Figure 1 As shown, the present invention provides the following technical solution:

[0026] A process for improving the voltage resistance of copper-chromium contacts prepared from vacuum-cast substrates includes the following steps:

[0027] CuCr25 material was selected and produced by machining. The original surface roughness of the CuCr25 parts was 3.7μm.

[0028] Vacuum degree higher than 6×10 -3 Under Pa conditions, CuCr25 parts were subjected to solution treatment and aging for 4 hours within the range of 850℃~980℃ to homogenize the grain structure.

[0029] Fine grinding for 74 minutes yielded a surface roughness less than Ra1.58.

[0030] The parts are ultrasonically treated to remove foreign matter from the surface of the CuCr25 parts. Then, industrial alcohol is applied to the surface of the CuCr25 parts, with the alcohol level covering the parts by 10 mm. The parts are ultrasonically vibrated for 10 minutes. The parts are then removed with a wooden frame and placed in a constant temperature oven at 30±0.5℃ for 30 minutes to dry.

[0031] A withstand voltage test was conducted. The withstand voltage gap was 4mm, and the withstand voltage was 69kV for 1 minute, which was acceptable; 70kV was unacceptable.

[0032] A process for improving the voltage resistance of copper-chromium contacts prepared from vacuum-cast substrates includes the following steps:

[0033] CuCr30 material was selected and produced by machining. The original surface roughness of the CuCr30 parts was 3.8μm.

[0034] Vacuum degree higher than 6×10 -3 Under Pa conditions, CuCr30 parts were subjected to solution treatment and aging for 4 hours within the range of 850℃~980℃ to homogenize the grain structure.

[0035] Fine grinding for 85 minutes yielded a surface roughness less than Ra1.57.

[0036] The parts are ultrasonically treated to remove foreign matter from the surface of the CuCr30 parts. Then, industrial alcohol is applied to the surface of the CuCr30 parts, with the alcohol level covering the CuCr30 parts by 10 mm. The parts are ultrasonically vibrated for 10 minutes. Then, the parts are taken out with a wooden frame and placed in a constant temperature oven at 30±0.5℃ for drying for 30 minutes.

[0037] A withstand voltage test was conducted with a withstand voltage gap of 4mm and a withstand voltage of 75kV for 1 minute, which was acceptable; 76kV was unacceptable.

[0038] A process for improving the voltage resistance of copper-chromium contacts prepared from vacuum-cast substrates includes the following steps:

[0039] CuCr35 material was selected and produced by machining. The original surface roughness of the CuCr35 parts was 3.7μm.

[0040] Vacuum degree higher than 6×10 -3 Under Pa conditions, CuCr35 parts were subjected to solution treatment and aging for 4 hours within the range of 850℃~980℃ to homogenize the grain structure.

[0041] After 91 minutes of fine grinding, a surface roughness of less than Ra1.56 was obtained.

[0042] The CuCr35 parts are ultrasonically treated to remove foreign matter from their surface. Then, industrial alcohol is applied to the surface of the CuCr35 parts, with the alcohol level covering the parts by 10 mm. The parts are ultrasonically vibrated for 10 minutes. The parts are then removed using a wooden frame and placed in a constant temperature oven at 30±0.5℃ for 30 minutes to dry.

[0043] A withstand voltage test was conducted with a withstand voltage gap of 4mm and a withstand voltage of 78kV for 1 minute, which was acceptable; however, a withstand voltage of 79kV was unacceptable.

[0044] A process for improving the voltage resistance of copper-chromium contacts prepared from vacuum-cast substrates includes the following steps:

[0045] CuCr40 material was selected and CuCr40 parts were produced through machining. The original surface roughness of the CuCr40 parts was 3.6μm.

[0046] Vacuum degree higher than 6×10 -3 Under Pa conditions, CuCr40 parts were subjected to solution treatment and aging for 4 hours within the range of 850℃~980℃ to homogenize the grain structure.

[0047] Fine grinding for 120 minutes yields a surface roughness less than Ra1.56.

[0048] The CuCr40 parts are ultrasonically treated to remove foreign matter from their surface. Then, industrial alcohol is applied to the surface of the CuCr40 parts, with the alcohol level covering the parts by 10 mm. The parts are ultrasonically vibrated for 10 minutes. The parts are then removed using a wooden frame and placed in a constant temperature oven at 30±0.5℃ for 30 minutes to dry.

[0049] A withstand voltage test was conducted with a withstand voltage gap of 4mm and a withstand voltage of 82kV for 1 minute, which was acceptable; 83kV was unacceptable.

[0050] A process for improving the voltage resistance of copper-chromium contacts prepared from vacuum-cast substrates includes the following steps:

[0051] CuCr45 material was selected and produced by machining. The original surface roughness of the CuCr45 parts was 3.7μm.

[0052] Vacuum degree higher than 6×10 -3 Under Pa conditions, copper-chromium alloys are subjected to solution treatment and aging for 4 hours within the range of 850℃ to 980℃ to homogenize the grain structure.

[0053] Fine grinding for 141 minutes yielded a surface roughness less than Ra1.56.

[0054] The CuCr45 parts are ultrasonically treated to remove foreign matter from their surface. Then, industrial alcohol is applied to the surface of the CuCr45 parts, with the alcohol level covering the parts by 10 mm. The parts are ultrasonically vibrated for 10 minutes. The parts are then removed using a wooden frame and placed in a constant temperature oven at 30±0.5℃ for drying for 30 minutes.

[0055] A withstand voltage test was conducted with a withstand voltage gap of 4mm and a withstand voltage of 87kV for 1 minute, which was acceptable; 88kV was unacceptable.

[0056] A process for improving the voltage resistance of copper-chromium contacts prepared from vacuum-cast substrates includes the following steps:

[0057] CuCr50 material was selected and produced by machining. The original surface roughness of the CuCr50 parts was 3.4μm.

[0058] Vacuum degree higher than 6×10 -3 Under Pa conditions, CuCr50 was subjected to solution treatment and aging for 4 hours within the range of 850℃ to 980℃ to homogenize the grain structure.

[0059] Fine grinding for 120 minutes yields a surface roughness less than Ra1.56.

[0060] The CuCr50 parts are ultrasonically treated to remove foreign matter from their surface. Then, industrial alcohol is applied to the surface of the CuCr50 parts, with the alcohol level covering the parts by 10 mm. The parts are ultrasonically vibrated for 10 minutes. The parts are then removed using a wooden frame and placed in a constant temperature oven at 30±0.5℃ for 30 minutes to dry.

[0061] A withstand voltage test was conducted with a withstand voltage gap of 4mm and a withstand voltage of 93kV for 1 minute, which was acceptable; however, a withstand voltage of 94kV was unacceptable.

[0062] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A process for improving the pressure resistance of copper-chromium contacts prepared from vacuum-cast substrates, characterized in that: Includes the following steps: S1: Manufacturing copper-chromium contact components; S2: Perform a withstand voltage test on the copper-chromium contact components prepared in S1 under preset conditions and record the withstand voltage results; S3: Under conditions exceeding the preset vacuum level, within the range of the first preset temperature, the copper-chromium contact components are subjected to solution treatment and aging for the first preset duration to homogenize the grain structure and improve their hardness and conductivity. S4: Select the abrasive particle size and perform fine grinding on the copper-chromium contact parts after solution treatment and aging to reduce the surface roughness of the copper-chromium contact parts; S5: Apply industrial alcohol to the surface of the ultrasonically treated copper-chromium contact parts to a depth of 10mm. Perform ultrasonic treatment on the finely ground copper-chromium contact parts for 10 minutes to remove foreign matter from the surface of the copper-chromium contact parts. After ultrasonic treatment, remove the copper-chromium contact parts using a wooden frame. S6: After the copper-chromium contact components are removed, they are placed in a constant temperature oven at the second preset temperature and dried for the second preset time. S7: Perform a pressure test under preset conditions and record the pressure test results.

2. The process method for improving the pressure resistance of copper-chromium contacts prepared from vacuum-cast substrates according to claim 1, characterized in that: The copper-chromium contact components include CuCr25 contact components, CuCr30 contact components, CuCr35 contact components, CuCr40 contact components, CuCr45 contact components, and CuCr50 contact components.

3. The process method for improving the pressure resistance of copper-chromium contacts prepared from vacuum-cast substrates according to claim 1, characterized in that: The preset vacuum level includes 6×10 -3 Pa.

4. The process method for improving the pressure resistance of copper-chromium contacts prepared from vacuum-cast substrates according to claim 1, characterized in that: The preset temperature ranges from 850℃ to 980℃.

5. The process method for improving the pressure resistance of copper-chromium contacts prepared from vacuum-cast substrates according to claim 1, characterized in that: The first preset duration includes 4 hours.

6. The process method for improving the pressure resistance of copper-chromium contacts prepared from vacuum-cast substrates according to claim 1, characterized in that: The second preset temperature includes 30±0.5℃.

7. The process method for improving the pressure resistance of copper-chromium contacts prepared from vacuum-cast substrates according to claim 1, characterized in that: The second preset duration is 30 minutes.

8. The process method for improving the pressure resistance of copper-chromium contacts prepared from vacuum-cast substrates according to claim 1, characterized in that: The foreign matter includes metal particles and abrasive particles.

9. The process method for improving the pressure resistance of copper-chromium contacts prepared from vacuum-cast substrates according to claim 1, characterized in that: The preset conditions are a 4mm opening distance and a 1-minute test duration.

10. The process method for improving the pressure resistance of copper-chromium contacts prepared from vacuum-cast substrates according to claim 1, characterized in that: The abrasive particle size is Ra2.

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