Preparation method of CuCr50Te contact material with high resistance to welding

Abstract

The invention discloses a preparation method of a CuCr50Te contact material with high resistance to welding, comprising: weighing and mixing Cu and Cr in a ratio of 1:1 by weight, and then weighing and mixing Te in a copper-chromium mixture with a weight ratio of 0.003-0.6wt%; using the weighed raw material powder to prepare a consumable electrode rod, and then performing vacuum sintering degassing, arc melting, forging annealing, and machining to obtain the CuCr50Te contact material with high resistance to welding. The overall process design of the invention is reasonable. The CuCr50Te contact material prepared by vacuum consumable arc melting technology has good electrical and thermal conductivity while reducing the welding force of the CuCr material contact, achieving grain refinement and uniform distribution of components, reducing the material cutoff value, improving the material's voltage resistance, and enhancing the breaking current capability. In addition, the overall process of the invention is simple, and has the advantages of low process cost and short preparation process.

Description

Technical Field

[0001] The invention relates to the technical field of copper-chromium contact preparation, and in particular to a method for preparing a CuCr50Te contact material with high resistance to fusion welding. Background Art

[0002] As vacuum interrupters develop towards high voltage levels of 40.5kV, 72.5kV and even higher levels of 126kV and 252kV, as well as miniaturization, the contact materials are required to have higher stability during arcing, excellent breaking performance, low current cutoff value, as well as high voltage resistance, resistance to welding, high electrical conductivity, thermal conductivity and mechanical strength.

[0003] When designing materials, improving interrupting performance by modifying them to reduce metal vapor volatilization during the interruption process inevitably results in a higher cutoff current, which can cause overvoltage. Adding a third element with a low melting point to reduce the material's cutoff current also reduces its withstand voltage. Research has found that a particular electrical contact performance can be affected by one or more material parameters, and conversely, a single material performance parameter can affect several electrical performance parameters.

[0004] The relationship between the comprehensive performance and electrical performance of the contact is complex and interrelated, and the vacuum switch has very stringent requirements on the contact material. Moreover, some of the requirements are contradictory to the inherent physical properties of the contact material, which adds more difficulty to the design and manufacture of the contact material.

[0005] The addition of Te to CuCr contact materials is generally limited to materials with a Cr content below 40%. However, CuCr contact materials with high Cr contents exhibit strong arc extinguishing capabilities. Therefore, increasing the Cr content can lead to even better development of CuCr contact materials. Existing processes for preparing CuCr contact materials with high Cr contents suffer from complex, lengthy production cycles, high production costs, and uneven microstructures in the resulting copper-chromium contact materials. Therefore, a process for preparing CuCr contact materials with high Cr contents is urgently needed. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention provides a method for preparing a CuCr50Te contact material with high resistance to fusion welding.

[0007] The design scheme of the present invention is: a method for preparing a CuCr50Te contact material with high resistance to welding, comprising:

[0008] S1. Ingredients

[0009] Cu and Cr are weighed and mixed in a ratio of 1:1 by weight, and then Te is weighed and mixed in a ratio of 0.003 to 0.6 wt% of the copper-chromium mixture; wherein Cu is added in the form of copper powder, Cr is added in the form of chromium powder, and Te is added in the form of tellurium powder or CuTe alloy powder;

[0010] S2. Preparation of consumable electrode rods

[0011] S2-1, Mixing

[0012] The weighed raw material powders are placed in an automatic mixer and mixed with protective inert gas for 1 to 6 hours to obtain a uniformly mixed copper, chromium and tellurium powder;

[0013] S2-2, cold isostatic pressing

[0014] The uniformly mixed copper, chromium and tellurium powder is filled into a mold by an automatic powder loading machine, and then placed in a cold isostatic pressing device at a pressure of 80 to 500 MPa for 5 to 30 minutes to obtain a consumable electrode rod of a certain size;

[0015] S3, vacuum sintering

[0016] The consumable electrode rod is subjected to vacuum sintering and degassing in a vacuum sintering furnace;

[0017] S4. Arc Melting

[0018] The electrode rods after S3 vacuum sintering are melted in a vacuum consumable arc melting furnace and cooled to obtain ingots;

[0019] S5, forging annealing

[0020] The ingot in S4 is turned outward, the riser and the bottom plate are sawed off, and then forged and annealed to obtain a forged alloy ingot;

[0021] S6, machining

[0022] The alloy ingot described in S5 is processed into dimensions according to the requirements of the drawing to obtain a CuCr50Te contact material with high resistance to welding.

[0023] Furthermore, the copper powder in S1 adopts electrolytic copper powder or atomized copper powder, and the powder particle size is 30-150μm; the specific preparation process of the atomized copper powder is: placing the electrolytic copper plate in a vacuum induction melting furnace for smelting to obtain copper melt; then using an atomizing device to use argon as a gas source to atomize and make powder under the condition of an atomization pressure of 15-20MPa; wherein, the specific smelting process is: when the vacuum induction melting furnace is evacuated to P≤1Pa, the power is increased to 90-100kW at a rate of 10kW / min, and after the raw materials in the vacuum induction melting furnace are uniform, the power is reduced to 35-40kW and high-purity argon is filled into the furnace body at the same time so that the pressure rises to 0.1MPa, the argon is stopped, and the power is increased to 90kW at a rate of 20kW / min, and refined for 5min; the purity of the copper powder raw material is ensured to be greater than 99.7%.

[0024] Furthermore, the chromium powder in S1 is electrolytic chromium powder or aluminothermic reduced chromium powder, and the powder particle size is 20 to 100 μm; and the purity of the chromium powder raw material is ensured to be greater than 99.5%.

[0025] Furthermore, the CuTe alloy powder described in S1 is prepared by vacuum ball milling, and the powder particle size is 50 to 200 μm; the specific preparation process of the CuTe alloy powder is: tellurium powder and copper powder are placed in a planetary ball mill according to a weight percentage of 10 to 15:30 to 50, and ball milled for 40 to 50 hours at a ball-to-material ratio of 15 to 20:1, a rotation speed of 300 r / min and high-purity argon as a protective gas; ensuring that the purity of the tellurium powder raw material is ≥99.9%.

[0026] Furthermore, the S3 specifically comprises: placing the consumable electrode rod in a vacuum sintering furnace and keeping the temperature at 500-1080° C. for 1-30 minutes.

[0027] Furthermore, the S3 is specifically as follows: placing the consumable electrode rod in a vacuum sintering furnace, filling it with argon after vacuuming, vacuuming it again, heating it to 450-500°C at a rate of 50°C / min and keeping it warm for 1-2 minutes; then heating it to 800-100°C at a rate of 20°C / min and keeping it warm for 5-10 minutes.

[0028] Furthermore, the S4 is specifically as follows: placing the electrode rod vacuum-sintered in S3 in a vacuum consumable arc melting furnace, melting it under the conditions of a melting point current of 1.0 to 5KA and an arc voltage of 10 to 30V, and obtaining an ingot after cooling; and the number of short circuits during the melting process is ≤3 times, and the ambient temperature and humidity requirements are: temperature ≤30°C, humidity ≤60%RH.

[0029] Furthermore, the S5 specifically comprises: turning the ingot in S4, sawing off the riser and the bottom plate, and then forging at 500-1000° C., and then annealing at 600-1100° C. to obtain a forged alloy ingot.

[0030] Furthermore, the S5 needs to be preheated before forging; the preheating treatment is specifically: heating to 300°C at a rate of 30-50°C / min, keeping warm for 10-15 minutes, and then heating to the forging temperature at a rate of 10-20°C / min.

[0031] Compared with the prior art, the present invention has the following beneficial effects: the overall process design of the present invention is reasonable, and the CuCr50Te contact material prepared by vacuum consumable arc melting technology has good electrical and thermal conductivity while reducing the welding force of the CuCr material contact, achieving grain refinement and uniform distribution of components, reducing the material cutoff value, improving the material's voltage resistance, and enhancing the breaking current capability; and the overall process of the present invention is simple, with the advantages of low process cost and short preparation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a process flow chart of the present invention;

[0033] Figure 2 is a metallographic image (100×) of the CuCr50Te0.003 contact material prepared in Example 7;

[0034] Figure 3 is a metallographic image (100×) of the CuCr50Te0.001 contact material prepared in Example 8;

[0035] Figure 4 is a metallographic image (100×) of the CuCr50Te0.3 contact material prepared in Example 9;

[0036] Figure 5 This is a metallographic image (100×) of the CuCr50Te0.6 contact material prepared in Example 10. DETAILED DESCRIPTION

[0037] Example 1

[0038] like Figure 1 The method for preparing a CuCr50Te contact material with high resistance to welding is shown, comprising:

[0039] S1. Ingredients

[0040] Cu and Cr are weighed and mixed in a ratio of 1:1 by weight, and then Te is weighed and mixed in a ratio of 0.003 wt% to the weight of the copper-chromium mixture; wherein Cu is added in the form of copper powder, Cr is added in the form of chromium powder, and Te is added in the form of tellurium powder or CuTe alloy powder; the copper powder is electrolytic copper powder with a powder particle size of 30 to 150 μm; the chromium powder is electrolytic chromium powder or aluminothermic reduced chromium powder with a powder particle size of 20 to 100 μm; the CuTe alloy powder is prepared by vacuum ball milling with a powder particle size of 50 to 200 μm; the specific preparation process of the CuTe alloy powder is as follows: tellurium powder and copper powder in a ratio of 10:30 by weight are placed in a planetary ball mill, and ball milled for 40 hours at a ball-to-material ratio of 15:1, a rotation speed of 300 r / min, and high-purity argon as a protective gas;

[0041] S2. Preparation of consumable electrode rods

[0042] S2-1, Mixing

[0043] The weighed raw material powders were placed in an automatic mixer and stirred with protective inert gas for 1 hour to obtain a uniformly mixed copper, chromium and tellurium powder.

[0044] S2-2, cold isostatic pressing

[0045] The uniformly mixed copper, chromium and tellurium powder is filled into a mold by an automatic powder loading machine, and then placed in a cold isostatic pressing device at a pressure of 80 MPa for 30 minutes to obtain a consumable electrode rod of a certain size;

[0046] S3, vacuum sintering

[0047] Place the consumable electrode rod in a vacuum sintering furnace and keep it at 500℃ for 30 minutes;

[0048] S4. Arc Melting

[0049] The electrode rods after S3 vacuum sintering are placed in a vacuum consumable arc melting furnace and melted under the conditions of melting point current of 1.0KA and arc voltage of 10V. After cooling, ingots are obtained. The number of short circuits during the melting process is ≤3 times. The ambient temperature and humidity requirements are: temperature ≤30℃, humidity ≤60%RH.

[0050] S5, forging annealing

[0051] The S4 ingot is turned to the outer circle, the riser and the bottom plate are sawed off, and then it is forged at 500℃ and then annealed at 600℃ to obtain a forged alloy ingot;

[0052] S6, machining

[0053] The S5 alloy ingot is processed into dimensions according to the drawing requirements to obtain the CuCr50Te contact material with high resistance to welding.

[0054] Example 2

[0055] like Figure 1 The method for preparing a CuCr50Te contact material with high resistance to welding is shown, comprising:

[0056] S1. Ingredients

[0057] Cu and Cr are weighed and mixed in a ratio of 1:1 by weight, and then Te is weighed and mixed in a ratio of 0.1 wt% to the weight of the copper-chromium mixture; wherein Cu is added in the form of copper powder, Cr is added in the form of chromium powder, and Te is added in the form of tellurium powder or CuTe alloy powder; the copper powder is electrolytic copper powder with a powder particle size of 30 to 150 μm; the chromium powder is electrolytic chromium powder or aluminothermic reduced chromium powder with a powder particle size of 20 to 100 μm; the CuTe alloy powder is prepared by vacuum ball milling with a powder particle size of 50 to 200 μm; the specific preparation process of the CuTe alloy powder is as follows: tellurium powder and copper powder in a ratio of 15:50 by weight are placed in a planetary ball mill, and ball milled for 45 hours at a ball-to-material ratio of 18:1, a rotation speed of 300 r / min, and high-purity argon as a protective gas;

[0058] S2. Preparation of consumable electrode rods

[0059] S2-1, Mixing

[0060] The weighed raw material powders were placed in an automatic mixer and stirred with inert gas for 3 hours to obtain a uniformly mixed copper, chromium and tellurium powder.

[0061] S2-2, cold isostatic pressing

[0062] The uniformly mixed copper, chromium and tellurium powder is filled into a mold by an automatic powder loading machine, and then placed in a cold isostatic pressing device at a pressure of 200 MPa for 15 minutes to obtain a consumable electrode rod of a certain size;

[0063] S3, vacuum sintering

[0064] Place the consumable electrode rod in a vacuum sintering furnace and keep it at 800℃ for 10 minutes;

[0065] S4. Arc Melting

[0066] The electrode rods after S3 vacuum sintering are placed in a vacuum consumable arc melting furnace and melted under the conditions of melting point current of 3KA and arc voltage of 20V. After cooling, ingots are obtained. The number of short circuits during the melting process is ≤3 times. The ambient temperature and humidity requirements are: temperature ≤30℃, humidity ≤60%RH.

[0067] S5, forging annealing

[0068] The S4 ingot is turned to the outer circle, the riser and the bottom plate are sawed off, and then it is forged at 900℃ and then annealed at 800℃ to obtain a forged alloy ingot;

[0069] S6, machining

[0070] The S5 alloy ingot is processed into dimensions according to the drawing requirements to obtain the CuCr50Te contact material with high resistance to welding.

[0071] Example 3

[0072] like Figure 1 The method for preparing a CuCr50Te contact material with high resistance to welding is shown, comprising:

[0073] S1. Ingredients

[0074] Cu and Cr are weighed and mixed in a ratio of 1:1 by weight, and then Te is weighed and mixed in a ratio of 0.6 wt% to the copper-chromium mixture; wherein Cu is added in the form of copper powder, Cr is added in the form of chromium powder, and Te is added in the form of tellurium powder or CuTe alloy powder; the copper powder is electrolytic copper powder with a powder particle size of 150 μm; the chromium powder is electrolytic chromium powder or aluminothermic reduced chromium powder with a powder particle size of 100 μm; the CuTe alloy powder is prepared by vacuum ball milling with a powder particle size of 200 μm; the specific preparation process of the CuTe alloy powder is as follows: tellurium powder and copper powder in a ratio of 15:50 by weight are placed in a planetary ball mill, and ball milled for 50 hours at a ball-to-material ratio of 20:1, a rotation speed of 300 r / min, and high-purity argon as a protective gas;

[0075] S2. Preparation of consumable electrode rods

[0076] S2-1, Mixing

[0077] The weighed raw material powders were placed in an automatic mixer and stirred with protective inert gas for 6 hours to obtain a uniformly mixed copper, chromium and tellurium powder.

[0078] S2-2, cold isostatic pressing

[0079] The uniformly mixed copper, chromium and tellurium powder is filled into a mold by an automatic powder loading machine, and then placed in a cold isostatic pressing device at a pressure of 500 MPa for 5 minutes to obtain a consumable electrode rod of a certain size;

[0080] S3, vacuum sintering

[0081] Place the consumable electrode rod in a vacuum sintering furnace and keep it at 1080℃ for 1 minute;

[0082] S4. Arc Melting

[0083] The electrode rods after S3 vacuum sintering are placed in a vacuum consumable arc melting furnace and melted under the conditions of melting point current of 5KA and arc voltage of 30V. After cooling, ingots are obtained. The number of short circuits during the melting process is ≤3 times. The ambient temperature and humidity requirements are: temperature ≤30℃, humidity ≤60%RH.

[0084] S5, forging annealing

[0085] The S4 ingot is turned to a circle, the riser and bottom plate are sawed off, and then it is forged at 1000℃ and then annealed at 1100℃ to obtain a forged alloy ingot;

[0086] S6, machining

[0087] The S5 alloy ingot is processed into dimensions according to the drawing requirements to obtain the CuCr50Te contact material with high resistance to welding.

[0088] Example 4

[0089] The difference from Example 1 is that the copper powder uses atomized copper powder, and the powder particle size is 30 to 150 μm; the specific preparation process of the atomized copper powder is: placing an electrolytic copper plate in a vacuum induction melting furnace for smelting to obtain a copper melt; then using an atomizing device to use argon as a gas source to atomize and prepare powder under the condition of a gas atomization pressure of 15 MPa; wherein, the specific smelting process is: when the vacuum induction melting furnace is evacuated to P≤1Pa, the power is increased to 90 kW at a rate of 10 kW / min, and after the raw materials in the vacuum induction melting furnace are uniform, the power is reduced to 35 kW and high-purity argon is filled into the furnace body at the same time so that the pressure rises to 0.1 MPa, the argon filling is stopped, the power is increased to 90 kW at a rate of 20 kW / min, and refining is carried out for 5 minutes.

[0090] Example 5

[0091] The difference from Example 2 is that the copper powder uses atomized copper powder, and the powder particle size is 30 to 150 μm; the specific preparation process of the atomized copper powder is: placing an electrolytic copper plate in a vacuum induction melting furnace for smelting to obtain a copper melt; then using an atomizing device to use argon as a gas source to atomize and prepare powder under the condition of a gas atomization pressure of 18 MPa; wherein, the specific smelting process is: when the vacuum induction melting furnace is evacuated to P≤1Pa, the power is increased to 95 kW at a rate of 10 kW / min, and after the raw materials in the vacuum induction melting furnace are uniform, the power is reduced to 40 kW and high-purity argon is filled into the furnace body at the same time so that the pressure rises to 0.1 MPa, the argon filling is stopped, the power is increased to 90 kW at a rate of 20 kW / min, and refining is carried out for 5 minutes.

[0092] Example 6

[0093] The difference from Example 3 is that the copper powder uses atomized copper powder, and the powder particle size is 30 to 150 μm; the specific preparation process of the atomized copper powder is: placing an electrolytic copper plate in a vacuum induction melting furnace for smelting to obtain a copper melt; then using an atomizing device to use argon as a gas source to atomize and prepare powder under a gas atomization pressure of 20 MPa; wherein, the specific smelting process is: when the vacuum induction melting furnace is evacuated to P≤1Pa, the power is increased to 100 kW at a rate of 10 kW / min, and after the raw materials in the vacuum induction melting furnace are uniform, the power is reduced to 40 kW and high-purity argon is filled into the furnace body at the same time so that the pressure rises to 0.1 MPa, the argon filling is stopped, the power is increased to 90 kW at a rate of 20 kW / min, and refining is carried out for 5 minutes.

[0094] Example 7

[0095] A method for preparing a CuCr50Te contact material with high resistance to fusion welding, comprising:

[0096] S1. Ingredients

[0097] Cu and Cr are weighed and mixed in a ratio of 1:1 by weight, and then Te is weighed and mixed in a ratio of 0.003 wt% to the weight of the copper-chromium mixture; wherein Cu is added in the form of copper powder, Cr is added in the form of chromium powder, and Te is added in the form of tellurium powder or CuTe alloy powder; the copper powder is atomized copper powder with a powder particle size of 30 to 150 μm; the chromium powder is electrolytic chromium powder or aluminothermic reduced chromium powder with a powder particle size of 20 to 100 μm; the CuTe alloy powder is prepared by vacuum ball milling with a powder particle size of 50 to 200 μm; the specific preparation process of the CuTe alloy powder is as follows: tellurium powder and copper powder in a ratio of 10:30 by weight are placed in a planetary ball mill, and ball milled for 40 hours at a ball-to-material ratio of 15:1, a rotation speed of 300 r / min, and high-purity argon as a protective gas;

[0098] The specific preparation process of atomized copper powder is as follows: placing an electrolytic copper plate in a vacuum induction melting furnace for smelting to obtain a copper melt; then using an atomizing device with argon as the gas source at a gas atomization pressure of 15 MPa to atomize and prepare the powder;

[0099] The specific melting process is as follows: when the vacuum induction melting furnace is evacuated to P≤1Pa, the power is increased to 90kW at a rate of 10kW / min. After the raw materials in the vacuum induction melting furnace are uniform, the power is reduced to 35kW and high-purity argon is injected into the furnace body to increase the pressure to 0.1MPa. Then, the argon injection is stopped and the power is increased to 90kW at a rate of 20kW / min. Refining is continued for 5 minutes.

[0100] S2. Preparation of consumable electrode rods

[0101] S2-1, Mixing

[0102] The weighed raw material powders were placed in an automatic mixer and stirred with protective inert gas for 1 hour to obtain a uniformly mixed copper, chromium and tellurium powder.

[0103] S2-2, cold isostatic pressing

[0104] The uniformly mixed copper, chromium and tellurium powder is filled into a mold by an automatic powder loading machine, and then placed in a cold isostatic pressing device at a pressure of 80 MPa for 5 minutes to obtain a consumable electrode rod of a certain size;

[0105] S3, vacuum sintering

[0106] The consumable electrode rod was placed in a vacuum sintering furnace, vacuumed and filled with argon, vacuumed again and heated to 450°C at a rate of 50°C / min and kept at that temperature for 2 minutes; then heated to 800°C at a rate of 20°C / min and kept at that temperature for 10 minutes;

[0107] S4. Arc Melting

[0108] The electrode rods after S3 vacuum sintering are placed in a vacuum consumable arc melting furnace and melted under the conditions of melting point current of 1KA and arc voltage of 10V. After cooling, ingots are obtained. The number of short circuits during the melting process is ≤3 times. The ambient temperature and humidity requirements are: temperature ≤30℃, humidity ≤60%RH.

[0109] S5, forging annealing

[0110] The S4 ingot was turned, the riser and bottom plate were sawed off, and then heat treated; then forged at 500°C, and then annealed at 600°C to obtain a forged alloy ingot; wherein, the preheat treatment was specifically as follows: heating to 300°C at a rate of 30°C / min, holding at that temperature for 10 minutes, and then heating to the forging temperature at a rate of 10°C / min;

[0111] S6, machining

[0112] The S5 alloy ingot is processed into dimensions according to the drawing requirements to obtain the CuCr50Te contact material with high resistance to welding.

[0113] Example 8

[0114] The difference from Example 7 is that Cu and Cr are weighed and mixed in a ratio of 1:1 by weight, and then Te is weighed and mixed in a ratio of 0.01 wt % to the copper-chromium mixture.

[0115] Example 9

[0116] A method for preparing a CuCr50Te contact material with high resistance to fusion welding, comprising:

[0117] S1. Ingredients

[0118] Cu and Cr are weighed and mixed in a ratio of 1:1 by weight, and then Te is weighed and mixed in a ratio of 0.3 wt% to the weight of the copper-chromium mixture; wherein Cu is added in the form of copper powder, Cr is added in the form of chromium powder, and Te is added in the form of tellurium powder or CuTe alloy powder; the copper powder is atomized copper powder with a powder particle size of 30 to 150 μm; the chromium powder is electrolytic chromium powder or aluminothermic reduced chromium powder with a powder particle size of 20 to 100 μm; the CuTe alloy powder is prepared by vacuum ball milling with a powder particle size of 50 to 200 μm; the specific preparation process of the CuTe alloy powder is as follows: tellurium powder and copper powder in a ratio of 15:40 by weight are placed in a planetary ball mill, and ball milled for 45 hours at a ball-to-material ratio of 18:1, a rotation speed of 300 r / min, and high-purity argon as a protective gas;

[0119] The specific preparation process of atomized copper powder is as follows: placing an electrolytic copper plate in a vacuum induction melting furnace for smelting to obtain a copper melt; then using an atomizing device with argon as the gas source at a gas atomization pressure of 18 MPa to atomize and prepare the powder;

[0120] The specific melting process is as follows: when the vacuum induction melting furnace is evacuated to P≤1Pa, the power is increased to 95kW at a rate of 10kW / min. After the raw materials in the vacuum induction melting furnace are uniform, the power is reduced to 40kW and high-purity argon is injected into the furnace body to increase the pressure to 0.1MPa. Then, the injection of argon is stopped and the power is increased to 90kW at a rate of 20kW / min. Refining is continued for 5 minutes.

[0121] S2. Preparation of consumable electrode rods

[0122] S2-1, Mixing

[0123] The weighed raw material powders were placed in an automatic mixer and stirred with inert gas for 5 hours to obtain a uniformly mixed copper, chromium and tellurium powder.

[0124] S2-2, cold isostatic pressing

[0125] The uniformly mixed copper, chromium and tellurium powder is filled into a mold by an automatic powder loading machine, and then placed in a cold isostatic pressing device at a pressure of 300 MPa for 20 minutes to obtain a consumable electrode rod of a certain size;

[0126] S3, vacuum sintering

[0127] The consumable electrode rod was placed in a vacuum sintering furnace, vacuumed and filled with argon, vacuumed again and heated to 500°C at a rate of 50°C / min and kept at that temperature for 1 minute; then heated to 100°C at a rate of 20°C / min and kept at that temperature for 5 minutes;

[0128] S4. Arc Melting

[0129] The electrode rods after S3 vacuum sintering are placed in a vacuum consumable arc melting furnace and melted under the conditions of melting point current of 3KA and arc voltage of 25V. After cooling, ingots are obtained. The number of short circuits during the melting process is ≤3 times. The ambient temperature and humidity requirements are: temperature ≤30℃, humidity ≤60%RH.

[0130] S5, forging annealing

[0131] The S4 ingot was turned to a rounded shape, and after the riser and bottom plate were sawed off, it was heat treated. It was then forged at 950°C and annealed at 650°C to obtain a forged alloy ingot. The preheating treatment was as follows: heating to 300°C at a rate of 30°C / min, holding at that temperature for 15 minutes, and then heating to the forging temperature at a rate of 20°C / min.

[0132] S6, machining

[0133] The S5 alloy ingot is processed into dimensions according to the drawing requirements to obtain the CuCr50Te contact material with high resistance to welding.

[0134] Example 10

[0135] A method for preparing a CuCr50Te contact material with high resistance to fusion welding, comprising:

[0136] S1. Ingredients

[0137] Cu and Cr are weighed and mixed in a ratio of 1:1 by weight, and then Te is weighed and mixed in a ratio of 0.6 wt% to the weight of the copper-chromium mixture; wherein Cu is added in the form of copper powder, Cr is added in the form of chromium powder, and Te is added in the form of tellurium powder or CuTe alloy powder; the copper powder is atomized copper powder with a powder particle size of 30 to 150 μm; the chromium powder is electrolytic chromium powder or aluminothermic reduced chromium powder with a powder particle size of 20 to 100 μm; the CuTe alloy powder is prepared by vacuum ball milling with a powder particle size of 50 to 200 μm; the specific preparation process of the CuTe alloy powder is as follows: tellurium powder and copper powder in a ratio of 15:50 by weight are placed in a planetary ball mill, and ball milled for 50 hours at a ball-to-material ratio of 20:1, a rotation speed of 300 r / min, and high-purity argon as a protective gas;

[0138] The specific preparation process of atomized copper powder is as follows: placing an electrolytic copper plate in a vacuum induction melting furnace for smelting to obtain a copper melt; then using an atomizing device with argon as the gas source at a gas atomization pressure of 20 MPa to atomize and prepare the powder;

[0139] The specific melting process is as follows: when the vacuum induction melting furnace is evacuated to P≤1Pa, the power is increased to 100kW at a rate of 10kW / min. After the raw materials in the vacuum induction melting furnace are uniform, the power is reduced to 40kW and high-purity argon is injected into the furnace body to increase the pressure to 0.1MPa. Then, the injection of argon is stopped and the power is increased to 90kW at a rate of 20kW / min. Refining is continued for 5 minutes.

[0140] S2. Preparation of consumable electrode rods

[0141] S2-1, Mixing

[0142] The weighed raw material powders are placed in an automatic mixer and mixed with protective inert gas for 1 to 6 hours to obtain a uniformly mixed copper, chromium and tellurium powder;

[0143] S2-2, cold isostatic pressing

[0144] The uniformly mixed copper, chromium and tellurium powder is filled into a mold by an automatic powder loading machine, and then placed in a cold isostatic pressing device at a pressure of 500 MPa for 5 minutes to obtain a consumable electrode rod of a certain size;

[0145] S3, vacuum sintering

[0146] The consumable electrode rod was placed in a vacuum sintering furnace, vacuumed and filled with argon, vacuumed again and heated to 500°C at a rate of 50°C / min and kept at that temperature for 2 minutes; then heated to 100°C at a rate of 20°C / min and kept at that temperature for 10 minutes;

[0147] S4. Arc Melting

[0148] The electrode rods after S3 vacuum sintering are placed in a vacuum consumable arc melting furnace and melted under the conditions of melting point current of 5KA and arc voltage of 30V. After cooling, ingots are obtained. The number of short circuits during the melting process is ≤3 times. The ambient temperature and humidity requirements are: temperature ≤30℃, humidity ≤60%RH.

[0149] S5, forging annealing

[0150] The S4 ingot is turned, the riser and bottom plate are sawed off, and then heat treated; then forged at 1000℃, and then annealed at 1100℃ to obtain a forged alloy ingot; wherein, the preheat treatment is specifically: heating to 300℃ at a rate of 50℃ / min, holding at that temperature for 15 minutes, and then heating to the forging temperature at a rate of 20℃ / min;

[0151] S6, machining

[0152] The S5 alloy ingot is processed into dimensions according to the drawing requirements to obtain the CuCr50Te contact material with high resistance to welding.

[0153] Test example

[0154] The physical and chemical properties of the CuCr50Te contact materials prepared in Examples 1 to 10 were tested, and the specific test results are shown in Table 1. The microstructure of the CuCr50Te contact materials prepared in Examples 7 to 10 was observed, and the following results were obtained: Figures 2 to 5 Metallographic diagram of

[0155] Table 1: Physical and chemical properties test results of CuCr50Te contact materials prepared in Examples 1 to 10

[0156]

[0157]

[0158]

[0159] Conclusion: The CuCr50Te contact materials prepared in Examples 1 to 10 of the present invention all have good electrical and thermal conductivity, and the compressive strength of the materials is relatively good.

Claims

1. A method for preparing a CuCr50Te contact material with high resistance to welding, characterized in that: include: S1. Ingredients Cu and Cr are weighed and mixed in a ratio of 1:1 by weight, and then Te is weighed and mixed in a ratio of 0.003-0.6 wt% to the copper-chromium mixture; wherein Cu is added in the form of copper powder, Cr is added in the form of chromium powder, and Te is added in the form of tellurium powder or CuTe alloy powder; S2. Preparation of consumable electrode rods S2-1, Mixing The weighed raw material powders are placed in an automatic mixer and mixed with protective inert gas for 1 to 6 hours to obtain a uniformly mixed copper, chromium and tellurium powder; S2-2, cold isostatic pressing The uniformly mixed copper, chromium and tellurium powder is filled into a mold by an automatic powder loading machine, and then placed in a cold isostatic pressing device at a pressure of 80-500 MPa for 5-30 minutes to obtain a consumable electrode rod of a certain size. S3, vacuum sintering The consumable electrode rod is subjected to vacuum sintering and degassing in a vacuum sintering furnace; S4. Arc Melting The electrode rods after S3 vacuum sintering are melted in a vacuum consumable arc melting furnace and cooled to obtain ingots; S5, forging annealing The ingot in S4 is turned outward, the riser and the bottom plate are sawed off, and then forged and annealed to obtain a forged alloy ingot; S6, machining The alloy ingot described in S5 is processed into dimensions according to the drawing requirements to obtain a CuCr50Te contact material with high resistance to welding; S1 The copper powder adopts electrolytic copper powder or atomized copper powder, and the powder particle size is 30~150μm; the specific preparation process of the atomized copper powder is: placing the electrolytic copper plate in a vacuum induction melting furnace for smelting to obtain copper melt; then using an atomizing device to use argon as a gas source to atomize and prepare powder under the condition of a gas atomization pressure of 15~20MPa; wherein, the specific process of placing the electrolytic copper plate in a vacuum induction melting furnace for smelting is: when the vacuum induction melting furnace is evacuated to P≤1Pa, the power is increased to 90~100kW at a rate of 10kW / min, and after the raw materials in the vacuum induction melting furnace are uniform, the power is reduced to 35~40kW and high-purity argon is filled into the furnace body at the same time so that the pressure rises to 0.1MPa, the argon filling is stopped, the power is increased to 90kW at a rate of 20kW / min, and the refining is carried out for 5min; The chromium powder in S1 is electrolytic chromium powder or aluminothermic reduced chromium powder, and the powder particle size is 20-100 μm; The CuTe alloy powder in S1 is prepared by vacuum ball milling, and the powder particle size is 50-200 μm. The specific preparation process of the CuTe alloy powder is as follows: tellurium powder and copper powder are placed in a planetary ball mill at a weight percentage of 10-15:30-50, and the ball-to-material ratio is 15-20:1, and the ball milling is carried out at a speed of 300 r / min and high-purity argon as a protective gas for 40-50 hours; The S3 is specifically as follows: placing the consumable electrode rod in a vacuum sintering furnace, evacuating the furnace and then filling it with argon, evacuating the furnace again and heating it to 450-500°C at a rate of 50°C / min and keeping it warm for 1-2 minutes; then heating it to 800-1000°C at a rate of 20°C / min and keeping it warm for 5-10 minutes.

2. The method for preparing a CuCr50Te contact material with high resistance to welding according to claim 1, characterized in that: The S4 is specifically as follows: placing the electrode rod vacuum-sintered in S3 in a vacuum consumable arc melting furnace, melting it under the conditions of a melting point current of 1.0-5KA and an arc voltage of 10-30V, and obtaining an ingot after cooling; and the number of short circuits during the melting process is ≤3 times, and the ambient temperature and humidity requirements are: temperature ≤30°C, humidity ≤60%RH.

3. The method for preparing a CuCr50Te contact material with high resistance to welding according to claim 1, characterized in that: The S5 specifically includes: turning the ingot in S4, sawing off the riser and the bottom plate, and then forging at 500-1000° C., and then annealing at 600-1100° C. to obtain a forged alloy ingot.

4. The method for preparing a CuCr50Te contact material with high resistance to welding according to claim 3, characterized in that: The S5 needs to be preheated before forging; the preheating treatment is specifically: heating to 300°C at a rate of 30-50°C / min, keeping warm for 10-15 minutes, and then heating to the forging temperature at a rate of 10-20°C / min.

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