Method for effectively inhibiting copper ion migration in copper alloy

Abstract

The invention relates to the technical field of copper alloys, in particular to a method for effectively inhibiting copper ion migration in a copper alloy, which comprises the following steps: step 1, putting electrolytic copper with the purity of more than 99.9% into a smelting furnace for smelting, covering by using a covering agent, and obtaining a copper solution after smelting; 2, recycled copper alloy powder is put into the copper solution in batches, the interval time between two adjacent times of feeding is 20-40 min, the feeding amount is increased in sequence, and smelting is conducted for 20-40 min; 3, prefabricated palladium-lanthanum binary alloy, prefabricated palladium-cesium binary alloy, prefabricated palladium-indium binary alloy and metal palladium are put into the mixed copper solution in the step 2, and a copper alloy solution doped with rare earth elements is obtained; 4, the copper alloy solution is subjected to standing and then converter casting, according to the preparation method, by adding palladium and rare earth elements such as lanthanum, indium and cesium, the organization structure of the alloy can be improved, and therefore migration channels of copper ions are reduced, and the migration rate of the copper ions is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of copper alloys, and in particular to a method for effectively inhibiting the migration of copper ions in copper alloys. Background Art

[0002] Ion migration refers to the ionization of metals on a circuit board, such as copper, silver, and tin, under certain conditions. The metals migrate through the insulating layer to the other side under the influence of an electric field, causing a decrease in insulation performance. Ion migration occurs when a DC electric field is applied between the metals on either side of an insulator, causing them to become two electrodes. The anode ionizes and, under the influence of the electric field, migrates through the insulator to the other metal (the cathode), causing the insulator to become ionically conductive. Ion migration can degrade the insulation performance of the insulator and even cause it to become a conductor, resulting in a short circuit.

[0003] Copper-palladium alloys have excellent electrical and thermal conductivity, corrosion resistance, and stable contact resistance, enabling reliable electrical connections under diverse operating conditions. Therefore, they are often used in the manufacture of various electrical contact components, such as switches, relays, and connectors. However, the migration of copper ions within copper-palladium alloys can create a risk of short circuits, reducing the lifespan of the device. Therefore, we have developed a method to effectively inhibit copper ion migration in copper alloys to address this issue. Summary of the Invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a method for effectively inhibiting the migration of copper ions in copper alloys.

[0005] A method for effectively inhibiting copper ion migration in a copper alloy comprises the following steps:

[0006] Step 1: electrolytic copper with a purity greater than 99.9% is put into a smelting furnace for smelting, and covered with a covering agent to obtain a copper solution after smelting;

[0007] Step 2: Add recycled copper alloy powder to the copper solution in batches, with the interval between two adjacent additions being 20 to 40 minutes, and the addition amount increasing sequentially. After the addition is completed, smelting is performed for 20 to 40 minutes;

[0008] Step 3: adding a prefabricated palladium-lanthanum binary alloy, a prefabricated palladium-cesium binary alloy, a prefabricated palladium-indium binary alloy, and metallic palladium into the mixed copper solution of step 2, and smelting the mixture to obtain a copper alloy solution doped with rare earth elements;

[0009] Step 4: After the copper alloy solution is allowed to stand, it is cast in a converter.

[0010] In the step 1, the smelting temperature is 1150°C to 1220°C.

[0011] In step 2, recycled copper alloy powder is added to the copper solution in 2 to 4 times, the amount of copper alloy powder added for the first time is 2% to 5% of the initial mass of the copper solution, and the amount of copper alloy powder added subsequently is 1.2 to 2 times the amount added in the previous time.

[0012] In the step 3,

[0013] The preparation process of the prefabricated palladium-lanthanum binary alloy includes the following steps: placing metallic palladium with a purity greater than 99.9% into a vacuum medium-frequency melting furnace, adding metallic lanthanum with a purity greater than 99.9% into the vacuum medium-frequency melting furnace, melting at a temperature of 1600°C to 1650°C, and melting to obtain a palladium-lanthanum binary alloy; wherein the content of lanthanum in the palladium-lanthanum binary alloy is 5% to 20%;

[0014] The preparation process of the prefabricated palladium-indium binary alloy includes the following steps: placing metallic palladium with a purity greater than 99.9% into a vacuum medium-frequency melting furnace, adding metallic indium with a purity greater than 99.9% into the vacuum medium-frequency melting furnace, melting at a temperature of 1600°C to 1650°C, and melting to obtain a palladium-indium binary alloy; wherein the content of indium in the palladium-indium binary alloy is 2% to 10%;

[0015] The preparation process of the prefabricated palladium-cesium binary alloy includes the following steps: placing metallic palladium with a purity greater than 99.9% into a vacuum medium-frequency melting furnace, adding metallic cesium with a purity greater than 99.9% into the vacuum medium-frequency melting furnace, melting at a temperature of 1600°C to 1650°C, and melting to obtain a palladium-cesium binary alloy; wherein the content of cesium in the palladium-cesium binary alloy is 2% to 20%.

[0016] In step 3, the copper alloy solution obtained includes the following components in weight percentage: 0.3% to 3% of palladium, 0.02% to 0.05% of lanthanum, 0.003% to 0.005% of indium, 0.003% to 0.005% of cesium, and the rest are copper and impurities.

[0017] In the step 3, the total content of lanthanum, indium and cesium in the copper alloy solution obtained does not exceed 0.05%.

[0018] In step 4, the copper alloy solution is kept at a temperature of 1200° C. for a time of 10 to 15 minutes.

[0019] The content of each element in the recycled copper alloy powder is consistent with the content of each element in the copper alloy solution prepared in step 3.

[0020] The beneficial effects of the present invention are:

[0021] 1. The preparation method proposed in the present invention can improve the microstructure of the alloy by adding palladium and rare earth elements such as lanthanum, indium and cesium, thereby reducing the migration channels of copper ions and lowering the migration rate of copper ions.

[0022] 2. The preparation method proposed in the present invention adds recycled copper alloy powder to the copper solution in batches. On the one hand, the recycled copper alloy can be fully utilized and the use of raw materials can be saved. On the other hand, the content of palladium and rare earth elements in the copper solution is gradually increased, which can make the distribution of palladium and rare earth elements more uniform. When adding multiple times, the previously added palladium and rare earth elements can attract the subsequently added palladium and rare earth elements, so that the palladium and rare earth elements are evenly distributed. DETAILED DESCRIPTION

[0023] The present invention will be further explained below with reference to specific embodiments.

[0024] In Example 1, a method for effectively inhibiting the migration of copper ions in a copper alloy comprises the following steps:

[0025] Step 1: electrolytic copper with a purity greater than 99.9% is put into a smelting furnace for smelting, and covered with a covering agent to obtain a copper solution after smelting;

[0026] Step 2: Add recycled copper alloy powder to the copper solution in batches, with the interval between two adjacent additions being 20 minutes, and the addition amount increasing sequentially. After the addition is completed, smelting is carried out for 20 minutes;

[0027] Step 3: adding a prefabricated palladium-lanthanum binary alloy, a prefabricated palladium-cesium binary alloy, a prefabricated palladium-indium binary alloy, and metallic palladium into the mixed copper solution of step 2, and smelting the mixture to obtain a copper alloy solution doped with rare earth elements;

[0028] Step 4: After the copper alloy solution is allowed to stand, it is cast in a converter.

[0029] In step 1, the melting temperature is 1150°C.

[0030] In step 2, recycled copper alloy powder is added to the copper solution in two times. The amount of copper alloy powder added in the first time is 2% of the initial mass of the copper solution, and the amount of copper alloy powder added in the subsequent time is 1.2 times the amount added in the previous time.

[0031] In step 3,

[0032] The preparation process of the prefabricated palladium-lanthanum binary alloy includes the following steps: placing metallic palladium with a purity greater than 99.9% into a vacuum medium-frequency melting furnace, adding metallic lanthanum with a purity greater than 99.9% into the vacuum medium-frequency melting furnace, melting at a temperature of 1600°C, and melting to obtain a palladium-lanthanum binary alloy; wherein the content of lanthanum in the palladium-lanthanum binary alloy is 5%;

[0033] The preparation process of the prefabricated palladium-indium binary alloy includes the following steps: placing metallic palladium with a purity greater than 99.9% into a vacuum medium-frequency melting furnace, adding metallic indium with a purity greater than 99.9% into the vacuum medium-frequency melting furnace, melting at a temperature of 1600°C, and melting to obtain a palladium-indium binary alloy; wherein the content of indium in the palladium-indium binary alloy is 2%;

[0034] The preparation process of the prefabricated palladium-cesium binary alloy includes the following steps: placing metallic palladium with a purity greater than 99.9% into a vacuum medium-frequency melting furnace, adding metallic cesium with a purity greater than 99.9% into the vacuum medium-frequency melting furnace, and melting at a melting temperature of 1600°C to obtain a palladium-cesium binary alloy; wherein the content of cesium in the palladium-cesium binary alloy is 2%.

[0035] In step 3, the copper alloy solution obtained includes the following components in weight percentage: 0.3% palladium element, 0.02% lanthanum element, 0.003% indium element, 0.003% cesium element, and the rest is copper element and impurities.

[0036] In step 3, the total content of lanthanum, indium and cesium in the prepared copper alloy solution does not exceed 0.05%.

[0037] In step 4, the copper alloy solution is kept at a temperature of 1200° C. and a standing time of 10 minutes.

[0038] In Example 2, a method for effectively inhibiting copper ion migration in a copper alloy comprises the following steps:

[0039] Step 1: electrolytic copper with a purity greater than 99.9% is put into a smelting furnace for smelting, and covered with a covering agent to obtain a copper solution after smelting;

[0040] Step 2: Add recycled copper alloy powder to the copper solution in batches, with the interval between two adjacent additions being 40 minutes, and the addition amount increasing sequentially. After the addition is completed, smelting is carried out for 40 minutes;

[0041] Step 3: adding a prefabricated palladium-lanthanum binary alloy, a prefabricated palladium-cesium binary alloy, a prefabricated palladium-indium binary alloy, and metallic palladium into the mixed copper solution of step 2, and smelting the mixture to obtain a copper alloy solution doped with rare earth elements;

[0042] Step 4: After the copper alloy solution is allowed to stand, it is cast in a converter.

[0043] In step 1, the melting temperature is 1220°C.

[0044] In step 2, recycled copper alloy powder is added to the copper solution in 4 times, the amount of copper alloy powder added in the first time is 5% of the initial mass of the copper solution, and the amount of copper alloy powder added in subsequent times is 1.5 times the amount added in the previous time.

[0045] In step 3,

[0046] The preparation process of the prefabricated palladium-lanthanum binary alloy includes the following steps: placing metallic palladium with a purity greater than 99.9% into a vacuum medium-frequency melting furnace, adding metallic lanthanum with a purity greater than 99.9% into the vacuum medium-frequency melting furnace, melting at a temperature of 1650°C, and melting to obtain a palladium-lanthanum binary alloy; wherein the content of lanthanum in the palladium-lanthanum binary alloy is 20%;

[0047] The preparation process of the prefabricated palladium-indium binary alloy includes the following steps: placing metallic palladium with a purity greater than 99.9% into a vacuum medium-frequency melting furnace, adding metallic indium with a purity greater than 99.9% into the vacuum medium-frequency melting furnace, melting at a temperature of 1650°C, and melting to obtain a palladium-indium binary alloy; wherein the content of indium in the palladium-indium binary alloy is 10%;

[0048] The preparation process of the prefabricated palladium-cesium binary alloy includes the following steps: placing metallic palladium with a purity greater than 99.9% into a vacuum medium-frequency melting furnace, adding metallic cesium with a purity greater than 99.9% into the vacuum medium-frequency melting furnace, melting at a temperature of 1650°C, and melting to obtain a palladium-cesium binary alloy; wherein the content of cesium in the palladium-cesium binary alloy is 20%.

[0049] In step 3, the copper alloy solution obtained includes the following components in weight percentage: 3% palladium element, 0.042% lanthanum element, 0.003% indium element, 0.003% cesium element, and the rest is copper element and impurities.

[0050] In step 3, the total content of lanthanum, indium and cesium in the prepared copper alloy solution does not exceed 0.05%.

[0051] In step 4, the copper alloy solution is kept at a temperature of 1200° C. and a standing time of 15 minutes.

[0052] In Example 3, a method for effectively inhibiting copper ion migration in a copper alloy comprises the following steps:

[0053] Step 1: electrolytic copper with a purity greater than 99.9% is put into a smelting furnace for smelting, and covered with a covering agent to obtain a copper solution after smelting;

[0054] Step 2: Add recycled copper alloy powder to the copper solution in batches, with an interval of 30 minutes between two adjacent additions, and the amount of feeding increases sequentially. After the addition is completed, smelting is carried out for 30 minutes;

[0055] Step 3: adding a prefabricated palladium-lanthanum binary alloy, a prefabricated palladium-cesium binary alloy, a prefabricated palladium-indium binary alloy, and metallic palladium into the mixed copper solution of step 2, and smelting the mixture to obtain a copper alloy solution doped with rare earth elements;

[0056] Step 4: After the copper alloy solution is allowed to stand, it is cast in a converter.

[0057] In step 1, the melting temperature is 1200°C.

[0058] In step 2, recycled copper alloy powder is added to the copper solution in three times. The amount of copper alloy powder added in the first time is 4% of the initial mass of the copper solution, and the amount of copper alloy powder added in subsequent times is twice the amount added in the previous time.

[0059] In step 3,

[0060] The preparation process of the prefabricated palladium-lanthanum binary alloy includes the following steps: placing metallic palladium with a purity greater than 99.9% into a vacuum medium-frequency melting furnace, adding metallic lanthanum with a purity greater than 99.9% into the vacuum medium-frequency melting furnace, melting at a temperature of 1600°C, and melting to obtain a palladium-lanthanum binary alloy; wherein the content of lanthanum in the palladium-lanthanum binary alloy is 10%;

[0061] The preparation process of the prefabricated palladium-indium binary alloy includes the following steps: placing metallic palladium with a purity greater than 99.9% into a vacuum medium-frequency melting furnace, adding metallic indium with a purity greater than 99.9% into the vacuum medium-frequency melting furnace, melting at a temperature of 1630°C, and melting to obtain a palladium-indium binary alloy; wherein the content of indium in the palladium-indium binary alloy is 50%;

[0062] The preparation process of the prefabricated palladium-cesium binary alloy includes the following steps: placing metallic palladium with a purity greater than 99.9% into a vacuum medium-frequency melting furnace, adding metallic cesium with a purity greater than 99.9% into the vacuum medium-frequency melting furnace, melting at a temperature of 1630°C, and melting to obtain a palladium-cesium binary alloy; wherein the content of cesium in the palladium-cesium binary alloy is 10%.

[0063] In step 3, the copper alloy solution prepared includes the following components in weight percentage: 2% palladium element, 0.03% lanthanum element, 0.004% indium element, 0.004% cesium element, and the rest is copper element and impurities.

[0064] In step 3, the total content of lanthanum, indium and cesium in the prepared copper alloy solution does not exceed 0.05%.

[0065] In step 4, the copper alloy solution is kept at a temperature of 1200° C. and a standing time of 12 minutes.

[0066] In Examples 1-3, the contents of the elements in the recycled copper alloy powder are consistent with the contents of the elements in the copper alloy solution prepared in step 3. The recycled copper alloy powder is the powder produced by cutting and other operations during the subsequent processing of the copper alloy, which is obtained after washing and drying.

[0067] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for effectively inhibiting the migration of copper ions in a copper alloy, characterized in that: The following steps are involved: Step 1: electrolytic copper with a purity greater than 99.9% is put into a smelting furnace for smelting, and covered with a covering agent to obtain a copper solution after smelting; Step 2: Add recycled copper alloy powder to the copper solution in batches, with the interval between two adjacent additions being 20 to 40 minutes, and the addition amount increasing sequentially. After the addition is completed, smelting is performed for 20 to 40 minutes; Step 3: adding a prefabricated palladium-lanthanum binary alloy, a prefabricated palladium-cesium binary alloy, a prefabricated palladium-indium binary alloy, and metallic palladium into the mixed copper solution of step 2, and smelting the mixture to obtain a copper alloy solution doped with rare earth elements; Step 4: After the copper alloy solution is allowed to stand, it is cast in a converter.

2. The method for effectively inhibiting copper ion migration in a copper alloy according to claim 1, characterized in that: In the step 1, the smelting temperature is 1150°C to 1220°C.

3. The method for effectively inhibiting copper ion migration in a copper alloy according to claim 1, characterized in that: In step 2, recycled copper alloy powder is added to the copper solution in 2 to 4 times, the amount of copper alloy powder added for the first time is 2% to 5% of the initial mass of the copper solution, and the amount of copper alloy powder added subsequently is 1.2 to 2 times the amount added in the previous time.

4. The method for effectively inhibiting copper ion migration in a copper alloy according to claim 1, characterized in that: In the step 3, The preparation process of the prefabricated palladium-lanthanum binary alloy includes the following steps: placing metallic palladium with a purity greater than 99.9% into a vacuum medium-frequency melting furnace, adding metallic lanthanum with a purity greater than 99.9% into the vacuum medium-frequency melting furnace, melting at a temperature of 1600°C to 1650°C, and melting to obtain a palladium-lanthanum binary alloy; wherein the content of lanthanum in the palladium-lanthanum binary alloy is 5% to 20%; The preparation process of the prefabricated palladium-indium binary alloy includes the following steps: placing metallic palladium with a purity greater than 99.9% into a vacuum medium-frequency melting furnace, adding metallic indium with a purity greater than 99.9% into the vacuum medium-frequency melting furnace, melting at a temperature of 1600°C to 1650°C, and melting to obtain a palladium-indium binary alloy; wherein the content of indium in the palladium-indium binary alloy is 2% to 10%; The preparation process of the prefabricated palladium-cesium binary alloy includes the following steps: placing metallic palladium with a purity greater than 99.9% into a vacuum medium-frequency melting furnace, adding metallic cesium with a purity greater than 99.9% into the vacuum medium-frequency melting furnace, melting at a temperature of 1600°C to 1650°C, and melting to obtain a palladium-cesium binary alloy; wherein the content of cesium in the palladium-cesium binary alloy is 2% to 20%.

5. The method for effectively inhibiting copper ion migration in a copper alloy according to claim 4, characterized in that: In step 3, the copper alloy solution obtained includes the following components in weight percentage: 0.3% to 3% of palladium, 0.02% to 0.05% of lanthanum, 0.003% to 0.005% of indium, 0.003% to 0.005% of cesium, and the rest are copper and impurities.

6. The method for effectively inhibiting copper ion migration in a copper alloy according to claim 5, characterized in that: In the step 3, the total content of lanthanum, indium and cesium in the copper alloy solution obtained does not exceed 0.05%.

7. The method for effectively inhibiting copper ion migration in a copper alloy according to claim 5, characterized in that: In step 4, the copper alloy solution is kept at a temperature of 1200° C. for a time of 10 to 15 minutes.

8. The method for effectively inhibiting copper ion migration in a copper alloy according to claim 5, characterized in that: The content of each element in the recycled copper alloy powder is consistent with the content of each element in the copper alloy solution prepared in step 3.