High corrosion-resistant high-temperature oxidation-resistant copper alloy and preparation method thereof

Abstract

The application provides a high-corrosion-resistance high-temperature-resistant copper alloy and a preparation method thereof. Alloy elements and their weight percentage contents added during smelting of the alloy are as follows: Ni: 10%, Sn: 1%-5%, and the balance being Cu, forming a ternary copper alloy. Heat treatment is carried out in a protective atmosphere, a composite protective film with a certain thickness is formed on the surface to cover the alloy substrate, the alloy is protected, the further diffusion of harmful ions in a salt spray environment to the inside is inhibited, and the corrosion resistance of the copper alloy is improved. The ternary copper alloy is annealed by controlling the oxygen partial pressure atmosphere, including ultra-low oxygen partial pressure gas regulation and heat treatment, a composite oxidation film with a certain thickness of Ni and Sn elements is formed, the oxidation resistance is improved, no obvious surface oxidation phenomenon occurs at 600 DEG C for 12 hours, and the alloy can cope with more complex corrosion environments. The application has the advantages of simple and effective process, green and no pollution, and important significance for the development of modern metal materials.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal material corrosion prevention, in particular to a high-corrosion-resistance and high-temperature-oxidation-resistance copper alloy and a preparation method thereof. BACKGROUND

[0002] Copper is widely used in various fields due to its excellent electrical conductivity and high ductility, and has a very high value for the development of social economy and technology. Copper-nickel alloy is a copper-based alloy with good ductility, high hardness, beautiful color, corrosion resistance and deep drawing performance, which is widely used in marine engine condenser pipeline systems. Sn is an indispensable metal in modern industry, and has many applications in the metallurgical industry due to its corrosion resistance, and is known as "industrial monosodium glutamate". It is also a non-toxic green material, and has strong corrosion resistance to many gases and weak acids or weak bases, and has no effect on water, water vapor and carbon dioxide at room temperature.

[0003] However, with the increase of the breadth and depth of marine development, the basic role of materials is becoming more and more prominent. The traditional copper alloy cannot meet the demand of marine engineering for corrosion resistance of materials. The economic loss caused by marine corrosion is as high as 600-120 billion yuan per year, accounting for 2%-4% of the gross national product. In recent years, with the increasing demand for corrosion-resistant materials, improving the corrosion resistance of copper alloy has become a research hotspot. In addition, most of the packaging processes of integrated circuits are carried out at high temperatures, which inevitably leads to the oxidation of copper wire. Therefore, it is necessary to study the high-temperature oxidation resistance of copper. SUMMARY

[0004] The present application provides a high-corrosion-resistance and high-temperature-oxidation-resistance copper alloy and a preparation method thereof to solve the problem that the traditional copper alloy cannot meet the demand for corrosion resistance and high-temperature-oxidation resistance. The preparation method comprises the following steps:

[0005] Step 1: mix nickel, tin and copper as alloy raw materials, the mass fraction of nickel in the alloy raw material is 10%, and the mass fraction of tin is 1%-5%;

[0006] Step 2: put the alloy raw materials into the smelting tank in the electric arc smelting furnace, use titanium ingot as a standard deoxidizing sample, then perform gas washing operation on the furnace to make the oxygen concentration in the smelting furnace meet the smelting requirements, and finally introduce argon to balance the atmospheric pressure, so that the whole smelting process is in an argon protection environment;

[0007] Step 3: before smelting the alloy, first repeatedly smelt the titanium ingot to remove residual oxygen, and then smelt the alloy raw material to obtain an alloy ingot with uniform composition;

[0008] Step 4: Grind and polish the alloy obtained from smelting; then put it into acetone and alcohol for ultrasonic cleaning to remove surface impurities; then put the alloy into the electrolyte for electrolytic polishing, and then ultrasonically clean the electrolytic polished alloy with deionized water and ethanol respectively, and use filter paper to absorb the remaining liquid on the surface.

[0009] Step 5: Place the treated copper alloy sample into a tube furnace and purge the atmosphere inside the furnace at least three times. Then, perform heat treatment in a flowing H2 atmosphere, controlling the flow rate regulating valve of the hydrogen generator to maintain a flow rate of 60-70 cm⁻¹. 3 The oxygen partial pressure inside the tubular furnace is adjusted by controlling the flow rate valve of the hydrogen generator. The first stage of heat treatment is conducted at 500℃-800℃ for 240-1440 minutes, which is the protective film growth stage. After the protective film growth stage, the gas flow rate is reduced to 30-40 cm³ / min by controlling the flow rate regulating valve of the hydrogen generator. 3 The oxygen partial pressure in the atmosphere inside the tubular furnace is increased by 1 / min, and the heat treatment temperature is increased to 600℃-900℃. The second stage of heat treatment lasts for 120min-720min, which is the protective film enhancement stage. A protective atmosphere is introduced throughout the heat treatment process.

[0010] After heat treatment, the temperature is slowly reduced by programmed temperature control. The cooling rate is 1℃ / min when the temperature is above 600℃ and 2℃ / min when the temperature is below 600℃. After cooling to room temperature, a highly corrosion-resistant and high-temperature resistant copper oxide alloy is obtained.

[0011] Preferably, in step 1, the raw materials nickel and tin are in small particle form with a particle diameter ranging from 2 to 3 mm; the purity of the raw materials nickel, tin, and copper is not less than 99.99%.

[0012] Preferably, in step 2, the step of performing gas washing in the furnace is as follows: evacuating the furnace to 10... -1 A low vacuum of Pa was introduced, and high-purity argon gas was introduced until the pressure reached 10 Pa. 5 Repeat the above operation 5 times or more until all the oxygen in the smelting furnace is exhausted.

[0013] Preferably, in step 3, the titanium ingot is repeatedly smelted for more than 30 seconds each time, and smelted more than 8 times to remove residual oxygen in the smelting furnace; during the smelting of the alloy raw materials, the electromagnetic stirring of the smelting furnace is turned on, and the alloy is manually turned over by a metal spoon in the smelting furnace. After each turning, the titanium ingot needs to be remelted to remove the oxygen that escapes into the smelting furnace due to the movement of the metal spoon; each sample is smelted at least twice per side, each time for no less than 30 seconds.

[0014] Preferably, in step 4, the copper alloy is sequentially mechanically polished with 1000, 2000, 3000, and 5000 grit sandpaper to remove possible surface oxides and obtain a smooth surface, avoiding affecting the subsequent experimental results; the electrolyte is a mixed solution of phosphoric acid and ethanol, and the volume ratio of phosphoric acid, ethanol and deionized water is 2:2:1; the copper alloy sample is placed in the anode, and copper sheets are inserted on the left and right sides as cathodes to ensure uniform polishing of both sides of the sample.

[0015] Preferably, in step 5, the protective atmosphere can be high-purity hydrogen.

[0016] The working principle and beneficial effects of the present application are as follows:

[0017] In the present application, by adding nickel element (10wt%) and tin element (1wt%-5wt%) to pure copper raw materials, ternary copper alloy is formed by smelting, and then heat treatment is carried out in a protective atmosphere to form a composite protective film with a certain thickness on the surface to cover the alloy substrate and protect the alloy, inhibit the further diffusion of harmful ions in the salt spray environment to cause alloy corrosion, and greatly improve the corrosion resistance of the copper alloy.

[0018] In the present application, the ternary copper alloy formed is annealed by controlling the oxygen partial pressure atmosphere, including ultra-low oxygen partial pressure gas regulation and heat treatment process. The ternary copper alloy is first formed in a low-oxygen partial pressure protective atmosphere, so that the more active Ni and Sn elements preferentially form a composite oxide film, so that a more dense and stable protective layer is formed, and the diffusion of oxygen into the copper material in high-temperature environment is inhibited, which leads to the oxidation and corrosion of the copper material. The low-oxygen partial pressure protective atmosphere avoids the reaction of more Cu in some areas due to too high oxygen partial pressure, which leads to the decrease of the density and stability of the composite film.

[0019] The more active nickel and tin elements diffuse to the alloy surface during annealing to form a composite oxide film with a certain thickness of Ni and Sn elements, and then the oxygen partial pressure is adjusted to strengthen the protective film and form a more dense protective film. After 12 hours of oxidation at 600℃, no obvious surface oxidation occurs, so that the alloy can cope with more complex corrosion environments and its oxidation resistance is significantly improved.

[0020] The present application significantly enhances the corrosion resistance of the copper alloy, so that the alloy can cope with more complex corrosion environments, the shelf life is improved, the operation process is simple and easy to repeat, the production process is green, environmentally friendly and pollution-free, and can meet the industrial production requirements of copper consumables, which has important significance for the development of modern metal materials. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1Effect diagram of the present application comparative example 1 (1), example 1 (2), example 2 (3) and example 3 (4) after 15 days of salt spray test in the salt spray test machine;

[0022] Figure 2 Nyquist diagram of the present application comparative example 1 (1), example 1 (2), example 2 (3) and example 3 (4) after 15 days of salt spray test in the salt spray test machine;

[0023] Figure 3 Potentiodynamic polarization curve diagram of the present application comparative example 1 (1), example 1 (2), example 2 (3) and example 3 (4) after 15 days of salt spray test in the salt spray test machine;

[0024] Figure 4 SEM diagram of the present application comparative example 1 (1), example 1 (2), example 2 (3) and example 3 (4) after 15 days of salt spray test in the salt spray test machine;

[0025] Figure 5 Effect diagram of the present application comparative example 2 (1), comparative example 3 (2), comparative example 4 (3) and comparative example 5 (4) after 15 days of salt spray test in the salt spray test machine;

[0026] Figure 6 Effect diagram of the present application comparative example 2 (1), comparative example 3 (2), comparative example 4 (3) and comparative example 5 (4) after 600℃ 12h oxidation.

[0027] Figure 7 Effect diagram of the present application comparative example 1 (1), example 1 (2), example 2 (3) and example 3 (4) after 600℃ 12h oxidation. DETAILED DESCRIPTION

[0028] Example 1,

[0029] The embodiment provides a preparation method of a high corrosion-resistant high-temperature oxidation-resistant copper alloy, comprising the following steps:

[0030] Step 1: high-purity nickel particles (99.99%) and high-purity tin particles (99.99%) and pure copper (99.99%) are mixed as alloy raw materials, the mass fraction of nickel in the alloy raw material is 10%, and the mass fraction of tin is 1%;

[0031] Step 2: the alloy raw material is placed in the smelting tank in the electric arc smelting furnace, titanium ingot is used as a standard deoxidizing sample; then, gas washing operation is performed on the furnace, the furnace body is pumped to 10 -1 Pa low vacuum, high-purity argon is introduced to 10 5Pa, repeat the above operation more than 5 times to make the oxygen concentration in the smelting furnace reach the smelting required conditions, finally pass argon to balance atmospheric pressure, so that the whole process is in argon protection environment;

[0032] Step 3: Before melting the alloy, first repeatedly melt the titanium ingot, more than 30s each time, and melt for more than 8 times to remove residual oxygen; then melt the alloy raw material, melt twice on each side of each sample, 30s each time, to obtain an alloy ingot with uniform composition;

[0033] Step 4: The alloy obtained by melting is polished and polished; then it is ultrasonically cleaned in acetone and alcohol to remove surface impurities; then the alloy is placed in an electrolyte for electrolytic polishing, and the alloy after electrolytic polishing is ultrasonically cleaned with deionized water and ethanol, respectively, and the surface remaining liquid is absorbed with filter paper;

[0034] Step 5: Place the treated copper alloy sample in a tube furnace, and wash the gas in the tube furnace at least three times, then heat treat in a flowing H2 atmosphere, control the flow rate regulating valve of the hydrogen generator to adjust the oxygen partial pressure in the tube furnace; the flow rate is 60-70cm 3 / min; the first stage heat treatment temperature is 600℃, and the heat treatment time is 24h, which is the protective film growth stage; after the protective film growth stage, the gas flow rate is reduced by controlling the flow rate regulating valve of the hydrogen generator, so that the gas flow rate is 30-40cm 3 / min, the oxygen partial pressure is increased and the heat treatment temperature is increased to 700℃, and the heat treatment time is 12h, which is the protective film strengthening stage; a protective atmosphere is passed through the whole heat treatment process;

[0035] After heat treatment, the temperature is slowly reduced to room temperature by program control, and a high corrosion-resistant, high-temperature oxidation-resistant copper alloy is obtained.

[0036] Example 2,

[0037] The embodiment provides a preparation method of a high corrosion-resistant, high-temperature oxidation-resistant copper alloy, comprising the following steps:

[0038] Step 1: Mix high-purity nickel particles (99.99%) with high-purity tin particles (99.99%) and pure copper (99.99%) as alloy raw materials, the mass fraction of nickel in the alloy raw material is 10%, and the mass fraction of tin is 3%;

[0039] Step 2: Put the alloy raw materials into the smelting tank in the electric arc smelting furnace, and use titanium ingot as a standard deoxidizing sample; then wash the gas in the furnace, and the furnace body is pumped to 10 -1 Pa low vacuum, and pass high-purity argon to 10 5Pa, repeat the above operation more than 5 times to make the oxygen concentration in the melting furnace reach the conditions required for melting, and finally introduce argon gas to balance the atmospheric pressure so that the melting process is protected by argon gas throughout.

[0040] Step 3: Before melting the alloy, the titanium ingot is first repeatedly melted for more than 30 seconds each time, and the melting is repeated more than 8 times to remove residual oxygen; then the alloy raw materials are melted, and each sample is melted twice on each side, for 30 seconds each time, to obtain an alloy ingot with uniform composition.

[0041] Step 4: Grind and polish the alloy obtained from smelting; then put it into acetone and alcohol for ultrasonic cleaning to remove surface impurities; then put the alloy into the electrolyte for electrolytic polishing, and then ultrasonically clean the electrolytic polished alloy with deionized water and ethanol respectively, and use filter paper to absorb the remaining liquid on the surface.

[0042] Step 5: Place the treated copper alloy sample into a tube furnace and purge the atmosphere inside the furnace at least three times. Then, perform heat treatment in a flowing H2 atmosphere, controlling the flow rate regulating valve of the hydrogen generator to maintain a flow rate of 60-70 cm⁻¹. 3 The oxygen partial pressure inside the tubular furnace is adjusted by controlling the flow rate valve of the hydrogen generator. The first stage of heat treatment is at 600℃ for 24 hours, which is the protective film growth stage. After the protective film growth stage, the gas flow rate is reduced to 30-40 cm³ / min by controlling the flow rate regulating valve of the hydrogen generator. 3 / min, increase oxygen partial pressure and heat treatment temperature to 700℃, heat treatment time 12h, this stage is the protective film enhancement stage; protective atmosphere is introduced throughout the heat treatment process;

[0043] After heat treatment, the temperature is slowly reduced to room temperature under programmed temperature control to obtain a highly corrosion-resistant and high-temperature-resistant copper oxide alloy.

[0044] Example 3

[0045] This embodiment provides a method for preparing a highly corrosion-resistant and high-temperature-resistant copper oxide alloy, comprising the following steps:

[0046] Step 1: Mix high-purity nickel granules (99.99%), high-purity tin granules (99.99%), and pure copper (99.99%) as alloy raw materials. The mass fraction of nickel in the alloy raw materials is 10%, and the mass fraction of tin is 5%.

[0047] Step 2: Place the alloy raw materials together in the melting tank of the electric arc melting furnace, using titanium ingots as a standard deoxygenation sample; then perform a gas washing operation in the furnace, evacuating the furnace to 10... -1 A low vacuum of Pa was introduced, and high-purity argon gas was introduced until the pressure reached 10 Pa. 5Pa, and the oxygen concentration in the smelting furnace is made to reach the required conditions for smelting by repeating the above operation for more than 5 times. Finally, argon is introduced to balance the atmospheric pressure, so that the whole smelting process is in an argon protective environment.

[0048] Step 3: Before smelting the alloy, the titanium ingot is repeatedly smelted for more than 30s each time, and the residual oxygen is removed after smelting for more than 8 times. Then the alloy raw materials are smelted, and each sample is smelted twice on each side for 30s, so that the alloy ingot with uniform composition is obtained.

[0049] Step 4: The smelted alloy is polished and polished, then ultrasonic cleaned in acetone and alcohol to remove surface impurities, and then placed in an electrolyte for electrolytic polishing. The alloy after electrolytic polishing is ultrasonically cleaned with deionized water and ethanol respectively, and the surface remaining liquid is absorbed with filter paper.

[0050] Step 5: The treated copper alloy sample is placed in a tube furnace, and the atmosphere in the tube furnace is washed at least three times, and then heat treated in a flowing H2 atmosphere. The flow rate regulating valve of the hydrogen generator is controlled to adjust the oxygen partial pressure in the tube furnace, and the flow rate is adjusted to 60-70cm 3 / min. The first stage heat treatment temperature is 600℃, and the heat treatment time is 24h. This stage is the protective film growth stage. After the protective film growth stage, the flow rate regulating valve of the hydrogen generator is controlled to reduce the gas flow rate, so that the gas flow rate is 30-40cm 3 / min, the oxygen partial pressure is increased, and the heat treatment temperature is increased to 700℃, and the heat treatment time is 12h. This stage is the protective film strengthening stage. The protective atmosphere is introduced during the whole heat treatment process.

[0051] After the heat treatment, the temperature is slowly reduced to room temperature by programming, and a high corrosion-resistant and high-temperature-resistant copper alloy is obtained.

[0052] Comparative Example 1,

[0053] The preparation method of the copper alloy provided in the comparative example comprises the following steps:

[0054] Step 1: high-purity nickel particles (99.99%) and pure copper (99.99%) are mixed as alloy raw materials, and the mass fraction of nickel in the alloy raw materials is 10%;

[0055] Step 2: the alloy raw materials are placed in the smelting tank of the electric arc smelting furnace, and a titanium ingot is used as a standard deoxidizing sample. Then, the furnace is washed, and the furnace body is pumped to 10 -1 Pa, high-purity argon is introduced to 10 5 Pa, and the oxygen concentration in the smelting furnace is made to reach the required conditions for smelting by repeating the above operation for more than 5 times. Finally, argon is introduced to balance the atmospheric pressure, so that the whole smelting process is in an argon protective environment.

[0056] Step 3: Before melting the alloy, the titanium ingot is first repeatedly melted for more than 30s for more than 8 times to remove residual oxygen; then the alloy raw materials are melted, each sample is melted twice on each side for 30s, and an alloy ingot with uniform composition is obtained;

[0057] Step 4: The alloy obtained by melting is polished and polished; then it is placed in acetone and alcohol for ultrasonic cleaning to remove surface impurities; then the alloy is placed in an electrolyte for electrolytic polishing, and the alloy after electrolytic polishing is ultrasonically cleaned with deionized water and ethanol, respectively, and the surface remaining liquid is absorbed with filter paper;

[0058] Step 5: The treated copper alloy sample is placed in a tube furnace, and the atmosphere in the tube furnace is washed at least three times, and then heat treated in a flowing H2 atmosphere, the flow rate adjusting valve of the hydrogen generator is controlled to adjust the oxygen partial pressure in the tube furnace, the flow rate is 60-70cm3 / min; the first stage heat treatment temperature is 600℃, the heat treatment time is 24h, and this stage is the protective film growth stage; after the protective film growth stage, the flow rate adjusting valve of the hydrogen generator is controlled to reduce the gas flow rate, the gas flow rate is 30-40cm3 / min, the oxygen partial pressure is increased and the heat treatment temperature is increased to 700℃, the heat treatment time is 12h, and this stage is the protective film strengthening stage; protective atmosphere is passed throughout the heat treatment process;

[0059] After heat treatment, the temperature is slowly reduced to room temperature by program control, and a copper alloy which is not resistant to corrosion and easy to oxidize at high temperature is obtained.

[0060] Comparative Example 2:

[0061] The preparation method of the copper alloy provided in this comparative example comprises the following steps:

[0062] Step 1: Mix high-purity nickel particles (99.99%) and pure copper (99.99%) as alloy raw materials, the mass fraction of nickel in the alloy raw materials is 10%;

[0063] Step 2: Put the alloy raw materials into the melting tank in the arc melting furnace, use titanium ingot as a standard deoxidizing sample; then wash the furnace, draw the furnace body to 10 -1 Pa low vacuum, pass high-purity argon gas to 10 5 Pa, repeat the above operation for more than 5 times to make the oxygen concentration in the melting furnace meet the melting requirements, finally pass argon gas to balance atmospheric pressure, so that the whole melting process is in an argon protective environment;

[0064] Step 3: Before melting the alloy, first repeatedly melt the titanium ingot for more than 30s each time, and melt for more than 8 times to remove residual oxygen; then melt the alloy raw material, melt each sample twice on each side for 30s each time, to obtain a composition-uniform alloy ingot;

[0065] Step 4: The alloy obtained by melting is polished and polished; then it is ultrasonically cleaned in acetone and alcohol to remove surface impurities; then the alloy is placed in an electrolyte for electrolytic polishing, and the alloy after electrolytic polishing is ultrasonically cleaned with deionized water and ethanol respectively, and the surface remaining liquid is absorbed with filter paper; to obtain a copper alloy that is not resistant to corrosion and is easily oxidized at high temperature.

[0066] Comparative Example 3:

[0067] The preparation method of the copper alloy provided in this comparative example includes the following steps:

[0068] Step 1: Mix high-purity nickel particles (99.99%) with high-purity tin particles (99.99%) and pure copper (99.99%) as alloy raw materials, the mass fraction of nickel in the alloy raw material is 10%, and the mass fraction of tin is 1%;

[0069] Step 2: Put the alloy raw material into the melting tank in the arc melting furnace, use titanium ingot as a standard deoxidizing sample; then perform gas washing operation on the furnace, and the furnace body is pumped to 10 -1 Pa low vacuum, and high-purity argon gas is introduced to 10 5 Pa, repeat the above operation for more than 5 times to make the oxygen concentration in the melting furnace reach the required condition for melting, and finally introduce argon to balance the atmospheric pressure, so that the whole process is in an argon protection environment;

[0070] Step 3: Before melting the alloy, first repeatedly melt the titanium ingot for more than 30s each time, and melt for more than 8 times to remove residual oxygen; then melt the alloy raw material, melt each sample twice on each side for 30s each time, to obtain a composition-uniform alloy ingot;

[0071] Step 4: The alloy obtained by melting is polished and polished; then it is ultrasonically cleaned in acetone and alcohol to remove surface impurities; then the alloy is placed in an electrolyte for electrolytic polishing, and the alloy after electrolytic polishing is ultrasonically cleaned with deionized water and ethanol respectively, and the surface remaining liquid is absorbed with filter paper; to obtain a copper alloy that is not resistant to corrosion and is easily oxidized at high temperature.

[0072] Comparative Example 4:

[0073] The preparation method of the copper alloy provided in this comparative example includes the following steps:

[0074] Step 1: high-purity nickel particles (99.99%) are mixed with high-purity tin particles (99.99%) and pure copper (99.99%) as alloy raw materials, the mass fraction of nickel in the alloy raw materials is 10%, and the mass fraction of tin is 3%;

[0075] Step 2: the alloy raw materials are placed in the melting tank of the electric arc melting furnace, titanium ingots are used as standard oxygen removal samples, then the gas in the furnace is washed, the pressure in the furnace is reduced to 10 -1 Pa low vacuum, high-purity argon gas is introduced to 10 5 Pa, the above operation is repeated more than 5 times to make the oxygen concentration in the melting furnace meet the required conditions for melting, and finally argon gas is introduced to balance the atmospheric pressure, so that the whole process of melting is in an argon gas protection environment;

[0076] Step 3: before melting the alloy, the titanium ingots are repeatedly melted for more than 30s each time, and the residual oxygen is removed after 8 times of melting; then the alloy raw materials are melted, each sample is melted twice on each side for 30s each time, and a composition-uniform alloy ingot is obtained;

[0077] Step 4: the alloy obtained by melting is polished and polished; then it is ultrasonically cleaned in acetone and alcohol to remove surface impurities; then the alloy is placed in an electrolyte for electrolytic polishing, and the alloy after electrolytic polishing is ultrasonically cleaned with deionized water and ethanol respectively, and the surface remaining liquid is absorbed with filter paper; a copper alloy which is not resistant to corrosion and easy to oxidize at high temperature is obtained.

[0078] Comparative Example 5:

[0079] The preparation method of the copper alloy provided in the comparative example comprises the following steps:

[0080] Step 1: high-purity nickel particles (99.99%) are mixed with pure copper (99.99%) as alloy raw materials, the mass fraction of nickel in the alloy raw materials is 10%, and the mass fraction of tin is 5%;

[0081] Step 2: the alloy raw materials are placed in the melting tank of the electric arc melting furnace, titanium ingots are used as standard oxygen removal samples, then the gas in the furnace is washed, the pressure in the furnace is reduced to 10 -1 Pa low vacuum, high-purity argon gas is introduced to 10 5 Pa, the above operation is repeated more than 5 times to make the oxygen concentration in the melting furnace meet the required conditions for melting, and finally argon gas is introduced to balance the atmospheric pressure, so that the whole process of melting is in an argon gas protection environment;

[0082] Step 3: before melting the alloy, the titanium ingots are repeatedly melted for more than 30s each time, and the residual oxygen is removed after 8 times of melting; then the alloy raw materials are melted, each sample is melted twice on each side for 30s each time, and a composition-uniform alloy ingot is obtained;

[0083] Step 4: The smelted alloy is polished and polished; then it is ultrasonically cleaned in acetone and alcohol to remove surface impurities; then the alloy is placed in an electrolyte for electrolytic polishing, and the electrolytically polished alloy is ultrasonically cleaned with deionized water and ethanol, respectively, and the remaining liquid on the surface is absorbed with filter paper; thus a copper alloy which is not resistant to corrosion and is easily oxidized at high temperature is obtained.

[0084] The above examples and comparative examples are analyzed by experiments, and the following conclusions are drawn:

[0085] Referring to Figure 1 It can be seen that the comparative example 1 without adding Sn element has obvious corrosion phenomenon after 15 days of salt spray test in the salt spray machine, and copper green is generated on the surface, while the examples 1, 2 and 3 with Sn element do not have obvious corrosion phenomenon.

[0086] Referring to Figure 2 It can be seen that in the electrochemical impedance test results of the examples, the capacitive arc radius of the examples 1, 2 and 3 with Sn element is much larger than that of the comparative example 1 without Sn element, and the corrosion resistance is obviously improved.

[0087] Referring to Figure 3 It can be seen that in the potentiodynamic polarization curve test results of the examples, the self-corrosion potential of the examples 1, 2 and 3 with Sn element is more positive than that of the comparative example 1 without Sn element, the corrosion tendency is lighter, and the self-corrosion current is smaller than that of the comparative example 1 without Sn element, and the corrosion rate is smaller, and the corrosion resistance is obviously improved.

[0088] Referring to Figure 4 It can be seen that the corrosion degree of the matrix surface under the protective film of the examples 1, 2 and 3 with Sn element is slight, and there is no large and deep corrosion pit, and the surface of the example 3 has no obvious corrosion pit, while the matrix surface of the comparative example 1 without Sn element has corrosion pits of different sizes and depths, and the matrix is not effectively protected.

[0089] Referring to Figure 5 It can be seen that the comparative examples 2, 3, 4 and 5 without annealing treatment under the oxygen partial pressure atmosphere all have obvious corrosion phenomenon after 15 days of salt spray test in the salt spray machine, and large pieces of copper green appear.

[0090] Referring to Figure 6 It can be seen that the comparative examples 2, 3, 4 and 5 without annealing treatment are oxidized at 600 DEG C for 12 hours, and the surface appears blackening phenomenon visible to the naked eye.

[0091] Referring to Figure 7It can be seen that the surface of the alloys of Example 1, Example 2 and Example 3 after oxidation at 600℃ for 12h in oxygen atmosphere has no oxidation phenomenon and still maintains obvious metallic luster after annealing treatment by controlling oxygen partial pressure atmosphere; while the surface of the alloy of Comparative Example 1 without Sn element is obviously oxidized.

Claims

1. A method for preparing a highly corrosion-resistant and high-temperature oxidation-resistant copper alloy, characterized in that: Includes the following steps: Step 1: Mix nickel, tin and copper as alloy raw materials. The mass fraction of nickel in the alloy raw materials is 10%, and the mass fraction of tin is 1% to 5%. Step 2: Place the alloy raw materials together in the melting tank of the electric arc melting furnace, and use titanium ingots as standard deoxygenation samples; then perform gas washing operation in the furnace to make the oxygen concentration in the melting furnace reach the conditions required for melting, and finally introduce argon gas to balance atmospheric pressure so that the melting process is protected by argon gas throughout. Step 3: Before smelting the alloy, the titanium ingot is first repeatedly smelted to remove residual oxygen; then the alloy raw materials are smelted to obtain an alloy ingot with uniform composition. Step 4: Grind and polish the alloy obtained from smelting; then put it into acetone and alcohol for ultrasonic cleaning to remove surface impurities; then put the alloy into the electrolyte for electrolytic polishing, and then ultrasonically clean the electrolytic polished alloy with deionized water and ethanol respectively, and use filter paper to absorb the remaining liquid on the surface. Step 5: Place the treated copper alloy sample into a tube furnace and purge the atmosphere inside the furnace at least three times. Then, perform heat treatment in a flowing H2 atmosphere, controlling the flow rate regulating valve of the hydrogen generator to maintain a flow rate of 60-70 cm⁻¹. 3 The oxygen partial pressure inside the tubular furnace is adjusted by controlling the flow rate regulating valve of the hydrogen generator to maintain a gas flow rate of 30-40 cm / min. The first stage of heat treatment involves a temperature of 500℃-800℃ and a treatment time of 240-1440 min. 3 The oxygen partial pressure inside the tubular furnace is increased by 1 / min, and the heat treatment temperature is increased to 600℃-900℃. The heat treatment time is 120min-720min. A protective atmosphere is introduced throughout the heat treatment process. After heat treatment, the temperature is slowly reduced by programmed temperature control until it reaches room temperature, resulting in a highly corrosion-resistant and high-temperature-resistant copper oxide alloy.

2. The method for preparing a high corrosion-resistant and high-temperature oxidation-resistant copper alloy according to claim 1, characterized in that: In step 1, the raw materials nickel and tin are both in granular form, with a particle diameter ranging from 2 to 3 mm; the purity of the raw materials nickel, tin, and copper is not less than 99.99%.

3. The method for preparing a high corrosion-resistant and high-temperature oxidation-resistant copper alloy according to claim 1, characterized in that: Step 2, the procedure for washing the gas inside the furnace is as follows: evacuate the furnace to 10... -1 A low vacuum of Pa was introduced, and high-purity argon gas was introduced until the pressure reached 10 Pa. 5 Repeat the above operation 5 times or more until all the oxygen in the smelting furnace is exhausted.

4. The method for preparing a high corrosion-resistant and high-temperature oxidation-resistant copper alloy according to claim 1, characterized in that: In step 3, the titanium ingot is repeatedly smelted for more than 30 seconds each time, and smelted more than 8 times to remove residual oxygen in the smelting furnace. During the smelting of the alloy raw materials, the electromagnetic stirring of the smelting furnace is turned on, and the alloy is manually turned over by a metal spoon in the smelting furnace. After each turning, the titanium ingot needs to be remelted to remove the oxygen that escaped into the smelting furnace due to the movement of the metal spoon. Each sample is smelted at least twice per side, and each time for no less than 30 seconds.

5. The method for preparing a high corrosion-resistant and high-temperature oxidation-resistant copper alloy according to claim 1, characterized in that: In step 4, the copper alloy is mechanically polished with 1000, 2000, 3000, and 5000 grit sandpaper in sequence to remove any oxides that may be present on the surface, resulting in a smooth and flat surface to avoid affecting the subsequent experimental results. The electrolyte is a mixed solution of phosphoric acid and ethanol, with a volume ratio of phosphoric acid:ethanol:deionized water of 2:2:

1. The copper alloy sample is placed in the anode, and copper sheets are inserted on the left and right sides as cathodes to ensure that both sides of the sample are polished evenly.

6. The method for preparing a high corrosion-resistant and high-temperature oxidation-resistant copper alloy according to claim 1, characterized in that: In step 5, the first stage heat treatment temperature is 600℃ and the heat treatment time is 1440 min; the second stage heat treatment temperature is 700℃ and the heat treatment time is 720 min; the protective atmosphere is high-purity hydrogen.

7. The method for preparing a high corrosion-resistant and high-temperature oxidation-resistant copper alloy according to claim 1, characterized in that: In step 5, the cooling rate is: 1℃ / min when the temperature is above 600℃; and 2℃ / min when the temperature is below 600℃.

8. A high corrosion-resistant and high-temperature resistant copper oxide alloy, prepared according to any one of claims 1-7.

Images