Copper-aluminum-nickel alloy grounding material and preparation method thereof

Abstract

The invention discloses a copper-aluminum-nickel alloy grounding material and a preparation method thereof, and relates to the field of grounding materials.The copper-aluminum-nickel alloy grounding material is characterized by comprising, by mass, 5-9% of Ni, 6-9% of Al and the balance Cu; in the smelting process, firstly, electrolytic copper is molten, then cupronickel with the designed proportion is added, finally, pure aluminum is added, and after all the raw materials are molten and subjected to heat preservation for 1-3 min, the raw materials are poured into a mold to be cooled and demolded to obtain a cast ingot; the invention provides a novel copper alloy grounding material, and discusses the rule of the influence of the content of the Ni element on the performance of the novel copper alloy grounding material. The Cu-Al-Ni alloy with different Ni contents is subjected to microstructure observation, the influence of different Ni contents on the mechanical property is discussed, and the influence of the Ni contents on the corrosion property of the Cu-Al-Ni alloy is explored through an electrochemical polarization curve.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of grounding materials, in particular to a copper-aluminum-nickel alloy grounding material and a preparation method thereof. BACKGROUND

[0002] With the continuous improvement of the scale and voltage level of the power grid, the requirement for the safety of the power grid grounding is more and more strict, which puts forward higher requirements for the grounding material. The grounding material should adapt to different soil conditions, and its performance and service life are affected by factors such as soil temperature, water content, microorganisms, stray current and pH value. Therefore, the grounding material should meet the following requirements: good corrosion resistance, excellent electrical conductivity and certain strength and processability. At present, the grounding materials are mainly divided into metal type, non-metal type and other anti-corrosion processes. The non-metal grounding material is mainly flexible graphite composite material; the anti-corrosion process is to spray conductive anti-corrosion paint on the surface of the metal, and the paint mainly uses epoxy resin as the matrix and adds corresponding conductive fillers; the metal grounding material is widely used due to its good electrical conductivity, low price and easy processing and preparation, and mainly includes carbon steel, galvanized steel, copper-coated steel and stainless steel. At present, the most commonly used grounding material for the power grid is steel, especially galvanized steel, but since the plating layer of the galvanized steel is less than 0.1mm, it is quickly consumed under complex soil conditions, and has a limited service life, which is difficult to continuously ensure the safety and stability of the power grid.

[0003] The pH value of the soil has a great influence on the service life of the grounding material. Therefore, it is an urgent problem to be solved at present to develop a new type of grounding material with high corrosion resistance, low cost and long service life to ensure the long-term safe and stable operation of the power grid.

[0004] Pure copper has excellent electrical conductivity and corrosion resistance, and is an ideal metal for grounding material, but it is not widely used in grounding material due to the shortage of copper resources and high cost. SUMMARY

[0005] The present application aims to at least solve one of the problems in the prior art, and provides a copper-aluminum-nickel alloy grounding material and a preparation method thereof.

[0006] The technical solution of the present application is as follows:

[0007] A copper-aluminum-nickel alloy grounding material, comprising the following components by mass percentage: 5-9% Ni, 6-9% Al, and the balance of Cu.

[0008] Preferably, it comprises the following components by mass percentage: 7% Ni, 9% Al, and the balance of Cu.

[0009] The application further discloses a preparation method of the copper-aluminum-nickel alloy grounding material.

[0010] Preferably, 1-3wt% silicon, 0.5-1% magnesium, 0.05-0.1% manganese, 0.05-0.2wt% chromium, 0.001-0.1wt% rare earth elements and 0.5-1wt% nanoparticles are added in the melting process.

[0011] Preferably, the rare earth elements are yttrium and / or lanthanum.

[0012] Preferably, the nanoparticles are a mixture of 5-20nm tungsten disulfide and molybdenum disulfide.

[0013] Preferably, the mass addition ratio of the tungsten disulfide and the molybdenum disulfide is 1:1-3.

[0014] Preferably, the melting temperature is 800-1200 DEG C.

[0015] The application has the beneficial effects that the application provides a new copper alloy grounding material, and discusses the influence law of the content of the Ni element on the performance of the new copper alloy grounding material. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is an electrochemical test schematic diagram; (a) is a working electrode schematic diagram; (b) is an electrode system of an electrochemical workstation.

[0017] Figure 2 It is a metallographic photo of Cu-9Al-xNi alloy; (a) is 0Ni; (b) is 1Ni; (c) is 3Ni; (d) is 5Ni; (e) is 7Ni; (f) is 9Ni.

[0018] Figure 3 It is a micrograph of the alloy material, (a) and (b) are respectively SEM photos and EDS results of Cu-9Al-7Ni and Cu-9Al-9Ni alloys; (c) is an XRD spectrum of Cu-9Al-9Ni alloy.

[0019] Figure 4 It is a variation curve of microhardness of Cu-9Al-xNi alloy.

[0020] Figure 5Potentiodynamic polarization curves of Cu-9Al-xNi alloys in NaCl solution.

[0021] Figure 6 Surface morphologies of Cu-9Al-xNi alloys after corrosion in NaCl solution; (a): 0Ni, (b): INi, (c): 3Ni, (d): 5Ni, (e): 7Ni, (f): 9Ni.

[0022] Figure 7 Potentiodynamic polarization curves of Cu-9Al-xNi alloys in HCl solution.

[0023] Figure 8 Surface morphologies of Cu-9Al-xNi alloys after corrosion in HCl solution; (a): 0Ni, (b): INi, (c): 3Ni, (d): 5Ni, (e): 7Ni, (f): 9Ni.

[0024] Figure 9 Surface morphologies of Cu-9Al-7Ni alloy after corrosion in different solutions; (a): NaCl solution, (b): HCl solution.

[0025] Figure 10 Elemental distribution maps of different alloys, (a): Cu-9Al-7Ni, (b): Cu-9Al-9Ni. DETAILED DESCRIPTION

[0026] Embodiments of the present application are described in detail below. The embodiments described below are examples only and are not to be construed as limiting the present application. Unless otherwise defined, scientific and technical terms used in the embodiments are to be construed in accordance with the descriptions provided in the literature referred to herein or according to the commonly understood and accepted meanings as set forth herein. When terms are used in this disclosure and not explicitly defined, they shall be understood as taking their ordinary meaning.

[0027] Example 1

[0028] Cu-Al-Ni alloys with different Ni contents were prepared by non-vacuum melting using electrolytic copper blocks (purity 99.96%), industrial pure aluminum 1060 and B30 white copper (Cu-30Ni) as raw materials. In order to prevent the appearance of CuAl intermetallic phase which reduces the corrosion resistance of the alloy, the Al content was controlled within the maximum solid solubility of 9.4wt% according to the Cu-Al binary alloy phase diagram. In addition, considering the cost of power grid grounding materials, the Al content was selected as 9wt%, and 1%, 3%, 5%, 7% and 9% of Ni was added to the Cu-9Al alloy respectively to study the effect of different Ni contents on the microstructure and properties of Cu-9Al-xNi alloy. During the melting process, the electrolytic copper was first melted, then the B30 white copper with the designed ratio was added, and finally the pure aluminum and nickel were added. After the raw materials were completely melted (melting temperature was 1200℃), the ingot was poured into the mold for air cooling, and the ingot was obtained after demolding.

[0029] The ingot obtained by melting was cut into 10mm×10mm×5mm square samples, and then the sample surface was polished and polished using 600-2000 mesh SiC sandpaper in turn, and then polished using W1.0 diamond polishing paste until the sample surface was bright and had no obvious scratches. The sample was etched using a corrosion solution with a ratio of 5g FeCl3, 10mL HCl and 100ml H2O, and the sample was observed under an optical microscope (Leica, DMI8A), and the phase structure analysis of the alloy was carried out on an X-ray diffractometer (Bruker, D8 Advance). The field emission scanning electron microscope (Zeiss, GeminiSEM 300) equipped with an energy spectrometer (Oxford, ULTIM Max) was used to observe the surface morphology and element distribution of the sample. The Vickers hardness of the sample was tested using XHVT-30Z type Vickers hardness tester, load 50g, loading time 10s, and the hardness of 5 different positions of the sample was tested and the average value was taken as the test result.

[0030] At room temperature, the electrochemical workstation (CHI660E) was used to test the corrosion resistance of the sample, and 3.5wt% NaCl solution (pH=7) and pH=3 HCl solution were selected as test electrolyte respectively. The sample to be tested was welded with copper tail line and cold mounted with epoxy resin, and only 1cm 2 of the side surface to be exposed as the working electrode; the electrochemical test used a three-electrode system, the reference electrode was a saturated calomel electrode, and the auxiliary electrode was a platinum electrode. The electrochemical test schematic diagram is as Figure 1The open circuit potential (OCP) test was conducted for 30 min before the polarization curve test. The polarization curve was tested at a scanning rate of 1 mV / s in the range of ±250 mV of the open circuit potential after the open circuit potential was stable. In order to ensure the reliability of the experiment, the polarization curve test was repeated more than twice. After the electrochemical test, the surface morphology of the sample after corrosion was observed by scanning electron microscopy.

[0031] Test Example 1

[0032] (1) Microstructure of Cu-9Al-xNi alloy

[0033] The metallographic microstructure of Cu-9Al-xNi alloy is shown in Figure 2 . Figure 2 (a) is the microstructure of Cu-9Al alloy without adding Ni, at this time the alloy is mainly α-Cu phase, the grain size is about 70 μm, and short dendritic crystals appear in the structure, which should be CuAl intermediate phase. The metallographic structure of Cu-9Al-xNi alloy is shown in Figure 2 (b-f), the alloys with different Ni contents are composed of α main phase (light etching area) and β phase (dark etching area). With the increase of Ni content, the microstructure of the alloy changes obviously. In Cu-9Al-1Ni alloy, the α-Cu phase is a cluster formed by columnar crystals in different directions, and the β phase is a dark strip between the columnar crystals. When the addition amount of Ni is 3%, the microstructure of the alloy changes significantly compared with 1%, the grain boundary of the α matrix is not obvious, and the fine and discontinuous β phase is precipitated on the matrix. When the content of Ni is more than 3%, the volume fraction of black β phase increases obviously. In Cu-9Al-5Ni and Cu-9Al-9Ni alloys, the fully developed dendritic β phase is precipitated in the matrix, and the higher the content of Ni, the coarser the dendritic crystal. The microstructure of Cu-9Al-7Ni alloy is similar to that of Cu-9Al-3Ni, and the coarser β phase is precipitated at the grain boundary of the α matrix. Different Ni contents result in different alloy structures, which will have different effects on the corrosion performance of the alloy.

[0034] In order to study the composition of the β phase in the alloy, the Cu-Al-Ni alloys with Ni contents of 7% and 9% were observed by SEM and analyzed by EDS and XRD. Figure 3(a) and (b) show the SEM images and EDS point scan results of Cu-9Al-7Ni and Cu-9Al-9Ni alloys, respectively. The high-magnification image of the β phase shows that its morphology is mainly a multilayered structure along a certain direction, with substances of similar color to the α-Cu matrix distributed between the lamellae. To confirm the composition of each phase, EDS point scan analysis was performed on the lamellar (point 1), interlamellar (point 2), and matrix (point 3) regions. The results show that the elemental composition of the interlamellar and matrix regions is similar, indicating they are both α phases. However, the Al and Ni content on the lamellars is significantly higher, indicating they are β phases. This suggests that the β phase is distributed in a multilayered structure on the α matrix, and the numerous lamellar structures constitute the dendritic morphology observed at low magnification. Figure 2 ).

[0035] Furthermore, the energy dispersive spectroscopy (EDS) analysis results show that the contents of Cu, Al, and Ni in the α-Cu matrix are close to the designed composition of the alloy; the Al and Ni contents in the β phase are significantly higher than their proportions in the α phase, indicating that the β phase is some kind of intermediate compound composed of Al and Ni elements. Although the mass percentages of Al and Ni elements in the β phase differ between the Cu-9Al-7Ni and Cu-9Al-9Ni alloys, the atomic percentages of Al and Ni are close to 1:1, suggesting that the β phase is an AlNi compound. To further determine the composition of the β phase, XRD analysis was performed on the Cu-9Al-9Ni alloy, such as... Figure 3 As shown in (c), in addition to the α-Cu main phase, the β phase in the XRD pattern is an AlNi intermediate compound, and the phase composition is consistent with the EDS analysis results.

[0036] (2) Microhardness of Cu-9Al-xNi alloy

[0037] The microhardness of Cu-9Al-xNi alloy as a function of Ni content is shown in the following results. Figure 4 As shown, the Cu-9Al alloy has a hardness of 110 HV. With the addition of Ni, the hardness increases rapidly. When the Ni content is 1%, the hardness increases to 132 HV. Further increasing the Ni content results in a slower increase in hardness, reaching 148 HV for Cu-9Al-9Ni. The addition of Ni forms a solid solution and a strengthening phase (AlNi), refining the alloy's grain size. The combined effects of grain refinement, solid solution strengthening, and the second phase strengthening further enhance the alloy's performance. This property gives the alloy a certain load-bearing capacity in vertical grounding materials applications, which is beneficial for its use in practical engineering.

[0038] (3) Corrosion resistance of Cu-9Al-xNi alloy in NaCl solution

[0039] The electrochemical tests were used to study the effect of Ni content on the corrosion resistance of Cu-9Al-xNi alloys. Figure 5 The potentiodynamic polarization curves of Cu-9Al-xNi alloys with different Ni contents in 3.5wt% NaCl aqueous solution were shown in Table 1, and the corresponding fitting results were shown in Table 1. The self-corrosion potential corresponding to the horizontal coordinate of the polarization curve is related to the corrosion tendency. The more it moves to the positive direction, the weaker the corrosion tendency. From Table 1, it can be seen that the self-corrosion potential of Cu-9Al-7Ni alloy is obviously more positive, indicating that the alloy of this composition has the smallest tendency to corrode. However, the corrosion potential does not have a decisive effect on the corrosion rate, which is mainly determined by the corrosion current density. The smaller the corrosion current density, the better the corrosion resistance. Figure 5

[0040] From the corrosion current density, with the addition of Ni element, the corrosion current density of Cu-9Al-xNi alloy is smaller than that of Cu-9Al alloy, indicating that the addition of Ni can effectively improve the corrosion performance of the alloy in NaCl solution. According to the polarization curve fitting results in Table 1, when the addition amount of Ni is 7%, the corrosion current density and corrosion rate of the alloy are the lowest, which are 10.17μA / cm 2 and 0.1285mm / a, respectively, indicating that the Cu-9Al-7Ni alloy has the best corrosion resistance; followed by Cu-9Al-3Ni alloy, whose corrosion current density and corrosion rate are 13.58μA / cm 2 and 0.1722mm / a, respectively. From the microstructure of Cu-9Al-xNi alloy Figure 2 , it can be seen that the microstructure of Cu-9Al-3Ni and Cu-9Al-7Ni alloys is similar, both of which are composed of short and discontinuous β phase distributed at the grain boundaries, and the volume fraction of β phase is small. While the β phase in other component alloys develops completely, forming continuous dendrites, and the volume fraction is larger. It indicates that the corrosion behavior of Cu-9Al-xNi alloy preferentially occurs in the intermetallic phase, and the β phase will reduce the overall corrosion performance of the alloy.

[0041] Table 1 Fitting results of potentiodynamic polarization curves of Cu-9Al-xNi alloys in NaCl solution

[0042] Materials E corr mV]]> I corr μA / cm 2 ]]> Corr Rate mm / a Cu-9Al -307 29.05 0.3693 Cu-9Al-1Ni -324 23.83 0.3028 Cu-9Al-3Ni -309 13.58 0.1722 Cu-9Al-5Ni -324 17.95 0.2274 Cu-9Al-7Ni -299 10.17 0.1285 Cu-9Al-9Ni -316 21.26 0.2685

[0043] Figure 6 The SEM morphology of Cu-9Al-xNi alloy after electrochemical corrosion in NaCl solution. From the figure, it can be seen that the β phase of the alloy is preferentially corroded, and the corrosion gullies and pits are formed according to the morphology of the β phase, while the α phase is relatively smooth as a whole. In the alloy with Ni content not more than 3%, the β phase is mostly thin and narrow strip-shaped, and the corrosion occurs mainly in the β phase, forming long and deep corrosion gullies, such as Figure 6 ​(a-c). While when the Ni content is greater than 3%, the area of β phase in the alloy increases, and most of them are coarse dendritic, and in a relatively short corrosion time, only small corrosion pits and corrosion textures are formed on the surface of β phase, as shown in Figure 6 (d-f). The corrosion degree of the surface of Cu-9Al-7Ni alloy is the lowest, and only shallow corrosion lines appear; although the surface of Cu-9Al-3Ni alloy forms strip-shaped corrosion grooves, the corrosion area is not large due to the small amount of β phase; while the corrosion area of Cu-9Al-9Ni alloy is larger, and the corrosion texture is deeper, in addition, due to the higher content of Al and Ni in β phase, more Ni elements are left after dealuminization corrosion, and a dark corrosion morphology is presented. Overall, the surface corrosion morphology of the alloy is consistent with the fitting results of the electrochemical polarization curve.

[0044] (4) Corrosion resistance of Cu-9Al-xNi alloy in HCl solution

[0045] The effect of Ni content on the corrosion resistance of Cu-9Al-xNi alloy in acidic solution was studied in the same way. Figure 7 is the potentiodynamic polarization curve of Cu-9Al-xNi alloy in HCl solution with pH=3, and the corresponding fitting results are listed in Table 2. From Figure 7 It can be seen that, as in the NaCl solution, the self-corrosion potential of Cu-9Al-7Ni alloy in HCl solution is the largest, indicating that its corrosion tendency is the smallest.

[0046] From the fitting results of the polarization curve, when 1%-7% of Ni is added, the corrosion current density of Cu-9Al-xNi alloy in HCl solution is reduced compared with Cu-9Al alloy, the corrosion rate is slowed down, and the corrosion resistance is improved. Among them, the corrosion current density of Cu-9Al-7Ni alloy is the lowest, which is 4.316 μA / cm 2 , the corrosion rate is 0.0546 mm / a, and the corrosion rate of Cu-9Al-1Ni alloy is very close to it, and the corrosion resistance of these two alloys is the best. When the Ni content reaches 9%, the corrosion current density and corrosion rate of the alloy are larger than those of Cu-9Al alloy, and the corrosion resistance is poor. Therefore, the addition of Ni element is beneficial to improve the corrosion resistance of Cu-9Al-xNi alloy in HCl solution, but too much Ni will reduce the corrosion resistance of the alloy.

[0047] Table 2 Fitting results of potentiodynamic polarization curve of Cu-9Al-xNi alloy in HCl solution

[0048]

[0049]

[0050] Figure 8 The images show the surface SEM morphology of Cu-Al-Ni alloys after electrochemical etching in HCl solution. Compared to the corrosion morphology in NaCl solution, the corrosion of the alloy in acidic solution is more severe. Besides the severe etching of the β phase, forming deep grooves or pits, the α matrix is ​​also corroded to varying degrees. Wavy corrosion streaks appear on the surface of the Cu-Al alloy matrix, while the Ni-added alloy matrix shows pitting corrosion and corrosion pits, revealing the shape of the alloy grains as tetrahedral and irregularly shaped protrusions. The β phase on the alloy surface is almost completely etched, leaving corrosion traces with the same morphology as the β phase, such as grooves and pits formed along dendritic corrosion. The surface corrosion of the Cu-Al-Ni alloy is the most severe; after exfoliation etching, the β phase leaves a lamellar surface morphology, and some β phase corrosion products leave large corrosion pits due to detachment.

[0051] (5) Corrosion mechanism of Cu-9Al-xNi alloy

[0052] Copper alloys in neutral Cl-containing - When corrosion occurs in ionic solutions, the primary anodic reaction is the dissolution of copper to form CuCl2. - Ions, CuCl2 - The ions then undergo hydrolysis in the solution to form Cu₂O. If soaked for a prolonged period, Cu₂O will undergo further oxidation to form Cu(OH)₂ or Cu₂(OH)₃Cl. The reaction process is as follows:

[0053]

[0054] 2CuCl2 - +H₂O→Cu₂O+4Cl - +2H + (2)

[0055] Cu₂O + Cl - +2H₂O→Cu₂(OH)₃ Cl+H + +2e - (3)

[0056] like Figure 9 As shown, the Cu-9Al-7Ni alloy contains Cl - After being corroded in the solution, the α-Cu matrix is ​​subjected to Cl... - The erosion created corrosion pits of varying sizes on the surface. In neutral Cl-containing environments... - In a NaCl solution, the generated Cu₂O, Cu(OH)₂, or Cu₂(OH)₃Cl precipitates adhere to the alloy surface, hindering the absorption of Cl₂. - Further erosion of the newly formed surface after corrosion occurs, therefore the degree of corrosion on the alloy surface in neutral solution is relatively mild, such as...Figure 9 (a). While in acidic Cl - containing solution (HCl), the corrosion product Cu2(OH)3Cl is easily dissolved under acidic condition due to the presence of H + , which leads to the lack of effective protective layer on the alloy surface and makes the corrosion process continue, so the corrosion condition on the alloy surface is more severe, as shown in (b). Figure 9 (b).

[0057] Cu-Al-Ni alloy, in addition to the dissolution corrosion of Cu, Al element also occurs de-aluminization corrosion. When Cu continues to dissolve, the Al element on the surface of nickel aluminum bronze gradually increases, Al and Cl - complexing to form AlCl4 - , and then hydrolysis to form Al2O3, the reaction process is as follows:

[0058] Al + 4Cl - → AlCl4 - + 3e - (4)

[0059] AlCl4 - + 2H2O → Al2O3 + 4Cl - + 3H + (5)

[0060] In Cu-Al-Ni alloy, due to the higher content of Al element in β phase, de-aluminization corrosion preferentially occurs in β phase. Similar to the dissolution corrosion process of copper, in neutral NaCl solution, Al2O3 generated by de-aluminization corrosion can form a protective film with Cu2O or Cu(OH)2, which hinders the progress of the corrosion reaction, at this time the β phase in the alloy forms a shallow corrosion groove after de-aluminization corrosion. In hydrochloric acid solution, Al2O3 protective film cannot be formed, so the β phase in the alloy is severely de-aluminized, forming large and deep corrosion gullies and pits.

[0061] The addition of Ni element has a significant effect on improving the corrosion resistance of copper aluminum alloy, but the Ni element must be uniformly distributed in the alloy matrix, so as to effectively penetrate into the oxide film and enhance the corrosion resistance of the alloy. As can be seen from the figure, Figure 10 when the content of Ni does not exceed 7%, the Ni element in the alloy is uniformly distributed in the matrix, only a small amount of Ni is concentrated in the β phase; while in Cu-9Al-9Ni alloy, Ni and Al elements are mainly concentrated in the form of intermetallic compounds in β phase, and the content of Ni in the alloy matrix is relatively small. This excessive concentration of Al and Ni elements cannot form an effective protective film, but will exacerbate the de-aluminization process. Therefore, in Cu-9Al-xNi alloy, excessive addition of Ni element cannot improve the corrosion resistance of the alloy.

[0062] In summary, Cu-9Al-xNi alloys with different Ni contents were prepared by induction melting. The microstructure and composition of the alloys were uniform. The β phase was composed of lamellar structure dendrites. Analysis showed that the β phase was an AlNi compound, and the volume fraction of the β phase gradually increased with the increase of Ni content. The hardness of the alloy gradually increased with the increase of Ni content, and when the Ni content reached 9%, the microhardness of the alloy reached 148 HV.

[0063] Cu-9Al-xNi alloys have different corrosion resistance in 3.5wt% NaCl solution and pH=3 HCl solution. In NaCl solution, the addition of Ni element can effectively improve the corrosion resistance of Cu-9Al alloy, and the corrosion current density and corrosion rate of Cu-9Al-7Ni alloy are 10.17 μA / cm2 and 0.1285 mm / a, respectively. In HCl solution, when the content of Ni does not exceed 7%, the corrosion performance of the alloy is improved, and the corrosion rate of Cu-9Al-7Ni alloy is the lowest, which is 0.0546 mm / a. Considering the performance of the alloy and the complexity of the soil environment, Cu-9Al-7Ni alloy is more suitable as grounding material in acidic soil conditions in the south.

[0064] The corrosion of Cu-9Al-xNi alloy mainly includes Cu dissolution corrosion and dealuminization corrosion, of which dealuminization corrosion is the main one. In neutral salt solution, the corrosion products such as Cu2O and Al2O3 formed can act as a protective film to slow down the further corrosion of the alloy. In acidic solution, the alloy surface is more severely corroded because a stable oxide protective film cannot be formed. In Cu-9Al-9Ni alloy, Ni is concentrated in the β phase and cannot effectively penetrate into the oxide film to enhance corrosion resistance, resulting in a decrease in the corrosion resistance of the alloy.

[0065] Example 2

[0066] A method for preparing a copper-aluminum-nickel alloy grounding material, in the melting process, first melt the electrolytic copper, then add the designed proportion of cupronickel, and finally add pure aluminum and nickel. After the raw materials are completely melted, cool in the mold after holding for 3 min, and demold to get the ingot.

[0067] In the melting process, 2wt% silicon, 0.5% magnesium, 0.05% manganese, 0.05wt% chromium, 0.001wt% rare earth elements and 0.5wt% nanoparticles are also added to the electrolytic copper. The rare earth element is yttrium. The nanoparticles are a mixture of 10nm tungsten disulfide and molybdenum disulfide. The mass ratio of tungsten disulfide to molybdenum disulfide is 1:2. The melting temperature is 1200℃.

[0068] Comparative Example 1

[0069] Different from example 2, no silicon was added.

[0070] Comparative example 2

[0071] Different from example 2, no nanoparticles were added.

[0072] Comparative example 3

[0073] Different from example 2, no rare earth elements were added.

[0074] Comparative example 4

[0075] Different from example 2, no manganese was added.

[0076] Comparative example 5

[0077] Different from example 2, no magnesium was added.

[0078] Comparative example 6

[0079] Different from example 2, no chromium was added.

[0080] The above examples and comparative examples were tested for performance, specifically for corrosion resistance in a 3.5wt.% NaCl solution at 50°C, and the results are shown in Table 3.

[0081] Table 3 Performance test results of examples and comparative examples

[0082] Sample Corrosion Rate (mm / a) Example 2 0.0523 Comparative Example 1 0.0951 Comparative Example 2 0.1212 Comparative Example 3 0.0911 Comparative Example 4 0.0815 Comparative Example 5 0.1010 Comparative Example 6 0.1142

[0083] From the above table, it can be seen that the examples greatly improve the corrosion resistance of the alloy at high temperatures by adding silicon, magnesium, manganese, chromium, rare earth elements and nanoparticles to the alloy. Chromium refines the grains and forms a stable oxide film, which can hinder the penetration of corrosive media at high temperatures, greatly improving the corrosion resistance of the alloy at high temperatures. Manganese can inhibit crystallization and improve the corrosion resistance of the alloy; copper, magnesium and silicon can form a strengthening phase, which can improve the strength at high temperatures and enhance the corrosion resistance, but the amount of addition needs to be controlled to avoid intergranular corrosion; nanoparticles can improve the high temperature wear resistance of the alloy material, thereby improving its corrosion resistance.

[0084] The above examples only express the preferred embodiments of the present application, which are described in detail and specifically, but should not be construed as limiting the scope of the patent of the present application. It should be noted that for ordinary skilled in the art, other various corresponding changes and modifications can be made according to the above described technical solutions and concepts, and all of these changes and modifications should be within the scope of protection of the claims of the present application.

Claims

1. A copper-aluminum-nickel alloy grounding material, characterized by, Comprise the following mass percent components: 5-9% Ni, 6-9% Al, the balance is Cu.

2. The copper-aluminum-nickel alloy grounding material according to claim 1, characterized in that, Comprise the following mass percent components: 7% Ni, 9% Al, the balance is Cu.

3. A method of producing a copper-aluminum-nickel alloy grounding material, characterized by, In the melting process, first melt electrolytic copper, then add designed proportion of cupronickel, finally add pure aluminum and nickel, after the raw materials are completely melted, pour into the mold after 1-3 min of heat preservation for cooling, and get the ingot after demolding.

4. The method of claim 3, wherein the copper-aluminum-nickel alloy grounding material is prepared by the steps of: preparing a copper-aluminum-nickel alloy by mixing copper, aluminum, and nickel; and performing a heat treatment on the copper-aluminum-nickel alloy. In the melting process, also add 1-3wt% silicon, 0.5-1% magnesium, 0.05-0.1% manganese, 0.05-0.2wt% chromium, 0.001-0.1wt% rare earth elements and 0.5-1wt% nanoparticles to electrolytic copper.

5. The method of claim 3, wherein the copper-aluminum-nickel alloy grounding material is prepared by the steps of: preparing a copper-aluminum-nickel alloy by mixing copper, aluminum, and nickel; and performing a heat treatment on the copper-aluminum-nickel alloy. The rare earth elements are yttrium and / or lanthanum.

6. The method of claim 3, wherein the copper-aluminum-nickel alloy grounding material is prepared by the steps of: preparing a copper-aluminum-nickel alloy by mixing copper, aluminum, and nickel; and performing a heat treatment on the copper-aluminum-nickel alloy. The nanoparticles are a mixture of 5-20nm tungsten disulfide and molybdenum disulfide.

7. The method of claim 6, wherein the copper-aluminum-nickel alloy ground material is prepared by the steps of: preparing a copper-aluminum-nickel alloy material; and heat-treating the copper-aluminum-nickel alloy material at a temperature of 400 to 600°C for 1 to 10 hours. The mass addition ratio of tungsten disulfide and molybdenum disulfide is 1:1-3.

8. The method of claim 3, wherein the copper-aluminum-nickel alloy grounding material is prepared by the steps of: preparing a copper-aluminum-nickel alloy by mixing copper, aluminum, and nickel; and performing a heat treatment on the copper-aluminum-nickel alloy. The melting temperature is 800-1200℃.

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