Cu-Ag-Zn series joint coating material with low Zn loss and preparation method of Cu-Ag-Zn series joint coating material

Abstract

The invention provides a Cu-Ag-Zn series joint coating material with low Zn loss and a preparation method of the Cu-Ag-Zn series joint coating material, and belongs to the technical field of jewelry joint coating materials. The preparation method comprises the following steps: putting Cu, Ag, Ge, In and Sn particles into a furnace, smelting at 1100-1180 DEG C until a matrix is completely in a liquid state, then cooling the melt to 880-900 DEG C, adding Zn and borax, and finishing smelting; and after the smelted joint coating material is polished, the joint coating material is put into an anti-corrosion solution prepared by uniformly mixing benzotriazole, hydrogen peroxide, sodium silicate, sodium molybdate, fatty alcohol-polyoxyethylene ether and deionized water to be soaked, and the low-Zn-loss Cu-Ag-Zn series joint coating material is obtained. According to the preparation method, Zn is basically not consumed in the smelting preparation process, the oxidation resistance of the joint coating material is remarkably improved, the prepared joint coating material can be exposed in air for more than one year without an obvious color change phenomenon, the problem of oxidation color change is avoided, and the use benefit and economical efficiency of the material are improved.

Description

Technical Field

[0001] This application relates to the field of jewelry repair materials technology, specifically to a Cu-Ag-Zn based repair material with low Zn loss and its preparation method. Background Technology

[0002] With the continuous development of jewelry manufacturing technology and the increasing demands of consumers for jewelry quality, K gold jewelry has become a widely used material in the jewelry industry due to its diverse colors, moderate hardness, and high cost performance.

[0003] The manufacture of karat gold jewelry typically requires the melting of molten gold alloys with finishing materials to ensure the alloy's melting point, formability, and appearance quality. In traditional jewelry manufacturing processes, commonly used red finishing materials are mostly copper-silver-zinc (Cu-Ag-Zn) alloys. These alloys are widely used in the processing of gold alloys due to their good wettability and low melting point.

[0004] However, existing Cu-Ag-Zn alloy materials face certain technical bottlenecks. While their low melting point makes them easy to handle, their oxidation resistance is poor. After prolonged exposure to air, the alloys are prone to oxidation and discoloration, resulting in noticeable black spots or discoloration. This not only affects the aesthetic appearance of the jewelry but also alters the material's composition, thus impacting its quality and lifespan.

[0005] Existing Cu-Ag-Zn series smelting alloys and gold have high melting points, and zinc is easily lost during the smelting process, leading to unstable material composition, greater smelting difficulty, and affecting the performance and economic benefits of the alloy.

[0006] Therefore, there is an urgent need for an improved jointing material and its preparation process to enhance the oxidation resistance of Cu-Ag-Zn alloys, slow down their oxidation and discoloration, and ensure their stability during prolonged exposure to air. In particular, existing preparation methods have not yet provided a Cu-Ag-Zn alloy jointing material with good oxidation resistance and the ability to maintain stable appearance over a long period, especially considering the need to reduce zinc loss and improve overall material performance.

[0007] Application content In view of the technical problems existing in the background art, this application provides a Cu-Ag-Zn-based filler material with low Zn loss and its preparation method. The method achieves a Zn loss of only 0.41-1.7% during the smelting and preparation process by optimizing the composition ratio and subsequent processing method, that is, there is basically no loss. Moreover, the oxidation resistance of the alloy is significantly improved, so that it can be exposed to air for more than a year without obvious discoloration, avoiding the problem of oxidation and discoloration, while reducing zinc loss and improving the efficiency and economy of the material.

[0008] In a first aspect, embodiments of this application provide a method for preparing a Cu-Ag-Zn-based patching material with low Zn loss, the specific steps of which are as follows: S1 is prepared according to the following mass percentages: copper 75-95%, silver 3-20%, zinc 1-4%, germanium 0.01-0.1%, indium 0.4-1%, and tin 0.01%. First, Cu, Ag, Ge, In, and Sn particles are added to the furnace and melted at 1100-1180℃ until the matrix is ​​completely liquid. Then, the melt temperature is lowered to 880-900℃, and Zn and borax are added. After the alloy is completely melted, it is stirred, and the stopper is lifted to allow the melt to fall into water. After the melt has completely fallen, it is removed. The molten joint material is then cleaned, dried, and polished. S2. The polished joint material is immersed in an anti-corrosion solution made by uniformly mixing benzotriazole, hydrogen peroxide, sodium silicate, sodium molybdate, fatty alcohol polyoxyethylene ether and deionized water to obtain Cu-Ag-Zn joint material with low Zn loss.

[0009] In some embodiments, in step S2, the concentration of benzotriazole is 1-5 g / L.

[0010] In some embodiments, in step S2, the concentration of sodium silicate is 1-3 g / L.

[0011] In some embodiments, in step S2, the concentration of the fatty alcohol polyoxyethylene ether is 0.1-0.5 g / L.

[0012] In some embodiments, in step S2, the concentration of sodium molybdate is 0.5-2 g / L.

[0013] In some embodiments, in step S2, the concentration of hydrogen peroxide is 1-5 mL / L.

[0014] In some embodiments, in step S1, the amount of borax added is 0.1-0.2 wt% of the total mass of the patching material.

[0015] In some embodiments, the soaking time in step S2 is 30-60 seconds.

[0016] Secondly, embodiments of this application provide a Cu-Ag-Zn-based patching material with low Zn loss. The Cu-Ag-Zn-based patching material with low Zn loss is prepared according to any one of the foregoing technical solutions. The Cu-Ag-Zn-based patching material with low Zn loss comprises the following components and weight percentages: copper 75-95%, silver 3-20%, zinc 1-4%, germanium 0.01-0.1%, indium 0.4-1%, and tin 0.01%.

[0017] The beneficial effects of this application are: This application provides a method for preparing a Cu-Ag-Zn-based filler material with low Zn loss. This method optimizes the composition ratio of the filler material and involves first adding Cu, Ag, Ge, In, and Sn particles into a furnace and melting them at 1100-1180℃ (first temperature) until the matrix is ​​completely liquid. After cooling the melt to 880-900℃ (second temperature), Zn and borax are added. This achieves a Zn loss of only 0.41-1.7% during the melting process, essentially eliminating loss and significantly reducing the difficulty of Zn melting.

[0018] This application involves polishing the smelted patching material and then immersing it in an anti-corrosion solution made by uniformly mixing benzotriazole, hydrogen peroxide, sodium silicate, sodium molybdate, fatty alcohol polyoxyethylene ether, and deionized water for 30-60 seconds. This significantly improves the alloy's oxidation resistance, allowing it to be exposed to air for more than a year without significant discoloration, thus avoiding oxidation and discoloration problems. At the same time, it reduces zinc loss and improves the material's efficiency and economy.

[0019] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0021] Figure 1 The image shows the Cu-Ag-Zn-based patching material with low Zn loss prepared in Example 1 after being exposed to air for six months. Figure 2 The image shows the Cu-Ag-Zn-based patching material with low Zn loss prepared in Example 2 after being exposed to air for six months. Figure 3 The image shows the Cu-Ag-Zn-based patching material with low Zn loss prepared in Example 3 after being exposed to air for six months. Figure 4 A photograph of the patching material prepared for Comparative Example 1 after being exposed to air for six months; Figure 5 A photograph of the patching material prepared for Comparative Example 3 after being exposed to air for six months.

[0022] Figure 6 A photograph of the patching material prepared for Comparative Example 4 after being exposed to air for six months. Detailed Implementation

[0023] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0025] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0026] In the description of the embodiments of this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0027] Existing Cu-Ag-Zn alloys have poor oxidation resistance and are prone to oxidation and discoloration after prolonged exposure to air.

[0028] In a first aspect, embodiments of this application provide a method for preparing a Cu-Ag-Zn-based patching material with low Zn loss, the specific steps of which are as follows: S1 is prepared according to the following mass percentages: copper 75-95%, silver 3-20%, zinc 1-4%, germanium 0.01-0.1%, indium 0.4-1%, and tin 0.01%. First, Cu, Ag, Ge, In, and Sn particles are added to the furnace and melted at 1100-1180℃ until the matrix is ​​completely liquid. Then, the melt temperature is lowered to 880-900℃, and Zn and borax are added. After the alloy is completely melted, it is stirred, and the stopper is lifted to allow the melt to fall into water. After the melt has completely fallen, it is removed. The molten joint material is then cleaned, dried, and polished. The amount of borax added is 0.1-0.2 wt% of the total filler material. Borax is applied to the surface to prevent the volatilization of Zn.

[0029] S2. The polished jointing material is immersed in an anti-corrosion solution prepared by uniformly mixing 1-5 g / L benzotriazole, 1-5 mL / L hydrogen peroxide, 1-3 g / L sodium silicate, 0.5-2 g / L sodium molybdate, 0.1-0.5 g / L fatty alcohol polyoxyethylene ether and deionized water for 30-36 seconds to obtain Cu-Ag-Zn jointing material with low Zn loss.

[0030] Secondly, this application also provides a Cu-Ag-Zn-based patching material with low Zn loss. The Cu-Ag-Zn-based patching material with low Zn loss is prepared by the preparation method described in any of the foregoing technical solutions. The Cu-Ag-Zn-based patching material with low Zn loss includes the following components and weight percentages: copper 75-95%, silver 3-20%, zinc 1-4%, germanium 0.01-0.1%, indium 0.4-1%, and tin 0.01%.

[0031] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0032] Example 1 Example 1 provides a method for preparing a Cu-Ag-Zn-based patching material with low Zn loss, comprising the following steps: S1 is formulated with the following percentages by weight: copper (Cu) 93%, silver (Ag) 4%, zinc (Zn) 2.44%, germanium (Ge) 0.05%, indium (In) 0.5%, and tin (Sn) 0.01%. First, Cu, Ag, Ge, In, and Sn particles are added to the furnace. After closing the furnace door, a vacuum is drawn and argon is introduced to standard atmospheric pressure. The temperature is raised to 1150±10℃ at 9KW power. After melting for 30 minutes, the mixture is stirred for 5 minutes until the matrix is ​​completely liquid. Then, the power is reduced to control the melt temperature at 900℃. The remaining Zn and 0.1wt% of borax (by weight of the total patching material) are added. After the alloy is completely melted, the mixture is stirred for 5 minutes. The stopper is then lifted to allow the melt to fall into the water through a 1mm aperture. After the melt has completely fallen, the mixture is removed. The molten patching material is then cleaned, dried, and polished in sequence. S2, then immerse it in an anti-corrosion solution prepared by mixing 3g / L benzotriazole, 3mL / L hydrogen peroxide, 2g / L sodium silicate, 1g / L sodium molybdate, 0.2g / L fatty alcohol polyoxyethylene ether and the remainder deionized water for 30 seconds to complete the preparation of the patching material.

[0033] Example 2 Example 2 provides a method for preparing a Cu-Ag-Zn-based patching material with low Zn loss, comprising the following steps: S1 is formulated with the following percentages by weight: copper (Cu) 92.5%, silver (Ag) 4.5%, zinc (Zn) 2.3%, germanium (Ge) 0.06%, indium (In) 0.6%, and tin (Sn) 0.04%. First, Cu, Ag, Ge, In, and Sn particles are added to the furnace. After closing the furnace door, a vacuum is drawn and argon is introduced to standard atmospheric pressure. The temperature is raised to 1180±10℃ at 8.5KW power. After melting for 25 minutes, the mixture is stirred for 8 minutes until the matrix is ​​completely liquid. Then, the power is reduced to control the melt temperature at 880℃. The remaining Zn and 0.15wt% of borax (based on the total mass of the patching material) are added. After the alloy is completely melted, the mixture is stirred for 5 minutes. The stopper is then lifted to allow the melt to fall into the water through a 1.2mm aperture. After the melt has completely fallen, the mixture is removed. The molten patching material is then cleaned, dried, and polished in sequence. S2, then immerse it in an anti-corrosion solution prepared by mixing 4 g / L benzotriazole, 3.5 mL / L hydrogen peroxide, 2.5 g / L sodium silicate, 1.2 g / L sodium molybdate, 0.3 g / L fatty alcohol polyoxyethylene ether and the remainder deionized water for 35 seconds to complete the preparation of the repair material.

[0034] Example 3 Example 3 provides a method for preparing a Cu-Ag-Zn based patching material with low Zn loss, comprising the following steps: S1 is formulated with the following percentages by weight: copper (Cu) 92.6%, silver (Ag) 4.5%, zinc (Zn) 2.33%, germanium (Ge) 0.06%, indium (In) 0.5%, and tin (Sn) 0.01%. First, Cu, Ag, Ge, In, and Sn particles are added into the furnace. After closing the furnace door, a vacuum is first drawn, and then argon gas is introduced to standard atmospheric pressure. The temperature is then raised to 1100±10℃ at 9KW power and melted for 35 minutes, followed by stirring for 5 minutes to ensure that the matrix is ​​completely melted into a liquid state. Next, the power is reduced, and the melt temperature is adjusted to 880℃. The remaining Zn and 0.15wt% of borax (based on the total mass of the patching material) are added. After the alloy is completely melted, it is stirred for 5 minutes. The stopper rod is then lifted, allowing the melt to fall into the water through a 1 mm aperture. After all the melt has fallen, it is removed. The melted patching material is then cleaned, dried, and polished in sequence. S2, then immerse it in an anti-corrosion solution prepared by uniformly mixing 3g / L benzotriazole, 3.6mL / L hydrogen peroxide, 1.8g / L sodium silicate, 1.2g / L sodium molybdate, 0.15g / L fatty alcohol polyoxyethylene ether and the remainder deionized water for 36 seconds to complete the preparation of the repair material.

[0035] Figures 1 to 3 The images show the Cu-Ag-Zn-based patching materials with low Zn loss prepared in Examples 1-3 after being exposed to air for six months.

[0036] As can be seen, the patching material remained glossy on the sample surface even after being exposed to air for six months.

[0037] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that step S2 was not performed. The other contents are roughly the same as those in Example 1, and will not be repeated here.

[0038] The physical image of the patching material prepared in Comparative Example 1 after being exposed to air for six months is shown below. Figure 4 As shown.

[0039] As can be seen, the sample surface is completely oxidized and appears black.

[0040] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that in step S1, Cu, Ag, Ge, In, Sn were not added first, followed by Zn and 0.1 wt% of borax in total filler material. Instead, Cu, Ag, Ge, In, Sn, and Zn were added together at the beginning according to the formula mass percentage. The mixture was heated to 1150±10℃ at 9KW power and melted for 30 minutes, then stirred for 5 minutes until the matrix was completely liquid. Other contents are roughly the same as in Example 1 and will not be repeated here.

[0041] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that benzotriazole is not present in the preservative solution in step S2; the other contents are largely the same as in Example 1, and will not be repeated here.

[0042] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that sodium silicate and sodium molybdate are not present in the anticorrosive solution in step S2; the other contents are roughly the same as in Example 1, and will not be repeated here.

[0043] The zinc content test results of the patching material prepared in Comparative Example 2 are shown in Table 1.

[0044] As can be seen, in Comparative Example 2, the zinc loss during the smelting process reached 20.9%.

[0045] The physical image of the patching material prepared in Comparative Example 3 after being exposed to air for six months is shown below. Figure 5 As shown.

[0046] The physical image of the patching material prepared in Comparative Example 4 after being exposed to air for six months is shown below. Figure 6 As shown.

[0047] As can be seen, obvious spots appeared on the patching material prepared in Comparative Examples 3-4.

[0048] The Zn composition of the patching materials prepared in Examples 1-3 and Comparative Example 2 was tested by atomic absorption spectrometry, and the results are shown in Table 1.

[0049] The neutral salt spray test was conducted for 48 hours according to GB / T 10125, and the results are shown in Table 1.

[0050] Table 1 Comparing Example 1 with Comparative Example 1, it can be seen that the anti-corrosion solution used in this application can give the patching material good corrosion resistance and prevent discoloration when exposed to air for six months.

[0051] Comparing Example 1 and Comparative Example 2, it can be seen that the batch addition of Zn and borax significantly reduces Zn loss, and there is basically no Zn loss during the smelting preparation process.

[0052] Comparing Example 1 and Comparative Example 3, it can be seen that the addition of benzotriazole (BTA) significantly improves the corrosion resistance of the jointing material. The nitrogen atoms in the BTA molecule can react with copper ions (Cu... + Coordination reactions occur between copper atoms on the surface of the metal or the metal itself, forming an insoluble, dense polymeric complex film.

[0053] Comparing Example 1 with Comparative Example 4, it can be seen that the addition of sodium silicate and sodium molybdate further improves the corrosion resistance of the jointing material and has a passivating effect on the surface.

[0054] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A method for preparing a Cu-Ag-Zn based patching material with low Zn loss, characterized in that, Includes the following steps: S1 is prepared according to the following mass percentages: copper 75-95%, silver 3-20%, zinc 1-4%, germanium 0.01-0.1%, indium 0.4-1%, and tin 0.01%. First, Cu, Ag, Ge, In, and Sn particles are added to the furnace and melted at 1100-1180℃ until the matrix is ​​completely liquid. Then, the melt temperature is lowered to 880-900℃, and Zn and borax are added. After the alloy is completely melted, it is stirred, and the stopper is lifted to allow the melt to fall into water. After the melt has completely fallen, it is removed. The molten joint material is then cleaned, dried, and polished. S2. The polished joint material is immersed in an anti-corrosion solution made by uniformly mixing benzotriazole, hydrogen peroxide, sodium silicate, sodium molybdate, fatty alcohol polyoxyethylene ether and deionized water to obtain Cu-Ag-Zn joint material with low Zn loss.

2. The preparation method of the low Zn loss Cu-Ag-Zn system patching material according to claim 1, characterized in that, In step S2, the concentration of benzotriazole is 1-5 g / L.

3. The method for preparing the low-Zn-loss Cu-Ag-Zn-based patching material according to claim 1, characterized in that, In step S2, the concentration of sodium silicate is 1-3 g / L.

4. The preparation method of the low Zn loss Cu-Ag-Zn system patching material according to claim 1, characterized in that, In step S2, the concentration of the fatty alcohol polyoxyethylene ether is 0.1-0.5 g / L.

5. The method for preparing the low-Zn-loss Cu-Ag-Zn-based patching material according to claim 1, characterized in that, In step S2, the concentration of sodium molybdate is 0.5-2 g / L.

6. The method for preparing the low-Zn-loss Cu-Ag-Zn-based patching material according to claim 1, characterized in that, In step S2, the concentration of hydrogen peroxide is 1-5 mL / L.

7. The method for preparing the low-Zn-loss Cu-Ag-Zn-based patching material according to claim 1, characterized in that, In step S1, the amount of borax added is 0.1-0.2 wt% of the total mass of the patching material.

8. The method for preparing the low-Zn-loss Cu-Ag-Zn-based patching material according to claim 1, characterized in that, In step S2, the soaking time is 30-60 seconds.

9. A Cu-Ag-Zn based patching material with low Zn loss, characterized in that, The low-Zn-loss Cu-Ag-Zn-based patching material is prepared by the preparation method according to any one of claims 1-8. The low-Zn-loss Cu-Ag-Zn-based patching material comprises the following components and weight percentages: copper 75-95%, silver 3-20%, zinc 1-4%, germanium 0.01-0.1%, indium 0.4-1%, and tin 0.01%.

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