Gold Springs and Their Manufacturing Methods

Abstract

This invention provides a karat gold spring and its preparation method. The karat gold spring comprises: 75–92 wt% gold; 5–23 wt% copper; 0.4–2.0 wt% silver; 0.3–2.0 wt% nickel; 0.3–2.0 wt% cobalt; 0.3–2.0 wt% gallium; 0.1–0.5 wt% zirconium; and 0.1–0.5 wt% ruthenium. The karat gold spring formulation of this invention uses alloying elements that are non-toxic and harmless to the human body, have excellent solid solubility in gold, and can be directly smelted with gold. The alloying elements are low-cost, suitable for commonly used jewelry smelting equipment, have low smelting losses, high reusability, and low production costs. Furthermore, while ensuring a gold content of 18–22K or higher in the karat gold spring, the elastic modulus of the karat gold spring remains sufficiently high, and it can be repeatedly opened and closed without deformation, meeting the long-term use requirements of general jewelry clasps.

Description

Technical Field

[0001] This invention relates to the field of karat gold material technology, and in particular to a karat gold spring and its preparation method. Background Technology

[0002] In existing karat gold or gold jewelry products, elastic components are often used to achieve opening and closing or snap-fit ​​functions. Currently, stainless steel springs are commonly used in various jewelry clasps to achieve this function. However, using stainless steel springs in jewelry may reduce the purity of the product, causing the overall purity to fail to meet the requirements of the mandatory standard GB 11887 for the precious metal jewelry industry. Furthermore, stainless steel is prone to oxidation, and under long-term wear, sweat can easily penetrate, causing it to turn black. In addition, stainless steel wire is also magnetic, and consumers who find that the product can be attracted by a magnet often have doubts about its quality.

[0003] Of course, some jewelry currently uses gold springs, but the main components of existing gold springs are Au, Cu, Zn, and Ag. In order to ensure the elasticity and durability of the spring, a large amount of alloy components need to be added to the existing gold springs, which will reduce the purity of the gold springs to below 18K. When gold springs below 18K are used in jewelry clasps, the existing technology of gold springs has not eliminated consumers' doubts about insufficient purity, and they are prone to oxidation, making it difficult to meet user needs.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] The main objective of this invention is to solve the technical problems mentioned in the background section of the prior art regarding existing gold springs.

[0006] The contents of this invention are as follows:

[0007] The first aspect of the present invention provides a gold spring, the composition of which includes: 75-92 wt% gold; 5-23 wt% copper; 0.4-2.0 wt% silver; 0.3-2.0 wt% nickel; 0.3-2.0 wt% cobalt; 0.3-2.0 wt% gallium; 0.1-0.5 wt% zirconium; and 0.1-0.5 wt% ruthenium.

[0008] In an optional embodiment of the first aspect of the present invention, the composition of the gold spring includes: 75 wt% gold; 23 wt% copper; 0.5 wt% silver; 0.5 wt% nickel; 0.3 wt% cobalt; 0.3 wt% gallium; 0.2 wt% zirconium; and 0.2 wt% ruthenium.

[0009] In an optional embodiment of the first aspect of the present invention, the composition of the gold spring includes: 75.5 wt% gold; 19.0 wt% copper; 0.8 wt% silver; 1.5 wt% nickel; 1.5 wt% cobalt; 1.0 wt% gallium; 0.4 wt% zirconium; and 0.3 wt% ruthenium.

[0010] In an optional embodiment of the first aspect of the present invention, the composition of the gold spring includes: 92.0 wt% gold; 5.0 wt% copper; 0.4 wt% silver; 0.6 wt% nickel; 1.0 wt% cobalt; 0.6 wt% gallium; 0.2 wt% zirconium; and 0.2 wt% ruthenium.

[0011] A second aspect of this invention provides a method for preparing a karat gold spring, comprising the following steps:

[0012] Prepare the raw materials for the gold spring according to the following composition: 75-92 wt% gold; 5-23 wt% copper; 0.4-2.0 wt% silver; 0.3-2.0 wt% nickel; 0.3-2.0 wt% cobalt; 0.3-2.0 wt% gallium; 0.1-0.5 wt% zirconium; 0.1-0.5 wt% ruthenium, and mix them evenly.

[0013] The uniformly mixed raw materials are melted once in a medium-frequency induction furnace and then cast to obtain K gold bars;

[0014] The gold bars are fed into a continuous casting machine for secondary melting and then drawn to obtain gold rods.

[0015] The gold bar is drawn into a gold wire of a preset diameter using a wire drawing device;

[0016] The target gold wire is obtained by heat treatment followed by rapid quenching.

[0017] A preliminary gold spring is obtained by winding the target gold wire using a spring machine.

[0018] The preliminary K-gold spring is tempered to obtain the target K-gold spring.

[0019] In an optional embodiment of the second aspect of the present invention, after tempering the preliminary K-gold spring to obtain the target K-gold spring, the method further includes: polishing the target K-gold spring for more than 60 minutes using a vibratory polishing machine and ceramic beads with a diameter of less than 0.5 mm to obtain a refined K-gold spring.

[0020] In an optional embodiment of the second aspect of the present invention, the step of casting karat gold bars after melting the uniformly mixed raw materials in a medium-frequency induction furnace in one step includes:

[0021] Using a medium-frequency induction furnace, in a vacuum environment or an open environment with a covering agent added to the surface of the melt, the melting temperature is controlled at 1200-1350°C, and the uniformly mixed raw materials are melted once. The covering agent includes borax.

[0022] During the smelting process, the melt in the medium-frequency induction furnace is stirred and kept at a temperature of more than 30 minutes. After the smelting is complete, the melt is poured into a pre-made mold and cooled to obtain a gold bar.

[0023] In an optional embodiment of the second aspect of the present invention, the step of rapidly quenching the K gold wire after heat treatment to obtain the target K gold wire includes:

[0024] Under the protection of an inert gas, the gold wire is heat-treated at a temperature range of 600-700℃ for 10-20 minutes, and then rapidly quenched in water to obtain the target gold wire.

[0025] In an optional embodiment of the second aspect of the present invention, the tempering treatment of the preliminary karat gold spring to obtain the target karat gold spring includes:

[0026] Under inert gas protection, the preliminary gold spring is held at a temperature range of 450-550°C for 60-90 minutes and then tempered. After cooling to room temperature, the target gold spring is obtained.

[0027] In an optional embodiment of the second aspect of the present invention, drawing the gold bar into a gold wire of a predetermined diameter using a drawing device includes:

[0028] The gold bar is drawn into gold wire of a preset diameter (0.2-0.4 mm) multiple times using a wire drawing device.

[0029] Beneficial Effects: This invention provides a karat gold spring and its preparation method. The karat gold spring comprises: 75-92 wt% gold; 5-23 wt% copper; 0.4-2.0 wt% silver; 0.3-2.0 wt% nickel; 0.3-2.0 wt% cobalt; 0.3-2.0 wt% gallium; 0.1-0.5 wt% zirconium; and 0.1-0.5 wt% ruthenium. The karat gold spring formulation of this invention uses alloying elements with excellent solid solubility, allowing for direct melting with gold. The alloying elements are low-cost, suitable for commonly used melting equipment, and exhibit low melting loss, thus saving production costs. Furthermore, while ensuring a gold content of 18-22K or higher in the karat gold spring, the elastic modulus of the karat gold spring remains sufficiently high, and it can withstand repeated opening and closing without deformation, meeting the long-term use requirements of general jewelry clasps. Attached Figure Description

[0030] Figure 1This is a flowchart of a method for preparing a gold spring according to the present invention. Detailed Implementation

[0031] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention.

[0032] The first aspect of this invention provides a karat gold spring, the composition of which includes: 75-92 wt% gold; 5-23 wt% copper; 0.4-2.0 wt% silver; 0.3-2.0 wt% nickel; 0.3-2.0 wt% cobalt; 0.3-2.0 wt% gallium; 0.1-0.5 wt% zirconium; and 0.1-0.5 wt% ruthenium. The karat gold spring of this invention has a high gold content, good elasticity, and is not easily deformed after long-term use, meeting the requirements of common jewelry opening and closing components (such as jewelry clasps). Furthermore, the elastic component is not easily oxidized or discolored during long-term wear, and each alloying element has good solid solubility, allowing for direct melting with gold. This results in low alloying element costs, minimal melting losses, and reduced production costs.

[0033] In an optional embodiment of the first aspect of the present invention, the composition of the karat gold spring includes: 75 wt% gold; 23 wt% copper; 0.5 wt% silver; 0.5 wt% nickel; 0.3 wt% cobalt; 0.3 wt% gallium; 0.2 wt% zirconium; and 0.2 wt% ruthenium. In this embodiment, the karat gold spring produced by the present invention is an 18K gold spring. The cost of this composition of karat gold spring is moderate, and tests have shown that the fatigue test of this composition of karat gold spring can withstand up to 1.45 million cycles before fracture.

[0034] In another optional embodiment of the first aspect of the present invention, the composition of the karat gold spring includes: 75.5 wt% gold; 19.0 wt% copper; 0.8 wt% silver; 1.5 wt% nickel; 1.5 wt% cobalt; 1.0 wt% gallium; 0.4 wt% zirconium; and 0.3 wt% ruthenium. In this embodiment, the karat gold spring produced by the present invention is an 18K gold spring. In this embodiment, the karat gold spring produced by the present invention is an 18K gold spring. This formula reduces the copper content and increases the content of nickel, cobalt, and gallium. Testing showed that the karat gold spring with this composition can withstand 1.9 million cycles of fatigue testing before fracture.

[0035] In another optional embodiment of the first aspect of the present invention, the composition of the karat gold spring includes: 92.0 wt% gold; 5.0 wt% copper; 0.4 wt% silver; 0.6 wt% nickel; 1.0 wt% cobalt; 0.6 wt% gallium; 0.2 wt% zirconium; and 0.2 wt% ruthenium. In this embodiment, the karat gold spring produced by the present invention is a 22K gold spring. Even with a significantly increased gold content, tests have shown that the karat gold spring with this composition can withstand 1.06 million fatigue cycles before fracture.

[0036] See Figure 1 The second aspect of this invention provides a method for preparing a karat gold spring, comprising the following steps:

[0037] S100: Prepare the raw materials for the K-gold spring according to the following proportions: 75-92 wt% gold; 5-23 wt% copper; 0.4-2.0 wt% silver; 0.3-2.0 wt% nickel; 0.3-2.0 wt% cobalt; 0.3-2.0 wt% gallium; 0.1-0.5 wt% zirconium; and 0.1-0.5 wt% ruthenium, and mix them evenly. In step S100, the high-melting-point cobalt, zirconium, and ruthenium in the raw materials can be in powder form to facilitate melting. Other raw materials can be in sheet or block form. The mixing method of each component of the raw materials is to first fully and evenly mix the alloying elements except gold, then wrap them with gold sheets, and then melt the evenly mixed alloying elements together with gold. The K-gold spring of the present invention solves the problems of easy oxidation of alloying elements, high difficulty in material melting, inability to be processed by existing jewelry equipment, low reusability, and insufficient elasticity.

[0038] S200: The uniformly mixed raw materials are smelted once using a medium-frequency induction furnace and then cast to obtain K gold bars. In this invention, the purpose of casting K gold bars after one smelting is to facilitate the secondary smelting and rod forming in the continuous casting machine in the subsequent step S300. Of course, the K gold obtained after one smelting and casting can also be in other shapes that are convenient for secondary smelting and rod forming in the continuous casting machine, and is not limited to bars. All other shapes should fall within the protection scope of this invention.

[0039] In step S200, one embodiment of the process of casting karat gold bars after melting the uniformly mixed raw materials once using a medium-frequency induction furnace can be as follows: using a medium-frequency induction furnace, under vacuum conditions, controlling the melting temperature at 1200-1350℃, the uniformly mixed raw materials are melted once; during the melting process, the melt in the medium-frequency induction furnace is stirred (the stirring tool can be, for example, a quartz rod); after the melting is complete, the melt is cast into a pre-made mold, and after cooling, karat gold bars are obtained; in step S200, melting the raw materials in a vacuum environment can reduce the oxidation and loss of the raw materials.

[0040] In step S200, another embodiment of casting the uniformly mixed raw materials into K gold bars after one melting in a medium-frequency induction furnace can be as follows: using a medium-frequency induction furnace, in an open environment, a covering agent (e.g., borax, for heat preservation and fluxing) is added to the surface of the melt, and the melting temperature is controlled at 1200-1350°C to melt the uniformly mixed raw materials once; during the melting process, the melt in the medium-frequency induction furnace is stirred (the stirring tool can be, for example, a quartz rod), and after the melting is sufficient, the melt is cast into a pre-made mold, and after cooling, K gold bars are obtained.

[0041] S300. The gold bar is fed into a continuous casting machine for secondary melting and drawing to obtain a gold bar. In this invention, the purpose of making the gold bar into a gold bar in step S300 is to facilitate wire drawing by the wire drawing equipment. The size and specifications of the gold bar depend on the parameters of the continuous casting machine and the wire drawing equipment. This invention does not make specific limitations here.

[0042] S400. The gold bar is drawn into a gold wire of a preset diameter using a drawing device. In step S400, for example, drawing the gold bar into a gold wire of a preset diameter using the drawing device includes: drawing the gold bar into a gold wire of a preset diameter multiple times using the drawing device, where the preset diameter is 0.2–0.4 mm. In this invention, drawing into the preset diameter multiple times means, for example, if the initial diameter of the gold bar is N1 and the preset diameter is N2, taking two times as an example, first the gold bar is drawn to the range between N1 and N2, and then the gold bar is drawn from the range between N1 and N2 to the preset diameter N2. The multiple times are not limited to two times; the specific number of times can be determined based on the performance of the drawing device and the actual situation.

[0043] S500. The K gold wire is heat-treated and then rapidly quenched to obtain the target K gold wire. In step S500, for example, the heat treatment and rapid quenching of the K gold wire to obtain the target K gold wire includes: heat-treating the K gold wire at a temperature range of 600-700°C for 10-15 minutes under the protection of an inert gas, and then rapidly quenching it in water to obtain the target K gold wire. In this invention, the inert gas can be, for example, nitrogen.

[0044] S600: The target gold wire is wound into a preliminary gold spring using a spring machine. It should be noted that the winding in step S600 of this invention is not limited to the winding action. In specific implementation, it can also be, for example, bending. Any action that can make the gold wire into the shape of a spring is within the protection scope of this invention.

[0045] S700. The preliminary karat gold spring is tempered to obtain the target karat gold spring. In step S700, for example, the tempering of the preliminary karat gold spring to obtain the target karat gold spring includes: tempering the preliminary karat gold spring at a temperature range of 500–550°C for 60–90 minutes under inert gas protection, and then cooling it to room temperature to obtain the target karat gold spring. In this invention, the tempering equipment can be a tempering furnace, and the inert gas used in the tempering process can also be nitrogen.

[0046] In an optional embodiment of the second aspect of the present invention, after tempering the preliminary karat gold spring to obtain the target karat gold spring, the method further includes:

[0047] S800: The target gold spring is polished for at least 60 minutes using a vibratory polishing machine and ceramic beads with a diameter of less than 0.5 mm to increase the spring's strength and elasticity, thereby obtaining a refined gold spring. In this invention, step S800 removes the oxide layer from the surface of the target gold spring, increasing its surface brightness.

[0048] Furthermore, to illustrate the technical effects of the present invention, please refer to Table 1 below. The present invention constructed the following sets of embodiments and comparative examples of the prior art for performance testing, expressed in weight percentage (wt%). In each embodiment, the K-gold springs were manufactured according to the above-mentioned K-gold spring preparation method of the present invention, with a melting temperature of 1200-1350℃, a heat treatment temperature of 600-700℃, a heat treatment time of 10-20 min, a tempering temperature of 450-550℃, a holding time of 60-90 min, a K-gold wire diameter of 0.2 mm, and a K-gold spring pitch of 0.5 mm.

[0049] Table 1. Formulation composition of each embodiment and comparative example.

[0050]

[0051]

[0052] Performance testing:

[0053] Test Method 1

[0054] The tensile test was conducted according to the method specified in GB / T 35777 "Metallic and Alloy Jewelry Chains - Mechanical Properties Test - Tensile Test". A tensile testing machine of level 1 or above was selected. The two ends of the spring were clamped by fixtures. The tensile performance of the gold springs prepared in Examples 1 to 4 and Comparative Examples 1 and 2 in Table 1 were tested. The test conditions were: tensile speed of 20 mm / min, and the test machine was stopped when the gold wire of the spring broke. The maximum tensile force (unit: N) was recorded. The test results are shown in Table 2 below.

[0055] Table 2. Test results of tensile strength of gold spring wire in various embodiments and comparative examples.

[0056] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Maximum tension 32.3 40.6 18.5 26.1 12.5 8.3

[0057] As can be seen from the test results in Table 2, the K-gold spring wires prepared in Examples 1-4 of the present invention have a maximum tensile force that is more than twice that of the commercially available K-gold spring wires in Comparative Examples 1 and 2, indicating that the K-gold spring wire material of the present invention has higher strength and better durability.

[0058] Test Method Two

[0059] The fatigue tests were conducted on the gold springs prepared in Examples 1 to 4 and Comparative Examples 1 and 2, as shown in Table 1, according to GB / T 16947-2009 "Specification for Fatigue Testing of Helical Springs". The test conditions were: load 0.40 N, operating frequency 20 Hz, and stroke 2.0 mm. The number of cycles (in ten thousand cycles) at which the spring broke was recorded. The test results are shown in Table 3 below.

[0060] Table 3 Performance test table of gold springs in various embodiments and comparative examples

[0061] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Loop count 145 190 106 125 46 31

[0062] As can be seen from the test results in Table 3, the gold springs prepared in Examples 1-4 of the present invention have at least three times more cycles than the gold springs of Comparative Examples 1 and 2, and the gold springs of the present invention have a longer service life.

[0063] In summary, this invention provides a karat gold spring and its preparation method. The karat gold spring comprises: 75–92 wt% gold; 5–23 wt% copper; 0.4–2.0 wt% silver; 0.3–2.0 wt% nickel; 0.3–2.0 wt% cobalt; 0.3–2.0 wt% gallium; 0.1–0.5 wt% zirconium; and 0.1–0.5 wt% ruthenium. The karat gold spring formulation of this invention uses alloying elements with excellent solid solubility, allowing for direct melting with gold. The alloying elements are low-cost, suitable for commonly used melting equipment, and exhibit low melting loss, thus saving production costs. Furthermore, while ensuring a gold content of 18–22K or higher in the karat gold spring, the elastic modulus of the karat gold spring remains sufficiently high, and it can withstand repeated opening and closing without deformation, meeting the long-term use requirements of general jewelry clasps.

[0064] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A gold spring, characterized in that, The composition of the gold spring is: 75.5 wt% gold; 19.0 wt% copper; 0.8 wt% silver; 1.5 wt% nickel; 1.5 wt% cobalt; 1.0 wt% gallium; 0.4 wt% zirconium; 0.3 wt% ruthenium; The gold spring is prepared by the following method: Prepare the raw materials for the K-gold spring according to the composition of the K-gold spring and mix them evenly; The raw materials, which are mixed evenly, are melted once in a medium-frequency induction furnace and then cast to obtain K gold bars; The gold bars are fed into a continuous casting machine for secondary melting and then drawn to obtain gold rods. The gold bar is drawn into a gold wire of a preset diameter using a wire drawing device; The target gold wire is obtained by heat treatment followed by rapid quenching. A preliminary gold spring is obtained by winding the target gold wire using a spring machine. The preliminary K-gold spring is tempered to obtain the target K-gold spring.

2. A method for preparing a karat gold spring, characterized in that, Includes the following steps: Based on 75.5wt% gold; Prepare the raw materials for the gold springs and mix them evenly: 19.0 wt% copper; 0.8 wt% silver; 1.5 wt% nickel; 1.5 wt% cobalt; 1.0 wt% gallium; 0.4 wt% zirconium; 0.3 wt% ruthenium. The raw materials, which are mixed evenly, are melted once in a medium-frequency induction furnace and then cast to obtain K gold bars; The gold bars are fed into a continuous casting machine for secondary melting and then drawn to obtain gold rods. The gold bar is drawn into a gold wire of a preset diameter using a wire drawing device; The target gold wire is obtained by heat treatment followed by rapid quenching. A preliminary gold spring is obtained by winding the target gold wire using a spring machine. The preliminary K-gold spring is tempered to obtain the target K-gold spring.

3. The method for preparing a K-gold spring according to claim 2, characterized in that, After tempering the preliminary K-gold spring to obtain the target K-gold spring, the process further includes: polishing the target K-gold spring using a vibratory polishing machine and ceramic beads to obtain a refined K-gold spring.

4. The method for preparing a gold spring according to claim 2 or 3, characterized in that, The process of using a medium-frequency induction furnace to melt the uniformly mixed raw materials once and then casting them to obtain K-gold bars includes: Using a medium-frequency induction furnace, in a vacuum environment or an open environment with a covering agent added to the surface of the melt, the melting temperature is controlled at 1200~1350℃ to melt the uniformly mixed raw materials once. The covering agent includes borax. During the smelting process, the melt in the medium-frequency induction furnace is stirred and kept at a temperature of more than 30 minutes. After the smelting is complete, the melt is poured into a pre-made mold and cooled to obtain a gold bar.

5. The method for preparing a gold spring according to claim 2 or 3, characterized in that, The process of obtaining the target gold wire by heat treatment followed by rapid quenching includes: Under the protection of an inert gas, the gold wire is heat-treated at a temperature range of 600~700℃ for 10-20 minutes, and then rapidly quenched in water to obtain the target gold wire.

6. The method for preparing a gold spring according to claim 5, characterized in that, The step of tempering the preliminary karat gold spring to obtain the target karat gold spring includes: Under inert gas protection, the preliminary K-gold spring is held at a temperature range of 450~550℃ for 60~90 minutes and then tempered. After naturally cooling to room temperature, the target K-gold spring is obtained.

7. The method for preparing a karat gold spring according to claim 2, characterized in that, The process of drawing the gold bar into a gold wire of a predetermined diameter using a drawing device includes: The gold bar is drawn into gold wire of a preset diameter (0.2-0.4 mm) multiple times using a wire drawing device.

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