Manufacturing method of anti-deformation silver jewelry

Abstract

The invention discloses a manufacturing method of anti-deformation silver jewelry. The manufacturing method comprises the following steps: S1, preparing alloy components; s2, manufacturing a blank; s3, solution treatment; s4, rolling the bar; s5, drawing the silver wire; s6, a filament blank is manufactured; s7, aging treatment; s8, post-treatment is carried out; the alloy comprises the following components in percentage by weight: 0.1 to 0.5 percent of copper, 0.1 to 0.3 percent of zinc, 0.04 to 0.2 percent of tin, 0.03 to 0.15 percent of germanium, 0.1 to 0.3 percent of titanium, 0.02 to 0.1 percent of rare earth and the balance of silver. According to the method, alloy components and processes are optimally combined, solid solution treatment, bar rolling, silver wire drawing, aging treatment and other processes are combined, and the jewelry formed through welding is subjected to low-temperature aging treatment, so that an intermediate phase can be dispersed and separated out, the hardness of the filament jewelry piece is obviously improved, a self-healing passivation protective film can be formed on the surface of the alloy, and the discoloration resistance is improved.

Description

Technical Field

[0001] This invention relates to the field of jewelry manufacturing technology, and in particular to a method for manufacturing anti-deformation silver jewelry. Background Technology

[0002] Filigree jewelry making involves drawing silver into wires of varying specifications, then using several of eight techniques—pinching, filling, piling, stacking, braiding, weaving, assembling, and soldering—to shape the wires into jewelry blanks of different shapes, structures, and patterns. These blanks are then inlaid and surface-treated to enhance their artistic effect. Filigree is an intricate and ornate craft, appearing in court ornaments and ceremonial objects throughout Chinese dynasties, reaching its peak during the Ming and Qing dynasties, and is one of my country's most important traditional jewelry crafts. Filigree jewelry is made from silver wire, with a complex and delicate structure. Pinning requires the silver wire to have excellent flexibility, so traditional filigree jewelry is generally made from pure silver. However, pure silver has too low strength and hardness, especially when used for filigree. Because of the soldering process during shaping, the hardness of the silver after soldering is only around HV27, making it too soft and difficult to meet the requirements for setting, and it is also very easy to deform during wear.

[0003] Existing technologies offer several methods for strengthening silver alloys, but these methods do not meet the requirements for filigree jewelry production. For example, Chinese patent CN00124064.1 discloses a method for manufacturing a hardenable pure silver alloy that resists discoloration. This method uses internal oxidation, placing the silver alloy in a high-temperature oxidizing atmosphere to promote oxidation of the alloying elements and thus harden the material. However, this method is unsuitable for filigree jewelry production because filigree jewelry typically requires repeated welding, using solders with decreasing melting points. During high-temperature oxidation, the welded areas will melt and burn or undergo severe oxidation. Another example is Chinese patent CN200580044546.6, which discloses a precipitation hardening treatment method for Ag alloys. However, this alloy is unsuitable for filigree jewelry production in terms of both its color and initial strength. Chinese patent CN202110345678X discloses a high-strength silver wire and its preparation method. It uses an Ag-Cu-Zn alloy (silver content 90-95%), and by adjusting the ratio of copper (2-5%) and zinc (1-3%), combined with solid solution strengthening and grain refinement strengthening, the tensile strength of the silver wire is increased from 200 MPa of pure silver to over 350 MPa, while maintaining good ductility (elongation ≥30%). However, this material has a low silver content, making it difficult to meet the needs of mass consumers. Its purity is also lower than the national standard for 925 silver, and it is also difficult to draw to the small diameter required for the slip-through wire drawing process. Chinese patent CN202011234567A discloses a silver filigree composite material containing nano-ceramic particles. It adds nano-alumina or silicon carbide particles (0.5-2% by volume) to a silver matrix and prepares composite silver wires using powder metallurgy. The ceramic particles hinder dislocation movement, significantly improving wear resistance and fatigue resistance. However, the rods prepared by powder metallurgy are difficult to draw to the required wire diameter. Some studies have also explored ways to disperse external forces and avoid fractures caused by localized stress concentration by modifying the filigree's structural design (such as adding supports and optimizing connection nodes). For example, Chinese patent CN201921567890.1 discloses a reinforced silver filigree jewelry frame with a double-layer structure of "main wire + auxiliary wire." The main wire, a thick silver wire with a diameter of 0.5-0.8 mm, forms the main outline. The auxiliary wires are made of fine silver wire with a diameter of 0.1-0.3 mm, embedded in the gaps between the main wires in a grid or radial pattern to form a "skeleton-filler" support system, improving the overall deformation resistance of the jewelry by 40%. However, the silver wires used in this structure are too coarse and differ significantly from genuine silver filigree. Chinese patent CN202210876543B discloses a reinforcement structure for the welding nodes of silver filigree jewelry. Addressing the problem of easy breakage at traditional welding points, it proposes a "stepped welding groove" design, processing tiny grooves (0.05-0.1 mm deep, 0.2-0.3 mm wide) in the welding area to increase the contact area between the solder and the silver wire. After welding, the nodes are micro-upset, increasing the welding point strength by 50%. However, this approach does not change the problem of easy deformation of silver filigree.In addition, some studies have improved the surface hardness, corrosion resistance, and connection reliability of silver filigree by using surface coatings, chemical plating, or improved welding processes. For example, Chinese patent CN202111234567C discloses a surface nano-coating for silver filigree jewelry and its preparation method. It uses magnetron sputtering technology to deposit a diamond-like carbon coating or titanium nitride coating with a thickness of 50-200 nm on the surface of the silver filigree, increasing the surface hardness from HV25 of pure silver to over HV800. However, such a thin coating cannot change the problem of silver filigree jewelry being easily deformed. Chinese patent CN202010987654D discloses a low-temperature brazing process for silver filigree. Traditional silver brazing requires high temperatures (700-800℃), which easily leads to softening and deformation of the silver wire. By using a low-temperature brazing filler metal (such as Sn-Ag-Cu alloy with a melting point ≤450℃) and ultrasonic-assisted vibration, the welding temperature is reduced by 30%, the heat-affected zone of the silver wire is reduced to less than 0.1 mm, and the strength of the weld point is increased by 30%.

[0004] In summary, the existing silver filigree jewelry suffers from problems such as low strength, easy deformation, easy wear and tear, and easy discoloration, necessitating the research and development of strengthening technologies for silver filigree jewelry. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention provides a method for manufacturing anti-deformation silver jewelry. The silver filigree jewelry produced by this method has significantly better performance in terms of anti-deformation, wear resistance, and anti-discoloration than traditional silver filigree jewelry.

[0006] This invention is achieved using the following technical solution:

[0007] A method for manufacturing anti-deformation silver jewelry includes the following steps:

[0008] S1: Formulating alloy components

[0009] The alloy composition includes the following components by mass percentage:

[0010] Copper 0.1-0.5%, zinc 0.1-0.3%, tin 0.04-0.2%, germanium 0.03-0.15%, titanium 0.1-0.3%, rare earth elements 0.02-0.1%, the remainder being silver, and unavoidable impurity elements;

[0011] Among the above materials, copper is pure copper with a content of 99.95 wt% or higher, zinc is pure zinc with a content of 99.95 wt% or higher, tin is pure tin with a content of 99.95 wt% or higher, germanium is pure germanium with a content of 99.95 wt% or higher, titanium is pure titanium with a content of 99.95 wt% or higher, and silver is pure silver with a content of 99.95 wt% or higher.

[0012] S2: Making blanks

[0013] The materials are prepared in proportion, and a bottom-drawing vacuum induction melting and continuous casting machine is used. The vacuum is drawn to below 0.05Pa, and pure argon with a purity of over 99.99% is introduced. After heating until all the materials are melted, the traction device is started to produce round bar billets.

[0014] S3: Solution treatment

[0015] Solution treatment is performed on the round bar billet;

[0016] S4: Bar rolling

[0017] The solution-treated billet is rolled using a bar mill, with a single rolling reduction rate controlled at 15-20%. Intermediate annealing is performed when the total reduction rate reaches 40-50%, and the billet is rolled to... Round bars;

[0018] S5: Pulling Silver Wire

[0019] (1) From Pull-out reduction to For the rough drawing stage, a cemented carbide die is used and coated with a synthetic lubricant for lubrication. The shrinkage rate per pass is controlled at 15-25%, and the drawing speed is 5-8 m / min. When the cross-sectional shrinkage rate reaches 40-50%, an intermediate annealing is carried out in a box-type atmosphere furnace.

[0020] (2) From Pull-out reduction to For the intermediate drawing stage, a diamond die is used and high-purity mineral oil is used for lubrication. The single-pass shrinkage rate is controlled at 10-15%. When the total shrinkage rate reaches 45-60%, a box-type atmosphere furnace is used for intermediate annealing.

[0021] (3) From Pull-out reduction to For the fine drawing stage, a diamond die is used, and high-purity mineral oil and surfactants are used for lubrication. The single-pass shrinkage rate is controlled at 5-12%. When the total shrinkage rate reaches 40-50%, a box-type atmosphere furnace is used for intermediate annealing.

[0022] S6: Making filigree blanks

[0023] Make the pattern outline, anneal and shape it, arrange it according to the predetermined position, fold the plain thread in half, twist it into a twisted thread with a thread rolling board, flatten it into a ribbon of the required width with a rolling mill, take the required length and shape the pattern, fill it into the outline, spray borax liquid on the filled filigree blank, select the corresponding melting point of the solder according to the welding sequence, sprinkle the solder evenly on the part to be welded, use a scattered flame and keep moving the flame to make all parts heat evenly. When the blank is red-hot, the solder melts quickly and penetrates into the weld. After the blank cools, put it into alum water and boil it to remove the flux and oxide film. Put the filigree blank into a weak acid solution and clean it with ultrasonic cleaning to further remove residual solder marks and oxide scale, and obtain the filigree blank.

[0024] S7: Timeliness Processing

[0025] The filigree blanks are subjected to aging heat treatment;

[0026] S8: Post-processing

[0027] Polish and protect the surface of the silver filigree jewelry.

[0028] Furthermore, in step S1, the total content of the unavoidable impurity elements does not exceed 0.1%.

[0029] Further, in step S1, the rare earth element is one or more of cerium, yttrium, lanthanum, neodymium, and gadolinium.

[0030] In the above materials, cerium is pure cerium with a content of 99.95 wt% or higher, yttrium is pure yttrium with a content of 99.95 wt% or higher, lanthanum is pure lanthanum with a content of 99.95 wt% or higher, neodymium is pure neodymium with a content of 99.95 wt% or higher, and gadolinium is pure gadolinium with a content of 99.95 wt% or higher.

[0031] Furthermore, in step S2, the diameter of the round bar blank is 50-75 mm.

[0032] Furthermore, in step S3, the specific requirements for the solution treatment are as follows:

[0033] The treatment temperature is 650-700℃, a weakly reducing protective atmosphere is used, the holding time is 60-120 minutes, and then the water is quenched and cooled.

[0034] Further, in step S3, the weakly reducing protective atmosphere is a combination of nitrogen and hydrogen or a combination of argon and hydrogen, wherein the volume percentage of hydrogen in the combination gas is 3-5%.

[0035] Furthermore, in step S4, the specific requirements for intermediate annealing are as follows:

[0036] Intermediate annealing is performed in a box-type atmosphere furnace, using a weakly reducing protective atmosphere of a combination of nitrogen and hydrogen or a combination of argon and hydrogen. The volume percentage of hydrogen is 3-5%. The furnace is kept under a slight positive pressure of 30-50 Pa. The temperature is set at 460-500℃, and the holding time is 8-12 minutes. The furnace is then cooled to below 120℃ and removed from the furnace for air cooling.

[0037] Furthermore, in step S5, the specific requirements for the intermediate annealing during the rough drawing stage are as follows:

[0038] A weakly reducing protective atmosphere is used, consisting of a combination of nitrogen and hydrogen or a combination of argon and hydrogen, with hydrogen accounting for 3-5% of the volume. The furnace is kept under a slightly positive pressure of 30-50 Pa, the temperature is set at 450-480℃, and the holding time is 5-8 minutes. The furnace is then cooled to below 120℃ and removed from the furnace for air cooling.

[0039] Furthermore, in step S5, the specific requirements for the intermediate annealing during the intermediate drawing stage are as follows:

[0040] Set the temperature to 430-460℃, hold for 4-6 minutes, cool with the furnace to below 120℃, and then air cool after removal from the furnace.

[0041] Furthermore, in step S5, the specific requirements for the intermediate annealing during the fine drawing stage are as follows:

[0042] Set the temperature to 380–410℃ and the holding time to 2–4 minutes.

[0043] Furthermore, in step S6, the method for making the pattern outline is one or a combination of pinching, hammering, casting, and stamping.

[0044] Furthermore, in step S7, the specific requirements for the aging heat treatment are as follows:

[0045] The heating temperature is 220-250℃, and a reducing atmosphere of nitrogen and hydrogen or argon and hydrogen is used for protection. The volume percentage of hydrogen is 3-5%, and the holding time is 2-4 hours. After being taken out of the furnace, it is air-cooled to room temperature.

[0046] Furthermore, in step S8, the polishing method is one of electrolytic polishing, plasma polishing, or grinding polishing.

[0047] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0048] The manufacturing method of this invention optimizes the combination of alloy composition and process, and combines processes such as solution treatment, bar rolling, silver wire drawing, and aging treatment. After being welded and formed, the jewelry undergoes low-temperature aging treatment, which can disperse and precipitate intermediate phases, significantly improving the hardness of the filigree jewelry. The alloy surface can form a self-healing passivation protective film, improving its resistance to discoloration. Detailed Implementation

[0049] The method of this invention constructs a pure silver material through multi-element micro-alloying, meeting the purity requirements of pure silver in the national standard GB11887. The material possesses excellent cold-working properties, capable of being drawn into fine wires of 0.1 mm, which exhibit excellent skewing and shaping performance. After welding and forming, the jewelry undergoes low-temperature aging treatment, which disperses and precipitates intermediate phases, significantly increasing the hardness of the filigree jewelry. A self-healing passivation protective film can form on the alloy surface, improving its resistance to discoloration.

[0050] To achieve the above objectives, the present invention provides the following technical solution:

[0051] 1.Alloy composition

[0052] (1) Silver. To meet the fineness requirements of pure silver in the national standard GB11887, the silver content is controlled to be no less than 99.0%.

[0053] (2) Copper. It strengthens the silver matrix through solid solution and forms an intermediate phase with titanium in the alloy, resulting in age-hardening. Its content should be controlled at 0.1–0.5%.

[0054] (3) Zinc. Improves casting performance and enhances resistance to discoloration. Its content should be controlled at 0.1-0.3%.

[0055] (4) Tin. Improves the corrosion resistance of the alloy. Its content should be controlled at 0.04-0.2%.

[0056] (5) Germanium. Improves the alloy's resistance to discoloration. Its content should be controlled at 0.03–0.15%.

[0057] (6) Titanium. Improves corrosion resistance and forms a mesophase-reinforced matrix during aging treatment. Its content is controlled at 0.1-0.3%.

[0058] (7) Rare earth elements. They refine grain size, improve metallurgical quality, and enhance drawing performance. Their content is controlled at 0.02-0.1%, and can be one or more rare earth elements such as cerium, lanthanum, yttrium, gadolinium, and neodymium.

[0059] 2. Making the blank

[0060] The materials are proportioned and a bottom-drawing vacuum induction melting and continuous casting machine is used. The vacuum is reduced to below 0.05 Pa, and pure argon with a purity of over 99.99% is introduced. After the materials are completely melted, the traction device is activated to produce round bar billets with a diameter of 50–75 mm. Through vacuum and inert atmosphere protection during melting, and effective venting and feeding of the molten metal during bottom drawing, the round bars exhibit good metallurgical quality, higher density than traditional ingots, and a smooth surface, laying the foundation for the preparation of high-quality silver wire.

[0061] 3. Solution treatment

[0062] The billet is solution treated at 650–700℃ using a weakly reducing protective atmosphere of nitrogen or argon + hydrogen, with hydrogen comprising 3–5% by volume, for 60–120 minutes, followed by water quenching. This solution treatment improves the microstructure, eliminates casting stress, and allows alloying elements to dissolve uniformly into the silver matrix. The material exhibits excellent workability and prepares it for subsequent aging treatment to precipitate strengthening phases.

[0063] 4. Bar rolling

[0064] Clean the oxide layer and other impurities from the surface of the bar billet, then roll it using a bar mill with cemented carbide rolls and molybdenum disulfide lubricant applied to the groove surface. Control the single-pass shrinkage rate to 15-20%, and perform intermediate annealing when the total shrinkage rate reaches 40-50%. Roll to... Round bars were produced. Intermediate annealing was performed in a box-type atmosphere furnace using a weakly reducing protective atmosphere of nitrogen or argon + hydrogen, with hydrogen accounting for 3-5% of the volume. A slight positive pressure of 30-50 Pa was maintained inside the furnace, the temperature was set at 460-500℃, and the holding time was 8-12 minutes. The bars were then cooled in the furnace to below 120℃ and air-cooled. Through rolling and intermediate annealing, fine equiaxed grains were formed, further improving the material's internal density and facilitating subsequent filament drawing.

[0065] 5. Drawing silver wire

[0066] To ensure smooth silver wire drawing and guarantee its quality, based on the properties of this material, a multi-pass drawing process combined with intermediate annealing is required to avoid excessive shrinkage in a single pass, which could lead to wire breakage.

[0067] (1) From Pull-out reduction to For the rough drawing stage, a cemented carbide die is used, and the material is coated with synthetic ester grease or sulfonate lubricant. The reduction rate per pass is controlled at 15-25%, and the drawing speed is 5-8 m / min. When the reduction rate reaches 40-50%, intermediate annealing is performed in a box-type atmosphere furnace. A weakly reducing protective atmosphere of nitrogen or argon + hydrogen is used, with hydrogen accounting for 3-5% of the volume. The furnace is maintained at a slightly positive pressure of 30-50 Pa, the temperature is set at 450-480℃, and the holding time is 5-8 min. The furnace is then cooled to below 120℃ and air-cooled.

[0068] (2) From Pull-out reduction to This is the intermediate drawing stage. A diamond die is used, and high-purity mineral oil with a sulfur content of <0.1% and an aromatic hydrocarbon content of <0.5% is used for lubrication. The single-pass shrinkage rate is controlled at 10-15%. When the total shrinkage rate reaches 45-60%, an intermediate annealing is performed in a box-type atmosphere furnace. The set temperature is 430-460℃, the holding time is 4-6 minutes, and the furnace is cooled to below 120℃ before air cooling.

[0069] (3) From Pull-out reduction to The fine drawing stage is performed using a diamond die and lubricated with high-purity mineral oil containing <0.05% sulfur and <0.2% aromatics, along with nonionic or anionic surfactants. The single-pass shrinkage rate is controlled at 5–12%. When the total shrinkage rate reaches 40–50%, intermediate annealing is carried out in a chamber atmosphere furnace. The set temperature is 400–430℃, and the holding time is 3–5 minutes.

[0070] (4) From Pull-out reduction to This is the micro-drawing stage. A diamond mold is used, lubricated with high-purity mineral oil containing less than 0.02% sulfur and less than 0.1% aromatics. The single-pass shrinkage rate is controlled at 2-5%. When the total shrinkage rate reaches 30-50%, intermediate annealing is performed in a chamber atmosphere furnace. The set temperature is 380-410℃, and the holding time is 2-4 minutes.

[0071] 6. Making filigree blanks

[0072] The outer frame of the pattern is made using methods such as pinching, hammering, casting, and stamping. After annealing, it is pinched into shape and arranged in the predetermined position. The raw thread is folded in half, twisted into a spiral with a thread rolling tool, and flattened into a ribbon of the required width using a rolling mill. The desired length is pinched into the pattern and filled into the outer frame. Industrial pure borax (Na2B4O7·10H2O) liquid is sprayed onto the filled filigree blank. Solder with the appropriate melting point is selected according to the welding sequence, and silver-copper-zinc based powdered flux is evenly sprinkled on the areas to be welded. A scattered flame is used, and the flame is constantly moved to ensure uniform heating of all parts. When the entire blank is red-hot, the flux melts rapidly and penetrates into the weld. After the blank cools, it is boiled in alum water to remove flux and oxide film. The filigree blank is then placed in a weak acid solution and ultrasonically cleaned to further remove residual weld marks and oxide scale, and to prevent corrosion and discoloration.

[0073] 7. Timeliness processing

[0074] The filigree blanks are subjected to aging heat treatment at 220–250℃, protected by a reducing atmosphere of nitrogen + hydrogen or argon + hydrogen, with hydrogen accounting for 3–5% of the volume. The holding time is 2–4 hours, and the blanks are then air-cooled to room temperature after removal from the furnace. Through aging treatment, the strength and hardness of the silver filigree blanks are significantly improved, and their resistance to deformation is significantly enhanced.

[0075] 8. Post-processing

[0076] The surface of the silver filigree jewelry is polished using methods such as electrolytic polishing, plasma polishing, and abrasive polishing. Depending on the product design requirements, processes such as sandblasting, wire drawing, coloring, and electroplating are performed. Finally, protective treatments are applied, including immersion in a nano-silica-based or titanium dioxide-based protective agent and vacuum plating with a fluorine-modified silane protective film.

[0077] The present invention will be further described below in conjunction with specific embodiments. It should be noted that, without conflict, the embodiments or technical features described below can be arbitrarily combined to form new embodiments. In the following embodiments, in the drawing of silver wire, step (1) uses a sulfonate lubricant, step (2) uses high-purity mineral oil with a sulfur content of 0.05% and an aromatic content of 0.3%, step (3) uses high-purity mineral oil with a sulfur content of 0.04% and an aromatic content of 0.1%, and the surfactant is a nonionic or anionic surfactant, and step (4) uses high-purity mineral oil with a sulfur content of 0.01% and an aromatic content of 0.05%; in the preparation of the wire blank, the borax is Na2B4O7·10H2O liquid, and the flux is silver-copper-zinc based powdered flux; in the post-treatment, a nano-silica-based protective agent and a fluorinated silane protective film are used. All of the above materials are purchased externally and will not be described in detail here, unless otherwise specified.

[0078] Example 1: Pure Silver Filigree Pendant

[0079] 1. Chemical composition of alloy materials

[0080] This embodiment uses the filigree technique to make the pendant. The chemical composition of the silver material by weight percentage is: copper 0.3%, zinc 0.3%, germanium 0.06%, tin 0.07%, titanium 0.18%, lanthanum 0.03%, with the remainder being silver and unavoidable impurities.

[0081] 2. Making the blank

[0082] The materials are prepared in proportion and placed in a vacuum induction melting and continuous casting machine. The vacuum is evacuated to below 0.04 Pa, and 99.99% pure argon is introduced. After heating until all the materials are melted, the traction device is started to produce a round bar billet with a smooth surface and a diameter of 60 mm.

[0083] 3. Solution treatment

[0084] The billet was solution treated at 680℃ using a weak reducing protective atmosphere of nitrogen and hydrogen, with hydrogen accounting for 4% of the volume, and the holding time was 90 minutes, followed by water quenching.

[0085] 4. Bar rolling

[0086] The continuously cast round billets are rolled using a bar mill, with a single rolling reduction rate controlled at 15-20%, to produce thin bars with a diameter of 12mm. Intermediate annealing is performed in a box-type atmosphere furnace using a weakly reducing protective atmosphere of nitrogen or argon + hydrogen, with hydrogen accounting for 4% of the volume. The furnace is maintained at a slightly positive pressure of 40Pa, the set temperature is 480℃, and the holding time is 10 minutes. The bars are then cooled in the furnace to below 100℃ before being air-cooled.

[0087] 5. Drawing silver wire

[0088] (1) From Pull-out reduction to For the rough drawing stage, a cemented carbide die is used, and Kluber BEM41-132 synthetic ester-based grease is applied for lubrication. The reduction rate per pass is controlled at 15-25%, and the drawing speed is 6 m / min. When the reduction rate reaches 40-50%, intermediate annealing is performed in a chamber atmosphere furnace. A weakly reducing protective atmosphere of nitrogen or argon + hydrogen is used, with hydrogen accounting for 4% of the volume. The furnace is maintained at a slightly positive pressure of 40 Pa, the temperature is set at 460℃, the holding time is 6 min, and the furnace is cooled to below 100℃ before being air-cooled.

[0089] (2) From Pull-out reduction to This is the intermediate drawing stage. A diamond die is used, and Tellus S2MX 68 high-purity mineral oil is used for lubrication. The single-pass shrinkage rate is controlled at 10-15%. When the total shrinkage rate reaches 45-60%, an intermediate annealing is performed using a box-type atmosphere furnace. The set temperature is 450℃, the holding time is 5 minutes, and the furnace is cooled to below 100℃ before air cooling.

[0090] (3) From Pull-out reduction to The fine drawing stage is performed using a diamond die and lubricated with Tellus S2MX46 high-purity mineral oil and Lutensol TO 8 surfactant. The single-pass shrinkage rate is controlled at 5-12%. When the total shrinkage rate reaches 40-50%, intermediate annealing is carried out in a chamber atmosphere furnace. The set temperature is 420℃, and the holding time is 4 minutes.

[0091] (4) From Pull-out reduction to This is the micro-drawing stage. A diamond die is used, lubricated with Total CarteHD 32 high-purity mineral oil, and the single-pass shrinkage rate is controlled at 2-5%. When the total shrinkage rate reaches 30-50%, intermediate annealing is performed in a chamber atmosphere furnace. The set temperature is 390℃, and the holding time is 3 minutes.

[0092] 6. Making filigree blanks

[0093] The outer frame of the pattern is made using filigree and hammering techniques. After annealing, the shape is shaped and arranged according to the predetermined positions. The raw wire is folded in half, twisted into a spiral using a wire twisting tool, and flattened into a ribbon of the required width using a rolling mill. The desired length is then used to create the pattern, which is then inserted into the outer frame. Borax solution is sprayed onto the filled filigree blank. Solder with the appropriate melting point is selected according to the welding sequence, and the flux is evenly sprinkled on the areas to be welded. A diffused flame is used, constantly oscillating to ensure even heating of all parts. When the entire blank is red-hot, the flux melts rapidly and penetrates into the weld. After cooling, the blank is boiled in alum water to remove flux and oxide film. The filigree blank is then placed in a weak acid solution and ultrasonically cleaned to further remove residual weld marks and oxide scale, preventing corrosion and discoloration.

[0094] 7. Timeliness processing

[0095] The filigree blanks were subjected to aging heat treatment at a temperature of 230℃, protected by a reducing atmosphere of nitrogen and hydrogen, with hydrogen accounting for 4% of the volume, and held for 3 hours. After being removed from the furnace, they were air-cooled to room temperature.

[0096] 8. After polishing the surface of the silver filigree jewelry by electrolytic polishing, the surface is electroplated with rhodium, and finally vacuum-plated with a silicon dioxide film and an anti-fingerprint film.

[0097] Comparative Example 1 was made using the traditional pure silver filigree process. After aging treatment, the strength and hardness of the silver filigree blank in this embodiment were greatly improved, and its resistance to deformation was significantly better than that of Comparative Example 1, as shown in Table 1.

[0098] Table 1 Performance comparison between Example 1 and Comparative Example 1

[0099]

[0100] Example 2: Pure Silver Filigree Bangle

[0101] 1. Chemical composition of alloy materials

[0102] This embodiment uses the filigree technique to make the pendant. The chemical composition of the silver material by weight percentage is: copper 0.15%, zinc 0.1%, germanium 0.1%, tin 0.1%, titanium 0.15%, cerium 0.02%, gadolinium 0.02%, with the remainder being silver and unavoidable impurities.

[0103] 2. Making the blank

[0104] The materials are prepared in proportion and placed in a vacuum induction melting and continuous casting machine. The vacuum is evacuated to below 0.05 Pa, and 99.999% pure argon is introduced. After heating until all the materials are melted, the traction device is started to produce a round bar billet with a smooth surface and a diameter of 70 mm.

[0105] 3. Solution treatment

[0106] The billet was solution treated at 650℃ with a weak reducing protective atmosphere of nitrogen and hydrogen, with hydrogen accounting for 3% of the volume, and the holding time was 110 minutes, followed by water quenching.

[0107] 4. Bar rolling

[0108] The continuously cast round billets are rolled using a bar mill, with a single rolling reduction rate controlled at 15-20%, until they are rolled into thin bars with a diameter of 10.5 mm. When the total reduction rate reaches 40-50%, intermediate annealing is performed in a box-type atmosphere furnace. A weakly reducing protective atmosphere of nitrogen or argon + hydrogen is used, with hydrogen accounting for 3% of the volume. The furnace is maintained at a slightly positive pressure of 30 Pa, the temperature is set at 470℃, and the holding time is 10 min. The bars are then cooled in the furnace to below 110℃ before being removed from the furnace.

[0109] 5. Drawing silver wire

[0110] (1) Silver line from Pull-out reduction to A carbide mold is used, coated with Chevron DeloGrease EP 2 synthetic lubricant. The shrinkage rate per pass is controlled at 15-25%, and the drawing speed is 7 m / min. When the cross-sectional shrinkage rate reaches 40-50%, intermediate annealing is performed in a box-type atmosphere furnace. A weakly reducing protective atmosphere of nitrogen or argon + hydrogen is used, with hydrogen accounting for 3% of the volume. The furnace is maintained at a slightly positive pressure of 30 Pa, the temperature is set at 460℃, the holding time is 5 min, and the furnace is cooled to below 120℃ before being air-cooled.

[0111] (2) From Pull-out reduction to This is the intermediate drawing stage. A diamond die is used, and TotalCarte HD 68 high-purity mineral oil is used for lubrication. The single-pass shrinkage rate is controlled at 10-15%. When the total shrinkage rate reaches 45-60%, an intermediate annealing is performed using a box-type atmosphere furnace. The set temperature is 440℃, the holding time is 4 minutes, and the furnace is cooled to below 120℃ before air cooling.

[0112] (3) From Pull-out reduction to The fine drawing stage is performed using a diamond die and lubricated with L-HM 32 high-purity mineral oil and YD-1020 surfactant. The single-pass shrinkage rate is controlled at 5-12%. When the total shrinkage rate reaches 40-50%, intermediate annealing is carried out in a chamber atmosphere furnace. The set temperature is 410℃, and the holding time is 3.5 minutes.

[0113] (4) From Pull-out reduction to This is the micro-drawing stage. A diamond mold is used, lubricated with Total CarteHD 15 high-purity mineral oil, and the single-pass shrinkage rate is controlled at 2-5%. When the total shrinkage rate reaches 30-50%, intermediate annealing is performed in a chamber atmosphere furnace. The set temperature is 390℃, and the holding time is 2.5 minutes.

[0114] 6. Making filigree blanks

[0115] The outer frame of the pattern is made using filigree and stamping. After annealing, it is shaped and arranged according to the predetermined position. The raw wire is folded in half, twisted into a braid using a wire twisting tool, and flattened into a ribbon of the required width using a rolling mill. The desired length is then used to cut the pattern and fill it into the outer frame. Borax solution is sprayed onto the filled filigree blank. Solder with the appropriate melting point is selected according to the welding sequence, and the flux is evenly sprinkled on the areas to be welded. A diffused flame is used, constantly moving the flame to ensure even heating of all parts. When the entire blank is red-hot, the flux melts rapidly and penetrates into the weld. After the blank cools, it is boiled in alum water to remove flux and oxide film. The filigree blank is then placed in a weak acid solution and ultrasonically cleaned to further remove residual weld marks and oxide scale, preventing corrosion and discoloration.

[0116] 7. Timeliness processing

[0117] The filigree blanks were subjected to aging heat treatment at a temperature of 230℃, protected by a reducing atmosphere of argon and hydrogen, with hydrogen accounting for 3% of the volume, and held for 2.5 hours. After being removed from the furnace, they were air-cooled to room temperature.

[0118] 8. After polishing the surface of the silver filigree jewelry using plasma polishing, the surface is electroplated with gold and finally immersed in KBE-903 nano-silica-based protective agent.

[0119] The filigree bracelet made of silver alloy material in this embodiment has significantly improved resistance to deformation and wear, and exhibits excellent anti-discoloration properties after being soaked in artificial sweat, as shown in Table 2.

[0120] Table 2 Modification effects of Example 2

[0121]

[0122] Example 3: Pure Silver Filigree Ring

[0123] 1. Chemical composition of alloy materials

[0124] This embodiment uses the filigree technique to make the ring. The chemical composition of the silver material by weight percentage is: copper 0.4%, zinc 0.15%, germanium 0.05%, tin 0.05%, titanium 0.2%, yttrium 0.05%, with the remainder being silver and unavoidable impurities.

[0125] 2. Making the blank

[0126] The materials are prepared in proportion and placed in a vacuum induction melting and continuous casting machine. The vacuum is evacuated to below 0.03 Pa, and 99.999% pure argon is introduced. After heating until all the materials are melted, the traction device is started to produce a round bar billet with a smooth surface and a diameter of 55 mm.

[0127] 3. Solution treatment

[0128] The billet is solution treated at 700℃ with a weak reducing protective atmosphere of nitrogen and hydrogen, with hydrogen accounting for 5% of the volume, and the holding time is 80 minutes, followed by water quenching.

[0129] 4. Bar rolling

[0130] The continuously cast round billets are rolled using a bar mill, with a single rolling reduction rate controlled at 15-20%, to produce thin bars with a diameter of 6 mm. Intermediate annealing is performed in a box-type atmosphere furnace using a weakly reducing protective atmosphere of argon and hydrogen, with hydrogen accounting for 5% of the volume. The furnace is maintained at a slightly positive pressure of 50 Pa, the set temperature is 500℃, and the holding time is 11 minutes. The bars are then cooled in the furnace to below 90℃ before being air-cooled.

[0131] 5. Drawing silver wire

[0132] (1) Silver line from Pull-out reduction to A carbide mold was used, coated with BEM 41-132 synthetic lubricant. The shrinkage rate per pass was controlled at 15-25%, and the drawing speed was 6 m / min. When the cross-sectional shrinkage rate reached 40-50%, intermediate annealing was performed in a chamber atmosphere furnace. A weakly reducing protective atmosphere of argon + hydrogen was used, with hydrogen accounting for 5% of the volume. The furnace was maintained at a slightly positive pressure of 50 Pa, the temperature was set at 480℃, and the holding time was 6 min. After furnace cooling to below 90℃, the sample was air-cooled.

[0133] (2) From Pull-out reduction to A diamond mold is used, and L-HM 68 high-purity mineral oil is used for lubrication. The single-pass shrinkage rate is controlled at 10-15%, and when the total shrinkage rate reaches 45-60%, intermediate annealing is performed in a box-type atmosphere furnace. The set temperature is 450℃, the holding time is 6 minutes, and the furnace is cooled to below 90℃ before air cooling.

[0134] (3) From Pull-out reduction to The fine drawing stage is performed using a diamond die and lubricated with KTL 46 high-purity mineral oil and AE-9 surfactant. The single-pass shrinkage rate is controlled at 5-12%. When the total shrinkage rate reaches 40-50%, intermediate annealing is carried out in a chamber atmosphere furnace. The set temperature is 430℃, and the holding time is 4.5 minutes.

[0135] (4) From Pull-out reduction to This is the micro-drawing stage. A diamond mold is used, lubricated with Tellus S2MX 22 high-purity mineral oil. The single-pass shrinkage rate is controlled at 2-5%. When the total shrinkage rate reaches 30-50%, intermediate annealing is performed in a chamber atmosphere furnace. The set temperature is 410℃, and the holding time is 4 minutes.

[0136] 6. Making filigree blanks

[0137] The outer frame of the pattern is made using filigree and stamping. After annealing, it is shaped and arranged according to the predetermined position. The raw wire is folded in half, twisted into a braid using a wire twisting tool, and flattened into a ribbon of the required width using a rolling mill. The desired length is then used to cut the pattern and fill it into the outer frame. Borax solution is sprayed onto the filled filigree blank. Solder with the appropriate melting point is selected according to the welding sequence, and the flux is evenly sprinkled on the areas to be welded. A diffused flame is used, constantly moving the flame to ensure even heating of all parts. When the entire blank is red-hot, the flux melts rapidly and penetrates into the weld. After the blank cools, it is boiled in alum water to remove flux and oxide film. The filigree blank is then placed in a weak acid solution and ultrasonically cleaned to further remove residual weld marks and oxide scale, preventing corrosion and discoloration.

[0138] 7. Timeliness processing

[0139] The filigree blanks were subjected to aging heat treatment at a temperature of 250℃, protected by a reducing atmosphere of nitrogen and hydrogen, with hydrogen accounting for 5% of the volume, and held for 3.5 hours. After being removed from the furnace, they were air-cooled to room temperature.

[0140] 8. After polishing the surface of the silver filigree jewelry using plasma polishing, the surface is electroplated with gold, and finally vacuum-plated with a Fluoro-SiO230 fluorine-modified siloxane transparent protective film.

[0141] The silver alloy material in this embodiment significantly improves the filigree ring's resistance to deformation and wear. After being soaked in artificial sweat for 8 hours, the color difference is [value missing], demonstrating excellent anti-discoloration properties.

[0142] Table 3 Modification effects of Example 3

[0143]

[0144] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A method for manufacturing anti-deformation silver jewelry, characterized in that, Includes the following steps: S1: Formulating alloy components The alloy composition includes the following components by mass percentage: Copper 0.1-0.5%, zinc 0.1-0.3%, tin 0.04-0.2%, germanium 0.03-0.15%, titanium 0.1-0.3%, rare earth elements 0.02-0.1%, the remainder being silver, and unavoidable impurity elements; S2: Making blanks The materials are prepared in proportion, and a bottom-drawing vacuum induction melting and continuous casting machine is used. The vacuum is drawn to below 0.05Pa, and pure argon with a purity of over 99.99% is introduced. After heating until all the materials are melted, the traction device is started to produce round bar billets. S3: Solution treatment Solution treatment is performed on the round bar billet; S4: Bar rolling The solution-treated billet is rolled using a bar mill. The single rolling reduction rate is controlled at 15-20%. When the total reduction rate reaches 40-50%, intermediate annealing is performed, and the billet is rolled into round bars with a diameter of φ10-φ15mm. S5: Pulling Silver Wire (1) The drawing process from φ10~φ15mm to φ5~φ6mm is the rough drawing stage. A carbide die is used and a synthetic lubricant is applied for lubrication. The reduction rate of each pass is controlled at 15~25%, and the drawing speed is 5~8m / min. When the cross-sectional reduction rate reaches 40~50%, an intermediate annealing is carried out in a box-type atmosphere furnace. (2) When the drawing is reduced from φ5~φ6mm to φ2~φ3mm, it is the intermediate drawing stage. A diamond die is used and high-purity mineral oil is used for lubrication. The single-pass reduction rate is controlled at 10~15%. When the total reduction rate reaches 45~60%, a box-type atmosphere furnace is used for intermediate annealing. (3) When the drawing shrinks from φ2~φ3mm to φ0.5~φ1.0mm, it is the fine drawing stage. A diamond die is used, and high-purity mineral oil and surfactants are used for lubrication. The single-pass shrinkage rate is controlled at 5~12%. When the total shrinkage rate reaches 40~50%, a box-type atmosphere furnace is used for intermediate annealing. S6: Making filigree blanks Make the pattern outline, anneal and shape it, arrange it according to the predetermined position, fold the plain thread in half, twist it into a twisted thread with a thread rolling board, flatten it into a ribbon of the required width with a rolling mill, take the required length and shape the pattern, fill it into the outline, spray borax liquid on the filled filigree blank, select the corresponding melting point of the solder according to the welding sequence, sprinkle the solder evenly on the part to be welded, use a scattered flame and keep moving the flame to make all parts heat evenly. When the blank is red-hot, the solder melts quickly and penetrates into the weld. After the blank cools, put it into alum water and boil it to remove the flux and oxide film. Put the filigree blank into a weak acid solution and clean it with ultrasonic cleaning to further remove residual solder marks and oxide scale, and obtain the filigree blank. S7: Timeliness Processing The filigree blanks are subjected to aging heat treatment; S8: Post-processing Polish and protect the surface of the silver filigree jewelry.

2. The method for manufacturing anti-deformation silver jewelry according to claim 1, characterized in that, In step S1, the rare earth element is one or more of cerium, yttrium, lanthanum, neodymium, and gadolinium.

3. The method for manufacturing anti-deformation silver jewelry according to claim 1, characterized in that, In step S2, the diameter of the round bar blank is 50-75 mm.

4. The method for manufacturing anti-deformation silver jewelry according to claim 1, characterized in that, In step S3, the specific requirements for solution treatment are as follows: The treatment temperature is 650-700℃, a weakly reducing protective atmosphere is used, the holding time is 60-120 minutes, and then the water is quenched and cooled.

5. The method for manufacturing anti-deformation silver jewelry according to claim 4, characterized in that, In step S3, the weakly reducing protective atmosphere is a combination of nitrogen and hydrogen or a combination of argon and hydrogen, wherein the volume percentage of hydrogen in the combination gas is 3-5%.

6. The method for manufacturing anti-deformation silver jewelry according to claim 1, characterized in that, In step S4, the specific requirements for intermediate annealing are as follows: Intermediate annealing is performed in a box-type atmosphere furnace, using a weakly reducing protective atmosphere of a combination of nitrogen and hydrogen or a combination of argon and hydrogen. The volume percentage of hydrogen is 3-5%. The furnace is kept under a slight positive pressure of 30-50 Pa. The temperature is set at 460-500℃, and the holding time is 8-12 minutes. The furnace is then cooled to below 120℃ and removed from the furnace for air cooling.

7. The method for manufacturing anti-deformation silver jewelry according to claim 1, characterized in that, In step S5, the specific requirements for intermediate annealing during the rough drawing stage are as follows: A weakly reducing protective atmosphere is used, consisting of a combination of nitrogen and hydrogen or a combination of argon and hydrogen, with hydrogen accounting for 3-5% of the volume. The furnace is kept under a slightly positive pressure of 30-50 Pa, the temperature is set at 450-480℃, the holding time is 5-8 minutes, and the furnace is cooled to below 120℃ before being removed from the furnace and air-cooled. The specific requirements for intermediate annealing in the intermediate pulling stage are as follows: Set the temperature to 430-460℃, hold for 4-6 minutes, cool in the furnace to below 120℃, and then air cool after removal from the furnace. The specific requirements for intermediate annealing during the fine drawing stage are as follows: Set the temperature to 380–410℃ and the holding time to 2–4 minutes.

8. The method for manufacturing anti-deformation silver jewelry according to claim 1, characterized in that, In step S6, the method for making the pattern outline is one or a combination of pinching, hammering, casting, and stamping.

9. The method for manufacturing anti-deformation silver jewelry according to claim 1, characterized in that, In step S7, the specific requirements for aging heat treatment are as follows: The heating temperature is 220-250℃, and a reducing atmosphere of nitrogen and hydrogen or argon and hydrogen is used for protection. The volume percentage of hydrogen is 3-5%, and the holding time is 2-4 hours. After being taken out of the furnace, it is air-cooled to room temperature.

10. The method for manufacturing anti-deformation silver jewelry according to claim 1, characterized in that, In step S8, the polishing method is one of electrolytic polishing, plasma polishing, or abrasive polishing.

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