Process for hardening gold with micro-nano metal powder

Abstract

The present application relates to precious metal alloy material manufacturing technical field, specifically relates to a kind of micro-nano metal powder to gold hardening process, including blank loading furnace, smelting, vacuum ingot, surface cleaning, rolling stretching and aging hardening, product surface treatment and product welding etc.Step.The present application is characterized in that: material selection, micro-nano metal powder is diverse and small in quantity, such as titanium powder, cobalt powder etc., can provide a variety of strengthening mechanism and ensure economy.Smelting process is accurate, with good vacuum and temperature control, after adding micro-nano metal powder, stirring is uniform.Ingot is made of water-cooled copper mold rapid solidification, surface cleaning is treated after using aqua regia etc.Drying.Rolling stretching can be executed annealing in the middle, process is flexible.Product manufacturing process is diverse, surface treatment has polishing, electroplating and coloring etc.Welding uses advanced mode such as laser to avoid hardness reduction.The process improves the effect and quality of gold hardening from many aspects, meets different needs, with wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of precious metal alloy material manufacturing, in particular to a process for hardening gold by using micro-nano metal powder. BACKGROUND

[0002] Traditional gold processing technology has many shortcomings, which seriously restricts the quality and performance improvement of gold products, and also cannot meet the diversified market demand. In the gold hardening technology, the alloy adding method faces the problems of single material selection and limited adding ratio. Although the commonly used alloy elements can increase the hardness, they cannot provide the unique performance of micro-nano metal powder, and each has its own defects, which will also affect the purity, appearance and other performance of gold. The temperature control of the heat treatment method is not accurate, the energy consumption is high, which leads to uneven crystal structure, affects the hardness and performance stability, and increases the cost and environmental burden. The cold working method is not uniform in work hardening, which is easy to produce stress concentration, affects the quality and performance of the product, reduces the fatigue resistance and toughness, and shortens the service life. The electroforming technology is complex, high in cost, and has great limitations on products. Hollow hard gold products are different from traditional gold in terms of recycling and other aspects. The gold smelting and ingot casting technology also has defects. The vacuum degree is difficult to guarantee in the smelting process, which affects the purity and quality of gold, resulting in defects such as pores and inclusions. The temperature control is unstable in the ingot casting process, which affects the uniformity of alloy composition; the slow solidification speed leads to large grain size, many crystal defects, reduced strength and hardness; and the poor surface quality increases the difficulty and cost of subsequent processing. Gold surface treatment and welding technology also need to be improved. The surface treatment effect is limited and lacks diversification, which cannot meet the requirements of high gloss and flatness, and has poor corrosion resistance. The welding quality is unstable in the welding technology, the temperature and time of flame welding are difficult to control, which affects the product quality; and the technology has high requirements for the environment, generates waste gas and residue, and pollutes the environment. These shortcomings limit the development of gold processing technology and the quality improvement of gold products as a whole, and there is an urgent need for innovation and improvement of technology to meet market demand and industry development trend.

[0003] Chinese patent application with publication number CN105420650A discloses a hardening process for gold products, which puts the gold product workpiece to be treated into a hardness tester to test the hardness, and uses a balance to weigh the weight of the gold product workpiece to be treated; adjusts the amount of hardening raw materials used according to the hardness and weight data of the gold product workpiece to be treated; puts the hardening raw materials and the gold product workpiece to be treated into a heating crucible, and then puts the crucible into a sealed tank, and places the sealed tank in a box-type vacuum resistance furnace to perform several heating, temperature rising and heat preservation stages; takes out the baked gold product workpiece from the sealed tank, rinses it with clean water, puts the gold product workpiece into a hardness tester to test the hardness value after treatment, and uses a balance to weigh the weight of the gold product workpiece after treatment. It still cannot solve the above-mentioned shortcomings and cannot meet the needs of existing technology. SUMMARY

[0004] The present application aims to provide a process for hardening gold with micro-nano metal powder to solve the problems in the background art. To solve the above technical problems, the present application provides a process for hardening gold with micro-nano metal powder, comprising the following steps:

[0005] 1) Loading the blank into the furnace: weighing the gold base material, taking micro-nano metal powder according to 0.1-1% of the mass percentage of the gold base material, and placing it into the secondary boat, and placing the weighed gold base material into the crucible; the micro-nano metal powder is at least one of micro-nano titanium powder, micro-nano cobalt powder, micro-nano beryllium powder, and micro-nano aluminum powder;

[0006] 2) Melting: connecting the power supply, vacuumizing, and starting the diffusion pump heating at the same time, continuously heating to 1400-1700℃, adding micro-nano metal powder, and starting the mechanical stirrer for full stirring after the micro-nano metal powder is melted into the gold solution, completing the melting and compounding, and obtaining 999 gold melt;

[0007] 3) Vacuum ingot casting: the water-cooled copper mold is kept by passing in 15-18℃ water, the crucible is poured, the 999 gold melt is cast into the copper mold, and the water-cooled mold promotes the solution to solidify into a sub-millimeter smooth and dense body within ten seconds, the casting is completed, and the ingot is obtained;

[0008] 4) Surface cleaning: the ingot is soaked in a aqua regia beaker, heated to 80-90℃ for 30-40 minutes, rinsed clean, and dried in a 200℃ oven;

[0009] 5) Rolling and stretching, aging and hardening: cleaning the rollers and performing rolling operation;

[0010] 6) Product surface treatment: polishing treatment by mechanical polishing, making it have enough strength for inlaying gemstones, and performing electroplating and coloring treatment;

[0011] 7) Product welding.

[0012] As a preferred, in the step 5), the rolling pass and the feed amount are executed according to the designed flow, the rolling process causes material hardening phenomenon, and the predetermined intermediate annealing softening process is executed in the rolling process, and the annealing softening and aging and hardening are performed in a tunnel furnace or a muffle furnace.

[0013] As a preferred, in the step 7), the welding is performed by laser welding, energy storage welding or argon arc welding, avoiding long-time flame heating to reduce hardness.

[0014] As a preferred, in the step 2), a vacuum secondary feeding melting furnace is used in the melting process, and mechanical stirring is performed in the furnace during the melting and compounding process.

[0015] As preferred, in the step 2), the diffusion pump preheating time is 60 minutes; the vacuum degree reaches 100 Pa, then the heating is started, the temperature is continuously increased at a rate of 50-150℃ / min, the diffusion pump high vacuum deoxidation is started when the temperature reaches 750-950℃, the vacuum is kept for 6*10 -2 Pa, argon is filled to maintain 50-100 Pa, the mechanical stirrer is started to fully stir for 30 seconds after the micro-nano metal powder is melted into the gold solution, and the melting and blending are completed.

[0016] As preferred, in the step 2), the micro-nano metal powder is micro-nano cobalt powder which is pre-oxidized at room temperature under vacuum and filled with argon protection, and the pre-oxidation treatment method is pre-mixed with micro-nano titanium powder, mixed gas of oxygen, argon and nitrogen is introduced, heated and kept at 150℃, and the powder is used after the oxide film is generated on the surface of the powder.

[0017] As preferred, in the step 2), the micro-nano metal powder is micro-nano titanium powder which is pre-oxidized at room temperature under vacuum and filled with argon protection, and the pre-oxidation treatment method is pre-mixed with micro-nano cobalt powder, mixed gas of oxygen, argon and nitrogen is introduced, heated and kept at 150℃, and the powder is used after the oxide film is generated on the surface of the powder.

[0018] As preferred, in the step 2), the micro-nano metal powder is micro-nano aluminum powder which is pre-oxidized at room temperature under vacuum and filled with argon protection, and the pre-oxidation treatment method is pre-mixed with micro-nano beryllium powder and micro-nano cobalt powder, mixed gas of oxygen, argon and nitrogen is introduced, heated and kept at 150℃, and the powder is used after the oxide film is generated on the surface of the powder.

[0019] As preferred, in the step 2), the micro-nano metal powder is micro-nano beryllium powder which is pre-oxidized at room temperature under vacuum and filled with argon protection, and the pre-oxidation treatment method is pre-mixed with micro-nano cobalt powder, micro-nano cobalt powder and micro-nano titanium powder, mixed gas of oxygen, argon and nitrogen is introduced, heated and kept at 150℃, and the powder is used after the oxide film is generated on the surface of the powder.

[0020] The advantages of the present application are as follows:

[0021] 1) Material selection and ratio: the diversity of micro-nano metal powder: at least one of micro-nano titanium powder, micro-nano cobalt powder, micro-nano beryllium powder and micro-nano aluminum powder is used as an additive material, which provides multiple possible strengthening mechanisms for the hardening of gold. Different micro-nano metal powders have their own unique physical and chemical properties, for example, titanium has high strength and good corrosion resistance, cobalt can improve the magnetism and hardness of the alloy, etc. This diversity can select appropriate combinations of micro-nano metal powders according to different requirements and application scenarios. Only need to take micro-nano metal powder according to 0.1-1% mass percentage of gold base material, significant strengthening effect can be achieved under small amount of addition, which can ensure the main properties of gold and effectively improve its hardness and other performances, improve the utilization rate and economy of the material.

[0022] 2) Melting process, vacuum and temperature control precision: first through the mechanical pump pre-vacuum, and then start the Roots pump vacuum, while starting the diffusion pump heating, preheating time 60 minutes, to ensure the good vacuum environment in the furnace. After the vacuum degree reaches 100 Pa, start heating, and continuously heat at a rate of 50-150 ℃ / min. This precise temperature control and vacuum conditions are conducive to removing impurity gases in the gold raw material, improving the purity and quality of gold. After the temperature reaches 750-950 ℃, open the diffusion pump high vacuum deoxidation, vacuum 6x10- 2 Pa, reduce the occurrence of oxidation reaction, ensure the uniformity and stability of alloy composition, fill in argon to maintain 50-100 Pa, further optimize the smelting environment, reduce the occurrence of oxidation and other adverse reactions, ensure the uniformity and stability of alloy composition. Micro-nano metal powder addition and stirring optimization: add micro-nano metal powder at a high temperature of 1400-1700 ℃, at which the gold is in a liquid state, which is conducive to the uniform melting of micro-nano metal powder. After melting, start the mechanical stirrer to fully stir for 30 seconds, so that the micro-nano metal powder is evenly distributed in the gold solution, avoiding composition segregation, thereby ensuring the uniformity and consistency of the overall performance of the gold alloy. Vacuum secondary feeding melting furnace is used for smelting, which provides a stable vacuum and temperature environment for the entire smelting process, and facilitates accurate addition and stirring of micro-nano metal powder, improving the controllability and repeatability of the production process.

[0023] 3) Ingot casting process, water-cooled copper mold rapid solidification: can refine the grain, reduce the crystal defects, thereby improving the strength and hardness of the gold alloy. At the same time, the smooth and dense ingot surface is conducive to subsequent processing, reducing surface defects and processing allowance.

[0024] 4) Surface cleaning process, composite acid cleaning and drying treatment: the ingot is soaked in aqua regia beaker, heated to 80-90 ℃ for 30 minutes, the composite acid can effectively remove the oxides and impurities on the surface of the ingot, making the ingot surface cleaner. Then move to the water tank to rinse clean, dry in a 200 ℃ oven, ensuring the cleanliness and dryness of the ingot surface, providing good surface conditions for subsequent rolling and stretching processes, which is conducive to improving the processing quality and product performance.

[0025] 5) Regarding the rolling, stretching, and age-hardening processes, process flexibility and material performance optimization are achieved: the rolling passes and feed rates are executed according to the designed flow, inducing material hardening during rolling. Simultaneously, a predetermined mid-process annealing process can be performed based on actual conditions. This design not only achieves further hardening of the gold alloy, improving its strength, but also adjusts the material's hardness and toughness through the annealing process, giving it better processing and service performance. Annealing and softening, along with age hardening, are carried out in a tunnel furnace or muffle furnace, providing a stable heating environment for the process and ensuring the consistency and reliability of the processing results.

[0026] 6) In terms of product manufacturing and surface treatment processes, diversified processes meet different needs: Standard processes are used for processing sheet and wire jewelry or making chains, while precision-cast products utilize casting processes. This diversified manufacturing process can meet the production needs of different types of gold products, expanding the application range of this technology. Mechanical grinding and polishing processes ensure sufficient strength for setting gemstones, improving the practicality and aesthetics of the products. Simultaneously, electroplating and coloring treatments not only enhance the product's corrosion resistance but also give it a rich array of colors, satisfying the market's diverse aesthetic demands for gold jewelry.

[0027] 7) Regarding product welding processes, advanced welding methods ensure product quality: Laser welding, energy storage welding, or argon arc welding are used for product welding, avoiding the problem of reduced hardness caused by prolonged flame heating. These advanced welding technologies enable fast and precise welding, ensuring the quality and strength of the weld joints, while not affecting the overall performance of the gold alloy, thus improving product yield and reliability. Attached Figure Description

[0028] Figure 1 These are the hardening curves of Au-01%Me alloy at different aging temperatures.

[0029] Figure 2 It is a line graph showing the deformation-hardness variation.

[0030] Figure 3 This is a bar chart showing the change in hardness due to the amount of micro / nano metal powder added. Detailed Implementation

[0031] For the purposes of the detailed description below, it is to be understood that the application can assume various alternative variations and step sequences, except where expressly specified to the contrary. Moreover, other than in any operating examples, or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the making and use of the compositions herein and

[0032] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the application are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0033] Also, it should be understood that any numerical range recited herein is intended to include all sub-ranges of the same numerical precision subsumed

[0034] Example One

[0035] A process for hardening gold with micro-nano metal powder, comprising the following steps:

[0036] Charging the furnace with the billet:

[0037] Weigh the gold base material, take 0.1% of the mass percentage of micro-nano titanium powder according to the gold base material, put it into the secondary material boat, and put the weighed gold base material into the crucible.

[0038] Melting:

[0039] A vacuum secondary feeding melting furnace is used. Turn on the power, start the Roots pump for continuous vacuum after pre-vacuuming with the mechanical pump, and start the diffusion pump heating at the same time. The preheating time of the diffusion pump is 60 minutes. Start heating when the vacuum degree reaches 100 Pa, continuously increase the temperature at a rate of 50℃ / min, open the diffusion pump high vacuum deoxidization when the temperature reaches 750℃, and maintain the vacuum at 6x10- 2Pa, reduce the occurrence of oxidation reaction, ensure the uniformity and stability of alloy composition, fill in argon to maintain 50 Pa. Continue to heat to 1400 ℃, add micro-nano titanium powder, after melting into the gold solution, start the mechanical stirrer to stir fully for 30 seconds, and the melting is completed. The micro-nano titanium powder is pre-oxidized before use under vacuum and argon protection. The pre-oxidation treatment method is to pre-mix with micro-nano cobalt powder, heat to 150 ℃ under oxygen-argon-nitrogen mixed gas, and wait for the oxide film to be generated on the surface of the powder. Under vacuum and argon protection at room temperature, direct exposure to air will cause spontaneous combustion and direct oxidation.

[0040] Vacuum ingot casting:

[0041] Water-cooled copper mold is kept at 15 ℃ by passing water, heating is stopped, the crucible is slowly poured, the 999 gold melt is cast into the copper mold, and the water-cooled mold promotes high-speed solidification of the solution to form a smooth and dense sub-millimeter body within ten seconds.

[0042] Surface cleaning:

[0043] The ingot is soaked in an aqua regia beaker, heated to 80 ℃ for 30 minutes, then moved to a clean water pool for rinsing, and dried in a 200 ℃ oven.

[0044] Rolling and stretching, aging hardening:

[0045] The rollers are cleaned and the rolling operation is performed. The rolling pass and the feed amount are executed according to the designed process. The material hardening phenomenon is caused during the rolling process. The predetermined intermediate annealing process is performed during the rolling process. Annealing softening and aging hardening are performed in a tunnel furnace.

[0046] Product surface treatment:

[0047] Through mechanical polishing and polishing processing, it has sufficient inlaying gemstone strength, and is subjected to electroplating and coloring treatment.

[0048] Product welding:

[0049] Laser welding is used to avoid long-time flame heating and reduce hardness.

[0050] Example two

[0051] A process for hardening gold with micro-nano metal powder, comprising the following steps:

[0052] Blank loading:

[0053] The gold base material is weighed, the micro-nano cobalt powder is weighed according to 0.3% of the mass percentage of the gold base material, and is placed into a secondary material boat. The weighed gold base material is placed into a crucible.

[0054] Melting:

[0055] Vacuum secondary charging melting furnace is adopted. Connect the power, start the Roots pump for continuous vacuumizing after pre-vacuumizing by mechanical pump, and start the diffusion pump heating at the same time. The preheating time of the diffusion pump is 60 minutes. Start heating when the vacuum degree reaches 100 Pa, and continuously increase the temperature at the rate of 80 ℃ / min. Open the diffusion pump high vacuum deoxidization when the temperature reaches 800 ℃, and maintain the vacuum at 6*10- 2 Pa. Reduce the occurrence of oxidation reaction, ensure the uniformity and stability of alloy composition, and fill argon to maintain 60 Pa. Continue to heat to 1500 ℃, add micro-nano cobalt powder, and start the mechanical stirrer for full stirring for 30 seconds after melting into the gold solution. The micro-nano cobalt powder is pre-oxidized before use by pre-mixing with micro-nano titanium powder and heating at 150 ℃ in oxygen-argon-nitrogen mixed gas. After the oxide film is formed on the surface of the powder, it is ready for use.

[0056] Vacuum ingot casting:

[0057] The water-cooled copper mold is kept by passing 16 ℃ water, the heating is stopped, the crucible is slowly poured, the 999 gold melt is cast into the copper mold, and the water-cooled mold promotes high-speed solidification of the solution to form a sub-millimeter smooth and dense body within ten seconds. The casting is completed.

[0058] Surface cleaning:

[0059] The ingot is soaked in aqua regia beaker, heated to 83 ℃ for 40 minutes, then moved to a clean water pool for cleaning, and dried in a 200 ℃ oven.

[0060] Rolling, stretching, and aging hardening:

[0061] Clean the rollers and perform the rolling operation. The rolling pass and the feed amount are executed according to the designed process. The material hardening phenomenon is caused during the rolling process. The predetermined intermediate annealing process is executed during the rolling process. Annealing softening and aging hardening are carried out in a muffle furnace.

[0062] Product surface treatment:

[0063] Through mechanical polishing and polishing processing, it has sufficient strength for inlaying gemstones, and is subjected to electroplating and coloring treatment.

[0064] Product welding:

[0065] Use energy storage welding method to avoid long-time flame heating and reduce hardness.

[0066] Example three

[0067] A process for hardening gold with micro-nano metal powder, comprising the following steps:

[0068] Blank loading:

[0069] Weigh the gold base, take 0.5% of the mass percentage of the gold base, put it into the secondary material boat, and put the weighed gold base into the crucible.

[0070] Melting:

[0071] Vacuum secondary feeding melting furnace is used. Connect the power supply, start the Roots pump for continuous vacuum after pre-vacuuming with the mechanical pump, and start the diffusion pump heating at the same time. The preheating time of the diffusion pump is 60 minutes. Start heating when the vacuum degree reaches 100 Pa, and continuously increase the temperature at a rate of 100 ℃ / min. Open the diffusion pump high vacuum deoxidization when the temperature reaches 850 ℃, and maintain the vacuum at 6×10- 2 Pa for 6 hours to reduce the occurrence of oxidation reaction, ensure the uniformity and stability of the alloy composition, and fill argon to maintain 75 Pa. Continue heating to 1550 ℃, add the micro-nano beryllium powder, and start the mechanical stirrer for full stirring for 30 seconds after the micro-nano beryllium powder is melted into the gold solution. The micro-nano beryllium powder is pre-oxidized before use by pre-mixing with micro-nano cobalt powder and micro-nano titanium powder, and then heating at 150 ℃ in an oxygen-argon-nitrogen mixed gas. After the oxide film is formed on the surface of the powder, it is ready for use. The vacuum is extracted and the argon protection is filled at room temperature. Direct exposure to air will cause spontaneous combustion and direct oxidation.

[0072] Vacuum ingot casting:

[0073] The water-cooled copper mold is kept at 17 ℃ by passing water, the heating is stopped, the crucible is slowly poured, the 999 gold melt is cast into the copper mold, and the water-cooled mold is used to promote high-speed solidification of the solution to form a sub-millimeter smooth and dense body within ten seconds. The casting is completed.

[0074] Surface cleaning:

[0075] The ingot is soaked in an aqua regia beaker, heated to 85 ℃ for 30 minutes, then moved to a clean water pool for rinsing, and dried in a 200 ℃ oven.

[0076] Rolling, stretching, and aging hardening:

[0077] The rollers are cleaned and the rolling operation is performed. The rolling pass and the amount of feed are executed according to the designed process. The material hardening phenomenon occurs during the rolling process. The predetermined intermediate annealing process is performed during the rolling process. Annealing softening and aging hardening are performed in a tunnel furnace.

[0078] Product manufacturing:

[0079] The sheet and wire processing ornaments or chain making are executed according to the conventional process, and the precision casting products are executed according to the casting process.

[0080] Product surface treatment:

[0081] Mechanical polishing is used for polishing treatment to make it have enough strength for inlaying gemstones, and electroplating and coloring treatment are performed.

[0082] Product welding:

[0083] Argon arc welding is used to avoid the hardness reduction caused by prolonged flame heating.

[0084] Example 4

[0085] A process for hardening gold with micro / nano metal powder includes the following steps:

[0086] Raw material loading into the furnace:

[0087] Weigh the gold base material, and weigh out micro-nano aluminum powder at a mass percentage of 0.7% of the gold base material. Place the powder into a secondary material boat, and then place the weighed gold base material into a crucible.

[0088] Smelting:

[0089] A vacuum secondary feeding melting furnace is used. After power is connected and the mechanical pump pre-vacuums the furnace, the Roots pump is started to continuously evacuate the vacuum. Simultaneously, the diffusion pump is started for heating, with a preheating time of 60 minutes. Heating is initiated once the vacuum reaches 100 Pa, and the temperature is continuously increased at a rate of 120 °C / min. Once the temperature reaches 900 °C, the diffusion pump is activated for high-vacuum deoxidation, and the vacuum is maintained at 6 × 10⁻⁻⁶. 2 To reduce oxidation and ensure the uniformity and stability of the alloy composition, argon gas is introduced to maintain a pressure of 80 Pa. The mixture is continuously heated to 1600℃, and micro / nano aluminum powder is added. After it melts into the gold solution, a mechanical stirrer is activated to stir thoroughly for 30 seconds, completing the melting and mixing process. The micro / nano aluminum powder is then protected under vacuum and argon gas at room temperature. Before use, it undergoes pre-oxidation treatment by pre-mixing it with micro / nano beryllium powder and micro / nano cobalt powder, followed by heating and holding at 150℃ with an oxygen-argon-nitrogen mixture until an oxide film forms on the powder surface. It is then ready for use under vacuum and argon gas at room temperature, as direct exposure to air will cause spontaneous combustion and direct oxidation.

[0090] Vacuum casting ingot:

[0091] The water-cooled copper mold is kept warm with 18°C ​​water. Heating is stopped, and the crucible is slowly poured out. Molten 999 gold is poured into the copper mold. The water-cooled mold causes the solution to solidify rapidly within ten seconds, forming a smooth and dense sub-millimeter body. The casting is then complete.

[0092] Surface cleaning:

[0093] The ingots were immersed in aqua regia beakers, heated to 88°C and maintained for 30 minutes, then transferred to a clean water tank to rinse thoroughly, and dried in a 200°C oven.

[0094] Rolling, stretching, and age hardening:

[0095] Cleaning of the rolls, execution of the rolling operation, rolling passes, feed according to the design flow, hardening of the material during rolling, execution of the predetermined intermediate annealing process during rolling, annealing softening and aging in the muffle.

[0096] Product manufacturing:

[0097] Sheet wire processing jewelry or chain making execution of the conventional process, precision casting products execution of the casting process.

[0098] Product surface treatment:

[0099] Polishing by mechanical grinding, making it have enough strength to inlay gemstones, electroplating and coloring treatment.

[0100] Product welding:

[0101] Laser welding method is used to avoid long time flame heating hardness reduction.

[0102] Example five

[0103] A process for hardening gold with micro-nano metal powder, comprising the following steps:

[0104] Blank loading:

[0105] Weigh the gold base material, take micro-nano titanium powder and micro-nano beryllium powder (mass ratio 1:1) according to 0.2% of the mass percentage of the gold base material, put them into the secondary material boat, and put the weighed gold base material into the crucible.

[0106] Melting:

[0107] Vacuum secondary feeding melting furnace is used. Connect the power supply, start the Roots pump for continuous vacuum after pre-vacuuming with the mechanical pump, and start the diffusion pump heating at the same time. The preheating time of the diffusion pump is 60 minutes. Start heating when the vacuum degree reaches 100 Pa, continuously increase the temperature at a rate of 60℃ / min, open the diffusion pump high vacuum deoxidization when the temperature reaches 780℃, and keep the vacuum at 6×10- 2Pa, to reduce the occurrence of oxidation reaction, to ensure the uniformity and stability of alloy composition, fill in argon to maintain 55 Pa. Continue to heat to 1450 ℃, add the mixture of micro-nano titanium powder and micro-nano beryllium powder, start the mechanical stirrer after melting into the gold solution, and fully stir for 30 seconds. The micro-nano titanium powder and the micro-nano beryllium powder are protected by vacuuming and filling argon at room temperature. The micro-nano titanium powder is pre-oxidized before use. The pre-oxidation treatment method is to pre-mix with micro-nano cobalt powder, and to heat at 150 ℃ in oxygen-argon-nitrogen mixed gas. After the oxide film is generated on the surface of the powder, it is ready for use. The micro-nano beryllium powder is pre-oxidized before use. The pre-oxidation treatment method is to pre-mix with micro-nano cobalt powder and micro-nano titanium powder, and to heat at 150 ℃ in oxygen-argon-nitrogen mixed gas. After the oxide film is generated on the surface of the powder, it is ready for use. Direct exposure to air will cause spontaneous combustion and direct oxidation.

[0108] Vacuum ingot casting:

[0109] Water-cooled copper mold is kept at 15.5 ℃ by passing water, heating is stopped, the crucible is slowly poured, the 999 gold melt is cast into the copper mold, and the water-cooled mold promotes high-speed solidification of the solution to form a sub-millimeter smooth and dense body within ten seconds. The casting is completed.

[0110] Surface cleaning:

[0111] The ingot is soaked in an aqua regia beaker, heated to 82 ℃ for 30 minutes, then moved to a clean water pool for rinsing, and dried in a 200 ℃ oven.

[0112] Rolling, stretching, and aging hardening:

[0113] The rollers are cleaned and the rolling operation is performed. The rolling pass and the amount of feed are executed according to the designed process. The material hardening phenomenon occurs during the rolling process. The predetermined intermediate annealing process is performed during the rolling process. Annealing softening and aging hardening are performed in a tunnel furnace.

[0114] Product manufacturing:

[0115] Sheet and wire processing accessories or chain manufacturing are executed according to the conventional process. The precision casting product is executed according to the casting process.

[0116] Product surface treatment:

[0117] Mechanical polishing is used for polishing treatment, which has sufficient strength for inlaying gemstones, and electroplating and coloring treatment.

[0118] Product welding:

[0119] Energy storage welding method is used to avoid hardness reduction caused by long-time flame heating.

[0120] Example six

[0121] A process for hardening gold with micro-nano metal powder, comprising the following steps:

[0122] Charging of the embryo:

[0123] Weigh the gold base, take 0.4% of the mass percentage of the gold base, and put it into the secondary material boat. Put the weighed gold base into the crucible.

[0124] Melting:

[0125] Vacuum secondary feeding melting furnace is adopted. Connect the power supply, start the Roots pump for continuous vacuumizing after pre-vacuumizing by the mechanical pump, and start the diffusion pump heating at the same time. The preheating time of the diffusion pump is 60 minutes. Start heating when the vacuum degree reaches 100 Pa, and continuously increase the temperature at a rate of 90 ℃ / min. Open the diffusion pump high vacuum deoxidization when the temperature reaches 830 ℃, and maintain the vacuum at 6×10- 2 Pa for 6 hours to reduce the occurrence of oxidation reaction, ensure the uniformity and stability of the alloy composition, and fill argon to maintain 65 Pa. Continue heating to 1520 ℃, add the mixture of micro-nano cobalt powder and micro-nano aluminum powder, start the mechanical stirrer for full stirring for 30 seconds after the mixture is melted into the gold solution, and complete the melting of the materials. The micro-nano cobalt powder is pre-oxidized before use by pre-mixing with micro-nano titanium powder, heating at 150 ℃ with oxygen-argon-nitrogen mixed gas, and waiting for the formation of an oxide film on the surface of the powder before use; the micro-nano aluminum powder is pre-oxidized before use by pre-mixing with micro-nano beryllium powder and micro-nano cobalt powder, heating at 150 ℃ with oxygen-argon-nitrogen mixed gas, and waiting for the formation of an oxide film on the surface of the powder before use. The micro-nano aluminum powder is pre-oxidized before use by pre-mixing with micro-nano beryllium powder and micro-nano cobalt powder, heating at 150 ℃ with oxygen-argon-nitrogen mixed gas, and waiting for the formation of an oxide film on the surface of the powder before use. Direct exposure to air will cause spontaneous combustion and direct oxidation.

[0126] Vacuum ingot casting:

[0127] The water-cooled copper mold is kept at 16.5 ℃ by passing water, heating is stopped, the crucible is slowly poured, the 999 gold melt is cast into the copper mold, and the water-cooled mold promotes high-speed solidification of the solution to form a sub-millimeter smooth and dense body within ten seconds, and the casting is completed.

[0128] Surface cleaning:

[0129] The ingot is soaked in an aqua regia beaker, heated to 84 ℃ for 30 minutes, then moved to a clean water pool for rinsing, and dried in a 200 ℃ oven.

[0130] Rolling, stretching, and aging hardening:

[0131] The rollers are cleaned, and rolling operation is performed. The rolling passes and the amount of feed are executed according to the designed process. Material hardening occurs during the rolling process, and a predetermined intermediate annealing process is performed during the rolling process. Annealing softening and aging hardening are performed in a muffle furnace.

[0132] Product manufacturing:

[0133] Sheet wire processing ornaments or chain-making performs a conventional process, and precision casting products perform a casting process.

[0134] Product surface treatment:

[0135] Polish processing by mechanical grinding to have sufficient strength for inlaying gemstones, electroplating and coloring treatment.

[0136] Product welding:

[0137] Using argon arc welding method to avoid long time flame heating hardness reduction.

[0138] A process for hardening gold with micro-nano metal powder, comprising the following steps:

[0139] Example seven

[0140] Blank loading:

[0141] Weigh the gold base material, take micro-nano beryllium powder, micro-nano aluminum powder and micro-nano titanium powder (mass ratio 1:1:2) according to 0.6% mass percentage of gold base material, put them into the secondary material boat, and put the weighed gold base material into the crucible.

[0142] Melting:

[0143] Vacuum secondary feeding melting furnace is adopted. Connect the power supply, start the Roots pump for continuous vacuumizing after pre-vacuumizing by mechanical pump, and start the diffusion pump heating at the same time. The preheating time of the diffusion pump is 60 minutes. Start heating when the vacuum degree reaches 100 Pa, continuously increase the temperature at the rate of 110 ℃ / min, open the diffusion pump high vacuum deoxidization when the temperature reaches 870 ℃, and keep the vacuum at 6×10- 2Pa, reduce the occurrence of oxidation reaction, ensure the uniformity and stability of alloy composition, fill in argon to maintain 70 Pa. Continue to heat to 1570 ℃, add the mixture of micro-nano beryllium powder, micro-nano aluminum powder and micro-nano titanium powder, start the mechanical stirrer after melting into the gold solution, and fully stir for 30 seconds. The micro-nano beryllium powder is pre-oxidized before use under vacuum and argon protection at room temperature. The pre-oxidation treatment method is to pre-mix with micro-nano cobalt powder and micro-nano titanium powder, and to heat and keep at 150 ℃ after oxygen-argon-nitrogen mixed gas is introduced. After the oxide film is generated on the surface of the powder, it is ready for use. The micro-nano aluminum powder is pre-oxidized before use under vacuum and argon protection at room temperature. The pre-oxidation treatment method is to pre-mix with micro-nano beryllium powder and micro-nano cobalt powder, and to heat and keep at 150 ℃ after oxygen-argon-nitrogen mixed gas is introduced. After the oxide film is generated on the surface of the powder, it is ready for use. The micro-nano titanium powder is pre-oxidized before use under vacuum and argon protection at room temperature. The pre-oxidation treatment method is to pre-mix with micro-nano cobalt powder, and to heat and keep at 150 ℃ after oxygen-argon-nitrogen mixed gas is introduced. After the oxide film is generated on the surface of the powder, it is ready for use. Direct exposure to air will cause spontaneous combustion and direct oxidation.

[0144] Vacuum ingot casting:

[0145] The water-cooled copper mold is kept at 17.5 ℃ by passing water, the heating is stopped, the crucible is slowly poured, the 999 gold melt is cast into the copper mold, and the water-cooled mold promotes high-speed solidification of the solution to form a sub-millimeter smooth and dense body within ten seconds, and the casting is completed.

[0146] Surface cleaning:

[0147] The ingot is soaked in a aqua regia beaker, heated to 86 ℃ for 30 minutes, then moved to a clean water pool for rinsing, and dried in a 200 ℃ oven.

[0148] Rolling, stretching, and aging hardening:

[0149] The rollers are cleaned and the rolling operation is performed. The rolling pass and the amount of feed are executed according to the designed process. The material hardening phenomenon occurs during the rolling process. The predetermined intermediate annealing process is performed during the rolling process. Annealing softening and aging hardening are performed in a tunnel furnace.

[0150] Product manufacturing:

[0151] Sheet and wire processing accessories or chain making are executed according to the conventional process. The precision casting product is executed according to the casting process.

[0152] Product surface treatment:

[0153] Mechanical polishing is used for polishing treatment, which has sufficient strength for inlaying gemstones, and electroplating and coloring treatment is performed.

[0154] Product welding:

[0155] Laser welding is used to avoid the hardness reduction caused by prolonged flame heating.

[0156] The basic properties of 999 hard gold are shown in Table 1:

[0157] Table 1

[0158]

[0159]

[0160] Generally, the deformation heat treatment process required for common age-hardening alloys to achieve maximum strength is similar to that of aluminum alloys in the T8 state, i.e., solution treatment + cold deformation + aging. This is because defects introduced by cold deformation can promote the heterogeneous nucleation of most types of precipitates, improving precipitation strengthening. Au-01%Me alloy was first subjected to a solution treatment at 680℃ for 0.5h + 80% cold deformation + deformation heat treatment with different aging parameters, where Me:Ti,Be,Al,Co. The resulting precipitation strengthening pattern is shown in […]. Figure 1 .

[0161] like Figure 2 and Figure 3 As shown, at 350-400℃, the aging peak value is brought forward as the aging temperature increases, and the peak value of 192.6HV corresponding to 400℃-0.5h is the maximum hardness value at the above temperature, indicating that the alloy can obtain the required hardness of above 150HV.

[0162] Because it is difficult to precisely control the amount of deformation during jewelry manufacturing, and different amounts of deformation will change the precipitation kinetics of the alloy, thus affecting the age hardening law, from the perspective of process consistency, after obtaining the final desired product shape, performing solution-aging heat treatment (similar to the T6 state of aluminum alloys) can ensure that products from different process routes achieve similar high hardness. Therefore, this study also investigated the alloy hardening law of direct aging after solution treatment. The peak hardness corresponding to different process routes is shown in Table 2:

[0163] Table 2 shows the peak hardness corresponding to different processing routes for Au-0.1% Be / Al alloy.

[0164]

[0165] As can be seen from the table, direct aging after solution treatment can achieve a hardness comparable to that achieved after cold rolling and aging, indicating that the main strengthening phase Au4Ti of this alloy has a low nucleation energy, thus requiring only a large number of dislocations for nucleation. From a process feasibility perspective, an aging time of 2 hours is relatively easy to control and will not affect production efficiency due to prolonged aging.

[0166] The deformation heat treatment process of Au-1% Me can be summarized as follows: casting blank→ cold deformation→ softening annealing→ repeating the above two steps until the final required specification is obtained→ solid solution quenching→ aging at 350-450 °. Through the above process, the required shape can be obtained while obtaining high hardness. The above-mentioned cold deformation includes rolling, drawing and other means. The specific plastic deformation method depends on the final product and the shape of the casting blank.

[0167] The addition of different elements Me with different contents (0.1-1%) will change the corresponding heat treatment process, which is sensitive to process. Therefore, it is not listed here.

[0168] The innovative process of the present application introduces the concept of micro-nanometer, uses the controllable pre-oxidation film forming property, and exists in the form of hard phase in the gold body. The process implementation is guaranteed by the support of vacuum secondary casting technology. According to the requirements, the addition of elements in the range of 0.1-1% can be controlled according to the design requirements, which does not affect the design purity of gold.

[0169] The above is only the preferred embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can make equivalent replacements or changes within the technical scope disclosed by the present application according to the technical solution and inventive concept of the present application, which should be covered within the protection scope of the present application.

Claims

1. A process for hardening treatment of gold with micro-nano metal powder, characterized in that, It comprises the following steps: Embryo furnace: weighing gold base material, taking micro-nano metal powder according to 0.1-1% mass percentage of gold base material, putting into secondary material boat, putting weighed gold base material into crucible; the micro-nano metal powder is at least one of micro-nano titanium powder, micro-nano cobalt powder, micro-nano beryllium powder and micro-nano aluminum powder; Melting: connect power supply, vacuumize, start diffusion pump heating at the same time, continue heating to 1400-1700℃, add micro-nano metal powder, start mechanical stirrer after micro-nano metal powder is melted into gold solution for sufficient stirring, complete melting and blending, obtain 999 gold melt; Vacuum ingot casting: water-cooled copper mold is kept by passing 15-18℃ water, pour crucible, 999 gold melt is cast into copper mold, water-cooled mold promotes solution to solidify into sub-millimeter smooth and dense body within ten seconds, complete solidification casting, obtain ingot; Surface cleaning: put ingot into aqua regia beaker, heat to 80-90℃ and maintain for 30-40 minutes, rinse clean, dry in 200℃ oven; Rolling and stretching, aging hardening: clean rollers, perform rolling operation; Product surface treatment: perform polishing treatment by mechanical polishing, so that it has sufficient gem inlaying strength, perform electroplating and coloring treatment; Product welding.

2. The process for hardening treatment of micro-nano metal powder to gold according to claim 1, characterized in that, In step 5), rolling pass and feed amount are executed according to design flow, material hardening phenomenon is caused in rolling process, intermediate annealing softening process is executed in rolling process, annealing softening and aging hardening are performed in tunnel furnace or muffle furnace.

3. The process for hardening treatment of micro-nano metal powder to gold according to claim 1, characterized in that, In step 7), welding is performed by laser welding, energy storage welding or argon arc welding, so as to avoid hardness reduction caused by long time flame heating.

4. The process for hardening treatment of micro-nano metal powder to gold according to claim 1, characterized in that, In step 2), vacuum secondary feeding melting furnace is used in melting process, and mechanical stirring in furnace is performed in melting and blending process.

5. The process for hardening treatment of micro-nano metal powder to gold according to claim 4, characterized in that, In the step 2), the diffusion pump preheating time is 60 minutes; the vacuum degree reaches 100 Pa, the heating is started, the temperature is continuously increased at the temperature increasing rate of 50-150 ℃ / min, the diffusion pump high vacuum deoxidization is started after the temperature reaches 750-950 ℃, the vacuum is kept at 6×10 -2 Pa, the argon is filled to maintain 50-100 Pa, the mechanical stirrer is started to fully stir for 30 seconds after the micro-nano metal powder is melted into the gold solution, and the melting and blending are completed.

6. The process for hardening treatment of micro-nano metal powder against gold according to claim 4, characterized in that, In step 2), micro-nano cobalt powder is used in micro-nano metal powder, argon gas is filled under vacuum at room temperature, pre-oxidation treatment is performed before use, the pre-oxidation treatment method is pre-mixed with micro-nano titanium powder, oxygen, argon and nitrogen mixed gas is passed, heated and kept at 150℃, and the powder surface is generated after the oxide film is used.

7. The process for hardening treatment of micro-nano metal powder to gold according to claim 4, characterized in that, In step 2), micro-nano titanium powder is used in micro-nano metal powder, argon gas is filled under vacuum at room temperature, pre-oxidation treatment is performed before use, the pre-oxidation treatment method is pre-mixed with micro-nano cobalt powder, oxygen, argon and nitrogen mixed gas is passed, heated and kept at 150℃, and the powder surface is generated after the oxide film is used.

8. The process for hardening treatment of micro-nano metal powder to gold according to claim 4, characterized in that, In step 2), micro-nano aluminum powder is used in micro-nano metal powder, argon gas is filled under vacuum at room temperature, pre-oxidation treatment is performed before use, the pre-oxidation treatment method is pre-mixed with micro-nano beryllium powder and micro-nano cobalt powder, oxygen, argon and nitrogen mixed gas is passed, heated and kept at 150℃, and the powder surface is generated after the oxide film is used.

9. The process for hardening treatment of micro-nano metal powder to gold according to claim 4, characterized in that, In step 2), micro-nano beryllium powder is used in micro-nano metal powder, argon gas is filled under vacuum at room temperature, pre-oxidation treatment is performed before use, the pre-oxidation treatment method is pre-mixed with micro-nano cobalt powder, micro-nano cobalt powder and micro-nano titanium powder, oxygen, argon and nitrogen mixed gas is passed, heated and kept at 150℃, and the powder surface is generated after the oxide film is used.

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