CN107164651B - A kind of pink silver alloy for jewelry and preparation method thereof - Google Patents

Abstract

The invention discloses a kind of jewellery pink colour silver alloy, the ingredient comprising following mass percentage: silver-colored 33.10~42.50%, copper 55.00~61.50%.Silver alloy of the present invention, its color is in bright pink, hardness of cast form, fusing point are moderate, with good casting forming function and punch forming performance, meet jewellery forming and inlays requirement, there is good corrosion resistance, anti-oxidant discoloration, low in cost, the practical application value height of alloy in 37 DEG C of synthetic perspirations.Meanwhile invention additionally discloses a kind of preparation methods of jewellery pink colour silver alloy.

Description

A kind of pink silver alloy for jewelry and preparation method thereof

technical field

The invention relates to a silver alloy and a preparation method thereof, in particular to a pink silver alloy for jewelry and a preparation method thereof.

Background technique

Silver is a kind of precious metal, but its price is far lower than other precious metals such as gold, platinum, and palladium. Therefore, it is widely used in the jewelry industry and has been regarded as a fashion jewelry material to a large extent. Silver has good processing performance and relatively excellent chemical properties, and its reflectivity to visible light reaches 94%, which is the highest reflectivity among all metal elements. At present, the silver jewelry materials on the market are mainly 925 silver and 990 silver. Due to the high silver content, the alloys are all white without exception, which limits their decorative performance.

In order to make silver alloy jewelry more decorative in appearance, the color is generally presented through overall alloying, surface coating, and surface modification. Overall alloying is to add color-causing alloying elements, such as gold and copper, to silver alloys, and obtain the desired color by adjusting the ratio of color-causing elements to other elements. Surface coating is to deposit a layer of colored film on the surface of jewelry by electroplating, chemical plating, etc., such as black rhodium plating, rose gold, etc. Surface modification is to form a colored film layer on the surface of jewelry by means of chemical, electrochemical and other processes, such as vulcanization, high-temperature oxidation, etc. to produce black on the surface. Since the latter two processes are both surface treatment processes, the jewelry may lose its color due to wear after a period of use, causing a significant contrast between the base and the unworn area of the film layer, which seriously affects the decorative performance.

Japanese patent JP2005217314A discloses a similar pink silver alloy, which includes five components of silver, copper, gold, palladium, and germanium. These alloys can obtain pink to varying degrees, but because they contain a considerable amount of expensive gold , palladium, germanium and other alloying elements, their cost has far exceeded the acceptable range of silver alloy jewelry, is not accepted by the market, and has no practical application value. French patent FR0003707A discloses a pink silver alloy, whose constituent elements include silver, copper, palladium, indium, and gold, wherein the palladium content is as high as 3-20%, which is also difficult to be accepted by the market, and brings great difficulties to processing and manufacturing .

In existing studies, adding palladium to silver-copper alloys can have a certain bleaching effect on copper, and the combination of copper, silver, and palladium can easily prepare pink silver alloys. However, palladium has a high melting point, adding more than 2% palladium will significantly increase the difficulty of casting, and the high cost of palladium makes it unsuitable as an alloying element for pink silver alloys. Reports of pink silver alloys prepared with silver.

Contents of the invention

Based on this, the object of the present invention is to overcome the disadvantages of the above-mentioned prior art and provide a silver alloy for jewelry with high cost performance and bright pink color. In the pink silver alloy for jewelry of the present invention, silver and copper cooperate with each other, so that the color is not only bright pink, but also has good processing and manufacturing performance, anti-oxidation and discoloration performance, and the cost of the alloy is low, and it has good cost performance. High application value, among which:

Silver is one of the basic components of the alloy. Because silver has a strong reflection effect on visible light, it helps to improve the brightness of the alloy, but too high a The silver content is not conducive to the brightness, processing performance and anti-oxidation discoloration performance of the alloy.

Copper is the color-causing element of pink silver alloys. Copper itself is purple-red, and when combined with white metals, the purple-red color can be bleached, and the degree of bleaching depends on the type and content of other white metal elements. When the copper content is too high, the color of the alloy is purplish red, the brightness is reduced, the chemical stability of the alloy is not good, and it is not conducive to the casting quality; when the copper content is too low, the color of the alloy is light, and the decorative performance and hardness of the alloy will also be greatly affected.

Through the test and detection of silver-copper alloys with different proportions, it is found that when the ratio of copper and silver mass percentage is greater than 2.0, the color of the alloy is reddish and has deviated from the pink area; and when the ratio of copper and silver mass percentage is less than 2.0 At 1.2, the color of the alloy is off-white with only a slight pink tint. And when the mass percent ratio of copper and silver is between 1.3 and 1.86, the alloy shows a better pink color. Therefore, in order to achieve the above object, the technical solution adopted by the present invention is: a pink silver alloy for jewelry, comprising the following components in mass percentage: 33.10-42.50% silver and 55.00-61.50% copper.

Preferably, the silver alloy further contains zinc, and the mass percentage of zinc is 1.50-3.00%. Zinc has an auxiliary bleaching effect on silver alloys, can improve the anti-oxidation and discoloration properties of the alloys, can lower the melting point of the alloys, and can better improve the casting performance. However, in the silver alloy of the present invention, the inventor has found through a lot of attempts that when the zinc content is lower than 1.5%, the oxidation resistance and casting performance of the alloy are not ideal, and the surface is prone to blackening during casting and heat treatment, and when the zinc content is higher than When the content is 3.0%, the hardness of the alloy is low, and zinc oxide inclusions are likely to be produced during melting and casting. In the range of 1.50-3.00%, the effect of zinc on the color, oxidation resistance, casting performance, mechanical properties and other aspects of the alloy can be optimally matched, so this application chooses the range of 1.50-3.00%.

Preferably, the silver alloy further contains silicon, and the mass percentage of the silicon is 0.10-0.60%. Silicon can significantly improve the casting performance and anti-oxidation discoloration performance of the alloy, and can effectively bleach the color of the alloy to improve the brightness of the alloy. However, in the silver alloy of the present invention, the inventors have found through a lot of trials that when the silicon content is lower than 0.1%, the castability of the alloy is poor, the surface is easily blackened during casting and heat treatment, and the brightness of the alloy is not ideal. When the content is higher than 0.6%, it tends to lead to thermal cracking of the alloy and abnormally coarse crystal grains, deterioration of processing performance, and easy occurrence of hard spots, which affects the quality of surface polishing. In the range of 0.10-0.60%, the effects of silicon on the alloy's color, oxidation resistance, casting performance, etc. can be optimally matched, so this application chooses the range of 0.10-0.60%. Moreover, silicon in the above-mentioned content range has a strong bleaching effect, and their optimal matching with silver can produce a more beautiful pink color.

Preferably, the silver alloy further contains beryllium, and the mass percentage of the beryllium is 0.20-0.30%. Beryllium can improve the mechanical properties of the alloy, increase the strength and hardness of the alloy, improve the welding performance, and improve the corrosion resistance. But in the silver alloy of the present invention, the inventor has found through a lot of attempts that when the beryllium content is lower than 0.2%, the mechanical properties, welding performance and corrosion resistance of the alloy are not ideal, and when the beryllium content is higher than 0.3%, it will affect the alloy. ductility and comprehensive mechanical properties. In the range of 0.20-0.30%, the effect of beryllium on the mechanical properties, welding performance and corrosion resistance of the alloy can be optimally matched, so this application chooses the range of 0.20-0.30%.

Preferably, the silver alloy further contains cobalt, and the mass percentage of the cobalt is 0.26-0.50%. Cobalt plays the role of refining crystal grains, and can strengthen the aging effect of alloy, which is beneficial to the mechanical properties of alloy, but in the silver alloy of the present invention, the inventor has found through a lot of attempts that when the cobalt content is lower than 0.26%, the alloy The grain structure of the alloy is not ideal, especially the grains may grow during annealing, and when the cobalt content is higher than 0.5%, the castability of the alloy becomes poor, and the ductility and comprehensive mechanical properties deteriorate. In the range of 0.26-0.50%, the effect of cobalt on the grain structure, mechanical properties, welding performance and corrosion resistance of the alloy can be optimally matched, so this application chooses the range of 0.26-0.50%.

Preferably, the silver alloy further contains tin, and the mass percentage of the tin is 0.30-0.80%. Tin can improve the anti-oxidation and discoloration performance of the alloy, reduce the melting point of the alloy, and improve the fluidity and casting performance of the alloy. However, in the silver alloy of the present invention, the inventors have found through a lot of trials that when the tin content is lower than 0.3%, the casting performance and anti-oxidation discoloration performance of the alloy are not ideal, and when the tin content is higher than 0.8%, the casting performance of the alloy becomes poor. Poor, and the ductility and comprehensive mechanical properties deteriorate. In the range of 0.30-0.80%, the effect of cobalt on the grain structure, mechanical properties, welding performance and corrosion resistance of the alloy can be optimally matched, so this application chooses the range of 0.30-0.80%.

Preferably, the silver alloy further contains yttrium, and the mass percentage of the yttrium is 0.05-0.10%. Yttrium can improve the brightness and anti-oxidation discoloration performance of the alloy, refine the grain structure, increase the hardness of the alloy, and improve the casting performance. However, in the silver alloy of the present invention, the inventors have found through a lot of trials that when the yttrium content is lower than 0.05%, the castability and anti-oxidation and discoloration performance of the alloy are not ideal, and the microstructure and as-cast grain size are relatively large. When the yttrium content is higher than 0.10%, it is easy to segregate on site, produce oxidation inclusions, greatly reduce the ductility, cause the brittleness of the alloy, and deteriorate the polishing performance of the alloy. In the range of 0.05-0.10%, the effect of yttrium on the grain structure, mechanical properties, welding performance and corrosion resistance of the alloy can be optimally matched, so this application chooses the range of 0.05-0.10%.

At the same time, the present invention also provides a method for preparing the above-mentioned pink silver alloy for jewelry. The method is as follows: the raw material is placed in a crucible, vacuumized, filled with argon, and then smelted. Pour it into a steel ingot mold to obtain a pink silver alloy ingot, and wash and dry the ingot to obtain the pink silver alloy for jewelry.

The alloy of the present invention involves some alloying elements with high melting point or easy oxidation. In order to avoid problems such as high melting temperature, large compositional fluctuations and poor metallurgical quality caused by directly using pure metal materials to prepare the alloy, an intermediate alloy is prepared first.

Preferably, the above raw materials contain the following components in mass percentage: 33.2-42.6% pure silver, 22.5-35.6% oxygen-free pure copper, 5.3-10.7% brass, 0.3-4.8% copper-silicon alloy, 10.2-4.2% beryllium-copper alloy 15.1%, copper-tin alloy 3.1-8.1%, copper-yttrium alloy 1.1-2.1%, copper-cobalt alloy 2.5-4.3%.

Preferably, the copper-cobalt alloy contains 10 wt% cobalt, the copper-silicon alloy contains 10 wt% silicon, the copper-yttrium alloy contains 5 wt% yttrium, and the copper-tin alloy contains 10 wt% tin.

Compared with the prior art, the beneficial effects of the present invention are:

The silver alloy of the present invention is bright pink in color, moderate in cast hardness and melting point, has good casting and stamping performance, meets the requirements of jewelry forming and inlaying, and has good corrosion resistance in artificial sweat at 37°C , Anti-oxidation and discoloration performance, the cost of the alloy is low, and the practical application value is high.

Description of drawings

Fig. 1 is the differential thermal analysis figure of pink silver alloy for jewelry described in embodiment 1;

Fig. 2 is the differential thermal analysis diagram of the pink silver alloy for jewellery, described in Example 2.

Detailed ways

In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific examples.

Example 1

A kind of embodiment of pink silver alloy for jewelry of the present invention, the pink silver alloy for jewelry of the present embodiment comprises the composition of following mass percentage composition:

34.91 wt% silver, 60.24 wt% copper, 3.00 wt% zinc, 0.56 wt% silicon, 0.25 wt% beryllium, 0.39 wt% cobalt, 0.50 wt% tin, 0.06 wt% yttrium, and other unavoidable impurities.

A kind of preparation method of jewelry pink silver alloy described in the present embodiment is as follows:

(1) Alloy preparation

1) Preparation of master alloy: select oxygen-free pure copper with a copper content of 99.95wt%, metallic cobalt with a cobalt content of 99.99wt%, metallic silicon with a silicon content of 99.8wt%, and yttrium-containing 99.9wt% Metal yttrium and metal tin containing 99.95wt% tin are used to prepare copper-cobalt alloy containing 10wt% cobalt, copper-silicon alloy containing 10wt% silicon, copper-yttrium alloy containing 5wt% yttrium, and copper-yttrium alloy containing 10wt% tin. Copper-tin alloys, these master alloys are smelted and cast into ingots under a vacuum protection atmosphere.

2) Pure silver with a silver content of 99.95wt%, oxygen-free pure copper with a copper content of 99.95wt%, H70 brass with a zinc content of 29.8wt%, cast beryllium copper Cu-2Be with a beryllium content of 2wt% -0.5Co-0.3Si, and the master alloy prepared in the previous step are raw materials to prepare the pink silver alloy of the present invention, and the proportioning ratio is as follows:

35.0wt% pure silver, 28.2wt% oxygen-free pure copper, 10.7wt% H70 brass, 4.4wt% copper-silicon alloy, 12.7wt% beryllium copper, 5.1wt% copper-tin alloy, 1.3wt% copper-yttrium alloy, 3.3wt% % Copper Cobalt Alloy.

(2) Melting and casting

Place the raw materials and master alloy prepared in proportion in a graphite crucible, evacuate to -0.1MPa, and then fill it with industrial pure argon. Vacuum induction furnace is used for smelting. After all the furnace materials are melted and the temperature and composition are uniform, the molten metal is poured into the ingot mold to obtain a pink silver alloy ingot. After the ingot is washed and dried, it can be used as a raw material for jewelry casting or stamping.

(3) Performance test and research of alloy

The pink silver alloy prepared in this example is bright pink in color and moderate in hardness, which meets the requirements of jewelry forming and inlaying. The melting point of the alloy is suitable for precision casting technology. The alloy has good corrosion resistance in artificial sweat at 37°C, and the cost is low and far lower. In alloys containing gold, palladium and germanium.

1) As-cast hardness of the alloy: HV103

2) The color index of the alloy: L*=84.29, a*=4.11, b*=14.7, with a beautiful pink color.

3) The differential thermal analysis curve of the alloy is shown in Figure 1: the melting point range is 755.4-788.7°C, which is very suitable for gypsum precision casting.

4) Corrosion resistance of the alloy: In 37°C artificial sweat, the self-corrosion potential is -0.71V, the pitting potential is -0.1V, and it has good corrosion resistance and anti-discoloration performance.

Example 2

A kind of embodiment of pink silver alloy for jewelry of the present invention, the pink silver alloy for jewelry of the present embodiment comprises the composition of following mass percentage composition:

39.90wt% silver, 57.12wt% copper, 1.97wt% zinc, 0.12wt% silicon, 0.25wt% beryllium, 0.26wt% cobalt, 0.30wt% tin, 0.06wt% yttrium, and other unavoidable impurities.

A kind of preparation method of jewelry pink silver alloy described in the present embodiment is as follows:

(1) Alloy preparation

1) Preparation of master alloy: select oxygen-free pure copper with a copper content of 99.95wt%, metallic cobalt with a cobalt content of 99.99wt%, metallic silicon with a silicon content of 99.8wt%, and yttrium-containing 99.9wt% Metal yttrium and metal tin containing 99.95wt% tin are used to prepare copper-cobalt alloy containing 10wt% cobalt, copper-silicon alloy containing 10wt% silicon, copper-yttrium alloy containing 5wt% yttrium, and copper-yttrium alloy containing 10wt% tin. Copper-tin alloys, these master alloys are smelted and cast into ingots under a vacuum protection atmosphere.

2) Pure silver with a silver content of 99.95wt%, oxygen-free pure copper with a copper content of 99.95wt%, H70 brass with a zinc content of 29.8wt%, cast beryllium copper Cu-2Be with a beryllium content of 2wt% -0.5Co-0.3Si, and the master alloy prepared in the previous step are raw materials to prepare the pink silver alloy of the present invention, and the proportioning ratio is as follows:

40wt% pure silver, 34.3wt% oxygen-free pure copper, 7wt% H70 brass, 0.3wt% copper-silicon alloy, 12.7wt% beryllium copper, 3.1wt% copper-tin alloy, 1.3wt% copper-yttrium alloy, 2.0wt% copper cobalt alloy.

(2) Melting and casting

Place the raw materials and master alloy prepared in proportion in a graphite crucible, evacuate to -0.1MPa, and then fill it with industrial pure argon. Vacuum induction furnace is used for smelting. After all the furnace materials are melted and the temperature and composition are uniform, the molten metal is poured into the ingot mold to obtain a pink silver alloy ingot. After the ingot is washed and dried, it can be used as a raw material for jewelry casting or stamping.

(3) Alloy performance test analysis

The pink silver alloy prepared in this embodiment has a bright pink color and moderate hardness, which meets the requirements for jewelry forming and inlaying. The melting point of the alloy is suitable for precision casting. Lower than alloys containing gold, palladium, and germanium.

1) As-cast hardness of the alloy: HV104

2) The color index of the alloy: L*=84.68, a*=5.14, b*=14.62, with a beautiful pink color.

3) The differential thermal analysis curve of the alloy is shown in Figure 2: the melting point range is 755.0-790.1°C, which is very suitable for gypsum precision casting.

4) Polarization curve and corrosion resistance of the alloy: In 37°C artificial sweat, the self-corrosion potential is -0.53v, the pitting potential is -0.1V, and it has good corrosion resistance and anti-discoloration performance.

Example 3

A kind of embodiment of pink silver alloy for jewelry of the present invention, the pink silver alloy for jewelry of the present embodiment comprises the composition of following mass percentage composition:

33.10wt% silver, 61.50wt% copper, 3.00wt% zinc, 0.60wt% silicon, 0.30wt% beryllium, 0.50wt% cobalt, 0.80wt% tin, 0.10wt% yttrium, and other unavoidable impurities.

A kind of preparation method of jewelry pink silver alloy described in the present embodiment is as follows:

(1) Alloy preparation

1) Preparation of master alloy: select oxygen-free pure copper with a copper content of 99.95wt%, metal cobalt with a cobalt content of 99.99wt%, metal silicon with a silicon content of 99.8wt%, and yttrium-containing 99.9wt% Metal yttrium and metal tin containing 99.95wt% tin are used to prepare copper-cobalt alloy containing 10wt% cobalt, copper-silicon alloy containing 10wt% silicon, copper-yttrium alloy containing 5wt% yttrium, and copper-yttrium alloy containing 10wt% tin. Copper-tin alloys, these master alloys are smelted and cast into ingots under a vacuum protection atmosphere.

2) Pure silver with a silver content of 99.95wt%, oxygen-free pure copper with a copper content of 99.95wt%, H70 brass with a zinc content of 29.8wt%, cast beryllium copper Cu-2Be with a beryllium content of 2wt% -0.5Co-0.3Si, and the master alloy prepared in the previous step are raw materials to prepare the pink silver alloy of the present invention, and the proportioning ratio is as follows:

33.2wt% pure silver, 22.5wt% oxygen-free pure copper, 10.6wt% H70 brass, 4.8wt% copper-silicon alloy, 15.1wt% beryllium copper, 8.1wt% copper-tin alloy, 2.1wt% copper-yttrium alloy, 4.3wt% % Copper Cobalt Alloy.

(2) Melting and casting

Place the raw materials and master alloy prepared in proportion in a graphite crucible, evacuate to -0.1MPa, and then fill it with industrial pure argon. Vacuum induction furnace is used for smelting. After all the furnace materials are melted and the temperature and composition are uniform, the molten metal is poured into the ingot mold to obtain a pink silver alloy ingot. After the ingot is washed and dried, it can be used as a raw material for jewelry casting or stamping.

The pink silver alloy prepared in this embodiment has a bright pink color and moderate hardness, which meets the requirements for jewelry forming and inlaying. The melting point of the alloy is suitable for precision casting. Lower than alloys containing gold, palladium, and germanium.

1) As-cast hardness of the alloy: HV108

2) The color index of the alloy: L*=83.77, a*=4.23, b*=15.16, with a beautiful pink color.

3) The melting point range of the alloy is 761.6-781.0°C, which is very suitable for gypsum mold precision casting.

4) Corrosion resistance of the alloy: In artificial sweat at 37°C, the self-corrosion potential is -0.74V, the pitting potential is -0.08V, and it has good corrosion resistance and anti-discoloration performance.

Example 4

A kind of embodiment of pink silver alloy for jewelry of the present invention, the pink silver alloy for jewelry of the present embodiment comprises the composition of following mass percentage composition:

42.50wt% silver, 55.00wt% copper, 1.50wt% zinc, 0.10wt% silicon, 0.20wt% beryllium, 0.30wt% cobalt, 0.30wt% tin, 0.05wt% yttrium, and other unavoidable impurities.

A kind of preparation method of jewelry pink silver alloy described in the present embodiment is as follows:

(1) Alloy preparation

1) Preparation of master alloy: select oxygen-free pure copper with a copper content of 99.95wt%, metallic cobalt with a cobalt content of 99.99wt%, metallic silicon with a silicon content of 99.8wt%, and yttrium-containing 99.9wt% Metal yttrium and metal tin containing 99.95wt% tin are used to prepare copper-cobalt alloy containing 10wt% cobalt, copper-silicon alloy containing 10wt% silicon, copper-yttrium alloy containing 5wt% yttrium, and copper-yttrium alloy containing 10wt% tin. Copper-tin alloys, these master alloys are smelted and cast into ingots under a vacuum protection atmosphere.

2) Pure silver with a silver content of 99.95wt%, oxygen-free pure copper with a copper content of 99.95wt%, H70 brass with a zinc content of 29.8wt%, cast beryllium copper Cu-2Be with a beryllium content of 2wt% -0.5Co-0.3Si, and the master alloy prepared in the previous step are raw materials to prepare the pink silver alloy of the present invention, and the proportioning ratio is as follows:

42.6wt% pure silver, 35.6wt% oxygen-free pure copper, 5.3wt% H70 brass, 0.3wt% copper-silicon alloy, 10.2wt% beryllium copper, 3.1wt% copper-tin alloy, 1.1wt% copper-yttrium alloy, 2.5wt% % Copper Cobalt Alloy.

(2) Melting and casting

Place the raw materials and master alloy prepared in proportion in a graphite crucible, evacuate to -0.1MPa, and then fill it with industrial pure argon. Vacuum induction furnace is used for smelting. After all the furnace materials are melted and the temperature and composition are uniform, the molten metal is poured into the ingot mold to obtain a pink silver alloy ingot. After the ingot is washed and dried, it can be used as a raw material for jewelry casting or stamping.

The pink silver alloy prepared in this embodiment has a bright pink color and moderate hardness, which meets the requirements for jewelry forming and inlaying. The melting point of the alloy is suitable for precision casting. Lower than alloys containing gold, palladium, and germanium.

1) As-cast hardness of the alloy: HV104

2) The color index of the alloy: L*=84.26, a*=3.87, b*=15.73, with a beautiful pink color.

3) The melting point range of the alloy is 752.4-787.6°C, which is very suitable for gypsum mold precision casting.

4) Corrosion resistance of the alloy: In 37°C artificial sweat, the self-corrosion potential is -0.76V, the pitting potential is -0.13V, and it has good corrosion resistance and anti-discoloration performance.

Example 5

A kind of embodiment of pink silver alloy for jewelry of the present invention, the pink silver alloy for jewelry of the present embodiment comprises the composition of following mass percentage composition:

37.91 wt% silver, 58.85 wt% copper, 1.75 wt% zinc, 0.31 wt% silicon, 0.22 wt% beryllium, 0.43 wt% cobalt, 0.45 wt% tin, 0.08 wt% yttrium, and other unavoidable impurities.

A kind of preparation method of jewelry pink silver alloy described in the present embodiment is as follows:

(1) Alloy preparation

1) Preparation of master alloy: select oxygen-free pure copper with a copper content of 99.95wt%, metallic cobalt with a cobalt content of 99.99wt%, metallic silicon with a silicon content of 99.8wt%, and yttrium-containing 99.9wt% Metal yttrium and metal tin containing 99.95wt% tin are used to prepare copper-cobalt alloy containing 10wt% cobalt, copper-silicon alloy containing 10wt% silicon, copper-yttrium alloy containing 5wt% yttrium, and copper-yttrium alloy containing 10wt% tin. Copper-tin alloys, these master alloys are smelted and cast into ingots under a vacuum protection atmosphere.

2) Pure silver with a silver content of 99.95wt%, oxygen-free pure copper with a copper content of 99.95wt%, H70 brass with a zinc content of 29.8wt%, cast beryllium copper Cu-2Be with a beryllium content of 2wt% -0.5Co-0.3Si, and the master alloy prepared in the previous step are raw materials to prepare the pink silver alloy of the present invention, and the proportioning ratio is as follows:

38wt% pure silver, 33wt% oxygen-free pure copper, 6.2wt% H70 brass, 2.3wt% copper-silicon alloy, 11.3wt% beryllium copper, 4.5wt% copper-tin alloy, 1.6wt% copper-yttrium alloy, 3.8wt% copper cobalt alloy.

(2) Melting and casting

Place the raw materials and master alloy prepared in proportion in a graphite crucible, evacuate to -0.1MPa, and then fill it with industrial pure argon. Vacuum induction furnace is used for smelting. After all the furnace materials are melted and the temperature and composition are uniform, the molten metal is poured into the ingot mold to obtain a pink silver alloy ingot. After the ingot is washed and dried, it can be used as a raw material for jewelry casting or stamping.

The pink silver alloy prepared in this embodiment has a bright pink color and moderate hardness, which meets the requirements for jewelry forming and inlaying. The melting point of the alloy is suitable for precision casting. Lower than alloys containing gold, palladium, and germanium.

1) As-cast hardness of the alloy: HV105

2) The color index of the alloy: L*=83.58, a*=4.92, b*=14.84, with a beautiful pink color.

3) The melting point range of the alloy is 758.8-792.3°C, which is very suitable for gypsum mold precision casting.

4) Corrosion resistance of the alloy: In artificial sweat at 37°C, the self-corrosion potential is -0.56V, the pitting potential is -0.11V, and it has good corrosion resistance and anti-discoloration performance.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that The technical solution of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solution of the present invention.

Claims (7)

1. a kind of pink silver alloy for jewelry, it is characterized in that, described pink silver alloy is made up of silver, copper, silicon, cobalt, zinc, beryllium, tin, yttrium and other unavoidable impurity, the composition of mass percentage composition: Silver 33.10-42.50%, copper 55.00-61.50%; the ratio of the mass percentage of the copper to the silver is 1.3-1.86; the mass percentage of the silicon is 0.10-0.60%; the mass percentage of the cobalt content of 0.26-0.50%, the mass percentage of the zinc is 1.50-3.00%, the mass percentage of the beryllium is 0.20-0.30%, and the mass percentage of the tin is 0.30-0.80%. The mass percent content of the yttrium is 0.05-0.10%. 2. pink silver alloy for jewelry as claimed in claim 1, is characterized in that, described silver alloy is made up of the composition of following percentage by weight: 34.91wt% silver, 60.24wt% copper, 3.00wt% zinc, 0.56wt% % silicon, 0.25wt% beryllium, 0.39wt% cobalt, 0.50wt% tin, 0.06wt% yttrium, and other unavoidable impurities. 3. pink silver alloy for jewelry as claimed in claim 1, is characterized in that, described silver alloy is made up of the composition of following percentage by weight: 39.90wt% silver, 57.12wt% copper, 1.97wt% zinc, 0.12wt% % silicon, 0.25wt% beryllium, 0.26wt% cobalt, 0.30wt% tin, 0.06wt% yttrium, and other unavoidable impurities. 4. pink silver alloy for jewelry as claimed in claim 1, is characterized in that, described silver alloy is made up of the composition of following percentage by weight: 33.10wt% silver, 61.50wt% copper, 3.00wt% zinc, 0.60wt% % silicon, 0.30wt% beryllium, 0.50wt% cobalt, 0.80wt% tin, 0.10wt% yttrium, and other unavoidable impurities. 5. pink silver alloy for jewelry as claimed in claim 1, is characterized in that, described silver alloy is made up of the composition of following percentage by weight: 42.50wt% silver, 55.00wt% copper, 1.50wt% zinc, 0.10wt% % silicon, 0.20wt% beryllium, 0.30wt% cobalt, 0.30wt% tin, 0.05wt% yttrium, and other unavoidable impurities or 37.91wt% silver, 58.85wt% copper, 1.75wt% zinc, 0.31wt% silicon, 0.22wt% beryllium, 0.43wt% cobalt, 0.45wt% tin, 0.08wt% yttrium, and other unavoidable impurities. 6. A method for preparing the pink silver alloy for jewelry as claimed in any one of claims 1 to 5, wherein the method is as follows: the raw material is placed in a crucible, vacuumized, filled with argon, and then carried out Melting, after all the charge is melted, pouring molten metal into a steel ingot mold to obtain a pink silver alloy ingot, cleaning and drying the ingot to obtain the pink silver alloy for jewelry. 7. the preparation method of pink silver alloy for jewelry as claimed in claim 6, is characterized in that, described raw material comprises the composition of following mass percentage composition: pure silver 33.2～42.6%, oxygen-free pure copper 22.5～35.6%, Brass 5.3-10.7%, copper-silicon alloy 0.3-4.8%, beryllium-copper alloy 10.2-15.1%, copper-tin alloy 3.1-8.1%, copper-yttrium alloy 1.1-2.1%, copper-cobalt alloy 2.5-4.3%.