阅读说明：本技术 一种新型铂金电铸珠宝首饰工艺 (Novel process for electroforming jewelry by using platinum ) 是由 邓达贤 蔡维真 于 2021-07-21 设计创作，主要内容包括：本发明公开了一种新型铂金电铸珠宝首饰工艺,涉及珠宝首饰加工技术领域。本发明包括以下步骤：底模加工；铂金电铸,使用硫酸四氨铂作为主盐,酒石酸钾钠作为导电盐,形成电铸溶液,在电铸溶液中对底模的表面电镀100μm～500μm的铂金镀层,形成粗工件；铂金空心模成型,将粗工件的底模剔除,并对粗工件进行打磨、抛光,形成珠宝首饰。本发明通过各个步骤的配合能够电铸出100～500μm的厚度的铂金镀层,且电铸出的铂金镀层出现氢脆现象的概率较低,解决了铂金电镀100μm以上厚度时容易因为氢脆现象而脆性裂开的难题。(The invention discloses a novel process for electroforming jewelry by platinum, and relates to the technical field of jewelry processing. The invention comprises the following steps: processing a bottom die; electroforming platinum, namely forming an electroforming solution by using tetraammineplatinum sulfate as a main salt and potassium sodium tartrate as a conductive salt, and electroplating a platinum plating layer of 100-500 mu m on the surface of a bottom die in the electroforming solution to form a rough workpiece; and (3) forming a platinum hollow mold, removing the bottom mold of the coarse workpiece, and grinding and polishing the coarse workpiece to form the jewelry. According to the invention, the platinum plating layer with the thickness of 100-500 μm can be electroformed through the matching of the steps, the probability of hydrogen embrittlement of the electroformed platinum plating layer is low, and the problem that the platinum plating layer is easy to crack due to hydrogen embrittlement when the thickness of more than 100 μm is electroplated is solved.)

1. A novel process for electroforming jewelry by platinum is characterized by comprising the following steps:

processing a bottom die;

electroforming platinum, namely forming an electroforming solution by using tetraammineplatinum sulfate as a main salt and potassium sodium tartrate as a conductive salt, and electroplating a platinum plating layer of 100-500 mu m on the surface of a bottom die in the electroforming solution to form a rough workpiece;

and (3) forming a platinum hollow mold, removing the bottom mold of the coarse workpiece, and grinding and polishing the coarse workpiece to form the jewelry.

2. The novel process for electroforming jewelry and jewelry on platinum according to claim 1, wherein the bottom die processing comprises the following steps:

forming an alloy blank, namely performing injection molding on the indium tin to form the alloy blank;

electroplating a zinc coating, namely electroplating a zinc coating on the outer wall of the alloy blank to form a bottom die.

3. A novel platinum electroforming process for jewellery and jewellery as claimed in claim 2, wherein the ratio of indium to tin by weight is 9: 1.

4. A novel platinum electroformed jewellery and jewelry process according to claim 2, wherein the thickness of the zinc coating is 20 to 30 μm.

5. The novel platinum electroforming jewelry process according to claim 1, wherein the tetrammineplatinum sulfate is 10-15 g/L, and the potassium sodium tartrate is 50 g/L.

6. A novel process for electroforming jewellery and jewellery as claimed in claim 1, wherein the pH of the electroforming solution is between 8.0 and 9.0 and the temperature is between 50 and 65 ℃.

7. A novel platinum electroformed jewellery and jewelry process according to claim 2, wherein the platinum hollow mould forming comprises the steps of:

opening holes, namely, performing hole opening treatment on the surface of the rough workpiece to form circular holes;

removing the tin and indium, namely putting the rough workpiece with the hole into high-temperature heat conduction oil until the tin and indium in the rough workpiece are discharged through the circular hole;

removing the zinc coating, namely repeatedly putting the crude workpiece with the tin indium removed into hydrochloric acid to dissolve the tin indium and the zinc coating in the crude workpiece;

washing and drying, namely washing and drying impurities remained on the surface of the rough workpiece;

and (5) grinding and polishing, namely grinding and polishing the rough workpiece to form the jewelry.

8. A novel platinum electroforming jewelry process according to claim 1, wherein the preparation method of the tetraamineplatinum sulfate comprises the following steps:

preparing main salt, namely preparing a mixed solution by using sulfuric acid and ammonium nitrate as an electrolytic medium;

preparing positive and negative electrode plates, namely preparing a positive electrode plate by using a platinum sheet, and preparing a negative electrode plate by using a high-purity graphite plate;

separating positive and negative electrolyte media, and dividing the mixed solution into two parts by using a perfluorinated sulfonic acid proton exchange membrane as a separation membrane, wherein one part is the positive electrolyte medium, and the other part is the negative electrolyte medium;

heating the positive electrolysis medium, namely heating the positive electrolysis medium to 90-100 ℃ by using a Teflon heater;

dissolving a platinum sheet, using pulse current as output drive, dissolving the platinum sheet into the mixed solution to form a tetrammine platinum sulfate solution;

and (3) forming the tetrammine platinum sulfate crystals, and sequentially evaporating, freezing, filtering, washing and drying the tetrammine platinum sulfate solution.

9. A novel platinum electroformed jewellery process according to claim 8, characterized in that the ratio by weight of sulphuric acid and ammonium nitrate is 5: 2.

10. The novel platinum electroforming jewelry process according to claim 8, wherein the surface area ratio of the positive electrode sheet to the negative electrode sheet is 2: 1.

Technical Field

The invention belongs to the technical field of jewelry processing, and particularly relates to a novel process for electroforming jewelry by platinum.

Background

The jewelry is a raw material and a semi-finished product of jewelry jades and precious metals, and a wearing ornament, a craft ornament and an artistic collection which are made of the raw material and the semi-finished product of the jewelry jades and the precious metals;

in the prior art, in order to improve the aesthetic degree of the jewelry, platinum is often electroplated on the surface of the jewelry, but the prior electroforming process can only electroplate a platinum plating layer with the thickness of less than 100 microns, and the platinum plating layer with the thickness of more than 100 microns is easy to be cracked brittleness due to hydrogen embrittlement phenomenon when being electroplated.

Disclosure of Invention

The invention aims to provide a novel process for electroforming jewelry by using platinum, which aims to solve the existing problems: the existing electroforming process can only electroplate a platinum plating layer with the thickness less than 100 mu m, and the platinum plating layer with the thickness more than 100 mu m is easy to be cracked brittleness due to hydrogen embrittlement phenomenon.

In order to solve the technical problems, the invention is realized by the following technical scheme:

the invention relates to a novel process for electroforming jewelry by using platinum, which comprises the following steps:

processing a bottom die;

electroforming platinum, namely forming an electroforming solution by using tetraammineplatinum sulfate as a main salt and potassium sodium tartrate as a conductive salt, and electroplating a platinum plating layer of 100-500 mu m on the surface of a bottom die in the electroforming solution to form a rough workpiece;

and (3) forming a platinum hollow mold, removing the bottom mold of the coarse workpiece, and grinding and polishing the coarse workpiece to form the jewelry.

Further, the bottom die processing comprises the following steps:

forming an alloy blank, namely performing injection molding on the indium tin to form the alloy blank;

electroplating a zinc coating, namely electroplating a zinc coating on the outer wall of the alloy blank to form a bottom die.

Further, the weight part ratio of the tin to the indium is 9: 1.

Further, the thickness of the zinc coating is 20-30 μm.

Further, the tetrammine platinum sulfate is 10-15 g/L, and the potassium sodium tartrate is 50 g/L.

Further, the pH value of the electroforming solution is 8.0-9.0, and the temperature is 50-65 ℃.

Further, the platinum hollow mold forming comprises the following steps:

opening holes, namely, performing hole opening treatment on the surface of the rough workpiece to form circular holes;

removing the tin and indium, namely putting the rough workpiece with the hole into high-temperature heat conduction oil until the tin and indium in the rough workpiece are discharged through the circular hole;

removing the zinc coating, namely repeatedly putting the crude workpiece with the tin indium removed into hydrochloric acid to dissolve the tin indium and the zinc coating in the crude workpiece;

washing and drying, namely washing and drying impurities remained on the surface of the rough workpiece;

and (5) grinding and polishing, namely grinding and polishing the rough workpiece to form the jewelry.

Further, the preparation method of the tetramine platinum sulfate comprises the following steps:

preparing main salt, namely preparing a mixed solution by using sulfuric acid and ammonium nitrate as an electrolytic medium;

preparing positive and negative electrode plates, namely preparing a positive electrode plate by using a platinum sheet, and preparing a negative electrode plate by using a high-purity graphite plate;

separating positive and negative electrolyte media, and dividing the mixed solution into two parts by using a perfluorinated sulfonic acid proton exchange membrane as a separation membrane, wherein one part is the positive electrolyte medium, and the other part is the negative electrolyte medium;

heating the positive electrolysis medium, namely heating the positive electrolysis medium to 90-100 ℃ by using a Teflon heater;

dissolving a platinum sheet, using pulse current as output drive, dissolving the platinum sheet into the mixed solution to form a tetrammine platinum sulfate solution;

and (3) forming the tetrammine platinum sulfate crystals, and sequentially evaporating, freezing, filtering, washing and drying the tetrammine platinum sulfate solution.

Further, the weight ratio of the sulfuric acid to the ammonium nitrate is 5: 2.

Further, the surface area ratio of the positive electrode sheet to the negative electrode sheet is 2: 1.

The invention has the following beneficial effects:

according to the invention, the platinum plating layer with the thickness of 100-500 μm can be electroformed through the matching of the steps, the probability of hydrogen embrittlement of the electroformed platinum plating layer is low, and the problem that the platinum plating layer is easy to crack due to hydrogen embrittlement when the thickness of more than 100 μm is electroplated is solved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a process flow diagram of a novel process for electroforming jewelry from platinum according to the present invention;

FIG. 2 is a flow chart of a preparation method of the tetramine platinum sulfate for the novel platinum electroforming jewelry process.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention relates to a novel process for electroforming jewelry by using platinum, which comprises the following steps:

s1: processing a bottom die;

the bottom die processing comprises the following steps:

s101: forming an alloy blank, namely performing injection molding on the indium tin to form the alloy blank;

the weight ratio of the tin to the indium is 9:1, and the melting point of the alloy blank is 90-110 ℃;

s102: electroplating a zinc coating, namely electroplating a zinc coating on the outer wall of the alloy blank to form a bottom die;

the zinc coating is arranged between the alloy blank and the platinum coating, so that the problem of material replacement between the platinum coating and the alloy blank can be effectively avoided;

herein, the thickness of the zinc plating layer is 20 to 30 μm;

s2: electroforming platinum, namely forming an electroforming solution by using tetraammineplatinum sulfate as a main salt and potassium sodium tartrate as a conductive salt, and electroplating a platinum plating layer of 100-500 mu m on the surface of a bottom die in the electroforming solution to form a rough workpiece;

the content of the tetraammineplatinum sulfate is 10-15 g/L, the content of the potassium sodium tartrate is 50g/L, and L is the volume of the electroforming solution;

wherein the pH value of the electroforming solution is 8.0-9.0, and the temperature is 50-65 ℃;

wherein, the electroplating equipment is a rectifier, and the power supply of the rectifier is output in a sine wave type;

wherein the current density of the electroplating is 0.5-1.5A/cm²；

S3: forming a platinum hollow mold, removing a bottom mold of the coarse workpiece, and grinding and polishing the coarse workpiece to form jewelry;

the platinum hollow mold forming comprises the following steps:

s301: opening holes, namely, performing hole opening treatment on the surface of the rough workpiece to form circular holes;

the size of the round hole is phi 0.5 mm-0.8 mm;

s302: removing the tin and indium, namely putting the rough workpiece with the hole into high-temperature heat conduction oil until the tin and indium in the rough workpiece are discharged through the circular hole;

s303: removing the zinc coating, namely repeatedly putting the crude workpiece with the tin indium removed into hydrochloric acid to dissolve the tin indium and the zinc coating in the crude workpiece;

the number of times of putting the rough workpiece into hydrochloric acid is 3-4;

s304: washing and drying, namely washing and drying impurities remained on the surface of the rough workpiece;

s305: and (5) grinding and polishing, namely grinding and polishing the rough workpiece to form the jewelry.

The preparation method of the tetramine platinum sulfate comprises the following steps:

s1: preparing main salt, namely preparing a mixed solution by using sulfuric acid and ammonium nitrate as an electrolytic medium;

the weight ratio of the sulfuric acid to the ammonium nitrate is 5: 2;

s2: preparing a positive electrode plate and a negative electrode plate, wherein the positive electrode plate is prepared from a platinum sheet, the negative electrode plate is prepared from a high-purity graphite plate, and the surface area ratio of the positive electrode plate to the negative electrode plate is 2: 1;

s3: separating positive and negative electrolytic media, and dividing the mixed solution into two parts by using a perfluorinated sulfonic acid proton exchange membrane as a separation membrane, wherein one part is the positive electrolytic medium, and the other part is the negative electrolytic medium, so that the platinum ions after electrolytic dissolution are effectively prevented from being electrolyzed on a high-purity graphite plate;

s4: heating the positive electrolysis medium, namely heating the positive electrolysis medium to 90-100 ℃ by using a Teflon heater;

s5: dissolving a platinum sheet, using pulse current as output drive, dissolving the platinum sheet into the mixed solution to form a tetrammine platinum sulfate solution;

the frequency of the pulse current is more than 5000Hz, the rated maximum value of the power supply voltage output is not lower than 50V, the pulse on-off ratio is 70-85%, and the current density is 10A-20A/dm²；

S6: forming tetrammine platinum sulfate crystals, and sequentially evaporating, freezing, filtering, cleaning and drying tetrammine platinum sulfate solution;

wherein the freezing environment temperature is below-10 ℃, and absolute ethyl alcohol is used for cleaning;

in conclusion, the platinum plating layer with the thickness of 100-500 mu m can be electroformed through the matching of the steps, the probability of hydrogen embrittlement of the electroformed platinum plating layer is low, and the problem that the platinum plating layer is easy to crack due to hydrogen embrittlement when the thickness of more than 100 mu m is electroplated is solved.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The preferred embodiments of the invention disclosed above are intended to be illustrative only. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention. The invention is limited only by the claims and their full scope and equivalents.