TW546418B - Method of producing AuCuGa alloy coating using electrolysis, and alloys produced by such a method - Google Patents

Abstract

The present invention relates to a method of producing a gold-copper-gallium (AuCuGa) alloy coating by electrodeposition on a substrate (2), using an aqueous electrolytic bath. The method is characterized in that the aqueous electrolytic bath comprises potassium aurocyanide (KAu(CN)2), copper cyanide (CuCN), potassium cyanide (KCN) or sodium cyanide (NaCN), and a gallium salt (e.g. gallium sulfate Ga2(SO4)3). In particular, the molar concentration of gold cations ([Au+]), copper cations ([Cu+]) and gallium cations ([Ga3+]) in the electrolytic bath is respectively comprised within the following ranges: 0.19 g/l <= [Au+] <= 2.17 G/L (0.1X10<-2> mol/l <= [AU+] ≤ 1.1X10<-2> mol/l); 0.31 g/l <= [Cu+] <= 1.59 G/L (0.5X10<-2> mol/l <= [CU+] ≤ 2.5X10<-2> mol/l); and 0.69 g/l <= [Ga3+] <= 2.79 G/L (1X10<-2> mol/l <= [GA3+] ≤ 4X10<-2> mol/l). Such a method allows to provide an AuCuGa alloy coating having brightness and ductility properties which are equivalent to those of the prior art AuCuCd alloy coatings.

Description

546418 A7 B7 V. Description of the invention (1) Field of invention: (Please read the notes on the back before filling out this page) The present invention is related to the production of gold-copper-gallium (A u C u G a) by electrolytic method The method of alloy coating has the ductility and brightness which are particularly suitable for the necessary conditions for the sale of jewelry and gold jewelry. Background of the Invention: In the jewellery and gold jewelry industry, because of its brightness and ductility, the technology based on gold-copper-cadmium (Au C u C d) alloy coatings is well known. For example, the most commonly used 18-K (18-K) gold-copper-cadmium (AuCuCd) alloy coatings have weight percentages of gold, copper, and cadmium of 75%, 18%, and 7% ( The atomic percentages are 52. 4%, 39% and 8.6%, respectively. Such alloy coatings have ideal brightness, hardness (400 Vickers 2 400 Vickers) and ductility, which makes it extremely It ’s so attractive that it has been widely used since the last century. The Intellectual Property Bureau of the Ministry of Economic Affairs g: Industrial and Consumer Cooperatives printed the gold-copper-cadmium (A u C u C d) co-deposition using electrolytic method as a 'S is It is known that many electrolytic methods use different types of electrolytes, such as alkaline, alkaline and neutral cyanide or sulfuric acid electrolytes. When using the above electrolytic baths, in order to obtain gold-copper-cadmium (A u C u C d) i coating 'for the electrodeposition of gold, copper and cadmium cations, the required potential ranges are all the same. Material M is US Patent application No. 72/237513 (C Η 5 5 6 9 1 6 & CH542934 ) Reveals a coating method and an electrolytic bath deposition ', low one open &quot; [(Low-cam, 1 4 ~ -4- This paper is applicable in the standard Standard G (CNS) A4 (2iGx297 male thin) 546418 A7 B7 V. Description of the invention (2) (Please read the precautions on the back before filling this page) 19K (On)] and thick gold—copper-cadmium ( AuCuCd) alloy coating (2 0 ~ 4 0 // m), which contains soluble gold cyanide complex, soluble copper cyanide, soluble cadmium compound, free cyanide, and water-soluble polyoxyalcoylenic Bath of alkaline aqueous solution of brightener, electrodeposited gold-copper-cadmium (Au C u C d) alloy. When depositing `` low-open alloy '' (such as low concentration of gold and high concentration of copper and Cadmium), the use of brighteners can make the final thick coating very ideal brightness. However, regardless of the advantages of gold-copper-cadmium (Au C u C d) alloy coating, cadmium is very volatile and toxic This problem produces undesirable results when soldering jewellery made of this alloy coating. Especially when manufacturing electroformed parts of this alloy, 'it must make two holes to reduce its substrate, and then it needs to be soldered. When full, the volatility and toxicity of cadmium will cause very serious problems. Moreover, since 1 Since 1988, European regulations for health reasons have tended to limit the use of such compounds. Therefore, 'Au C u is printed to avoid the conventional technical gold-copper-cadmium (the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs) C d) alloy volatility and toxicity issues, it is necessary to provide a new alloy with the same quality as those of gold-copper-fine (A u C u C d) alloys. The gold-copper (Au Cu) two-element alloy without using any pots has been mentioned in the book Galvano-Organo Traitement de Surface &quot;, p.379 ~ 3 82, April 91/615. However, the alloy is not available in shopping malls. Indeed, the color of the two-element alloy seems to be red, because the additional copper required to supplement the cadmium deficiency makes the two-element alloy very sensitive to oxidation. As a result, the alloy can hardly be considered as suitable for jewelry. -5- The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) 546418 A7 B7 5. Application of the invention (3). (Please read the notes on the back before filling out this page.) Until now, some compounds have been proposed to replace cadmium in gold-based three-element alloys, such as gold-copper-zinc (A u C u Z η) alloys. Zinc (US 5,008,744, EP 0303 0 3 15, or EP 048 0 876), gold-copper-bismuth (

AuCuBi) alloy in bismuth (ep 0 1 26 9 2 1) and gold in copper-silver (Au CuAg) alloy (EP 0 566 054). In any case, these alloys are not suitable for consideration as jewelry and gold jewelry. In particular, gallium (G a), due to its melting point (gallium melts at 4 5 t), has never been considered as a possible substitute for cadmium in gold-based alloys. This makes the measurement required for the characteristics of the final alloy very difficult, so that the efficacy of gallium in the gold-copper-gallium (AuCuGa) three-element alloy is difficult to control. Gold-copper-gallium (Au C u G a) bulk alloy is used in the field of dentistry. However, this bulk alloy is produced by melting gold, copper and gallium into an ingot. This production method cannot be applied to jewelry. industry. The Intellectual Property Bureau of the Ministry of Economic Affairs a (Industrial and Consumer Cooperatives printed invention description: In order to overcome the above-mentioned problems of alloy coatings of the prior art, the main purpose of the present invention is to provide similar to those of AuCuCd alloy coatings. Au C u G a alloy coating with brightness and ductility properties, so that this Au C u G a alloy coating, especially in jewelry applications, can be used as Au C u C d alloy coating -6- This paper size applies Chinese National Standard (CNS) A4 specification (210X297 mm) 54641ο Α7 Β7 '~ ~~ ------5. Description of the invention (4) This purpose is to provide a use Aqueous solution electrolytic bath is a method for producing Au C u G a alloy coating by electrodeposition on a substrate (acceptor). It is characterized in that the aforementioned aqueous solution electrolytic bath contains: potassium gold cyanide [KA u (CN) 2 ], Copper cyanide (CuCN), potassium cyanide (KCN) or sodium cyanide (N a CN) and soluble gallium compounds. The above soluble gallium compounds may be at least one gallium salt or a mixture of the following gallium salts: gallium sulfate (G a 2 (S〇 4) 3), gallium chloride (G a C 1 3), 2,3-salicylic naphthyl ester Cyanogen gallium chloride salt ((2,3 — naphthalocyanine gallium monochloride salt), (C 4 8 H 2 4 C 1 G a N 8)), gallium nitrate nonahydrate (G a (N〇3) 3 · 9 Η 20), gallium nitrate hydrate (G a (N〇3) 3 · aq), gallium nitride (G a N), gallium oxide (G a 2 0 3), gallium phosphide (G a P), and benzene dichloride Methyl blue pigment gallium chloride [(phthalocya nine gallium monochloride salt), (C32H16C 1 GaNe)]. (Please read the notes on the back before filling this page)

, 1T

U C ion ion c gold c neutron ion ion gallium cation and bath} solution 3

G a

Contains c, c, c, and zi respectively, copper concentration, ear) Mo — of \) / U / — \ A Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs is listed below: 〇〇 ×: X Wai 1 Fan · 〇g 9 m 〇

〇m 2 〇 1X g 9 5 r—i U A N-f &lt; | &lt; | s τ—I 3 〇

/ X τ—I 7 · 1 ~ II .Vli 2] VII + Ju + A &lt;-u c νm 〇m 2 〇 IX X 5 o o 〇. And 1}, X 1) 1 / '—_ / V' ~~ _ / 101 / m 2 g I 9 〇 2 7 1 〇 X 12 4 X &lt; i VII 5]] 3 3 2 &lt;-om

a G &lt; lucg 9 6 〇m VII &lt; l This paper size applies Chinese National Standard (CNS) A4 specification (210 × 297 mm) Intellectual property of the Ministry of Economic Affairs (printed by the Industrial and Consumer Cooperatives 546418 A7 B7___) Explanation (5) In a preferred embodiment, the molar concentrations of gold ions ([A u +]), copper ions ([C u 1]), and gallium ions ([G ap]) in the electrolytic bath cations are respectively. [ Auf]. (Ϊ́χΐ〇2 m ο 1/1), CCu '] ^ li27g / 1 (2 x 10 2 m ο 1/1), and [G a 3 +] = work · 3 9 g / 1 (2xl 〇 2 m 〇 1 / i). In addition, the molar concentration of potassium cyanide (K c N) in the electrolytic bath must be at least 1.5 times the molar concentration of copper gaseous copper (C u CN). The range of p Η 値 is 7 ~ 1 3, which is favorable to be higher than or equal to 10 (more preferably, 1 2); the temperature range of the electrolytic bath is 1 5 to 8 0 ° c, and preferably 5 0 to 7 〇 ° C or about 60 ° C; when the electrolysis is performed, the flow rate is loose, and the degree range is 1 · 1 ~ 1 · 8 A / dm 2 (preferably 1.4 dm 2). In order to improve the brightness, color and or chemistry of the alloy Properties, certain complexing agents such as chelating agents or some mixtures thereof Aqueous electrolytic bath may be added.

For example, 'the aforementioned at least one chelating agent is an organic phosphate chelating agent or an aminocarboxylic acid or aminopolycarboxylic acid, particularly ethylenediaminetetraacetic acid (EDTA), nitriletriacetic acid (NTA), and 2-aminoethanesulfonic acid ( taimne) The present invention is also concerned about any Au C II Ga alloy produced by this method. Other features and advantages of the present invention will become more apparent after reading the following detailed description of the embodiments of the present invention, and referring to FIG. 1, it is applicable to the production of 18-K (18-K) gold according to an embodiment of the present invention— The copper-gallium A u C u G a alloy coating method represents a model electrostatic device. (Please read the precautions on the back and save this page)

This paper size applies Chinese National Standard (CNS) A4 specification (2i × 297mm) — 8 _ 546418 A7 B7 V. Description of the invention (6) Detailed description of the preferred embodiment: (Please read the precautions on the back first (Fill in this page) As shown in Figure 1, an exemplary electrostatic device contains: an electrolytic bath 3 ', in which the anode 1 and cathode 2 are immersed in the electrolytic bath, the motor 4 can be driven to rotate-pole 2, and the current generator 5 is connected to anode 1 And cathode 2. The thermocouple 6 is coupled to the electric heating device 7 to maintain a predetermined temperature of the electrolytic bath. When and before the electrolysis, the magnetic stirrer 8 is used to maintain the stable uniformity of the electrolysis bath. In the described embodiment, the cathode 2 is a copper plate covered with a thin gold film, and its thickness is 0 · 1 ~ 0 · 2 // m, and it is used as the bottom layer. This copper plate is suspended by a copper wire 'and is driven to rotate by a motor 4 at a speed of 7 · 5 rpm. This cathode can be made of any other electrically conductive material, e.g. nickel can be coated with any other suitable substrate. The anode 1 is titanium (T i -p t) coated with uranium, and the magnetic stirrer 8 can be obtained at a speed of 125 revolutions per minute. The desired thermocouple is used to maintain the electrolytic bath temperature at 60 t. Prepared in advance 'the cathode 2 substrate (receiver) in order to dissolve the emulsified grease' to skim off any grease on the substrate, and implement activation and use of ultrasonic washing procedures to remove impurities, followed by distilled water Rinse the substrate. The Intellectual Property Bureau of the Ministry of Economic Affairs (industrial and consumer cooperatives prints a special embodiment of the present invention. In order to electrolyze the bath according to the present invention, the electrolytic bath of P Η 値 12 is prepared in the electrolytic bath 3 described above, and the cyanide is added in the order described later. Compound complex. Potassium cyanide [KA u (C Ν) 2], copper cyanide (C u C Ν), potassium cyanide (KCN), and gallium sulfate (G a 2 (S〇4) 3) Under the aforementioned conditions of stirring, rotating the cathode, temperature and p 加入, adding the electrolyte to the solution, the Molar concentration of the following cations can be obtained: [Au1] 2 1 · 97g / l This paper is applicable to Chinese National Standard (CNS) A4 Specifications (210X 297 mm) -9-546418 A7 B7 V. Description of the invention (7) (1x10 2 m 〇1 / 1), [Cu4]:! * 27g / 1 (2x10 21) 〇1 / 1) And [〇33 +] 2,39 g / 1 (2x10 2 m 〇1 // 1). In this particular embodiment, in order to provide an electrolytic bath gallium cation, anhydrous gallium sulfate (G a 2 (S. 4) 3), however, many other types of gallium salts or mixtures of these salts can be used, for example: gallium chloride (G a C 1 3), 2,3-salicylate naphthoate blue Gallium salt [(2, 3 — naphthalocyanme gallium monochloride salt), (C 4 8 Η 2 4 C 1 G a N 8)], gallium nitrate nonahydrate (G a (N〇3) 3 · 9 Η 2〇) , Hydrated gallium nitrate (Ga (N03) 3.aq), gallium nitride (GaN), gallium oxide (G a 2 0 a), gallium phosphide (G a P), or xylolium gallium chloride Salt [(phthalocyanine gallium monochloride salt), (C32H16C 1 GaNe)] 0 In order to make copper cyanide (C u CN) soluble in the electrolytic bath, potassium cyanide (KCN) or sodium cyanide (N a CN) is added. Required. The molar concentration of potassium cyanide (KCN) in the electrolytic bath must be at least 1.5 times the molar concentration of copper cyanide (C u CN). That is [K .1] in this particular embodiment. 22, 1 7 3 g / 1 (3 X 1 0-2 m ◦ 1/1). However, any other cyanide complex which can promote the solubility of copper cyanide (C u CN) can be used for electrolysis However, under the same test conditions, a current density of 1.4 dm 2 was used between the anode 1 and the cathode 2 to catalyze the electrolytic solution. The stirring of the electrolytic bath and the rotation of the cathode can help obstruct the depletion of the diffusion layer (please read the precautions on the back before filling this page)

、 1T Wisdom of the Ministry of Economic Affairs printed on the paper printed by the Consumer Cooperatives of the Bureau of Industry to apply the Chinese National Standard (CNS) A4 specification (210 × 297 mm) -10- 546418 A7 B7 V. Description of the invention (8) (Please read the first Please fill in this page again.) Ion diffusion. The more intense the mixing, the higher the current density required to maintain the electrolysis, and thus achieve the fastest coating. In any case, in the case of the A u C u G a alloy coating, the stirring conditions of the electrolytic bath and the rotating conditions of the cathode are more conducive to helping the surface of the cathode to reduce chlorine gas bubbles that may occur when water is reduced. These chlorine gas foams often interfere with the co-deposition of dimetallic cations and impair the properties of the final alloy coating. Because the reduction of gallium occurs more than the reduction of water (the reduction potential of water is-2 V), in order to reduce the trimetal, it is necessary to provide an operating potential greater than L 2 V. In this particular embodiment of the invention, the operating potential is approximately 2.75 V. The above deposition conditions are maintained for a certain period of time depending on the desired coating thickness. In this embodiment, after the current density is maintained for 10 minutes, the thickness of the obtained coating is 4 // m. Increasing the applied potential time between the anode and the cathode results in a thicker coating. After the electrolysis stops and the thickness of the coating is 4 #m, the cathode copper plate 2 is removed from the electrolytic bath and washed, and the cathode copper plate is reserved for future use. In this particular embodiment, the final alloy coating is a printed composition of employees ’cooperatives of the Intellectual Property Bureau of the Ministry of Chemistry and Economy, with a percentage of gold, copper, and gallium atoms of 62%, 27.3%, and 10.7%, respectively. No. 18-K (1 8-K) gold-copper-gallium Au CuGa three-element alloy. This alloy hardness is suitable for jewelry and gold jewelry trading. The average particle size measured is 0. 3 Απι ', and the thickness of the Au C u G a alloy coating is similar to the brightness of those Au C u C d alloy coatings of the prior art. Moreover, because its surface is no longer rough, of course, its increased corrosion resistance is also its advantage. According to the invention of A u C u G a alloy coating -11-This paper size is applicable to Chinese National Standard (CNS) A4 specification (210x297 mm) 546418 5. Description of the invention (9) The color of the song is slightly lower than its golden yellow A u C u C d alloy of the prior art. (Please read the precautions on the back before filling this page.) Furthermore, the aging test carried out according to the A u C u G a alloy coating of the present invention shows that the test with air, sweat and acetic acid caused corrosion and Discoloration is not sensitive. The present invention is not limited to the above-mentioned exemplary preferred embodiments, in particular, many different forms of A u C u G a alloys have different K (K) contents (such as from 8 to 24 K (K)) and similar brightness, It can be obtained according to the method of the present invention. The molar concentrations of different cations in the electrolytic bath are included in the following ranges: 0.19 bogey / 1 ^ 〔八 11 +] $ 2.17 忌 / 1 (〇 · lxi0 &quot; 2m〇1 / 1 ^ [AuM · lx 10 2m〇l / l), 0.31 g / lS [Cu +] S 1 · 59 g / l (0.5 x 10-2 m〇1 / 1S [Cu +] = 2.5 x 10-2 mol / l), and 0.99 g / lS [Ga3l] S2.79 g / l (l × 10—2mmol / lS [G a 3 丨] $ 4 x 1 〇-2 mo 1/1). Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs According to the present invention, P Η 値 of the electrolytic bath which can be performed in the electrolytic solution of the aqueous solution is higher than or equal to 10, and the possible change of the electrolytic bath p Η 値 will affect the production of the electrolytic action. (Mg / A · mi η ·) and coating thickness electrolytic bath temperature range is 50 ~ 70 ° C. When the temperature is increased, it may increase the approved maximum current density, which will reduce the viscosity and therefore increase the electrochemical reaction and diffusion rate. For this reason, electrolytic deposition can be achieved with a higher concentration of electrolyte. The operating current density ranges from 1 · 1 to 1.8 A / d m 2. This paper size applies Chinese National Standard (CNS) A4 (210x 297 mm) -12-546418 A7 B7 V. Description of the invention (10) According to the above properties of the present invention, A u C u G a alloy coating deposition conditions can be provided , And has used different well-known chemical and structural characteristics to detect and analyze the final alloy: such as electronic spectroscopic analysis of chemical analysis (ESCA) 'energy dispersive X-ray spectrometry (EDXS), atomic absorption spectrometry (AAS), or X-ray diffraction analysis (XRD) and scanning electron microscopy (SE M). Under the control of varying potentials, the completion of different deposition tests can be used to determine the correct range of its parameters. ε s C Α measurement analysis shows the order of cation reduction (the potential is more negative from gold and copper to gallium) and EDXS gives the final alloy chemical composition. Its thickness is 1 ~ 4 # 1Ί1 'EDXS analysis can determine the surface of the alloy composition. For thicker alloys' such as greater than 4 4 // m, the chemical composition of the entire deposit can be analyzed by A A S. X R D pattern analysis can establish the entity of the electrodeposition periodic structure according to the present invention. In addition, in the Au C u G a alloy, the copper content can either increase the concentration of the electrolytic bath (resulting in a significant change) or increase the current density (resulting in a slight change). On the other hand, it establishes a simple method that does not change the gallium content of the alloy when the current density is increased. This increase in current is beneficial to the co-deposition of gallium and copper. Therefore, another advantage of the present invention is the change in the gold content (open number or copper and gallium content), which can be controlled by adjusting the current density between the two electrodes. Certain additives (calenders for polished particles, leveling agents such as soluble selenium or tellurium compounds, colloids, wetting agents, etc.) can be added to the electrolytic bath according to the present invention. In order to improve the yield or modify the co-deposition structure and the paper size, the Chinese National Standard (CNS) A4 specification (210X297 mm) is applied (please read the notes on the back before filling this page). Printed by the Consumer Cooperatives-13- 546418 A7 B7 V. Description of the invention (11) Goodness and or color of the aucu G a alloy coating, for example, some polyoxyalcoylemc compounds can be used as brighteners, and one (please first Read the notes on the back and fill in this page) Mixtures such as organic phosphate chelating agents or aminocarboxylic acids or aminopolycarboxylic acids can be used. For example, add ethylenediaminetetraacetic acid (EDTA, Η 2 Y) or nitrile triacetic acid (ΜΤΑ, Η3χ) (Molar concentration range is 0 · 1 ~ 2 m ◦ 1/1) in the electrolytic bath can improve the brightness and get a rosy coating. The test shows that the current density is 1 · 4 when electrolysis A / dm 2 increases the reduction of gold and gallium when EDTA or NTA is increased, but increases the reduction of copper 'and increases the current density, but only slightly increases the reduction of copper. In particular, the addition of 2-aminoethanoic acid (taunne) to Electrolytic bath Medium test 'with a current density of 1 A / dm 2 and an increase in the cathode efficiency of this method, it is possible to obtain a gold-copper-gallium A u C u G a three-element alloy. Increasing the use of taunne will reduce the reduction of gold, and The reduction of gallium and copper is increased. When the current density is increased, the reduction of copper is only slightly increased. The printing of the alloy according to the present invention by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs is particularly suitable for the sale of jewelry and gold jewelry. 2 4-K coating, it is also suitable for other people who need to use these alloys, such as in the application of microelectronics technology. The diagram is a simple illustration. Figure 1 shows an example of an electrostatic device. Component comparison table 1 Anode This paper size applies Chinese National Standard (CNS) A4 specification (210X297 mm) -14-546418 A7 V. Description of the invention (12) Printed by the Consumer Cooperative of Intellectual Property Bureau of the Ministry of Economic Affairs 2 Cathode 3 Electrolytic bath 4 Motor 5 Current generation Device 6 heat (¾ couple 7 electric device 8 magnetic stirrer (please read the precautions on the back before filling this page) This paper size is applicable to China National Standard (CNS) A4 specification (210 X 297 mm) _ 15-

Claims (1)

546418 A8B8C8B8 6. Scope of patent application It Part 2: Patent application No. 901 10429 Chinese application patent scope is not underlined Printed by the Consumer Cooperative of Intellectual Property Bureau of the Ministry of Economic Affairs The system contains: potassium gold cyanide [KA u (CN) 2), copper cyanide (CuCN), potassium cyanide (KCN) or sodium cyanide (N a CN), and soluble gallium compounds. 2. A method for producing a gold-copper-gallium (Au C uGa) alloy coating on a substrate (acceptor) by electrodeposition on the substrate (acceptor) according to item 1 of the patent application scope, wherein the soluble gallium compound is at least one gallium salt or the following gallium Mixture of salts: gallium sulfate (G a 2 (S04) 3), gallium chloride (G a C 1 3), 2, 3 -salicyl naphthalate blue pigment gallium chloride salt [(2 '3- naphthalocyanine gallium monochloride salt) '(C48H24C 1 GaNs)], gallium nitrate nonahydrate (Ga (N〇3) 3.9.20), gallium nitrate hydrate (Ga (N〇3) s-aq), gallium nitride (GaN ), Gallium oxide (G a 2 0 3), gallium phosphide (GaP), and phthalocyanine gallium monochloride salt [(C32H16C 1 GaNs)]. 3. The method according to item 1 of the scope of patent application, wherein the molar concentration of gold ions ([Au +]), copper ions ([C ^ +]) and graft ions ([G a 3 +]) in the cation of the electrolytic bath They are included in the following ranges: · 0. G 7 g 〇τ: Aw1T— (Please read the precautions on the back before filling this page) This paper size is applicable to China National Standard (CNS) A4 (210X: Z97 mm) 546418 A8 B8 C8 D8 VI.Applicable patent scope: 10-2mo Ι / Mg [Au +] · lx 102- 2mo 1 / l), 0.3lg / l $ [Cu +] $ 1.59g / l (〇-δχΙΟ '^ Ώοΐ / ι ^ ίΟηΜ ^^. Δχ 10-2m ol / i), and 0.69g / 1 $ [Ga3 +] = 2. 7 9 g / 1 (lx l〇_2m〇l / 1 ^ [Ga3 +] ^ 4xl0'2m〇i / i) 〇4. According to the method of item i in the scope of the patent application, among them, gold ion ([Au +]), copper ion ([Cu +]) and gallium ion ([ Ga3 +]) The molar concentrations are: [Au +] = 1.97g / l (lx 1〇-2 m〇1 / 1), [Cu +] = 1.27g / l (2xl〇_2m〇l / l ) And [G a 3 +] = i · 39 g / i (2xl0 ~ 2mol // l). 5. The method according to item i of the patent application, wherein the molar concentration of potassium cyanide (K C N) in the electrolytic bath must be at least 1.5 times the molar concentration of copper cyanide (CuCN). 6. The method according to item 1 of the patent application range, wherein the pH of the electrolytic bath ranges from 7 to 13. 7. The method of claim 6 in the scope of patent application, wherein the favorable P 电解 of the electrolytic bath is higher than or equal to 10. 8. The method according to item 1 of the scope of patent application, wherein the β-circle of the temperature bath of the electrolytic bath is 15 ~ 80 ° C. 9 · The method according to item 8 of the scope of patent application, wherein the preferred temperature range of the electrolytic bath is 50 to 70 ° C. 10 · If the method of the 9th scope of the patent application, the paper size of the electrolytic bath applies the Chinese National Standard (CNS) A4 specification (210 × 297 mm) -------; ------- ( Please read the notes on the back before filling out this page), 1T printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs, 546418 A8 B8 C8 D8 6. The range of patent application is better. The temperature range is 60 °. 1 1. The method according to item 1 of the scope of patent application, wherein the current density during electrolysis ranges from 1 · 1 to 1 · 8 A / d m 2. 12. The method according to item 1 of the patent application range, wherein the aforementioned water solution electrolytic bath contains at least one chelating agent. 1 3 _ The method according to item 12 of the scope of patent application, wherein at least one of the aforementioned chelating agents is an organic phosphate chelating agent or an aminocarboxylic acid or aminopolycarboxylic acid. 14. The method according to item 13 of the scope of patent application, wherein the aforementioned chelating agent is particularly ethylenediaminetetraacetic acid (EDTA), nitriletriacetic acid (NTA), or 2-aminoethanesulfonic acid (taurine). 15__ A kind of gold-copper-gallium alloy coating, which is produced by the method according to any one of the claims 1 to 14 of the patent application. — ^ ； -----— (Please read the notes on the back before filling out this page) Order the paper size printed by the Employees' Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs to apply the Chinese National Standard (CNS) A4 Specification (210 ×: Z97) Centimeters) -3-