阅读说明：本技术 一种造币铜合金坯饼电解质等离子抛光液及抛光工艺 (Electrolyte plasma polishing solution and polishing process for coinage copper alloy blank cake ) 是由 于宏 王菲 张晓男 朱慕平 胡云明 穆忠文 于 2019-08-14 设计创作，主要内容包括：一种造币铜合金坯饼电解质等离子抛光液,其成分由以下重量百分比的原料组成：磷酸铵1%~3%、硫酸铝钾1%~5%、柠檬酸0.2%~1.5%、柠檬酸钠0.4%~1%、光亮剂0.1%~1.5%、其余成分为水,抛光液的PH范围为6~8,抛光液成分为中性盐,环保无污染且可回收循环利用。抛光工艺,包括如下步骤：1)将抛光液加入到抛光机内的抛光槽中,加热至65~105℃；2)将待抛光的铜合金坯饼装置在抛光专用挂具上夹紧；3)将挂具挂在抛光机内的支架上,将支架下降,使挂具上的坯饼浸入抛光液中,保持在液面下50mm的位置；4)开启设备电源,电压为250~400V,电流密度为55~95A/dm<Sup>2</Sup>,抛光时间为60~110s；5)抛光后取出挂具,放入清洗槽内用去离子水冲洗5~15s,然后再用酒精冲洗后烘干,抛光工艺操作简单、抛光时间短、效率高。(A plasma polishing liquid for the electrolyte of copper alloy blank cake for making coin is prepared from ammonium phosphate (1- ~ 3 wt.%), aluminium potassium sulfate (1- ~ 5), citric acid (0.2- ~ 1.5.5), sodium citrate (0.4- ~ 1), brightening agent (0.1- ~ 1.5.5) and water (6-6 ~ 8), and neutral salt as polishing liquid, and features no environmental pollution and cyclic use, and includes such steps as (1) adding polishing liquid to polishing tank in polisher, heating to 65-65 ~ 105 deg.C, (2) clamping copper alloy blank cake to be polished on hanger, hanging hanger on hanger, lowering hanger to immerse blank cake in polishing liquid, holding it at 50mm position under liquid surface, and (4) turning on power supply, 250-250 ~ 400V and 55-55 ~ 95A/95/55 2 Polishing for 60 ~ 110s, 5) taking out the hanger after polishing, putting the hanger into a cleaning tank, washing the hanger with deionized water for 5 ~ 15s, then washing the hanger with alcohol and drying the hanger, wherein the polishing process is simple to operate, short in polishing time and high in efficiency.)

1. The electrolyte plasma polishing solution for the coinage copper alloy blank cake is characterized by comprising the following raw materials in percentage by weight:

1 percent of ammonium phosphate ~ 3 percent

1 percent of aluminum potassium sulfate ~ 5 percent

Citric acid 0.2% ~ 1.5.5%

Sodium citrate 0.4% ~ 1%

0.1 percent of brightener ~ 1.5.5 percent

The balance being water, the pH of the polishing slurry was in the range of 6 ~ 8.

2. The electrolyte plasma polishing solution for coinage copper alloy billet cake according to claim 1, which is characterized by comprising the following raw materials in percentage by weight:

1 percent of ammonium phosphate

1 percent of aluminum potassium sulfate

0.2 percent of citric acid

0.4 percent of sodium citrate

0.1 percent of brightener

The balance being water, the pH of the polishing slurry was in the range of 6 ~ 7.

3. The electrolyte plasma polishing solution for coinage copper alloy billet cake according to claim 1, which is characterized by comprising the following raw materials in percentage by weight:

2 percent of ammonium phosphate

3.5 percent of aluminum potassium sulfate

0.8 percent of citric acid

0.7 percent of sodium citrate

0.8 percent of brightener

The balance of water, and the pH range of the polishing solution is 7.

4. The electrolyte plasma polishing solution for coinage copper alloy billet cake according to claim 1, which is characterized by comprising the following raw materials in percentage by weight:

3 percent of ammonium phosphate

5 percent of aluminum potassium sulfate

1.5 percent of citric acid

1 percent of sodium citrate

1.5 percent of brightener

The balance being water, the pH of the polishing slurry was 7 ~ 8.

5. A coinage copper alloy blank cake electrolyte plasma polishing process is characterized by comprising the following steps:

1) adding electrolyte plasma polishing solution of coinage copper alloy blank cake into a polishing tank in an electrolyte plasma polishing machine, and heating to 65 ~ 105 ℃;

2) clamping a copper alloy blank cake to be polished on a special polishing hanger;

3) hanging the hanger full of the copper alloy blank cakes on a bracket in an electrolyte plasma polishing machine, and descending the bracket to ensure that the blank cakes on the hanger are immersed in polishing solution and are kept at a position 50mm below the liquid level;

4) turning on the power supply of the equipment, wherein the voltage is 250 ~ 400V, the current density is 55 ~ 95A/dm2, and the polishing time is 60 ~ 110 s;

5) and (4) taking out the hanging tool after polishing, putting the hanging tool into a cleaning tank, washing the hanging tool with deionized water for 5 ~ 15s, then washing the hanging tool with alcohol, and drying the hanging tool.

6. The electrolyte plasma polishing process of coinage copper alloy billet cakes according to claim 5, wherein the special hanger comprises a frame (2), a cross beam (3) and fixing rods (4), the frame (2) is of a square hollow structure, the cross beam (3) is arranged in the middle of the frame, the three fixing rods (4) protrude from the cross beam (3), and the front ends of the three fixing rods (4) are provided with fixing claws (6) so as to be distributed in a triangular shape on the same plane.

7. A coinage copper alloy billet electrolyte plasma polishing process according to claim 5, wherein the polished coinage copper alloy billet is free of oil stains, oxide scales and burrs on the surface, and the surface roughness is less than 0.4 μm.

Technical Field

The invention relates to the technical field of polishing of copper alloy memorial coin and medal blank cakes, in particular to electrolyte plasma polishing solution and a polishing process for coinage copper alloy blank cakes.

Background

In the manufacturing process of the commemorative coin and the commemorative medallion, the coinage copper alloy strip is firstly punched into a blank cake, and then the blank cake is subjected to annealing, finishing and cleaning and then is pressed and printed into a finished product. Along with the continuous improvement of the quality requirements of people on the commemorative coins and medals, the surface quality of the copper alloy commemorative coins and medals is also continuously improved. In particular, copper alloy fine coins have extremely high requirements on the roughness and the glossiness of a mirror surface area on the surface of a product. In the manufacturing process of the copper alloy commemorative coin and badge, the annealed copper alloy blank cake needs to be polished to eliminate surface burrs, oil stains and an oxide layer so as to obtain a blank cake with a smooth and clean surface.

The conventional polishing means mainly include mechanical polishing, chemical polishing, and electrolytic polishing. The mechanical polishing has high cost, low efficiency and poor polishing effect, and can not meet the requirements of the yield, the production efficiency and the quality of the coinage copper alloy blank cake. Although the chemical polishing and the electrolytic polishing have good effects, the two processes mostly adopt high-concentration acidic solutions, so that the operation is dangerous, the human health is harmed, and the waste liquid can cause environmental pollution.

The electrolyte plasma polishing technology is to utilize gas-liquid plasma generating technology to set the workpiece inside polishing liquid and apply certain voltage to vaporize the polishing liquid around the workpiece to form one gas film around the workpiece, and to form discharge channels in different positions to eliminate surface material selectively to polish the surface of the metal workpiece. Compared with the traditional mechanical polishing, chemical polishing and electrolytic polishing, the technology has the advantages of good polishing effect, high production efficiency, environmental protection, no pollution and the like. At present, the polishing agent is mainly applied to deburring and polishing the surfaces of products such as stainless steel, aluminum alloy, zinc alloy and the like, and has poor polishing effect on other metal materials. The core of the electrolyte plasma polishing technology is that different polishing solutions and polishing process parameters should be selected for the components and the heat treatment states of different metal materials, and due to the particularity of the components of the coinage copper alloy, the electrolyte plasma polishing solutions and the polishing processes disclosed in the currently disclosed patents and documents are not suitable, so that the effect cannot meet the quality requirement of the coinage copper alloy blank cake.

In the search of the patent and literature, the applicant found that chinese patent publication No. CN102516887B, "polishing solution and plasma polishing process", relates to a polishing solution and plasma polishing process for copper alloy. The method can polish the copper alloy by using a plasma polishing method, and the embodiment shows that the surface roughness Ra of the obtained copper alloy product is less than 10 mu m after the plasma polishing by using the polishing solution, but in practical application tests, the polishing solution is not suitable for electrolyte plasma polishing of coinage copper alloy due to special components of the coinage copper alloy, and the roughness of a copper alloy blank cake after polishing can not meet the coinage requirement, the brightness is not high, and the surface roughness Ra of the copper alloy coinage blank cake is less than 1 mu m.

In the chinese patent publication No. CN102953062A, "an environment-friendly plasma polishing solution, and a preparation process and a polishing process thereof", the contents relate to polishing a metal workpiece by using a plasma polishing technique, but the patent is mainly applicable to polishing of stainless steel, zinc alloy and oxygen-free copper, and is not applicable to coinage copper alloy.

Disclosure of Invention

The invention aims to overcome the defects of the prior polishing technology, provides electrolyte plasma polishing solution for manufacturing coinage copper alloy blank cakes of commemorative coins and medals and a polishing process thereof in order to meet the quality requirements of coinage copper alloy blanks and the blank cakes thereof with special components, and solves the problems in the prior art, and the technical scheme is as follows:

the electrolyte plasma polishing solution for the coinage copper alloy blank cake comprises the following raw materials in percentage by weight:

1 percent of ammonium phosphate ~ 3 percent

1 percent of aluminum potassium sulfate ~ 5 percent

Citric acid 0.2% ~ 1.5.5%

Sodium citrate 0.4% ~ 1%

0.1 percent of brightener ~ 1.5.5 percent

The balance being water, the pH of the polishing slurry was in the range of 6 ~ 8.

A coinage copper alloy billet cake electrolyte plasma polishing process comprises the following steps:

1) adding electrolyte plasma polishing solution of coinage copper alloy blank cake into a polishing tank in an electrolyte plasma polishing machine, and heating to 65 ~ 105 ℃;

2) clamping a copper alloy blank cake device to be polished on a special polishing hanger;

3) hanging the hanger full of the copper alloy blank cakes on a bracket in an electrolyte plasma polishing machine, and descending the bracket to ensure that the blank cakes on the hanger are immersed in polishing solution and are kept at a position 50mm below the liquid level;

4) the power supply of the equipment is turned on, the voltage is 250 ~ 400V, and the current density is 55 ~ 95A/dm²Polishing time 60 ~ 110 s;

5) and (4) taking out the hanging tool after polishing, putting the hanging tool into a cleaning tank, washing the hanging tool with deionized water for 5 ~ 15s, then washing the hanging tool with alcohol, and drying the hanging tool.

The special hanging tool comprises a frame, a cross beam and fixing rods, wherein the frame is of a square hollow structure, the cross beam is arranged in the middle of the frame, three fixing rods are arranged on the cross beam in a protruding mode, and fixing claws are arranged at the front ends of the three fixing rods and are distributed in a triangular mode on the same plane.

The polished surface of the coinage copper alloy billet cake has no oil stain, oxide skin and burrs, and the surface roughness is less than 0.4 mu m.

The invention is suitable for polishing and deburring the blank cakes of the coinage brass alloy, coinage white copper alloy, coinage red copper alloy and coinage aluminum bronze alloy, and the polished blank cakes of the coinage copper alloy with bright and clean surfaces are obtained.

Compared with the prior art, the invention has the beneficial effects that:

1. the electrolyte plasma polishing solution and the process prepared by the invention are suitable for coinage copper alloy, and meet the surface quality requirement of coinage billet cake, the surface of the billet cake is bright and clean, and the roughness is less than 0.4 mu m.

2. The prepared electrolyte plasma polishing solution is neutral salt, is environment-friendly and pollution-free, and can be recycled.

3. The electrolyte plasma polishing process is simple to operate, short in polishing time and high in efficiency.

Drawings

FIG. 1 is a schematic view of the overall structure of a special hanger;

FIG. 2 is a schematic diagram of a dedicated hanger test structure;

in the figure, 1, a connecting rod, 2, a frame, 3, a cross beam, 4, a fixed rod, 5, a supporting leg, 6 and a fixed claw.

Detailed Description

The invention is further described below by way of examples.