Coin-making copper alloy blank cake electrolyte plasma polishing solution and polishing process

Abstract

The invention relates to a coin-making copper alloy blank cake electrolyte plasma polishing solution. The polishing solution is prepared from, by weight percent, 1%-3% of ammonium phosphate, 1%-5% ofaluminum potassium sulfate, 0.2%-1.5% of citric acid, 0.4%-1% of sodium citrate, 0.1%-1.5% of brightening agents, and the balance water, wherein the pH range of the polishing solution is 6-8, the polishing solution component is neutral salt, the polishing solution is environment-friendly and pollution-free, and can be recycled. The polishing process comprises the following steps of, 1) adding thepolishing solution into a polishing tank in a polishing machine, and heating to 65-105 DEG C; 2) clamping a copper alloy blank cake device to be polished on a polishing special hanging tool; (3) hanging the hanging tool on a bracket in the polishing machine, lowering the bracket to enable the blank cake on the hanging tool to be immersed in the polishing solution, and keeping the blank cake at theposition 50 mm below the liquid level; 4) turning on the power supply of the machine, wherein the voltage is 250-400 V, the current density is 55-95 A / dm<2>, and the polishing time is 60-110 s; and 5) taking out the hanging tool after polishing treatment, putting the blank cake into a cleaning tank, performing washing with deionized water for 5-15s, then performing washing with alcohol, and thenperforming drying. The polishing process is simple to operate, short in polishing time, and high in efficiency.

Description

technical field [0001] The invention relates to the technical field of polishing the base cake of copper alloy commemorative coins and chapters, in particular to an electrolytic plasma polishing solution and a polishing process of the coinage copper alloy base cake. Background technique [0002] In the manufacturing process of commemorative coins and medals, the coinage copper alloy strip is first punched into a flat cake, and then the flat cake is annealed, polished and cleaned, and then embossed into a finished product. With the continuous improvement of the people's quality requirements for commemorative coins and badges, the surface quality of copper alloy commemorative coins and badges has also been continuously improved. Especially copper alloy refined coins have extremely high requirements on the roughness and gloss of the mirror surface area of ​​the product. This requires that in the manufacturing process of copper alloy commemorative coins and chapters, the anneal...

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Problems solved by technology

This method can utilize the method for plasma polishing to polish the copper alloy, and after the plasma polishing that utilizes this polishing solution to carry out is shown in its embodiment, the copper alloy product surface roughness Ra<10 μ m that obtains, but in actual application test, because make Due to the special composition of coin copper alloy, this polishing solution is not suitable for electrolytic plasma polishing of coinage copper alloy, and the roughness of the copper alloy blank cake after polishing cannot meet the coinage requirements, and the brightness is not high. The surface of the copper alloy coinage blank cake Roughness requirement Ra<1μm

[0006] Publication number CN102953062A Chinese patent "an environment-friendly plasma polishing liquid and its preparation process and polishing process", its content involves the use of plasma polishing technology to polish metal workpieces, but this patent is mainly applicable to stainless steel, zinc alloy and The polishing of oxygen copper is not suitable for minting copper alloys

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