100 Questions on Basic Electroplating Knowledge (Part 4)
16. What should be added to the nickel plating solution to promote anode dissolution? Can a large amount of boric acid be added? Answer: To promote the dissolution of the nickel anode, an appropriate amount of chloride ions should be added. Boric acid does not have the effect of promoting the dissolution of the nickel anode. 17. What harmful impurities should be noted in the bright nickel plating solution? Answer: In bright nickel plating, attention should be paid to: (1) Impurities in industrial raw materials. For example, nickel sulfate contains copper, zinc and nitrate, and the anode nickel plate contains iron and other impurities; (2) Pollution during the production process. Such as incomplete cleaning, copper and chromium brought in from products or hangers, decomposition products of organic additives. These are all harmful impurities in bright nickel plating and should be excluded. 18. Is the peeling and flaking of the chromium coating after nickel plating mainly caused by poor pre-treatment before plating? Answer: The peeling of the coating after nickel plating and chromium plating is not only due to poor pre-treatment before plating, but also related to the condition of the plating solution and the phenomenon of double-layer nickel. 19. Why can’t metallic chromium be used as the anode for chromium plating? Answer: Metallic chromium is not used as the anode for chromium plating mainly because it dissolves very easily during the plating process. The current efficiency of the anode metallic chromium dissolving is much higher than that of the cathode metallic chromium depositing. As a result, as the plating process proceeds, the chromium content in the plating solution will increase continuously, making normal plating impossible. Moreover, metallic chromium is very brittle and difficult to process into various shapes, so it cannot be used as a full metallic chromium anode. Generally,…
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100 Questions on Basic Electroplating Knowledge (Part 3)
11. How does pre-treatment before plating affect the quality of the electroplated layer? Answer: Long-term production practice has proved that most of the quality accidents in electroplating production are not caused by the electroplating process itself. They are mostly due to improper pre-treatment of metal products. Especially the smoothness, adhesion, and corrosion resistance of the electroplated layer are closely related to the quality of pre-treatment. The surface condition and cleanliness of metal products before electroplating are important links to obtaining high-quality electroplated layers. On rough metal surfaces, it is difficult to obtain smooth and bright electroplated layers, and the electroplated layers have more pores, reducing their anti-corrosion performance. If there is any oil or dirt on the metal surface, normal electroplated layers cannot be obtained. 12. What is the definition of free cyanide in cyanide plating solutions? Answer: In cyanide plating solutions, the excess cyanide not combined in complex salts is called free cyanide. For example, in cyanide copper plating solutions, free cyanide is the cyanide that is not part of the [Cu(CN)3]= complex ion. 13. In cyanide copper plating, when the anode becomes passivated and dissolves poorly, why does the content of free cyanide increase? Answer: During cyanide copper plating, if the anode dissolves poorly, although some cyanide ions are oxidized and consumed at the anode, more free cyanide ions are produced at the cathode due to the discharge of copper cyanide complex ions, thus increasing the content of free cyanide in the plating solution. 14. How does the anode material affect the quality of the electroplated layer in acid bright copper plating? Answer: In acid bright copper plating processes, if electrolytic copper anodes are used, copper powder is easily produced, causing rough electroplated layers and rapid consumption of brighteners. Therefore, copper anodes containing a small amount of phosphorus…
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100 Questions on Basic Electroplating Knowledge (Part 2)
6. Why is it necessary to rinse the workpiece with clean water between chemical degreasing and weak acid etching? Answer: Because the usual chemical degreasing solution is alkaline. If the degreasing solution is directly brought into the acid etching solution, an acid-base neutralization reaction will occur, reducing the concentration and effectiveness of the acid. The products of the neutralization reaction adhere to the workpiece, affecting the quality of the coating. Therefore, after chemical degreasing, the workpiece must be thoroughly rinsed with clean water before entering the acid etching solution. 7. What are the common causes of burrs and coarse grains on the electroplated layer, and how can they be solved? Answer: The appearance of burrs and coarse grains on the electroplated layer is mainly caused by the contamination of the plating solution with suspended impurities. The sources of these impurities include dust in the air, sludge from the anode, and hydrolysis products of metal impurities. In addition, there may be abnormal composition of the plating solution and unsatisfactory operating conditions. The solutions are: adjusting the composition of the plating solution and operating conditions. If the problem is caused by suspended impurities, the plating solution should be filtered. 8. What is the basic procedure for preparing an electroplating solution? Answer: The basic procedure for preparing an electroplating solution is as follows: (1) First, place the measured electroplating chemicals into a small tank (preparation tank), then add an appropriate amount of water to dissolve them. Do not directly pour the chemicals into the plating tank. (2) Use various chemical methods to remove impurities from the solution and treat it with activated carbon. (3) After the solution has been treated and allowed to settle, filter it into a clean plating tank and add water to the standard volume. (4) Adjust the process parameters…
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100 Questions on Basic Electroplating Knowledge (Part 1)
1.Why can electrolytes conduct electricity?Answer: The conductivity of electrolytes is different from that of metal conductors. In metal conductors, current is transported by the movement of free electrons, while in electrolytes, current is transported by charged ions. Due to the equal charge of positive and negative ions in the electrolyte, it does not exhibit electronegativity, which is called electrical neutrality. When we apply voltage to the electrolyte, due to the strong attraction of the electric field, ions run towards the electrodes with opposite polarity to themselves. Cations run towards the cathode, anions run towards the anode. Their movement allows current to pass through, which is the principle of electrolyte conductivity. What does Faraday’s law represent? Can you explain Faraday’s first law and second law?Answer: Faraday’s law describes the relationship between the amount of electricity passing through an electrode and the weight of the electrode reactants, also known as the law of electrolysis.Faraday’s first law: The weight of metal deposited during electrolysis is proportional to the current and time passing through the electrolyte. W=KItW – weight of precipitate (g) K – proportionality constant (electrical equivalent) I – current intensity (ampere) t – electrification time (hour)Faraday’s Second Law: When the same amount of current passes through different electrolytes, the weight of the precipitated metal is proportional to the chemical equivalent of each electrolyte. K=CEC – Proportional constant.E – Chemical Equivalent 2.During the electroplating process, is it due to the high temperature of the plating solution that causes the hanging fixture to heat up?Answer: Although the heating of the hanger is related to the temperature of the solution, the main reason is that: (1) the current passing through the hanger is too high. (2) Poor contact on the hanger, increased resistance and heating of the hanger. 3.What are the main factors controlling the…
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Difference between electrophoresis lattice frame and oil spraying of brand tag-A
“Brand tag electrophoresis lattice frame” and ‘oil spraying’ are two different surface treatment processes, there are significant differences in the process principle, application effects, scope of application and so on. First. difference in process principleElectrophoresis RackingPrinciple: Based on electrophoresis technology, the electrically charged lattice particles (usually resin-like substances) are deposited on the surface of the workpiece to form a uniform coating through the action of electric field.Process: The workpiece is immersed into the electrophoresis solution as an electrode, and the electrically charged particles move directionally and attach to the surface after energization, forming a protective layer after curing.Oil SprayingPrinciple: Using compressed air or mechanical pressure to atomize the paint and spray it on the surface of the workpiece to form a continuous coating.Process: Spray paint in the form of tiny particles through the spray gun, relying on solvent volatilization or chemical reaction curing.Second.comparison of application effectCoating qualityElectrophoretic lattice: The coating is uniform and dense, with controllable thickness (usually 10-30μm) and excellent edge coverage, suitable for complex shaped workpieces.Oil spraying: the coating thickness is affected by spraying parameters (15-50μm), easy to flow hanging, orange peel and other defects, the effect of flat workpiece is better.PerformanceElectrophoretic lattice: strong corrosion resistance (salt spray test can reach more than 500 hours), high hardness (2H-4H), excellent weather resistance.Oil spraying: weaker corrosion resistance (salt spray test 50-200 hours), lower hardness (HB-2H), need additional varnish to enhance protection.Environmentally friendlyElectrophoretic lattice: water-based system, low VOC emission (<50g/L), in line with environmental regulations. Oil spraying: solvent-based paint with high VOC emission (>200g/L), requires supporting exhaust gas treatment equipment. Third.differences in scope of applicationElectrophoretic lattice frameTypical applications: automobile parts (wheel hubs, chassis), household appliance shells, hardware products, etc.Advantageous areas: need high corrosion resistance, batch processing of complex structural parts.Oil sprayingTypical applications: wood furniture, plastic products, toys, handicrafts, etc.Advantageous areas: flat…
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