As one of the basic industrial process technologies, electroplating has a wide range of applications in processing. Industrial parts are processed using electroplating technology. Electroplating layers with special physical and chemical properties are plated on the surface of parts. On the one hand, it can increase the protection and wear resistance of parts, and on the other hand, it can also play a certain decorative role. The electroplating process can bring significant improvements to the performance of parts. In the manufacturing industry, some parts are mainly electroplated with chrome and zinc.
Chromium plating can improve the wear resistance of workpieces, and galvanized parts can enhance corrosion resistance and play a beautifying role. The quality of electroplated parts plays a decisive role in the quality of equipment. Therefore, it is necessary to analyze the main reasons for the quality of the electroplating layer and take targeted improvement measures. The main reasons for the quality of electroplating are analyzed from the perspectives of internal factors and external factors.
- Internal factors that determine the quality of electroplating
- The degree of tightness, aesthetics and anti-corrosion ability between the pre-treatment coating and the surface of the parts are closely related to the quality of the pre-treatment work on the surface of the parts. The residual oil, metal oxide scale and rust on the surface of the parts hinder the contact between the electroplating layer and the surface of the metal parts, which will have a great impact on the quality of electroplating.
If there is a very thin oil film or oxide film on the surface of the plated part, although the appearance of the electroplating layer will not be greatly affected, it will greatly weaken the bonding force of the electroplating layer. Therefore, properly implementing the pre-treatment of parts is an important prerequisite for obtaining high-quality electroplated products.
In the pre-treatment work, a degreasing, decontamination and rust removal solution with a suitable concentration should be used, and the floating oil on the surface of the solution should be removed in time. As the use process is prolonged, the impurity content in the liquid increases, and the cleaning ability will continue to decrease. Therefore, it must be replaced regularly during treatment;
- The influence of electroplating solution on the quality of electroplating layer
The ratio of different components in the electroplating solution needs to be maintained within the optimal electroplating process range. In electroplating production, the content of the liquid in the tank must be regularly tested and analyzed to ensure that the ratio of each group is within the range allowed by the process.
Secondly, based on the different production tasks, various components are replenished in time according to the test analysis. Before the impurity content in the electroplating solution exceeds the appropriate range, the electroplating solution is promptly treated and purified to keep the electroplating solution within the most appropriate operating range.
In addition, during the electroplating process, harmful impurities will be mixed into the electroplating solution for various reasons. Since the types and characteristics of these impurities are different, and the same impurities have different effects on different electroplating solutions, it is necessary to combine the actual electroplating production situation, use the Hershey tank, analyze the impact on the performance of the electroplating solution and the quality of the electroplating layer under specific circumstances, and deal with impurities in the electroplating solution in time;
- Control of electroplating process conditions
The control of electroplating process conditions determines the quality of the electroplating layer to a large extent. Therefore, the key to improving the quality of the coating is to reasonably control the process conditions of different electroplating tasks, which requires practical work experience. The adjustment and selection of electroplating process parameters such as current density, temperature, and pH environment are very important. Taking chrome plating as an example, when the current density and temperature conditions are not suitable, the cathode current efficiency of the electroplating solution, the compactness of the coating and the appearance are significantly affected.
When the temperature is high, the current density should be increased as appropriate to achieve the appropriate coating requirements. The various conditions will restrict each other, so if the process conditions cannot be correctly and reasonably controlled, the overall quality of the electroplated products will be greatly affected.
- Main external factors affecting the quality of electroplating layer
- Storage and packaging of products In the atmospheric environment, ferrous metals usually use zinc coating to avoid corrosion. However, once the zinc coating comes into contact with materials such as alkyd paint, phenolic paint, phenolic plastic, plywood, and damp wood, the zinc coating will be corroded rapidly, and the corrosion products will gradually thicken over time.
In the environment of a small amount of organic volatile gas, the atmospheric corrosion process is accelerated, which is usually called atmosphere corrosion. Paint, resin, plastic and other materials may cause atmosphere corrosion. The higher the concentration of organic volatile atmosphere in the atmospheric environment, the more serious the corrosion caused to the electroplating layer.
In addition, organic volatile atmosphere will only cause corrosion to the zinc coating under humid conditions, that is, in dry air, it is usually difficult to cause corrosion. Therefore, isolating the organic volatile atmosphere and keeping the air dry have a positive effect on the protection of the zinc coating. Therefore, when storing electroplated products, the environment of the warehouse must be controlled to prevent atmospheric corrosion of parts.
In addition, in the transportation process, the product packaging will have a direct impact on the corrosion resistance of electroplated parts. For galvanized parts, they must be packed in wooden boxes and an appropriate amount of desiccant must be added to the inner packaging to ensure that the parts do not corrode and ensure product quality;
- The impact of human factors on electroplating quality Human factors are the most significant and huge factor for the quality of the coating in the entire electroplating process. In the electroplating production process, it is not difficult to find that under the same conditions of electroplating process, production equipment and raw materials, due to differences in operators, the appearance quality of electroplated products will also be different, and there may even be product quality problems. Avoid or reduce the impact of human factors on the quality of the electroplating layer.
Therefore, in actual electroplating work, first of all, we should formulate and improve standardized operating specifications to promote the standardization process of electroplating work. Secondly, we should give full play to the management rights of management workers, supervise and inspect the implementation of electroplating process specifications at the production site from time to time, and improve the supervision and inspection files in a timely manner.
In addition, we should attach more importance to the test and analysis positions, and strive to improve the professional skills of the analysis team to ensure that the components of the electroplating solution are maintained within the most appropriate range. Again, we should organize the electroplating operators to conduct professional skills training and assessment regularly to ensure that the operating skills of the on-the-job workers meet the relevant requirements of electroplating production;
- The impact of the production system of electroplating enterprises on the quality of electroplating In the production of electroplating enterprises, the production process of some parts must go through the cooperation of multiple different departments, and electroplating is the last process. There are often scratches, tight schedules, and continuous shifts, which results in the electroplating time not meeting the process requirements and restricting the quality of electroplated products.
Coordinate the effective transportation and processing period of the production department, and reserve enough processing time for the electroplating process to ensure the quality of the electroplated products;
- The impact of design drawings on electroplating quality. Usually, for parts that need electroplating, only the plating type is marked on the drawings, and there are relatively few markings on the electroplating surface, which often results in defective products during electroplating processing. In key parts, the electroplating process should ensure the bonding strength and appearance of the electroplating layer, and no obvious defects should appear.
Therefore, the key positions of electroplating must be clearly marked on the drawings to better select the hangers and mounting positions to ensure the quality of the electroplated workpieces. The improvement of the quality of electroplated products will better serve the actual needs of the manufacturing industry and greatly promote the overall development of my country’s electroplating industry. In short, in electroplating production, whether it is internal or external reasons that affect the quality of electroplated parts, we should pay attention to and respond to them.
Combined with my own work experience, the author has made a simple analysis and discussion on the reasons that determine the quality of the electroplating layer. However, how to improve the quality of electroplated products depends on the joint efforts of the entire electroplating industry.