What’s the factor affecting the quality of electroplating layer? (I)

The quality of electroplated products affects the overall quality of the equipment directly. The factors affecting the quality of electroplating include internal factors and external factors. Therefore, it is not only necessary to have a comprehensive understanding of the internal factors, but also the external factors should not be ignored. Strict control of each step can ensure the electroplating quality.
The factors affecting the the electroplating quality include two aspects: internal factors and external factors:
1. Internal factors
Strict quality management in the electroplating workshop is a powerful guarantee for the quality of electroplated products. In order to fundamentally improve the quality of electroplating and obtain high-quality coatings, there should be a comprehensive understanding of every internal step that affects the quality of electroplating.
(1) Pre-processing factors
The bonding force, anti-corrosion performance and appearance quality between the plating layer and the substrate are directly related to the quality of the surface treatment before plating. Oil, rust, oxide scale and other dirt attached to the surface of the part are intermediate obstacles that prevent the plating solution from fully contacting the metal substrate. When extremely thin oil and oxide films are attached to the plated parts, although a coating with normal appearance and fine crystals is obtained, the bonding strength is greatly reduced.
Therefore, the pre-treatment of the parts is a prerequisite for obtaining good results in the entire electroplating process. First of all, the concentration and purity of the degreasing and pickling solution must be ensured. The floating oil in the solution must be cleaned up in time; secondly, when the rust removal solution reaches a certain amount of impurities, it will affect the quality of the coating, so it must be replaced regularly.
(2) Electroplating solution factors
In electroplating production, various harmful impurities are entered into the electroplating solution due to various reasons. There are many types of impurities, roughly including metal impurities, metal oxides, non-metal impurities, various insoluble suspended solids, and organic impurities. The types of impurities contained in various plating solutions are not the same, and the tolerance to the same impurity is also different. When one or several harmful impurities accumulate to a certain extent, it will affect the performance of the plating solution and the quality of the coating. Therefore, it is not necessary to wait for the accumulation of impurities to cause harm before processing the plating solution. In addition, the content of each component of the electroplating solution has an optimal process range, and the tank solution should be tested and analyzed regularly to ensure that each component is within the process range; at the same time, according to the production task volume, actual experience and test results, the electroplating solution should be purified to ensure the stability of the electroplating solution before affecting the quality of the electroplating.
(3) Process conditions factors
The control of process conditions affects the quality of the electroplated layer directly. Only by mastering and controlling the various process conditions of each plating species, we can obtain high-quality plating. Process conditions such as temperature, current density, pH value, and plating time must be matched. For example, for hard chromium plating, the temperature and current density are not properly matched, which will have a great impact on the cathode current efficiency, dispersion ability, coating hardness and brightness of the chromium plating solution. As shown when the temperature is high, the current density needs to be increased appropriately to obtain the desired coating. Therefore, if the process conditions are not well controlled, electroplating quality accidents will occur.
We will introduce the external factors affecting the electroplating quality for you next week.