Introduction
Electroplating is a widely used production technique for platting a thin coating of material on the surface of a part. The main purpose of electroplating is to protect the part from corrosion and improve its strength, electrical conductivity, and physical appearance. Electroplating is used industrially for many applications, including automotive parts, jewelry, medical devices, and more. Due to the complexity of the electroplating process, there are a number of common electroplating faults that can occur. This paper will discuss some of the most common electroplating faults, provide analysis of the causes, and offer solutions for preventing and correcting them.
Common Electroplating Faults
There are a number of common faults that can occur when electroplating. These include:
1. Low Adhesion: If the coating does not adhere properly to the substrate, it can result in the coating being peeled off. This is caused by improper cleaning of the substrate or inadequate wetting of the substrate.
2. High Liquid Waste: When too much of the plating solution is used, it can result in liquid waste. This can be caused by improper rinsing of the part before plating, an excessive flow rate of the solution, or improper agitation of the solution.
3. Plating Insufficient Thickness: This is caused by poor current distribution, improper rinsing or cleaning of the part prior to electroplating, or inadequate bath agitation.
4. Crater Formation: This is caused by poor current distribution or insufficient plating time.
Analysis of Causes
1. Low Adhesion: This fault occurs due to improper substrate cleaning and inadequate wetting of the substrate. This can be caused by poor surface preparation such as inadequate degreasing, deionization, or contamination. If proper surface preparation is not performed, the plating will not adhere properly.
2. High Liquid Waste: This is caused by improper rinsing of the part before plating, an excessive flow rate of the solution, or improper agitation of the solution. If the part is not properly rinsed, the plating solution will not be able to properly react with the part. If the flow rate of the solution is too high, it can cause the solution to be over-concentrated, leading to deposits that can be difficult to remove. If the agitation of the solution is inadequate, this can also lead to deposits forming on the part.
3. Plating Insufficient Thickness: This can be caused by poor current distribution, improper rinsing or cleaning of the part prior to electroplating, or inadequate bath agitation. Poor current distribution can cause uneven plating, resulting in an uneven coating. If the part is not properly cleaned and rinsed, the plating will be uneven as well. Finally, if the bath agitation is inadequate, this can also lead to an uneven coating.
4. Crater Formation: This occurs due to poor current distribution or insufficient plating time. Poor current distribution can cause local bubbles to form, trapping and smearing the plating solution, leading to the formation of craters. Insufficient plating time can also cause the plating solution to dry out before it is fully reacted, leading to the formation of craters.
Corrective Measures
1. Low Adhesion: In order to prevent low adhesion, proper surface preparation should be performed prior to electroplating. This includes degreasing, deionizing, and other required steps to ensure the surface is clean and free of any contaminants.
2. High Liquid Waste: In order to prevent high liquid waste, proper rinsing of the part before electroplating should be performed, and the flow rate of the solution should be monitored. Additionally, proper agitation of the solution should be employed to ensure proper mixing of the solution.
3. Plating Insufficient Thickness: To prevent this fault, the current distribution should be checked prior to electroplating and the part should be properly rinsed and cleaned prior to plating. Additionally, adequate bath agitation should be used to ensure uniform current distribution and proper plating.
4. Crater Formation: In order to prevent crater formation, the current distribution should be monitored and adequate plating time should be allowed. Additionally, if necessary, pre-plating treatment can be performed to eliminate the possibility of local bubbles forming.
Conclusion
Electroplating is an important production technique for many applications. However, due to the complexity of the electroplating process, common faults can occur. This paper has discussed some of the most common electroplating faults, provided analysis on the causes, and offered solutions for preventing and correcting them. By employing proper surface preparation practices, monitoring the current distribution, and allowing enough plating time, many electroplating faults can be prevented.
