Summary for nickel plating surface tension Discussion
Ring-plate vs. bubble pressure comes up in a discussion of how nickel plating baths are evaluated for surface tension and why that matters for gas pits. The thread opener explains that plating is not 100% efficient, so some current produces hydrogen and oxygen, and hydrogen bubbles can cling to the workpiece and cause defects. One practical way to reduce that problem is to lower the bath’s surface tension, which is why nickel plating solutions are measured with stalagmometers or tensiometers. The excerpt does not include a full technical debate or a final comparison of the two measurement methods, but it frames the issue as a plating-quality concern tied to bubble adhesion and defect prevention. The main takeaway is that surface tension control is used to help minimize gas pits in nickel plating.
Quickstart:
Plating processes do not operate at 100% efficiency ⇦ huh?. some of the applied electricity converts water to hydrogen and oxygen (or hydroxide) resulting in hydrogen bubbles which adhere to the article being plated, creating ‘gas pits’ ⇦ huh?
One way to limit this problem is to reduce the surface tension of the plating solution; therefore the surface tension of nickel plating baths is measured with stalagmometers or tensiometers.
Read on, join in …
Q. I am not familiar with the method of bubble pressure for surface tension measurements. Is it as sound as the ring-plate method? Any major disadvantages? My application is the daily testing of surface tension in a Nickel Sulfamate bath.
Chad Nicewonger
Plating shop – Titusville, Pennsylvania, United States
2004
A. The Bubble Pressure Method gives you a dynamic surface tension. Unlike the static methods by plate or ring, new surfaces will be generated with each bubble. The lifetime of the bubble can be controlled depending of the instrument in a range of ms up to 100s. This way, time-dependent surface tension values can be obtained. This is especially from interest in fast wetting processes. Further advantage of up to date bubble pressure tensiometer is the easy handling in comparison to Static Tensiometer (Cleaning and Calibrating). Surfactant concentration in metal cleaning baths or galvanic baths can be monitored in a broad surfactant concentration range, also above the CMC (critical micelle concentration). A new hand-held instrument is newly available.
Veit Huber
– Dresden, Saxony, Germany