Thickness Measurements
What are the most common ways of measuring thickness of metal deposits?
Q. What are the most common ways of measuring thickness of metal deposits? R.L.
A. Thickness measurements of plated deposits are probably the most common after plating test performed. Not surprisingly, there are many different ways of performing the measurements. There are two broad categories of tests: destructive and non-destructive.
Destructive Method
- Cross Sectioning/Microscopic Examination
- Coulometric Method
- Jet Test Method (Dropping Method)
- Strip and Weigh Method
Non-Destructive Methods
- Magnetic Methods
- Beta Backscatter Method
- X-Ray Fluorescence Method
- Optical Methods
- Eddy Current Method
- Micro-Resistance Method
Selection of a method depends on the type of deposit and the base material. Other factors include cost of equipment, ease of use and required accuracy.
In the modern plating environment, the most common methods for day-to-day measurements are magnetic, eddy current, X-ray fluorescence, beta backscatter and micro resistance methods. The cross sectioning/microscopic examination method has classically been used to resolve disputes but is not as widely used because of limitations due to the very small size of components and the very thin layers of coating that have become common today.
There is not enough space to describe all of the methods listed above but there are good sources of information that are available. A good place to start is at the Products Finishing web site, www.pfonline.com. Search under thickness measurements. The URL for an article that has a good discussion is www.pfonline.com/articles/pfd0027.html. A good book that discusses these various methods is Thickness Testing of Electroplated and Related Coatings by G. P. Ray. Electrochemical Publications, www.elchempub.com. The book is out-of-print but still can be purchased at the web site listed.
Related Content
-
Possibilities From Electroplating 3D Printed Plastic Parts
Adding layers of nickel or copper to 3D printed polymer can impart desired properties such as electrical conductivity, EMI shielding, abrasion resistance and improved strength — approaching and even exceeding 3D printed metal, according to RePliForm.
-
How to Choose Between Sulfate and Chloride-Based Trivalent Chromium
There are several factors to consider when choosing between sulfate and chloride-based baths for trivalent chromium plating. Mark Schario of Columbia Chemical discusses the differences and what platers should keep in mind when evaluating options.
-
Cleaning, Pretreatment to Meet Medical Specs ISO 13485 or FDA 21 CFR820
Maximilian Kessler from SurTec explains new practices for industrial parts cleaning, metal pretreatment and decorative electroplating in the medical device industry.