Film thickness test method overview

There are many methods for measuring coating thickness. According to different measurement forms, they can be divided into two types: non-destructive method and destructive method; if they are divided according to different measurement principles, they can be divided into magnetic method (such as magnetic method, eddy current method, etc.), electrolytic method method (such as anodic dissolution coulomb method), chemical method (such as time flow method, drop method, dissolution weighing method, etc.), ray method (such as back reflection method, X-ray fluorescence method, etc.), optical method (such as contour size measurement method, double-beam microscope method), mechanical method (measurement using mechanical measuring tools), etc. Each of these measurement methods has its own characteristics, scope of application and measurement error range.

GB6463-B6 "Review of Measurement Methods for Thickness of Metal and Other Inorganic Coatings" reviews the measurement methods for the thickness of metal and other inorganic coatings on metal and non-metallic substrates, which can be used as the basis for selecting thickness measurement methods. Commonly used thickness measurement methods are:

(1) Method for measuring the thickness of the non-magnetic coating on the magnetic metal substrate.

(2) Measurement method of nickel plating layer thickness on magnetic and non-magnetic metal substrates.

(3) Method for measuring the thickness of the non-conductive coating on the non-magnetic metal substrate.

(4) Coating thickness anodic dissolution pool combined measurement method.

(5) Method for measuring coating thickness by dissolution and weighing.

(6) Metallographic microscope measurement method of coating thickness.

(7) X-ray fluorescence measurement method of coating thickness.

(8) Measurement method of coating thickness profile dimension.

(9) Double-beam microscope thickness measurement method.

When choosing a measurement method, try to use a standard method to measure the thickness, which is conducive to the reliability of the measurement results and the comparison of data; when measuring the thickness of precious metals, large-scale plated parts or the coating thickness on a single plated surface, non-destructive methods should be used; According to whether the coating thickness we want to know is the average thickness or the local thickness, the thickness measurement method is selected; the thickness measurement method is selected according to the thickness of the coating.