Test method of quantitative adhesion for general purpose

The standard of quality judgement of surface finishing to metal material is adhesiveness (adhesion strength).Test method of plating process, or adhesiveness has been defined in JIS-H-8504. The test method defined in the JIS is by the file test, grinding wheel test, slice shaving test, and yet quantitative measurement method of adhesiveness is only chipping test. In this context, actual test cannot, in some cases, be applied to all machine parts.
Therefore, Nomura Plating recommends the JIS-G-0601 Clad Steel shearing strength test of adhesion effectiveness for quantitative judgement. For the purpose to measure the adhesiveness of plating process, shearing strength is the value that calculated from dividing P: breakage power of plating coat by coat adhesive area, after giving plating testing subject coat processing to the base metal.
The testing method (by the test piece of shearing strength) is shown as follows.

Adhesiveness test of plating processing by JIS- G-0601 clad steel testing method

Testing method to measure the plating adhesiveness which produce the practical and correct value by calculation.

This test requires of additional work, but it is justified by the secured quality assurance of surface finishing gained by choosing this testing method which produces the accurate and reliable value to make judgement.

Quality of processing judging from the broken part of surface finishing

In the course of quality confirmation of surface finishing, it is an important factor of the tested value of being high or low, and yet it is also important to confirm from where the breakage occur of base metal and surface finishing along with tested value.
Breakage shape and feature brought about on the surface finishing layer may occasionally indicate the quality of processing caused by the testing. The occurrence of boundary breakage (peeling) between base metal and plating may indicate that there exists something wrong in the plating process.  The breakage shape and feature of plating surface layer after shearing strength are classified as shown below.

3 patterns of breakage shape and feature of surface finishing after shearing strength test

Testing method of adhesiveness strength to draw accurate and practical value for judgement.

It makes it possible to find out appropriate measure to solve the problem in plating process by securing of correct understand of the content of peeling or breakage of plating layer. In case to wish to have the correct confirmation by observation or ingredient of metal, plating process or surface finishing, professional measurement and analyzers become necessary out of which there may be cases of true problems or causes.