What Does Buchholz Indentation Test Mean?
The Buchholz indentation test is a popular type of coating evaluation method that is used to determine the hardness of a coating, otherwise known as its ability to resist indentation. This test requires a special piece of equipment that is known as a Buchholz indentation tester. The indentation left by the tester is measured to determine the hardness of a coating.
Corrosionpedia Explains Buchholz Indentation Test
To perform the test, a Buchholz indentation tester is used on a coating sample. The tester consists of a sharp tool made out of metal. This sharp tool is impressed upon the coating sample using a constant load. A timer ends the load application. The combination of the load and the sharp tool creates an indentation in the coating.
After the indentation is made, a microscope with graduations displayed on the viewing lens is then used to measure the size of the depression made by the sharp tool. The observed measurement is then found in a table that equates the size of the depression to a hardness value.
Prior to testing it is absolutely critical to ensure that the tester is properly calibrated. This includes both the load being applied and the edge condition of the sharp tool that makes the indentation in the coating. A dull tool could give a false hardness reading when performing a Buchholz indentation test.