Determination of Coating Bond Strength by Filing and Grinding Test

       The filing test method refers to filing, grinding or sawing the sample from the substrate to the coating direction with a file, grinding wheel or hacksaw. During the filing, grinding and sawing, the coating and the substrate are subjected to different mechanical forces and thermal expansion. When the component force is greater than the bonding strength of the coating, the coating will peel off.



1) Fix the sample on the vise, and use the file to make one-way filing from the substrate to the coating direction, and the file and the coating surface are at an angle of about 45 degrees. After a certain number of filings, it is qualified that the coating does not peel or peel off.

2) Clamp the sample with a tool, and grind the edge of the sample on a high-speed rotating grinding wheel. The grinding direction is from the substrate to the coating. After a certain period of grinding, the coating will not peel or peel off. is qualified.

3) Use a hacksaw instead of the grinding wheel to saw the edge of the sample from the substrate to the coating direction, and it is qualified if the coating does not peel or peel off.

This test is not suitable for very thin coatings and soft metal coatings such as zinc and cadmium, but is more effective for harder metal coatings such as nickel and chromium. At the same time, this method is suitable for sprayed parts that are not easy to bend or are subjected to wear during use.