The purpose and precautions of metallographic inspection of coating

       Metallographic inspection is an important means to evaluate the quality of the coating. Through the metallographic inspection, the microstructure of the coating, the combination of the coating and the substrate, and the microscopic defects in the coating, such as holes, cracks, inclusions, etc., can be directly observed. , so that the quality of the coating can be identified.



     When preparing metallographic samples, the microstructure in the coating should not be damaged. For example, for the structure containing hard particles, the force should not be too large during polishing, otherwise the hard particles will be easily dragged away from the softer substrate to form voids. . In addition, when cutting the sample, it should be cut from the coating to the substrate, and attention should be paid to cooling when cutting and grinding the sample to prevent the coating from overheating.