Ultrasonic adhesion control of special coatings

Abstract

Quality control of coatings is an urgent task. Of interest is not only the detection of a defect in the coating in the form of detachment from the substrate or delamination between layers of a multilayer coating, but also the detection of the place of probable defect formation in the form of a site with reduced adhesion. The purpose of this work is to substantiate the possibility of using the reflected radiation method (echo method) of an acoustic type of non-destructive testing with optical-acoustic generation of acoustic vibrations to assess the adhesion between the coating layers and between the coating and the substrate. The objective of this work is to establish a correlation between the acoustic characteristics of coatings and the tear strength of coatings. The relevance of the work is emphasized by the lack of methods and means of non-destructive testing of adhesion of coatings with proven effectiveness and reliability to date. In order to achieve this goal, coating samples with embedded artificial defects were developed and manufactured. A correlation was established between the acoustic characteristics of the coating and the tear-off strength of the coating, confirmed as a result of mechanical tests, which emphasizes the scientific novelty of the research.