Ultrasonic diagnostics in the study of coatings applied by gas-flame spraying

Abstract

The quality control of coatings when selecting a powder material for the restoration of worn surfaces by gas-flame spraying is hampered by the lack of an operational method of non-destructive diagnostics. We present the results of studying coatings applied by gas-flame spraying using ultrasonic diagnostics. The powder coatings obtained using different technologies of gas-flame spraying were studied. Features of the structural state of coatings were evaluated using a model based on the effect of the structural inhomogeneities of the coating on the velocity and attenuation of ultrasonic waves. It is shown that the amplitude-time characteristics of the pulse of surface elastic waves when they pass along the coating are consistent with the data obtained from friction and hardness tests, the characteristics of the pulse being dependent on the quality of the coating material. The obtained results can be used to improve the quality control of coatings formed by gas-flame spraying.