Non-Destructive Evaluation of Coating Thickness Using Water Immersion Ultrasonic Testing

Abstract

The coating is applied to prevent corrosion on the surface of ships or marine structures, and the thickness of the coating affects its anti-corrosion effect. As a result, non-destructive testing (NDT) is required to measure coating thickness, and ultrasonic NDT is a convenient and quick way to measure the thickness of underwater coatings. However, the offshore coating’s energy attenuation and absorption rates are high, the ultrasonic pulse echo test is difficult, and the testing environment is harsh. Because of the coating’s high attenuation, the distance of the optimal water delay line designed based on the reflection coefficient of the vertically incident wave is used. To accurately measure the thickness of the coating material, TOF of the reflected echo on the time-domain waveform was evaluated. The experimental results show that, when compared to caliper measurements, the coating thickness measured by the proposed method has a lower error and can be used for accurate measurement. The use of ultrasonic water immersion measurement is almost limitless in terms of size, location, and material of the object to be measured, and it is expected to be used to measure the thickness of the surface coating of ships or marine structures in the water.

A Rank Model of Casting Non-Conformity Detection Methods in the Context of Industry 4.0

“…Reference samples or standards are used to specify the sensitivity level of the detection. The limits of non-compliance registration should be adopted criteria in accordance with standards, technical conditions or other binding requirements [ 5 , 12 ]. At this stage, attention should be paid to the following parameters: wavelength, speed of propagation of the wave in the casting under test, speed of propagation of transverse and surface waves and transition losses.…”

“…The implementation of this type of detection is necessary for the manufacturing industry to maintain an adequate level of quality and conformity of machinery, equipment and structures [ 5 ]. In particular, this is the case in aerospace [ 6 , 7 ], railway [ 8 , 9 ], oil and water [ 10 ], oil and gas [ 11 ], marine [ 12 ], nuclear [ 13 ], construction [ 14 ], automotive [ 15 , 16 , 17 ], as well as in the civil engineering [ 18 , 19 ] or timber industries [ 20 ]. This indicates that technological advances and user requirements have extended the application of NDT even to non-manufacturing-oriented industries, proving that these tests are not limited to anomaly detection only.…”

“…The penetrant method makes it possible to determine the severity and length of discontinuities [ 27 , 28 ], while the ultrasonic method determines the height, length and dimensions of discontinuities that are equivalent to certain reference discontinuities, as well as the severity of these discontinuities [ 4 , 5 , 12 , 26 ]. The radiographic method allows the determination of the length, height and severity of discontinuities [ 24 , 25 ], while the eddy current method allows the length, depth or height of the discontinuity and severity of the discontinuity [ 9 , 21 , 23 ], and the magnetic methods allow the characterisation of the discontinuity in terms of its length and severity [ 28 ].…”

Non-destructive Evaluation of Workpiece Properties along the Hybrid Bearing Bushing Process Chain

“…For the given task, the joining zone was non-destructively monitored by ultrasonic testing along the process chain. Ultrasonic testing is commonly used to analyze thin coatings on metals regarding their characteristics and possible cracks or debonded areas (Ref 19,20). This technology is a suitable and well-known method to characterize joints for various materials (Ref 21 -24).…”

Physical Simulation of Ultrasonic Imaging Logging Response

“…Ultrasonic imaging has been widely used in industrial inspections [ 4 , 5 , 6 ]. Zhang et al [ 7 ] proposed a nondestructive evaluation method of coating thickness using water immersion ultrasonic testing. Accurately estimating ultrasonic time-of-propagation is essential in ultrasonic nondestructive testing (NDT).…”