The technological background lies in excitation of ultrasonic oscillation of wide spectrum of frequencies in the object to be controlled with simultaneous defect detection by means of displaying differences in defective and non defective zones and determination of integrated picture reflecting the topography of layer joints on the whole surface of the object.
As the indicator to detect and display the differences in the defective and non-defective zone oscillation levels a special thin disperse powder is used ,which besides high sensibility is characterized by the unique capability to store and memorize the information about the defect during the whole process of control. The particles move above the defective zone in axial-symmetrical way, i.e. from the center to the borders, thus producing the visual display of defects.
Fully automatic control system, an acoustic- topographical device TITAN, was developed for the realization of this method. Compared to other methods already being used for the same purpose ( ultrasonic., impedance, etc.), this method:
- permits to perform the control in the shortest time ( 1-5 min./ object);
- has no limitation on the thickness of coating;
- gives visual information of the control results with precise (up to 0,1 mm) definition of size, configuration and defect area borders;
- is very simple in usage.
The method could be effectively applied in different branches of industry to carry out the control of layer joints in be-and trimetals, in different metal coating parts, in celular constructions, welding joints, etc.
Reference:
Kluev,V.V. Non- destructive testing and diagnostics.,l995,210-211
Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00
Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:
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