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DOI:

2014. . No. 3(65) - Sep 2014, pp. 56-58

Phased Array Flaw Detectors. Ascertaining the Capabilities of Ultrasonic Beam Focusing

A. A. Prohorenko

While developing a testing methodology for products of low-alloyed steel, it is important to choose a right phased array transducer regarding to product’s thickness. The main parameters of transducers that should be taken into consideration are discussed. It is noted that high values of ray and front resolution can be achieved only near a focus point. The focal zone sizing is calculated; precision of calculated data in comparison with experimental data is15-30%. Estimation of beam characteristics for inspection of welded seams with thicknesses of 8-15 mm has been fulfilled for the phased arrays batch-produced by “Sonatest”. It is concluded that phased array transducers with frequency less than 5 MHz and elements number less than 20 are not suited to focused ultrasound beam testing because of a small focal length rage.
Design features of phased array transducers affect reflectors images; as an example S-scanning images obtained with the 32- and 16-component phased array transducers are given. The ultrasound beam was focused vertically (with fixed bias). For best results it is necessary to use high-frequency (more than 7.5 MHz) phased array transducers with elements number not less than 16.
 
Keywords: phased array transducer, resolution, sizing
References
  1. Jacques F., Moreau F., Ginzel E. Ultrasonic Backscatter Sizing Using Phased Array — Developments in Tip Diffraction Flaw Sizing. Insight, 2003, vol. 45, no. 11, pp. 724–728.
  2. Ciorau P. A Contribution to Phased Array Ultrasonic Inspection of Welds. Part 3: Sizing Capability. Available at: http://www.ndt.net/article/v12n12/ciorau.pdf
  3. Bredif P., Poidevin C., Dupond O. A Phased Array Technique for Crack Characterization. Available at: http://www.ndt.net/article/ecndt2006/doc/Th.1.1.2.pdf
  4. Introduction to phased array ultrasonic technology applications: R/D Tech Guideline. Quebec (Canada), R/D Tech Inc., 2004, 348 pp.
  5. Krautkramer J., Krautkramer H. Ultrasonic testing of materials. Berlin-Hamburg-New-York, 1977, 667 p.
  6. Transducer Catalogue. Available at: www.sonatest.com
 
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