Table of Contents ECNDT '98 Session: Aerospace

First Routine Aircraft NDT with SQUID Gradiometer Yuri Tavrin, Johann H. Hinken* *Corresponding Author Contact: F.I.T. Messtechnik GmbH, Bodenburger Str. 25/26 TecCenter, D 31162 Bad Salzdetfurth fitm@fitm.com ; http://www.fitm.com Phone: +49-5069-89-580 Fax: +49-5069-89-666

Full-Text - Abstract

The HMT Magnetometer System is presented. It is based on SQUIDs from high-temperature superconductors and it is operated as a gradiometer of second order. The high balance of the system insures that the HMT is extremely unsensitive against external noise without having a magnetic shield. At the same time the magnetic field resolution of the HMT is extremely high. The system is suitable for non-destructive testing of technical components, especially for tests into large depths under the surface. The components may be rather large in size.

Two methods for non-destructive testing of aero turbine disks are described. The first method is presently used for routine tests to detect minute ferrous inclusions. The method is based on the detection of magnetic fields with stem from the magnetic remanence of the inclusions.

The second method allows to detect segregations, even if non-ferromagnetic. This is shown as a preliminary result of a feasibility study. This method makes use of spatial variations of the magnetic susceptibility of the disk material. This method has to be developed further on before routine tests can be performed.

The availability of the advanced HMT Magnetometer System allows for two new methods in NDT. Both allow for volume inspection in certain situations where standard techniques like ultrasonic testing fail.

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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