Publictions
Abstract submitted to: QNDE 2010
Type of Presentation: Poster
Title: Detection of minor outer flaws in titanium alloys using lockin eddy current testing system
Authors: Tomasz Chady, Grzegorz Psuj, Jacek Kowalczyk
Main body text:
The importance of titanium alloys as a resource material in modern leading industry branches such as aerospace is rapidly growing. Therefore, occurs the need of introducing new nondestructive testing measuring system that allows detection of outer flaw in thick titanium structures. In this paper, a newly developed lockin amplifier based eddy current NDT system was applied. Such system enables to detect signals caused by minor defects and having the amplitude lower than the noise level. The proposed system allows to monitor amplitude and phase responses of a transducer using single testing frequency ranging from 1 kHz up to 100 kHz. A software written in LabView was used to control the whole system, proceed data analysis and display results. A differential eddy current transducer was proposed and optimized taking into account testing requirements. Very high sensitivity of the proposed system was confirmed during experiments with test specimens. A set of flat and cylindrical titanium alloy test samples with artificial notches were used in order to evaluate performance of the proposed system and transducer. The full description of the system as well as the full set of results and discussion will be present in the final version of the paper.
Abstract submitted to: QNDE 2010
Type of Presentation: Poster
Title: Extremely short impulse eddy current testing system for Ti samples
Authors: Tomasz Chady and Pawel Frankowski
Main body text: This paper presents a new system for eddy current testing. The system enables to carry on tests with very short currents impulses. Therefore, the frequency spectrum of the excitation signal is very wide. It creates opportunity to achieve similar advantages as in case of the multi-frequency system. A main component of the measuring system is a dedicated short impulse current generator which is powered by regulated power supply. Generator can be triggered by internal or external trigger source with 1Hzâ?S100Hz frequency. Duration of the current impulses can be from several hundreds of nanoseconds to several microseconds. In order to achieve high reliability, current pulse width is always inspected by microcontroller. The system is controlled by the computer and it is possible to set up the impulse amplitude (up to 100A), impulse duration and repetition frequency. The generator supplies a newly developed differential eddy current transducer manufactured on the thin film.
The probe consists of two search coils fabricated on the top of the thin film and one excitation coil wound on the bottom side. This construction is aimed at probe™ miniaturization and improved spatial resolution. Test specimens used for the experiments are titanium plates with EDM notches. Results of preliminary experiments confirmed usability of the ESIECT system and the transducer.
Abstract submitted to: ENDE 2010
Type of Presentation: Poster
Title: Extremely short impulse eddy current testing system with a differential transducer
Authors: Tomasz Chady, Pawel Frankowski, Tomasz Jakubowski, Stanislaw Kalisiak
Main body text: This paper presents a new system for eddy current testing. The system enables to carry on tests with very short currents impulses. Therefore, the frequency spectrum of the excitation signal is very wide. It creates opportunity to achieve similar advantages as in case of the multi-frequency system. A main component of the measuring system is a dedicated short impulse current generator. Duration of the current impulses can be from several hundreds of nanoseconds to several microseconds. The system is controlled by the computer and it is possible to set up the impulse amplitude (up to 100A), impulse duration and repetition frequency. The generator supplies a newly developed differential eddy current transducer manufactured on the thin film. The probe consists of two search coils fabricated on the top of the thin film and one excitation coil wound on the bottom side. This construction is aimed at probe’s miniaturization and improved spatial resolution. The view of transducer is shown in Figure 1. Test specimens used for the experiments are titanium plates with EDM notches. Results of preliminary experiments confirmed usability of the newly developed ESIECT system and the transducer.
Abstract submitted to: ENDE 2010
Type of Presentation: Poster
Title: Stress corrosion cracks evaluation in 316 austenitic stainless steel plate
Authors: T. Chady, J. Kowalczyk And G. Psuj
Main body text: Nowadays, evaluation of stress corrosion cracks (SCC) in real construction is one of the most important problems. Artificial notches frequently utilized for NDT system calibration are not similar to the real defects. Therefore the need of cracks fabrication more equivalent to real one occurs. Previously, some work on the methodology of artificial SCC cracks preparation and observation has been published [1]. In this paper, comparative results of artificial stress corrosion cracks evaluation will be presented. A three crack were prepared in 16 mm thick austenitic stainless steel plate. The detailed description of the cracks can be found in [1]. The cracks evaluation was carried out using single frequency eddy current nondestructive testing system with lock-in amplifier (LOCKECT). The system allows to observe phase and amplitude of the signals having low value of SNR. A differential eddy current transducer was utilized for tests. The measurements ware carried out using excitation frequencies ranging from 70 kHz to 88 kHz. Selected results obtained during the experiment are presented in Figure 1. The set of achieved results as well as detailed discussion of the results will be given in the full version of the paper.
The authors would like to thank Dr Noritaka Yusa for providing the specimens that belong to the round robin test organized by the Japan Society of Maintenology (http://jsm.or.jp/at/scc/).
Abstract submitted to: BINDT 2009
Type of Presentation: Oral
Title: Validation of Phased array probe design for the inspection of Titanium billets
Authors: E M Rasselkorde and P W Wallace
Main body text: A novel Phased array inspection technique is being developed for the inspection of titanium billet, destined for use in aerospace applications. The sensors will be deployed by an automated system to minimise the use of manual inspections which aims to improve the quality and reliability of these critical inspections early on in the manufacturing process.
This paper presents the second part of the work which is the validation of the phased array ultrasonic inspection of the billets using simulation tools. The performance of a series of phased array transducers were simulated to optimise the ultrasonic inspection of a ten inch diameter billet made from Titanium 6Al-4V. A comparison between different probes including a Fermat type transducer, and equal and unequal element surface area type probes were performed.
Abstract submitted to: QNDE 2009
Type of Presentation: Oral
Title: Phased array probe optimisation for the inspection of Titanium billets
Authors: E M Rasselkorde and P W Wallace
Main body text: The manufacturing process of titanium billets can produce multiple sub-surface defects that are particularly difficult to detect during the early stages of production. Failure to detect these defects can lead to subsequent in-service failure.
A new and novel automated quality control system for the inspection of titanium billet, destined for use in aerospace applications, is being developed. The sensors will be deployed by an automated system to minimise the use of manual inspections which should improve the quality and reliability of these critical inspections early on in the manufacturing process.
This paper presents the first part of the work which is the design and the simulation of the phased array ultrasonic inspection of the billets. A series of phased array transducers were designed to optimise the ultrasonic inspection of a ten inch diameter billet made from Titanium 6Al-4V. A comparison between different probes including a Fermat type transducer, equal and unequal element surface area type probes was performed. The final transducer design was validated using simulation tools.
Abstract submitted to: QNDE 2009
Type of Presentation: Poster
Title: Comparative analysis of selected eddy current transducers for titanium alloy evaluation
Authors: T. Chady, R. Sikora, P. Baniukiewicz, P. Lopato, J. Kowalczyk, G. Psuj, M. Caryk
Main body text: Titanium alloy based details due to their mechanical properties continue to be in extensive use in various structures (mainly aerospace, automotive and petro-chemical industrial applications). In this paper comparative study of various types of eddy current NDT transducers for testing titanium elements was done. Probes of absolute, differential and array configurations were constructed and analyzed. Two and three dimensional numerical analysis (FEM) were done in order to find the best type and configuration of the proposed transducers.
Abstract submitted to: AeroMat08
Type of Presentation: Oral
Title: Detection of defects in aerospace low pressure compressor blades using ultrasonic technique
Authors: Mr. El Mahjoub Rasselkorde and Mr. Philip Wallace
Main body text: Complex geometry components made from titanium material such as aerospace gas turbine Fan engines is often classified as “safety critical” component, and subject to very high stresses and vibration. It required the highest structural integrity. NDT techniques such as Ultrasonic and eddy current have been developed to inspect these components. This paper presents an ultrasonic testing inspection for the fan blades components, modelling using CIVA and Continuum Ultrasonic Modeller has been performed in order to predict the ultrasound propagation and defects responses for different type of scans. A comparison between the experimental and modelling results was shown good accuracy of the modelling in predicting the ultrasonic inspection performance.