Badania diagnostyczne metali i stopów metodą PEC

W publikacji przedstawiono wyniki badań metali nieferromagnetycznych z wykorzystaniem zjawiska prądów wirowych techniką PEC (Pulsed Eddy Current). Badania przeprowadzono na próbkach metali i stopów o znanej konduktywności w których wykonano wady wzorcowe w formie nacięć i nawiertów o znanych (zmierzonych) wymiarach geometrycznych. Zarejestrowane napięcia wyjściowe z przetwornika wiroprądowego poddano analizie metodą falkową z wykorzystaniem falek typu Morleta (morl) oraz symlet ósmego rzędu (sym8).

In this paper the results of pulsed eddy current testing (PEC) for nonferrous materials are presented. The research deals with metal and alloy probe (Al) with known value of conductivity with artificial defects in form discontinuities (notches) with known depth and width. The output signals from eddy current transducer for PEC technique picked up with a digital oscilloscope were recorded in separate files and then investigated by the set of analyzing wavelets. The programming environment of Matlab with the Wavelet Toolbox of The MathWorks was employed .The local properties of signals were derived applying Morlet wavelet (morl) and symlet of eighth order (sym8). Based on one-dimensional real signal in time the jointly frequency and time analysis was performed to extract the localization distinguishing details of meaning energy correlated with type and size of fabricated material flaws. Detecting the fundamental properties was performed with the scalogram plots. Some kind of causality was observed depending on localization the sound details the more right on the time axis the deeper or more extensive was the size of material flaw.