Characterization of defects in non-ferromagnetic material using an electromagnetic acoustic transducer

In this paper a comprehensive finite element analysis of an Electromagnetic acoustic transducer is presented. EMAT is an emerging technology that provides a non contact process of testing materials compared to ultrasonic testing techniques that requires a coupling medium. The EMAT phenomenon can be particularly useful in rail, pipeline and aerospace industries for thickness measurements and defect detection in conductive materials. The Lorentz force and the effect of varying the EMAT parameters such as lift off was investigated to show the effects it has on the performance of EMAT. Additionally, the wave propagation in a conductive material is investigated, which involves the coupling of several physical parameters, which includes mechanical and electromagnetic properties. This led to the investigation of defect detection in an aluminum material. Results obtained shows the model is capable of detecting the depth, width and location of the surface defect using the mechanical displacement amplitude. © 2013 IFSA.