ملخص: According to the state of the art, eddy current testing (EC) has a strong application in defect detection. The sensitivity to characterize defects and other parameters can be improved by an optimal choice of probes and operation frequency.The work discussed here is a study to materials microstructure characterization and especially the heat affected zones (HAZ) near welds using eddy current techniques.These zones are sometimes brittle and characterized by a microstructure gradient. The aim of this work is to study by eddy current the behavior of such cases. For each damage mechanism, the authors have prepared series of samples. These specimens were tested using NDT methods based on magnetic and electric properties.Electric conductive material samples were made of Aluminum and steel and heated at different temperatures with variable exposure times.The aluminum samples were then exposed to corrosion using an electrochemical process.The applied NDT methods can characterize grain size changes, microstructure types, micro structural changes, hardness changes after thermal treatment.The objective of our work is to detect some metallurgical characteristics by non-destructive methods. The characterization of the microstructure modifications by eddy currents allows detecting mechanical and metallurgical parameters of materials.

لغة: إنجليزية