A Study of Defects in Iron Based Alloys by Positron Annihilation Techniques

Defects in different iron based alloys were studied at room temperature using positron annihilation techniques. In FeSi alloys, it was found that the Si content and the deformation temperature affect the positron annihilation parameters. In Fe-Mn-Si-Cr-Ni-C samples with different deformations, positron lifetime measurements were carried out before and after isochronal annealing. X-ray diffraction gave information about the different microstructural phases that exist in the deformed alloys before and after annealing. During deformation a martensiticεphase is induced. At 500°C, defects and theεmartensite phase were almost annealed out from the low deformed samples.