Application of positron annihilation spectroscopy on the ion implantation damaged Fe–Cr alloys

Four different Fe–Cr binary alloys with Cr content 2.5–11 wt% were studied in details using various methods. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were applied to obtain basic information, required for standard positron annihilation lifetime spectroscopy (PALS) spectra analysis. Additionally, PALS measurements were performed on as-received state as well as on helium implanted specimens. The He implantation was proposed for simulation of radiation damage and obtain high doses even in near surface areas (up to 1 μm). The implantation was based on the SRIM code simulation and next DPA calculations. Final concentration of vacancy type defects were calculated for 250 keV He2+ beam and the maximum was determined in 600 μm depth. Such specimens are very suitable for positron beam study of vacancy type defect mobility as a result of thermal treatment, which will be performed simultaneously in the future.