Enrichment of AISI 316L Steel Surface Layer with Rare Earth Elements Using Ion Beams

Enrichment of AISI 316L steel surface layers with rare earth elements was carried out using two methods with ion beam applying. The first one was the ion implantation with the doses in the range of $1 \times 10^{15} cm^{-2}$ up to $5 \times 10^{17} cm^{-2}$ where mishmetal (Ce+La) was used as the ion source. The second method was the high intensity pulsed plasma beams. The plasma pulses contained both ions/atoms of Ce+La from the electrodes material (mishmetal). The pulse energy densities $(3 J/cm^2)$ were sufficient to melt the near surface layer of the steel and introduce those elements into the surface layer. The aim of this work was to investigate the changes of stainless steel surface properties (morphology, rare earth elements concentration, presence of identified phases) after the rare earth elements addition with or without melting. Scanning electron microscopy, energy dispersion spectroscopy, and X-ray diffraction analysis were used for initial and modified surface characterisation. Grazing-incidence X-ray diffraction shows differences in the identified phase presence in the modified surface layer connected with the modification method.