Surface morphology of unalloyed steels remelted with intense plasma pulses.

The set of unalloyed steels with various carbon concentrations were irradiated with intense plasma pulses with following process parameters: energy density 5 J cm(-2), pulse duration 2 mus, argon or nitrogen atmosphere. The energy density of each pulse was high enough to melt the surface layer of material. The cooling rate was estimated for 10(8) K s(-1) using the modelling method which takes into account heat evolution in the iron sample. Samples were characterized using the scanning electron microscopy technique for remelted surface morphology investigations. The tests with profilometer allowed us to investigate the changes of roughness of the surface layers.

Characterization of the near-surface layers of carbon steels modified by interaction with intense pulsed plasma beams: scanning electron microscopy investigations.

Modification of materials is a wide area in materials science, especially surface modification. To investigate the results of the modification process, treated and nontreated samples were compared. Intense plasma pulses of argon or nitrogen were used to irradiate the carbon steels. In all samples, the near-surface layer was melted. Results of scanning electron microscopy investigations of the surface morphology and cross-sections, as well as the results of tribological tests, are presented. The obtained results allowed us to draw conclusions about changes in material properties and to propose subsequent studies using other investigation techniques.