In this study, the effect of rhenium addition (2, 4, and 6 wt pct) and building orientation (0 and 90 deg) on the microstructure and corrosion resistance of Inconel 718 (IN718) alloy processed by selective laser melting (SLM) was investigated. Microstructure characterization showed that the as-built IN718-Re alloys consist of columnar grains growing parallel to the building direction (Z-axis). Each columnar grain was characterized by a fine columnar/cellular dendritic substructure with Nb- and Mo-rich Laves phases and MC-type carbides embedded in the interdendritic spaces. Rhenium addition segregated to γ phase dendrites which resulted in an increase of the columnar/cellular substructures width with increasing Re content. Due to a strong microstructure anisotropy of SLM-processed IN718-Re alloys, the corrosion properties were examined for mutually perpendicular planes: XY (90 deg samples) and XZ (0 deg). The presence of rhenium enhanced the corrosion resistance of IN718 alloy in 0.1 M Na₂SO₄and NaCl solutions at both exposed planes. The corrosion current density was significantly reduced for IN718-Re alloys and increasing Re content correlated with a more positive shift in corrosion potential. Moreover, the XY plane possessed better corrosion resistance than the XZ plane due to the higher fraction of laser overlapping areas observed for the XZ plane.

Due to its suitable physical properties and good biocompatibility, the titanium (Ti) can be used for development of porous structures for biomedical applications. The state of art in the field of corrosion resistance showed problems with corrosion analysis of porous metals. Therefore, it is essential to understand the influence of porosity of metals on corrosion parameters. The aim of this study was to investigate the corrosion resistance of highly porous titanium scaffolds for biomedical application. The Ti scaffolds were fabricated by powder metallurgy technique. The total porosity of the scaffolds ranged from 45 to 75%. The cast Ti sample was also tested for comparison. The electrochemical behavior of the Ti samples was monitored by electrochemical impedance spectroscopy (EIS) and potentiodynamic method at the room temperature. All electrochemical experiments were performed by a three-electrode technique in a cell containing a 0.9% NaCl electrolyte solution. With use of AAF, the active area of porous Ti was estimated. The porous Ti with porosity of 75% shows a better resistance to corrosion than the other porous Ti scaffolds. However, the corrosion resistance of Ti scaffolds was lower than cast Ti.

A number of modern surface processing methods use an energy flux. The examples include electro-spark deposition (ESD) and laser beam processing (LBP). The work concerns the study of Cu-Mo coatings deposited on C45 carbon steel, which were then eroded with a laser beam. The analysis included the analysis of the microstructure, measurements of macrogeometry and microhardness, corrosion resistance tests of selected areas after laser treatment. The coatings were applied with ELFA-541 and subjected to Nd:YAG laser treatment with variable laser parameters. The problem presented in the work can be used to extend the knowledge of the areas of application of ESD coatings, especially in sliding friction pairs.