This work expands the processing window of the laser powder bed fusion (LPBF) processing of WE43 magnesium alloy by evaluating laser powers and scanning speeds up to 400 W and 1200 mm/s, and their effect on densification, microstructure, and electrochemical performance. Relative density of 99.9% was achieved for 300 W and 800 mm/s, showing that the use of high laser power is not a limitation for the manufacturing of Mg alloys, as has been usually considered. Microstructural characterisation revealed refined grains and the presence of RE-rich intermetallic particles, while microhardness increased with height due to thermal gradients. Electrochemical testing in 3.5 wt.% NaCl solution, a more aggressive media than those already used, indicated that the corrosion of samples with density values below 99% is conditioned by the porosity; however, above this value, in the WE43, the corrosion evolution is more related to the microstructure of the samples, according to electrochemical evaluation. This study demonstrates the viability of high-energy LPBF processing for WE43, offering optimised mechanical and corrosion properties for biomedical and structural applications.

The electrochemical corrosion behaviour of Ti6Al4V metal matrix composites reinforced in situ with TiN ceramic phases was investigated. The composites were fabricated by Direct Laser Deposition (DLD) under a nitrogen atmosphere at two scanning speeds (5 and 10 mm/s), which promoted the formation of TiN during processing. Microstructural analysis using SEM and XRD confirmed a uniform distribution of TiN dendrites within the $$\alpha $$ – $$\beta $$ titanium matrix. Electrochemical testing in naturally aerated 3.5 wt% NaCl solution, including polarization resistance and cyclic polarization measurements, showed that adding TiN significantly enhanced uniform corrosion resistance. The Ti TiN v10 sample had the highest polarization resistance and the lowest corrosion rate, indicating better overall corrosion performance. However, cyclic polarization curves and surface analysis revealed a clear tendency toward pitting corrosion in these samples, linked to passive film breakdown. In contrast, Ti TiN v5 showed a reduced tendency toward localized corrosion, suggesting improved passivation stability under lower input conditions. These results emphasize the dual influence of TiN reinforcement and processing parameters on corrosion mechanisms, offering valuable insights for optimizing additive manufacturing strategies for titanium-based composites in saline environments. Graphical Abstract