Microstructure and corrosion resistance of novel b-type titanium alloys manufactured by selective laser melting

Due to its unique characteristics selective laser melting offers the possibility to manufacture highly complex and functional parts out of otherwise difficult processable materials. One example is I3-type titanium alloys, which have very promising properties for various engineering applications. Two novel I3-type alloys Ti-42Nb and Ti-20Nb-6Ta were compared with commercially pure titanium and Ti-6Al-4V ELI alloy in this study. All four lightweight materials were SLM-processed and the microstructure and corrosion resistance were investigated. While pure titanium and Ti-6Al-4V showed only the martensitic a0-phase, Ti-42Nb consists solely of the I3-phase and Ti-20Nb-6Ta of the orthorhombic martensitic a00-phase. Potentiodynamic polarization showed a superior corrosion resistance for both I3-type alloys, whereas Ti-42Nb performed slightly better than Ti-20Nb -6Ta. Released V and Al could be clearly observed for the Ti-6Al-4V ELI alloy by mass spectrometry due to corrosion processes, in contrast the release of Nb or Ta was hardly detected for the new alloys. (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Selective laser melting enables the production of complex and functional parts from difficult processable materials. This study compares the microstructure and corrosion resistance of novel I3-type titanium alloys with traditional titanium alloys, revealing that the new alloys exhibit superior corrosion resistance.