Electron beam surface remelting enhanced corrosion resistance of additively manufactured Ti-6Al-4V as a potential in-situ re-finishing technique

Mohammadali Shahsavari; Amin Imani; Andaman Setavoraphan; Rebecca Filardo Schaller; Edouard Asselin

doi:10.1038/s41598-022-14907-2

Electron beam surface remelting enhanced corrosion resistance of additively manufactured Ti-6Al-4V as a potential in-situ re-finishing technique

Sci Rep. 2022 Jul 8;12(1):11589. doi: 10.1038/s41598-022-14907-2.

Authors

Mohammadali Shahsavari¹, Amin Imani², Andaman Setavoraphan¹, Rebecca Filardo Schaller^{1

3}, Edouard Asselin¹

Affiliations

¹ Department of Materials Engineering, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
² Department of Materials Engineering, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada. amin.imani@ubc.ca.
³ Sandia National Laboratories, Albuquerque, NM, USA.

Abstract

This study explores the effect of surface re-finishing on the corrosion behavior of electron beam manufactured (EBM) Ti-G5 (Ti-6Al-4V), including the novel application of an electron beam surface remelting (EBSR) technique. Specifically, the relationship between material surface roughness and corrosion resistance was examined. Surface roughness was tested in the as-printed (AP), mechanically polished (MP), and EBSR states and compared to wrought (WR) counterparts. Electrochemical measurements were performed in chloride-containing media. It was observed that surface roughness, rather than differences in the underlying microstructure, played a more significant role in the general corrosion resistance in the environment explored here. While both MP and EBSR methods reduced surface roughness and enhanced corrosion resistance, mechanical polishing has many known limitations. The EBSR process explored herein demonstrated positive preliminary results. The surface roughness (R_a) of the EBM-AP material was considerably reduced by 82%. Additionally, the measured corrosion current density in 0.6 M NaCl for the EBSR sample is 0.05 µA cm^-2, five times less than the value obtained for the EBM-AP specimen (0.26 µA cm^-2).