Heat treatment degrading the corrosion resistance of selective laser melted Ti-6Al-4V alloy
Abstract
Ti-6Al-4V alloy produced by selective laser melting (SLM) was reported to exhibit an inferior corrosion resistance compared with the traditionally processed Grade 5 alloy, due to the formation of high-energy metastable α′ martensite with regard to α martensite. This work manipulates the transformation of α′ martensite to α martensite by heat-treatment in SLM-produced Ti-6Al-4V alloy and studies the effect on its corrosion behavior using electrochemical tests and microstructural analysis. The electrochemical results reveal that the heat-treated SLM-produced samples exhibit a higher corrosion rate than the as-received counterparts. The microstructural characterization results show that the acicular α′ martensite vanishes gradually, and a plate-shaped α phase and a lamellar α + β mixture continuously form with enhancing heat-treatment temperature, which increases the grain size. The relation between changes in grain size and corrosion resistance of SLM-produced Ti-6Al-4V has been discussed in detail.
Document Type
Journal Article
Date of Publication
2017
Publication Title
Journal of The Electrochemical Society
Publisher
Electrochemical Society Inc.
School
School of Engineering
RAS ID
24698
Copyright
subscription content
Comments
Dai, N., Zhang, J., Chen, Y., & Zhang, L. C. (2017). Heat treatment degrading the corrosion resistance of selective laser melted Ti-6Al-4V alloy. Journal of The Electrochemical Society, 164(7), C428-C434. https://doi.org/10.1149/2.1481707jes