%0 journal article
%@ 0921-5093
%A Wang, D., Zhou, Y., Shen, J., Liu, Y., Li, D., Zhou, Q., Sha, G., Xu, P., Ebel, T., Yan, M.

%D 2019
%J Materials Science and Engineering  A

%P 138078 
%R doi:10.1016/j.msea.2019.138078
%T Selective laser melting under the reactive atmosphere: A convenient and efficient approach to fabricate ultrahigh strength commercially pure titanium without sacrificing ductility
%U https://doi.org/10.1016/j.msea.2019.138078
 
%X This study presents a novel approach for the fabrication of commercially pure titanium (CP–Ti) components. The approach conferred superb strength to CP-Ti without sacrificing its ductility. A yield strength of 807 MPa combined with 19.15% elongation was realized through selective laser melting (SLM) by using a high-power laser and incorporating solute atoms from the Ar−N2 reactive atmosphere. Mechanical properties and microstructures of the as-printed CP-Ti were systematically investigated. Transmission electron microscopy, electron backscatter diffraction, and atom probe tomography were employed to reveal the mechanism underlying the in-situ reaction between CP-Ti and the reactive atmosphere. Results suggested that nitrogen generally dissolved in the α′-Ti matrix as interstitial solute atoms. The beneficial N content has a critical limit of ~0.43 wt%. The ductility of CP-Ti will decrease drastically if its N content exceeds this limit. A constitutive model was developed for describing the tensile deformation behavior of the in-situ strengthened CP-Ti over various solute contents and grain sizes. This work demonstrates a promising methodology for the fabrication of high-performance metallic components and extends the fundamental understanding of SLM process under the reactive atmosphere.