Effect of silicon content on the microstructure evolution, mechanical properties, and biocompatibility of β-type TiNbZrTa alloys fabricated by laser powder bed fusion

X Luo; C Yang; R Y Li; H Wang; H Z Lu; T Song; H W Ma; D D Li; A Gebert; Y Y Li

doi:10.1016/j.msec.2021.112625

Effect of silicon content on the microstructure evolution, mechanical properties, and biocompatibility of β-type TiNbZrTa alloys fabricated by laser powder bed fusion

Biomater Adv. 2022 Feb:133:112625. doi: 10.1016/j.msec.2021.112625. Epub 2021 Dec 27.

Authors

X Luo¹, C Yang², R Y Li³, H Wang³, H Z Lu⁴, T Song⁴, H W Ma⁴, D D Li⁵, A Gebert⁶, Y Y Li⁷

Affiliations

¹ National Engineering Research Center of Near-net-shape Forming for Metallic Materials, Guangdong Provincial Key Laboratory for Processing and Forming of Advanced Metallic Materials, South China University of Technology, Guangzhou 510640, China; Institute for Complex Materials, Leibniz IFW Dresden, Helmholtzstrasse 20, 01069 Dresden, Germany.
² National Engineering Research Center of Near-net-shape Forming for Metallic Materials, Guangdong Provincial Key Laboratory for Processing and Forming of Advanced Metallic Materials, South China University of Technology, Guangzhou 510640, China. Electronic address: cyang@scut.edu.cn.
³ Department of Orthopedics, The Second Hospital of Jilin University, Jilin University, Changchun 130041, China.
⁴ National Engineering Research Center of Near-net-shape Forming for Metallic Materials, Guangdong Provincial Key Laboratory for Processing and Forming of Advanced Metallic Materials, South China University of Technology, Guangzhou 510640, China.
⁵ State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
⁶ Institute for Complex Materials, Leibniz IFW Dresden, Helmholtzstrasse 20, 01069 Dresden, Germany. Electronic address: A.Gebert@ifw-dresden.de.
⁷ National Engineering Research Center of Near-net-shape Forming for Metallic Materials, Guangdong Provincial Key Laboratory for Processing and Forming of Advanced Metallic Materials, South China University of Technology, Guangzhou 510640, China; State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074, China. Electronic address: mehjli@scut.edu.cn.

PMID: 35523650
DOI: 10.1016/j.msec.2021.112625

Abstract

Beta-type titanium alloys are excellent candidates for biomedical applications because of their very low elastic modulus, excellent corrosion resistance, and biocompatibility. However, many traditional β-type titanium alloys exhibit low yield strength. In this study, a small amount of Si (3 and 5 at.%) was added to a Ti-35Nb-7Zr-5Ta (wt%, TNZT) biomedical alloy prepared via laser powder bed fusion (LPBF) to increase its yield strength. The Si addition resulted in a significant increase in the compression yield strength of the alloy (from 802 to 1282 MPa). Meanwhile, the elastic moduli of the TNZT alloys (48.7-60.6 GPa) with 3 and 5 at.% Si were much lower than that of the Ti-6Al-4 V alloy (110 GPa), which is used extensively in clinical applications. The microstructural analyses indicated that the ultrahigh-strength of the TNZT alloy containing Si was due to the presence of ultrafine (Ti, Nb, Zr)₅Si₃ (S1) grains in the β-Ti matrix. In addition, thin shell-shaped S1 and (Ti, Nb, Zr)₂Si (S2) grains precipitated along the columnar β-Ti grain boundaries in the TNZT alloys containing 3 and 5 at.% Si, respectively. Moreover, the introduction of Si to the TNZT alloy significantly refined the grains, weakened the cubic texture, decreased surface roughness, and improved Vickers hardness. The ultrahigh strength of the Si-containing TNZT alloys was due to grain boundary strengthening and precipitation strengthening. In addition, in vitro studies with MC3T3-E1 cells revealed that the cytocompatibilities of the LPBF-fabricated TNZT and Si-containing TNZT alloys were equivalent and were better than that of the LPBF-fabricated Ti-6Al-4 V alloy. In particular, the TNZT alloy with 3 at.% Si showed the best elastic modulus (48.7 ± 1.0 GPa), yield strength (1151 ± 17 MPa), and cell biological response among all the alloys investigated in this study, and hence was found to be a suitable candidate for application in load-bearing bone implants.

Keywords: Biocompatibility; Laser powder bed fusion; Mechanical properties; Microstructure; β-Type titanium alloys.

MeSH terms

Alloys* / chemistry
Lasers
Powders
Silicon
Titanium* / chemistry

Substances

Alloys
Powders
Titanium
Silicon