Microstructural evolution and mechanical properties of laser-powder bed fusion-fabricated Ti-10Ta-2Nb-2Zr alloy as a potential orthopedic implant material

Abstract

Titanium alloys are gaining attention for their potential to improve implant performance in biomedical applications. This study investigates the Ti-10Ta-2Nb-2Zr alloy fabricated using laser-powder bed fusion (L-PBF) for potential biomedical applications. The research aims to examine the influence of processing parameters on material structure and properties, and to develop porous structures based on triply periodic minimal surfaces (TPMS) to reduce elastic modulus and improve mechanical compatibility with bone tissue. Spherical Ti-10Ta-2Nb-2Zr powder was processed using L-PBF with varying laser power (250 – 280 W), scanning speed (500 – 1000 mm/s), and hatch spacing (80 – 100 μm). Maximum relative density of 99.91% was achieved at volumetric energy density of 70 J/mm3. Differential scanning calorimetry revealed the β-transus temperature at 862°C. Microstructural analysis showed the formation of martensitic α’-phase in the as-built condition with acicular morphology. Heat treatment at 900°C resulted in the formation of a lamellar α + β structure. Mechanical properties in the as-built condition were characterized by yield strength of 551.8 MPa, ultimate tensile strength of 641.2 MPa, elongation of 19.0%, and elastic modulus of 89.0 GPa. After heat treatment, strength characteristics decreased by 15 – 18%, whereas elastic modulus reduced to 86.0 GPa. TPMS porous structures (gyroid, Schwarz, and split) with 50% porosity demonstrated an elastic modulus of 9.2 – 9.7 GPa, representing approximately 18% of the solid material value. These results demonstrate the potential of Ti-10Ta-2Nb-2Zr as a promising alternative to conventional Ti-6Al-4V for orthopedic applications, offering enhanced mechanical properties and reduced stress shielding due to its lower elastic modulus and tailored porous architectures.

Keywords

Titanium alloy / Laser powder bed fusion / Biomaterials / Triply periodic minimal surfaces / Mechanical properties / Microstructure

Funding

This research was supported by the Ministry of Science and Higher Education of the Russian Federation (agreement No. 075-15-2024-562).

Conflict of Interest

The authors declare they have no competing interests.

References

[1] Wu H, Chen X, Kong L, Liu P. Mechanical and biological properties of Ti and its alloys for oral implant with preparation techniques: A review. Materials (Basel). 2023;16(21):6860. doi: 10.3390/ma16216860

[2] Khorasani AM, Goldberg M, Doeven EH, Littlefair G. Titanium in biomedical applications-properties and fabrication: A review. J Biomater Tissue Eng. 2015;5(8):593-619. doi: 10.1166/jbt.2015.1361

[3] Zhang Y, Xiu P, Jia Z, et al. Effect of vanadium released from micro-arc oxidized porous Ti6Al4V on biocompatibility in orthopedic applications. Colloids Surf B Biointerfaces. 2018;169:366-374. doi: 10.1016/j.colsurfb.2018.05.044

[4] Abdel-Hady Gepreel M, Niinomi M. Biocompatibility of Ti-alloys for long-term implantation. J Mech Behav Biomed Mater. 2013;20:407-415. doi: 10.1016/j.jmbbm.2012.11.014

[5] Laheurte P, Prima F, Eberhardt A, Gloriant T, Wary M, Patoor E. Mechanical properties of low modulus β titanium alloys designed from the electronic approach. J Mech Behav Biomed Mater. 2010;3(8):565-573. doi: 10.1016/j.jmbbm.2010.07.001

[6] Han L, Che S. An overview of materials with triply periodic minimal surfaces and related geometry: From biological structures to self‐assembled systems. Adv Mater. 2018;30(17):e1705708. doi: 10.1002/adma.201705708

[7] Learmonth ID, Young C, Rorabeck C. The operation of the century: Total hip replacement. Lancet. 2007;370(9597):1508-1519. doi: 10.1016/S0140-6736(07)60457-7

[8] khan B, Kumar S. Implementation of Triply Periodic Minimal Surface (TPMS) Structure in Mesenchymal Stem Cell Differentiation. United States: Research Square; 2022. doi: 10.21203/rs.3.rs-2156625/v1

[9] Castro APG, Pires T, Santos JE, Gouveia BP, Fernandes PR. Permeability versus design in TPMS scaffolds. Materials (Basel). 2019;12(8):1313. doi: 10.3390/ma12081313

[10] Chen LY, Cui YW, Zhang LC. Recent development in beta titanium alloys for biomedical applications. Metals (Basel). 2020;10(9):1139. doi: 10.3390/met10091139

[11] Niinomi M, Boehlert CJ. Titanium alloys for biomedical applications. In: Advances in Metallic Biometerials. Berlin: Springer; 2015. p. 179-213. doi: 10.1007/978-3-662-46836-4_8

[12] Bahl S, Suwas S, Chatterjee K. Comprehensive review on alloy design, processing, and performance of  Titanium alloys as biomedical materials. Int Mater Rev. 2021;66(2):114-139. doi: 10.1080/09506608.2020.1735829

[13] Niinomi M. Mechanical biocompatibilities of titanium alloys for biomedical applications. J Mech Behav Biomed Mater. 2008;1(1):30-42. doi: 10.1016/j.jmbbm.2007.07.001

[14] Huang S, Sing SL, De Looze G, Wilson R, Yeong WY. Laser powder bed fusion of titanium-tantalum alloys: Compositions and designs for biomedical applications. J Mech Behav Biomed Mater. 2020;108:103775. doi: 10.1016/j.jmbbm.2020.103775

[15] Fuerst J, Medlin D, Carter M, Sears J, Vander Voort G. LASER additive manufacturing of titanium-tantalum alloy structured interfaces for modular orthopedic devices. JOM. 2015;67(4):775-780. doi: 10.1007/s11837-015-1345-4

[16] Sing SL, Yeong WY, Wiria FE. Selective laser melting of titanium alloy with 50 wt% tantalum: Microstructure and mechanical properties. J Alloys Compd. 2016;660:461-470. doi: 10.1016/j.jallcom.2015.11.141

[17] Plaine AH, Silva MR, Bolfarini C. Effect of thermo-mechanical treatments on the microstructure and mechanical properties of the metastable β-type Ti-35Nb- 7Zr-5Ta alloy. Mater Res. 2018;22(1):e20180462. doi: 10.1590/1980-5373-mr-2018-0462

[18] Ummethala R, Karamched PS, Rathinavelu S, et al. Selective laser melting of high-strength, low-modulus Ti–35Nb–7Zr– 5Ta alloy. Materialia. 2020;14:100941. doi: 10.1016/j.mtla.2020.100941

[19] Zhang LC, Klemm D, Eckert J, Hao YL, Sercombe TB. Manufacture by selective laser melting and mechanical behavior of a biomedical Ti-24Nb-4Zr-8Sn alloy. Scrip Mater. 2011;65(1):21-24. doi: 10.1016/j.scriptamat.2011.03.024

[20] Hao YL, Yang R, Niinomi M, et al. Young’s modulus and mechanical properties of Ti-29Nb-13Ta-4. 6Zr in relation to α” martensite. Metall Mater Trans A. 2002;33(10):3137-3144. doi: 10.1007/s11661-002-0299-7

[21] Yang K, Wang J, Tang H, Li Y. Additive manufacturing of in-situ reinforced Ti-35Nb-5Ta-7Zr (TNTZ) alloy by selective electron beam melting (SEBM). J Alloys Compd. 2020;826:154178. doi: 10.1016/j.jallcom.2020.154178

[22] Brodie EG, Medvedev AE, Frith JE, Dargusch MS, Fraser HL, Molotnikov A. Remelt processing and microstructure of selective laser melted Ti25Ta. J Alloys Compd. 2020;820:153082. doi: 10.1016/j.jallcom.2019.153082

[23] Ji G, Zhou Z, Meng F, et al. Effect of Zr addition on the local structure and mechanical properties of Ti-Ta-Nb-Zr refractory high-entropy alloys. J Mater Res Technol. 2022;19:4428-4438. doi: 10.1016/j.jmrt.2022.06.160

[24] Biesiekierski A, Lin J, Li Y, Ping D, Yamabe-Mitarai Y, Wen C. Investigations into Ti-(Nb,Ta)-Fe alloys for biomedical applications. Acta Biomater. 2016;32:336-347. doi: 10.1016/j.actbio.2015.12.010

[25] Zhenhuan W, Yu D, Junsi L, et al. Physiochemical and biological evaluation of SLM-manufactured Ti-10Ta-2Nb- 2Zr alloy for biomedical implant applications. Biomed Mater. 2020;15(4):045017. doi: 10.1088/1748-605X/ab7ff4

[26] Morita A, Fukui H, Tadano H, Hayashi S, Hasegawa J, Niinomi M. Alloying titanium and tantalum by cold crucible levitation melting (CCLM) furnace. Mater Sci Eng A. 2000;280(1):208-213. doi: 10.1016/S0921-5093(99)00668-1

[27] Zhao D, Han C, Li Y, et al. Improvement on mechanical properties and corrosion resistance of titanium-tantalum alloys in-situ fabricated via selective laser melting. J Alloys Compd. 2019;804:288-298. doi: 10.1016/j.jallcom.2019.06.307

[28] Soro N, Brodie EG, Abdal-hay A, Alali AQ, Kent D, Dargusch MS. Additive manufacturing of biomimetic titanium-tantalum lattices for biomedical implant applications. Mater Des. 2022;218:110688. doi: 10.1016/j.matdes.2022.110688

[29] Yoo DJ. Computer-aided porous scaffold design for tissue engineering using triply periodic minimal surfaces. Int J Precis Eng Manuf. 2011;12(1):61-71. doi: 10.1007/s12541-011-0008-9

[30] Yoo DJ. Porous scaffold design using the distance field and triply periodic minimal surface models. Biomaterials. 2011;32(31):7741-7754. doi: 10.1016/j.biomaterials.2011.07.019

[31] Dilip JJS, Zhang S, Teng C, et al. Influence of processing parameters on the evolution of melt pool, porosity, and microstructures in Ti-6Al-4V alloy parts fabricated by selective laser melting. Prog Addit Manuf. 2017;2(3):157-167. doi: 10.1007/s40964-017-0030-2

[32] Xiang S, Yuan Y, Zhang C, Chen J. Effects of process parameters on the corrosion resistance and biocompatibility of Ti6Al4V parts fabricated by selective laser melting. ACS Omega. 2022;7(7):5954-5961. doi: 10.1021/acsomega.1c06246

[33] Pesode P, Barve S. A review-metastable β titanium alloy for biomedical applications. J Eng Appl Sci. 2023;70(1):25. doi: 10.1186/s44147-023-00196-7

[34] Liu CC, Li YHZ, Gu J, Song M. Phase transformation in titanium alloys: A review. Trans Nonferrous Metals Soc China. 2024;34(10):3093-3117. doi: 10.1016/S1003-6326(24)66597-0

[35] Banerjee D, Williams JC. Perspectives on titanium science and technology. Acta Mater. 2013;61(3):844-879. doi: 10.1016/j.actamat.2012.10.043

[36] Ahmed T, Rack HJ. Phase transformations during cooling in α+β titanium alloys. Mater Sci Eng A. 1998;243(1-2):206-211. doi: 10.1016/S0921-5093(97)00802-2

[37] Bania PJ. Beta titanium alloys and their role in the titanium industry. JOM. 1994;46(7):16-19. doi: 10.1007/BF03220742

[38] Geetha M, Singh AK, Asokamani R, Gogia AK. Ti based biomaterials, the ultimate choice for orthopaedic implants - A review. Prog Mater Sci. 2009;54(3):397-425. doi: 10.1016/j.pmatsci.2008.06.004

[39] Jamshidi P, Aristizabal M, Kong W, et al. Selective laser melting of Ti-6Al-4V: The impact of post-processing on the tensile, fatigue and biological properties for medical implant applications. Materials. 2020;13(12):2813. doi: 10.3390/ma13122813

[40] Cho JY, Xu W, Brandt M, Qian M. Selective laser melting-fabricated Ti-6Al-4V alloy: Microstructural inhomogeneity, consequent variations in elastic modulus and implications. Opt Laser Technol. 2019;111:664-670. doi: 10.1016/j.optlastec.2018.08.052