Processing, microstructure and mechanical properties of beta-type titanium porous structures made by additive manufacturing

Author

Yujing Liu, Edith Cowan UniversityFollow

Date of Award

2017

Document Type

Thesis

Publisher

Edith Cowan University

Degree Name

Doctor of Philosophy

School

School of Engineering

First Supervisor

Associate Professor Lai-Chang Zhang

Second Supervisor

Professor Yu-Lin Hao

Abstract

Tissue engineering through the application of a low modulus, high strength format as a potential approach for increasing the durability of bone implants has been attracting significant attention. Titanium alloys are widely used for biomedical applications because of their low modulus, high biocompatibility, specific strength and corrosion resistance. These reasons affirm why titanium alloy is selected as the specific material to research. The development of low modulus biomaterials is considered to be an effective method to remove the mismatch between biomaterial implants and surrounding bone tissue, thereby reducing the risk of bone resorption. So far, Ti–24Nb–4Zr–8Sn alloy (abbreviated hereafter as Ti2448) is considered to be a biomedical titanium alloy with low modulus, and was invented for biomaterial application. However, the modulus of Ti2448 (42-50 GPa) is still higher than that of bone (1-30 GPa). A scaffold is an ideal structure for bone implants; such a structure can further reduce the modulus of an implant. This structure also has the desired effect of promoting bone in-growth. Additive manufacturing could prepare porous titanium parts with mechanical properties close to those of bone tissue. However, the properties of scaffolds are affected by manufacturing strategies and parameters such as the scanning speed, the input power, the layer thickness, the scanning strategy, the temperature of the platform and the hatch distance. Each of these parameters can affect a scaffold’s properties and performance in terms of density, hardness, super-elastic property, compressive and fatigue properties. For the Ti2448 alloy, all of these manufacturing parameters are still not clear enough to develop the perfect porous structure. This study will examine the performance of biomaterial Ti2448 scaffolds by tuning the main parameters of additive manufacturing (AM) systems through an analysis of the microstructure and the mechanical properties of the produced components.

Related Publications

Liu, Y. J., Li, X. P., Zhang, L. C., & Sercombe, T. B. (2015). Processing and properties of topologically optimised biomedical Ti–24Nb–4Zr–8Sn scaffolds manufactured by selective laser melting. Materials Science and Engineering: A, 642, 268-278. Link to article available here.

Liu, Y.J., Li, S.J., Hou, W.T., Wang, S.G., Hao, Y.L., Yang, R., Sercombe, T., & Zhang, L.C. (2016). Electron beam melted beta-type Ti-24Nb-4Zr-8Snporous structures with high strength-to-modulus ratio, Journal of Materials Science and Technology, 32, 505-508. doi: 10.1016/j.jmst.2016.03.020 Link to article available here.

Liu, Y. J., Li, S. J., Wang, H. L., Hou, W. T., Hao, Y. L., Yang, R., ... & Zhang, L. C. (2016). Microstructure, defects and mechanical behavior of beta-type titanium porous structures manufactured by electron beam melting and selective laser melting. Acta Materialia, 113, 56-67. Doi: 10.1016/j.actamat.2016.04.029. Link to article available here.

Liu, Y. J., Wang, H. L., Li, S. J., Wang, S. G., Wang, W. J., Hou, W. T., ... & Zhang, L. C. (2017). Compressive and fatigue behavior of beta-type titanium porous structures fabricated by electron beam melting. Acta Materialia, 126, 58-66. doi:10.1016/j.actamat.2016.12.052 Link to article available here.

Zhang, L. C., & Liu, Y. (2019). Additive manufacturing of titanium alloys for biomedical applications. In B. AlMangour (Ed.), Additive manufacturing of emerging materials (pp. 179-196). Springer, Cham.

https://doi.org/10.1007/978-3-319-91713-9_5

Li, X. P., Wang, X. J., Saunders, M., Suvorova, A., Zhang, L. C., Liu, Y. J., ... & Sercombe, T. B. (2015). A selective laser melting and solution heat treatment refined Al–12Si alloy with a controllable ultrafine eutectic microstructure and 25% tensile ductility. Acta Materialia, 95, 74-82. 10.1016/j.actamat.2015.05.017

Ehtemam-Haghighi, Shima (03.2016). "Influence of Nb on the β→α″ martensitic phase transformation and properties of the newly designed Ti–Fe–Nb alloys". Materials science & engineering. C, Materials for biological applications (0928-4931), 60, p. 503-510. 10.1016/j.msec.2015.11.072

https://ro.ecu.edu.au/ecuworkspost2013/1415/

Ehtemam-Haghighi, S., Liu, Y., Cao, G., & Zhang, L. C. (2016). Phase transition, microstructural evolution and mechanical properties of Ti-Nb-Fe alloys induced by Fe addition. Materials & Design, 97, 279-286. Available here

Li, X. P., Roberts, M., Liu, Y. J., Kang, C. W., Huang, H., & Sercombe, T. B. (2015). Effect of substrate temperature on the interface bond between support and substrate during selective laser melting of Al–Ni–Y–Co–La metallic glass. Materials & Design, 65, 1-6. Available here

Access Note

Access to Chapters 3, 4, 5 and 6 of this thesis is not available. See list of related publications.

Recommended Citation

Liu, Y. (2017). Processing, microstructure and mechanical properties of beta-type titanium porous structures made by additive manufacturing. Edith Cowan University. Retrieved from https://ro.ecu.edu.au/theses/2039