Ti alloys with lattice structures are garnering more and more attention in the field of bone repair or regeneration due to their superior structural, mechanical, and biological properties. In this study, six types of composite lattice structures with different strut radius that consist of simple cubic (structure A), body-centered cubic (structure B), and edge-centered cubic (structure C) unit cells are designed. The designed structures are firstly simulated and analysed by the finite element (FE) method. Commercially pure Ti (CP-Ti) lattice structures with optimised unit cells and strut radius are then fabricated by selective laser melting (SLM), and the dimensions, microtopography, and mechanical properties are characterised. The results show that among the six types of composite lattice structures, combined BA, CA, and CB structures exhibit smaller maximum von-Mises stress, indicating that these structures have higher strength. Based on the fitting curves of stress/specific surface area versus strut radius, the optimised strut radius of BA, CA, and CB structures is 0.28, 0.23, and 0.30 mm respectively. Their corresponding compressive yield strength and compressive modulus are 42.28, 30.11, and 176.96 MPa, and 4.13, 2.16, and 7.84 GPa, respectively. The CP-Ti with CB unit structure presents a similar strength and compressive modulus to the cortical bone, which makes it a potential candidate for subchondral bone restorations.
Bibliographical noteFunding Information:
This research work is supported by the National Natural Science Foundation of China ( 51922004 , 51874037 ), State Key Lab of Advanced Metals and Materials , University of Science and Technology Beijing (2019-Z14), and Fundamental Research Funds for the Central Universities ( FRF-TP-19005C1Z ). Chaozong Liu acknowledges the support from the European Commission via the H2020 MSCA RISE BAMOS programme ( 734156 ). Bo Su would like to thank the financial support from the MRC (MR/ S010343 /1) and the EU H2020 MSCA RISE Bio-TUNE programme . Wei Xu acknowledges the support from the China Scholarship Council (CSC) for a CSC Ph.D. scholarship ( 201906460106 ).
© 2020 [The Author/The Authors]
- composite lattice structure
- finite element modelling
- selective laser melting (SLM)