Flexural mechanical properties of Ti-6Al-4V multilayer micro-lattice biomaterials for skull repair

Novel skull repair biomaterials with matching skull porosity based on micro-lattice structure have been proposed and corresponding quasi-static compression performance has been investigated. However, the flexural strength of biomaterials is often a vital evaluation factor for material failure in clinical application. Herein, the flexural mechanical properties of multilayer micro-lattice biomaterials are investigated by experimental, theoretical and finite element (FE) methods. The stress distribution and failure mode under three-point bending load can be better displayed by FE. In multilayer micro-lattice biomaterial, the vertical strut of unit cell prevents the crack propagation path along inclined shear band and turning to direction parallel to vertical strut. The FE and theoretical results indicate a decrease in flexural property with the increase of three-point bending span. The flexural strength, stiffness and fracture toughness of multilayer micro-lattice biomaterials are in the range of 251.56 to 437.91 MPa, 6.63 to 10.63 GPa and 0.262 to 0.416 MPa m1/2, respectively. Comparing with human skull specimens, the multilayer micro-lattice biomaterial matches well in the flexural property. This work is an essential supplement to the field of mechanical research for multilayer micro-lattice biomaterials, and it plays a significance to promote the clinical application for achieving better skull tissue repair.

Automated summary

This study investigates the flexural mechanical properties of multilayer micro-lattice biomaterials using experimental, theoretical and finite element methods. The results show that the flexural property decreases with increasing bending span. Comparing with human skull specimens, the multilayer micro-lattice biomaterial shows good performance in flexural property.