Spatial Topological Structure Design of Porous Ti–6Al–4V Alloy with Low Modulus and Magnetic Susceptibility

Abstract

Ti–6Al–4V alloy is widely used as a biomaterial for hard tissue replacement, but its Young’s modulus is still higher than that of human bone tissue, which may cause a “stress shielding” effect and lead to implant loosening. In addition, metal implants with low magnetic susceptibility are beneficial for obtaining minimal artifacts in magnetic resonance imaging. To reduce Young’s modulus and magnetic susceptibility of Ti–6Al–4V alloy, a series of irregular prismatic porous structure models were designed based on the Voronoi principle, built by changing the irregularity, prism-diameter-to-initial-seed-spacing ratio, and seed number, and studied using finite-element analysis. Porous samples were prepared by selective laser melting and subjected to a compression test and magnetic susceptibility test. The simulation results show that the prism-diameter-to-initial-seed-spacing ratio has the greatest impact on porosity compared with the irregularity and seed number. The simulation-predicted porosity and compression modulus are highly consistent with the measured ones. The irregular prismatic porous Ti–6Al–4V samples exhibit mechanical properties similar to those of human bones and show a magnetic susceptibility of no more than 50% that of compact Ti–6Al–4V. A regulatable irregular prismatic porous structure is feasible for designing porous implants with desirable properties for biomedical applications.

Investigating mechanical properties of 3D printed porous titanium scaffolds for bone tissue engineering

“…Additionally, in the compression experiment, the square structure collapsed layer by layer starting from the top surface. The compression experiment conducted on the irregular prismatic porous Ti6Al4V scaffold, as designed by Li et al [5], revealed that an increase in porosity led to a decrease in the compression modulus. Excessive aperture size and unsuitable pore structure can lead to a reduction in the compressive strength of the scaffold, making it more susceptible to damage.…”

A 3D-printed scaffold composed of Alg/HA/SIS for the treatment of diabetic bone defects

“…As is well known, osteogenic capacity is the primary function of implanted biomaterials for treating bone defects [ 6 , [16] , [17] , [18] ]. Nowadays, various kinds of artificial biomaterials including metals, ceramics and synthetical polymers have been developed for bone implantation [ 6 , 19 ].…”