Influence of load orientation and of types of loads on the mechanical properties of porous Ti6Al4V biomaterials

Abstract Mechanical properties of human bone vary immensely depending on the type of bone and loads. Scaffolds manufactured by electron beam melting allow matching some of those mechanical properties. Different types of porous titanium alloy structures (body-centred-cubic: ‘BCC’; normal cubic: ‘cubic’ and cubic fabricated to 45°: ‘cross’), with different porosities were fabricated, to examine their mechanical properties under compression and torsional loads. Cubic structures were also analysed by finite element method for different load directions. As expected, cubic structures showed values of strength and stiffness higher than the BCC and cross structures when the load acted vertically. On the other hand, it was appreciated that the mechanical properties for torsion are better in cross structures than in cubic structures, which opposes the observations of the compression tests. Computational analysis showed that the cubic structures evolved from buckling to bending deformation with the decrease of the inclination of the loads with regard to their horizontal axis. In conclusion, it is suggested that all load directions that a scaffold is subjected to should be taken into account, in addition to other types of loads that may appear, such as torque, when designing and choosing the ideal typology in the reconstruction of bone defects.