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\r\nof bone and loads. Scaffolds manufactured by electron beam melting allow\r\nmatching some of thosemechanical properties. Different types of porous\r\ntitanium alloy structures (body-centred-cubic: `BCC'; normal cubic:\r\n`cubic' and cubic fabricated to 45 degrees: `cross'), with different\r\nporosities were fabricated, to examine their mechanical properties under\r\ncompression and torsional loads. Cubic structureswere also analysed by\r\nfinite elementmethod for different load directions. As expected, cubic\r\nstructures showed values of strength and stiffness higher than the BCC\r\nand cross structures when the load acted vertically. On the other hand,\r\nit was appreciated that the mechanical properties for torsion are better\r\nin cross structures than in cubic structures, which opposes the\r\nobservations of the compression tests. Computational analysis showed\r\nthat the cubic structures evolved from buckling to bending deformation\r\nwith the decrease of the inclination of the loads with regard to their\r\nhorizontal axis. In conclusion, it is suggested that all load directions\r\nthat a scaffold is subjected to should be taken into account, in\r\naddition to other types of loads that may appear, such as torque, when\r\ndesigning and choosing the ideal typology in the reconstruction of bone\r\ndefects.