The effect of geometry on mechanical properties of Ti6Al4V ELI scaffolds manufactured using additive manufacturing technology

Abstract

Owing to the possibility of direct processing of CAD models into three-dimensional objects, additive manufacturing (AM) is widely used in the production of individualized bone scaffolds that can lead to perfect restoration of anatomical structures of missing bone tissues. In this work, one of the AM technologies was applied, referred to as Electron Beam Melting (EBM), using Ti6Al4V ELI alloy to produce open-cell structures. Scaffold architecture influences its mechanical properties and is important from the point of view of biological considerations. To optimize mechanical properties, designed geometries were subjected to Finite Element Method analysis and experimental static compression tests. Also, geometric CT analysis of manufactured scaffolds was carried out (geometry deviations up to ± 300 µm). Obtained results have shown that AM can be used to produce Ti6Al4V ELI alloy scaffolds displaying mechanical parameters similar to those of bone tissue (E = 0.45-2.88 MPa). The EBM process affects the microstructure and macrostructural properties of manufactured parts, e.g., through internal porosities present in the material by to unmelted powder particles (internal porosity in range of 1.25-2.25%). To assess the quality and suitability of additively manufactured implants, a multidimensional verification of the impact of the manufacturing process on the properties of the final product was performed.

Experimental and Numerical Study of Ballistic Resistance of Composites Based on Sandwich Metallic Foams

“…According to the authors [28], future trends in these materials will include, among others, the development of syntactic foams for dynamic loading conditions." Metallic foams can be divided according to the method of manufacturing into cast ones and those obtained by powder metallurgical methods with the addition of blowing agents [29][30][31]. The above-mentioned studies described foams made by powder metallurgy.…”

Mechanical Properties of Porous Structures for Dental Implants: Experimental Study and Computational Homogenization

“…Concerning the invention of porous microstructures intended for bio-applications, the simulations are typically directed towards a numerical reproduction of a physical experiment while accounting for all geometrical details of the tested specimen ([ 9 , 10 , 11 , 27 ] to cite a few). The resulting finite element model then typically calls for fine meshes with a large number of degrees of freedom which makes the analysis time consuming.…”

“…A rapid boom in the design and modeling of porous microstructures, focusing on bone implants [ 9 , 10 , 11 ], has been observed with a recently developed additive manufacturing (AM) technique allowing for the production of porous titanium microstructures via 3D printing [ 12 ]. Either selective electron beam melting (SEBM) [ 10 , 13 , 14 ] or selective laser melting (SLM) [ 15 , 16 ] is typically adopted to fabricate microstructures of variable complexity, including both trabecular [ 10 , 17 , 18 ] and gyroid [ 9 , 11 , 14 ] types of cellular structures.…”

“…A rapid boom in the design and modeling of porous microstructures, focusing on bone implants [ 9 , 10 , 11 ], has been observed with a recently developed additive manufacturing (AM) technique allowing for the production of porous titanium microstructures via 3D printing [ 12 ]. Either selective electron beam melting (SEBM) [ 10 , 13 , 14 ] or selective laser melting (SLM) [ 15 , 16 ] is typically adopted to fabricate microstructures of variable complexity, including both trabecular [ 10 , 17 , 18 ] and gyroid [ 9 , 11 , 14 ] types of cellular structures. The latter technique has been selected in this study owing to a fruitful collaboration with ProSpon, Ltd. which has successfully exploited SLM in a variety of biomedical areas, including production of implants and medical devices in orthopedics, traumatology, and surgery applications.…”

“…To this goal, a computational approach is a suitable alternative [ 25 , 26 ]. In the framework of trabecular or gyroid structures, the interested reader is referred to [ 9 , 10 , 11 , 17 , 27 ], to cite a few. In this regard, triply periodic minimal surface (TPMS) structures have often been examined owing to their extraordinary mechanical properties that are easily tailored, through simple geometrical adjustments, to those of human trabecular bone [ 28 ].…”