Ti–6Al–4V triply periodic minimal surface structures for bone implants fabricated via selective laser melting

Abstract

Young, Ti-6Al-4V triply periodic minimal surface structures for bone implants fabricated via selective laser melting, Journal of the Mechanical Behavior of Biomedical Materials, http://dx.doi.org/10.1016/j.jmbbm. 2015.06.024 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. C for 4 h, the α' martensite was converted to a mixture of α and β, in which the α phase being the dominant fraction is present as fine laths with the width of 500-800 nm and separated by a small amount of narrow, interphase regions of dark β phase. Also, the microhardness is decreased to 3.71±0.35 GPa due to the coarsening of the microstructure. The 80-95% porosity TPMS lattices exhibit a comparable porosity with trabecular bone, and the modulus is in the range of 0.12-1.25 GPa and thus can be adjusted to the modulus of trabecular bone. At the same range of porosity of 5-10%, the moduli of cortical bone and of the Ti-6Al-4V TPMS lattices are in a similar range. Therefore, the modulus and porosity of Ti-6Al-4V TPMS lattices can be tailored to the levels of human bones and thus reduce or avoid "stress shielding"and increase longevity of implants. Due to the biomorphic designs, and high interconnected porosity and stiffness comparable to human bones, SLM-made Ti-6Al-4V TPMS lattices can be a promising material for load bearing bone implants.

A mechanical property evaluation of graded density Al-Si10-Mg lattice structures manufactured by selective laser melting

“…This is toward the lower end of the range given by Gibson and Ashby [2], which was 0.1 -4.0. The value of C 1 determined here agrees well with the values of 0.17 and 0.19 reported for two types of Ti-6Al-4V lattice by Yan et al [44], and is somewhat lower than the value of 0.44 ± 0.01 determined for the 280 same BCC lattice structure made in a polymer by SLS [19]. It is worth noting, however, that the deduction of C 1 is here based on the assumption that the lattices follow an E * ∝ ρ * 2 proportionality.…”

“…It is worth noting, however, that the deduction of C 1 is here based on the assumption that the lattices follow an E * ∝ ρ * 2 proportionality. It has been shown elsewhere [44][45][46] that the experimentally determined ρ n exponent can take values between 1.64 and 2.84, depending on the lattice cell type and the presence of surface 285 roughness and residual stresses resulting from the manufacturing process.…”

Defect Formation Mechanisms in Selective Laser Melting: A Review

“…With the development of high energy beams, it becomes possible to manufacture metal parts of high performance. Due to its unique advantages, the AM approach has been widely applied in many industries, such as aerospace, medical devices, military and automobile [3][4][5].…”

Additively Manufactured Scaffolds for Bone Tissue Engineering and the Prediction of their Mechanical Behavior: A Review

“…At present, the mainstream way of non-stochastic cellular structure design is arranging structural units, such as polyhedral units or point lattice periodically to get a porous architecture. The structural units can be designed through CAD [30], image-based designing [59], implicit surface modeling [27,60] and topology optimization [61,62]. The geometrical shape of structural units reported in the literature can roughly be classified as truss, polyhedron and triply periodic minimal surface.…”

“…Due to the ability to fabricate extremely complex parts without any tools or molds, this game-changing manufacturing technology has been used in the research community to create patient-specific implants for bone substitution. AM has proven itself to be a viable process to fabricate metallic BTE scaffolds, from a variety of metal powders or alloy powders, such as Ti [26], Ti-6Al-4V [27,28], Fe-30Mn [29] and Ta [30]. Most of the AM processes applied to the fabrication of BTE scaffolds are powder-bed-based or powder-fed-based ones.…”