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Mechanical behavior of a titanium alloy scaffold mimicking trabecular structure
BACKGROUND: Additively manufactured porous metallic structures have recently received great attention for bone implant applications. The morphological characteristics and mechanical behavior of 3D printed titanium alloy trabecular structure will affect the effects of artificial prosthesis replacemen...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
BioMed Central
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7006186/ https://www.ncbi.nlm.nih.gov/pubmed/32028970 http://dx.doi.org/10.1186/s13018-019-1489-y |
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author | Zhang, Chunqiu Zhang, Lan Liu, Lu Lv, Linwei Gao, Lilan Liu, Nian Wang, Xin Ye, Jinduo |
author_facet | Zhang, Chunqiu Zhang, Lan Liu, Lu Lv, Linwei Gao, Lilan Liu, Nian Wang, Xin Ye, Jinduo |
author_sort | Zhang, Chunqiu |
collection | PubMed |
description | BACKGROUND: Additively manufactured porous metallic structures have recently received great attention for bone implant applications. The morphological characteristics and mechanical behavior of 3D printed titanium alloy trabecular structure will affect the effects of artificial prosthesis replacement. However, the mechanical behavior of titanium alloy trabecular structure at present clinical usage still is lack of in-depth study from design to manufacture as well as from structure to mechanical function. METHODS: A unit cell of titanium alloy was designed to mimick trabecular structure. The controlled microarchitecture refers to a repeating array of unit-cells, composed of titanium alloy, which make up the scaffold structure. Five kinds of unit cell mimicking trabecular structure with different pore sizes and porosity were obtained by modifying the strut sizes of the cell and scaling the cell as a whole. The titanium alloy trabecular structure was fabricated by 3D printing based on Electron Beam Melting (EBM). The paper characterized the difference between the designs and fabrication of trabecular structures, as well as mechanical properties and the progressive collapse behavior and failure mechanism of the scaffold. RESULTS: The actual porosities of the EBM-produced bone trabeculae are lower than the designed, and the load capacity of a bearing is related to the porosity of the structure. The larger the porosity of the structure, the smaller the stiffness and the worse the load capacity is. The fracture interface of the trabecular structure under compression is at an angle of 45(o) with respect to the compressive axis direction, which conforms to Tresca yield criterion. The trabeculae-mimicked unit cell is anisotropy. Under quasi-static loading, loading speed has no effect on mechanical performance of bone trabecular specimens. There is no difference of the mechanical performance at various orientations and sites in metallic workspace. The elastic modulus of the scaffold decreases by 96%–93% and strength reduction 96%–91%, compared with titanium alloy dense metals structure. The apparent elastic modulus of the unit-cell-repeated scaffold is 0.39–0.618 GPa, which is close to that of natural bone and stress shielding can be reduced. CONCLUSION: We have systematically studied the structural design, fabrication and mechanical behavior of a 3D printed titanium alloy scaffold mimicking trabecula bone. This study will be benefit of the application of prostheses with proper structures and functions. |
format | Online Article Text |
id | pubmed-7006186 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-70061862020-02-11 Mechanical behavior of a titanium alloy scaffold mimicking trabecular structure Zhang, Chunqiu Zhang, Lan Liu, Lu Lv, Linwei Gao, Lilan Liu, Nian Wang, Xin Ye, Jinduo J Orthop Surg Res Research Article BACKGROUND: Additively manufactured porous metallic structures have recently received great attention for bone implant applications. The morphological characteristics and mechanical behavior of 3D printed titanium alloy trabecular structure will affect the effects of artificial prosthesis replacement. However, the mechanical behavior of titanium alloy trabecular structure at present clinical usage still is lack of in-depth study from design to manufacture as well as from structure to mechanical function. METHODS: A unit cell of titanium alloy was designed to mimick trabecular structure. The controlled microarchitecture refers to a repeating array of unit-cells, composed of titanium alloy, which make up the scaffold structure. Five kinds of unit cell mimicking trabecular structure with different pore sizes and porosity were obtained by modifying the strut sizes of the cell and scaling the cell as a whole. The titanium alloy trabecular structure was fabricated by 3D printing based on Electron Beam Melting (EBM). The paper characterized the difference between the designs and fabrication of trabecular structures, as well as mechanical properties and the progressive collapse behavior and failure mechanism of the scaffold. RESULTS: The actual porosities of the EBM-produced bone trabeculae are lower than the designed, and the load capacity of a bearing is related to the porosity of the structure. The larger the porosity of the structure, the smaller the stiffness and the worse the load capacity is. The fracture interface of the trabecular structure under compression is at an angle of 45(o) with respect to the compressive axis direction, which conforms to Tresca yield criterion. The trabeculae-mimicked unit cell is anisotropy. Under quasi-static loading, loading speed has no effect on mechanical performance of bone trabecular specimens. There is no difference of the mechanical performance at various orientations and sites in metallic workspace. The elastic modulus of the scaffold decreases by 96%–93% and strength reduction 96%–91%, compared with titanium alloy dense metals structure. The apparent elastic modulus of the unit-cell-repeated scaffold is 0.39–0.618 GPa, which is close to that of natural bone and stress shielding can be reduced. CONCLUSION: We have systematically studied the structural design, fabrication and mechanical behavior of a 3D printed titanium alloy scaffold mimicking trabecula bone. This study will be benefit of the application of prostheses with proper structures and functions. BioMed Central 2020-02-07 /pmc/articles/PMC7006186/ /pubmed/32028970 http://dx.doi.org/10.1186/s13018-019-1489-y Text en © The Author(s). 2020 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. |
spellingShingle | Research Article Zhang, Chunqiu Zhang, Lan Liu, Lu Lv, Linwei Gao, Lilan Liu, Nian Wang, Xin Ye, Jinduo Mechanical behavior of a titanium alloy scaffold mimicking trabecular structure |
title | Mechanical behavior of a titanium alloy scaffold mimicking trabecular structure |
title_full | Mechanical behavior of a titanium alloy scaffold mimicking trabecular structure |
title_fullStr | Mechanical behavior of a titanium alloy scaffold mimicking trabecular structure |
title_full_unstemmed | Mechanical behavior of a titanium alloy scaffold mimicking trabecular structure |
title_short | Mechanical behavior of a titanium alloy scaffold mimicking trabecular structure |
title_sort | mechanical behavior of a titanium alloy scaffold mimicking trabecular structure |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7006186/ https://www.ncbi.nlm.nih.gov/pubmed/32028970 http://dx.doi.org/10.1186/s13018-019-1489-y |
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