Research Article
Production and Digital Image Correlation Analysis of
Titanium Foams with Different Pore Morphologies as a
Bone-Substitute Material
Mohammed Shbeh ,
1
Elif Oner,
1
Ammar Al-Rubaye,
2
and Russell Goodall
1
1
Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street,
Sheffield S1 3JD, UK
2
Mechanical Engineering Department, University of Sheffield, Mappin Street, Sheffield S1 3JD, UK
Correspondence should be addressed to Mohammed Shbeh; mohammed.shbeh@gmail.com
Received 23 November 2018; Accepted 16 January 2019; Published 3 February 2019
Academic Editor: Joon-Hyung Lee
Copyright © 2019 Mohammed Shbeh et al. is is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is
properly cited.
Tifoamsaremesoporousstructuredmaterialsthatarecharacterizedbytheirhighsurfaceareaandinterconnectedporositywitha
huge potential for biomedical applications. In this study, we investigated the production of titanium foams with different pore
morphologies as a bone-substitute material via the addition of different amounts, shapes, and sizes of the space holder. Fur-
thermore,wealsocarriedoutstrainanalysisusingdigitalimagecorrelation(DIC)inordertoanalysethestraindistributionacross
theporoussamples.Inaddition,thenatureoftherelationshipbetweentheamountofthespaceholderaddedandfinalamountof
porosity in the foams produced was also examined. e results demonstrated that the relationship between the space holder
amountandporosityinthesamplesfollowsacomplexone-phaseexponentialdecayfunctioninanincreasingform.Ourfindings
alsosuggestthattheshapeofthespaceholderdoesnotplayasignificantroleindictatingtheporosityofthefoamsproducedinthe
currentstudy.However,thespaceholder’sshapedoeshaveasubstantialroleindictatingthemechanicalpropertiesofthefoams
produced,whereTifoamsproducedusingacubicorirregularspaceholderwerefoundtohavealoweryieldstressesthanthose
made with the spherical space holder.
1. Introduction
Human bone is a complex composite material composed of
organic and inorganic components. e organic part of the
bone is comprised of a matrix polymer known as collagen,
which is responsible for giving the bone its toughness,
whereas the inorganic element of the bone has a similar
chemical and crystal structure to that of a ceramic material,
hydroxyapatite,andplaysanimportantroleinprovidingthe
bonewithstrengthandstiffness[1,2].Bonetissueoccursin
two forms or types in our bodies, and both of these forms
haveananisotropicstructure.efirsttypeisthetrabecular
or spongy bone which is composed of an interconnected
porous network of plates and rods arranged in various
configurations, forming an open-celled foam [3, 4]. e
secondtypeisthecorticalorcompactbonecharacterizedby
havingahigherdensity,lessporosity,andmetabolicactivity
thanthatofatrabecularbone[5].etwoformsofbonecan
benormallyfoundtogetherindifferentarrangementsandin
such a manner so that the bone has a combination of ex-
cellent load-bearing ability derived from the spongy tissue
and improved mechanical strength acquired from the cor-
tical bone. For instance, the cortical bone constitutes the
outertubularshellofthelongbonesandtheexternalsurface
of the small and flat bones, while the trabecular bone
composestheinternalsurfaceofsmallbones,theendsofthe
long bones, and between the surfaces of flat bones [6]. In
somecases,suchasseveredamageorosteoporoticfractures,
bones need to be replaced. Successful replacement of such
hard tissue with an anisotropic complex structure and
mechanicalpropertiescanbechallengingwithouttheuseof
appropriate biocompatible and biomimetic materials.
Hindawi
Advances in Materials Science and Engineering
Volume 2019, Article ID 1670837, 14 pages
https://doi.org/10.1155/2019/1670837