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Journal of Materials Science and Nanotechnology | Volume: 2
August 20-21, 2018 | Paris, France
Materials Science and Materials Chemistry
International Conference on
M
agnesium alloys have a similar mechanical strength
and elastic modulus to those of human bones and are
dissolvable in the physiological environment, representing
a new generation of biomaterials for orthopaedic and
cardiovascular applications. However, the alloys lack adequate
strength and corrosion resistance as the implant material. The
present work was carried out to develop an optimum route for
fabricating magnesiummatrix particulate nanocomposites with
controllable strength and degradability. The matrix alloy was
selected with cytotoxicity free alloying elements and minimum
amount of second-phase particles. The reinforcing particles
including biocompatible hydroxyapatite (HA), beta-tricalcium
phosphate and magnesium oxide (MgO) were chosen to
improve strength and corrosion resistance. The composites
were fabricated by combined high shear solidification (HSS) and
severe plastic deformation via equal channel angular extrusion
(ECAE) or conventional extrusion. The cast nanocomposites
obtained by HSS showed a fine and equiaxed grain structure
with the globally uniformdistributionof nanoparticles, although
HA showed the best wetting effect. Both ECAE and conventional
extrusion at 350°C resulted in further microstructural
refinement and the improvement of particle distribution, but
the latter led to a finer grain structure. The microstructure and
particle distribution in the as-cast state and after deformation
processing were characterized by optical and electron
microscopy, EDS and XRD, etc. The mechanical properties were
tested by compression and electrochemical performance was
assessed by static polarization tests. Corrosion behaviour was
studied by immersion tests and electrical impedance analysis.
The detailed experimental results are presented in this paper
together with discussions on the benefits of both HSS and ECAE
and the mechanisms responsible for the enhanced materials
performance.
Speaker Biography
Yan Huang leads metallic biomaterials research at Brunel, working on both traditional
permanent titanium implants and novel biodegradable magnesium medical devices
for orthopaedic cardiovascular applications. He recently won three research grants in
biomaterials research from the Royal Society, EPSRC and European Commission. Huang is a
founding member and co-investigator of the EPSRC Future LiquidMetal Engineering (LiME)
HUBwhereheleadstheactivitiesonprocessdevelopmentandlightalloyprocessinginvolving
bothsolidificationandplasticdeformation.Hehasextensiveexperienceinprocessinnovation
for combined solidification and thermomechanical processing (semisolid forming, twin roll
casting, and integrated cast-forming), solid state joining, severe plastic deformation for light
alloys and light metal matrix composites. He has long-term interests in the characterization
of microstructure and texture evolution during thermomechanical processing and
fundamental issues of strengthening, plastic deformation and grain boundary migration.
e:
yan.huang@brunel.ac.ukYan Huang
Brunel University, UK
Material selection, fabrication and characterization of magnesiummatrix particulate
nanocomposites for biomedical applications