An Overview of Light Metals and Additive
Manufacturing Research at Monash
University
Andrey Molotnikov
Department of Materials Science andEngineering, Monash University
Contact: andrey.molotnikov@monash.edu

Monash University•••

Established in 1958 ~347
students
2015 ~65,000 students
1970 Department of MSE

2
andrey.molotnikov@monash.edu

Department of Materials Science and Engineering• Long history in light metal alloy research• 24 academic staff, very global reach• Strong track record of industrial delivery• Local
Structure'• International• Defense
Processing'
Proper+es'• Spin offs

3

Department of Materials Science andEngineering, Monash University
•

•

•

•
•

FACILITIES: Massive investment in worldclass infrastructure unique to the region(including the Australian Synchrotron, andthe Clayton Precinct…).
BREADTH: Capabilities in many materials
and advanced manufacturing areas(modelling, nanomaterials, alloys,
biomaterials, automotive/aerospace Al, 3D
printing…).
DEPTH: Focused research with world-classexpertise in key areas (e.g. light metals,
additive manufacturing, aerospacematerials, functional materials materials
durability).
DELIVERY: Strong track record of delivering
useful results to industry (internationally).
COLLABORATION: Collaborations aroundthe world.

4

Light metals areas of research

•
•
•
•
•
•
•
•
•

Physical metallurgy
Al, Ti, Mg
Glasses and High entropy alloys
Modelling
Characterisation (structure andproperties)
Corrosion and coatings
FatigueAlloy design
Processing

Light metals capabilities
•
•
•
•
•

Induction melting, arc melting
Extrusion, rolling, SPD (HPT,
ECAP, etc)
Spark plasma sintering
Laser powder processing
HIPing
5

ds.
an
es

Zr
her
erity
on
2%
ile

the geometrical test set-up described in the ISO 14801 standard(compare Fig. 2). Fig. 9 shows implant system (implant-abutment-screw) fatigue test data for Ø 3.3 mm bone level implants
made of Ti–15Zr and Ti-Grade4. These test results indicate alarger scattering than in the previous ﬁgure, which is a result of
testing not only one piece, but an assembled system composedof an implant, a basal screw, an abutment, an occlusal screw, acoping and embedding media. Nonetheless, the calculated test
results show superior fatigue endurance strength of Ti–15Zr
implants compared to those made of Ti-Grade4. The endurance
limit for Ti–15Zr implants has been calculated to be 196 N, while

3D roughness parameters were calculated with msoft Analysis

Light metals alloys for dental application
Example of output• Ti–15Zr alloy• Institut Straumann AG, Basel,
Switzerland

Table 3 – Mean values for yield (YS), ultimate tensile
strength (UTS) and uniform elongation (%) of Ti–15Zr andTi-Grade4, measured for machined and SLA-treated surfaces. Samples are randomly chosen out of one production lot measuring 8 samples each. Bar diameter is 5 mm.
YS (MPa) UTS (MPa) Uniform elongation
(%)

.

4

Grade4 was used as a reference material.

Ti-Grade4, SLA
Ti-Grade4,
machined
Ti–15Zr, SLA
Ti–15Zr, machined

71279
72278

85177
8647116.870.6
6.170.3

Fig. 1 – Different implant designs available with different implants diameters exist in order to suit the various clinicalsituations in the patient's mouth. The dark colored area of the implants has the roughened (SLA-treated) surface and is injournal of the mechanical behavior of biomedical materials 62 (2016) 384 –398
contact with bone, whereas the grey area has a smooth surface and is in contact with soft tissue. Implant diameters Ø areeither 3.3 (not shown here) or 4.1 mm, implants with a grey neck are referred to as soft tissue level (sTL) implants, while theothers are bone level (BL) implants. Both types of implant families have different internal design conﬁguration. S and SP
implants differ only in the height of implant shoulder, whereas the TE implant
exhibitsa morerobust implant shoulder. BL
Available
onlineat www.sciencedirect.com
versus BLT implants differ only in the apical (bottom) part, where the latter has a tapered end. Dashed patterns indicate crosssectional views.

www.elsevier.com/locate/jmbbm

Research Paper

Microstructure and mechanical properties of Ti–15Zr
alloy used as dental implant material
Alexander E. Medvedeva,n, Andrey Molotnikova, Rimma Lapovokb,
Rolf Zellerc, Simon Bernerd, Philippe Habersetzerd, Florian Dalla TorredaDepartment of Materials Science and Engineering, Monash University, Clayton, Victoria 3800, Australia
Institute for Frontier Materials, Deakin University, Geelong, Victoria 3216, Australia
Fraunhofer-Institut für Werkstoffmechanik IWM, 79108 Freiburg, GermanydInstitut Straumann AG, Basel, Switzerlandbcar t ic l e in f o

abs tra ct

Article history:

Ti–Zr alloys have recently started to receive a considerable amount of attention as

Received 20 November 2015

promising materials for dental applications. This work compares mechanical properties

Received in revised formof a new Ti–15Zr alloy to those of commercially pure titanium Grade4 in two surface

2 May 2016

conditions – machined and modiﬁed by sand-blasting and etching (SLA). As a result of

Accepted 4 May 2016

signiﬁcantly smaller grain size in the initial condition (1–2 mm), the strength of Ti–15Zr

Available online 11 May 2016

alloy was found to be 10–15% higher than that of Grade4 titanium without reduction in the

Keywords:

tensile elongation or compromising the fracture toughness. The fatigue endurance limit ofDental implants
Fatigue
Ti–Zr alloy

the alloy was increased by around 30% (560 MPa vs. 435 MPa and 500 MPa vs. 380 MPa formachined and SLA-treated surfaces, respectively). Additional implant fatigue tests showedenhanced fatigue performance of Ti–15Zr over Ti–Grade4.

Microstructure

799726784734

9687269877356.270.5
6.070.7& 2016 Elsevier Ltd. All rights reserved.

SLA (Sand blasting and acid etching)1.

Introduction

1.1.

Ti-alloys used as implant materials

6

6Al–4V (TAV) (also known as Ti-Grade5) is one of the mostwidely used alloys for orthopedic implants (Geetha et al.,2009; Long and Rack, 1998; Ye et al., 2015).

Corrosion of light metals
Example of outputs
Key focus areas are ‘stainless light metals’• Development of corrosion resistant Mg-alloys• Development of corrosion resistant Al-alloys

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PUBLISHED ONLINE: 19 OCTOBER 2015 | DOI: 10.1038/NMAT4435
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Ultra-lightweight alloys with high strength, ductility and corrosion resistance are desirable for applications in the automotive,assur As such, systems 1 nd high r osion and g as use a meet ligh g alloys h and there
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g
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ter fohydr lm for p ccurs rea
g + 2 O + 2e − tials for M thermod oys remain
cus h the adve seo ge n
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as tu
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The alloy is Li-rich and a solute nanostructure within a body-centred cubic matrix is achieved by a series of extrusion,
heatw
hen2016,
are g < 11 10,13 ily in mos 2e ) 12.
r
icnq
2 + 2Or
Cite this: RSC Adv.,
6,
43408
a
e
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r
M
ll
d
ie
e
en
.F
y
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g
ta
r to
to
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nviro unsta
treatment and rolling processes. Corrosion resistance from the environment is believed to occur by a uniform lithium carbonate( ER is anodica erated as urtheramo queous a ac ble 9,10 the widdthebpJ. eR.
n
n
Y.-J.
Wu,
X.-B.
Chen,
G.
Williams,
Scully,T.
Gengenbach
andN. Birbilis*a
effect”H
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ll
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16
al cath nts are w nd highly applicafilm in which surface coverage is much greater than in traditional hexagonal close-packed Mg-based alloys, explaining, is in creases wpolarised sult of th during op tmospher
disso theell beelectrdic
ic envodic
en cir
it ap , the ra e cath
lu
lo
r
o
w
o
ir
e
c
anod tion 15. A ative of ( hThe
te
puse
d
a
u
o
superior corrosion resistance of the alloy.
−
liction has beenic reit(Mg)
nmas engineering materials
magnesium
hampered in part due toof th
ed of light-weight
ex alloysi)icthat a 1 VSHE 11
mean kinetics s such, th a persiste anodic po e partia action b posure in ents, as M
ccoissuea work aims to address the corrosionle their poor corrosion performance.
Thismpa- of Mg by introducing
rela s that th of Mg d corrosi nt catho tential 15 cathodi lancing aqueou g does n

A high-specific-strength and corrosion-resistantmagnesium alloy
Wanqiang Xu , Nick Birbilis , Gang Sha , Yu Wang , John E. Daniels , Yang Xiao
and Michael Ferry *RSC Advances
PAPER• A magnesium alloy containing (at.%/wt%)
30.30/10.95Li, 2.34/3.29Al, 0.039/0.19Zr
and 0.128/0.59Y

Stiﬂing magnesium corrosion via a novel anodic
coating

7

 



Corrosion of light metals

Credit: Prof Nick Birbilis

8

Monash Centre for Electron Microscopy§

Provides advanced instrumentation, expertise and training to conduct specialist
research in advanced electron microscopy and atom probe microscopy;§

The suite of instrumentation can determine the composition, structure andbonding of materials down to the atomic scale;§

Building designed to provide exceptional mechanical, thermal and electromagnetic stability to optimise instrument performance.

www.mcem.monash.edu

9tion and growth of twins. Understanding the structure and chemistry of twint the atomic scale is crucial if we are to properly tailor twins to achieve a new range
operties. We report an unusual phenomenon in magnesium alloys that until now
unlikely: the equilibrium segregation of solute atoms into patterns within fully
races of deformation twin boundaries. This ordered segregation provides a pinning
n boundaries, leading to a concomitant but unusual situation in which annealingrather than weakens these alloys. The findings point to a platform for engineeringd structures through solute atoms. This may lead to new alloy compositions andanical processes.

scale experimental evidence and an understandingof the structure and chemistry of twin boundaries
in alloys.
In contrast with partially coherent interfaces
such as high-angle grain boundaries and symmetrical tilt boundaries with arrays of misfit dislocations, for which segregation of alloying elements
is well established (20–22), fully coherent twinboundaries have low interfacial energies, and solutesegregation in such boundaries is therefore nottwinning modes for plastic deformation. As an expected. We studied this issue using high-angle
REPORTSemerging class of engineering materials,
Mg al- annular dark-field scanning transmission electronloys are less strong than the counterpart alumi- microscopy (HAADF-STEM) to observe the miFig. 1. Periodic segrenum alloys, implying the need for more efficientgation of Gdgrationin variousand segregation of randomly distributed
soluteatoms to fully coherent terraces of deforbarriers in order to impede the motion oftwindisboundaries(TBs).
(A) Schematic
illustrationtwin boundaries in Mg alloys. Solutes
locations and twin boundaries. The controlof mationand (B)[1210]-perspective
consisted of gadolinium (Gd) (which is larger
deformation twinning during thermomechanicalview of a-Mg lattice.
than Mg
processes and applications is a major technical
The {1011}, {1012},
and and represents rare-earth elements thatarearemajor
barrier to the wider application of Mg (7). Twinningblue, alloying additions in many commercial{1013} planes
and purple,
Mgrespecalloys), Zn (which is smaller than Mg and aoccurs predominantly in the 〈1011〉f1012g red,systemtively. (C, E, and G) HAADFmajor alloying element in some commonly used(where f1012g is the twinning plane and 〈1011〉
STEM images showing
Mg alloys),and mixtures of Gd and Zn (table
is the twinning direction in the twinning {1011},
plane), {1012},
andWe also analyzed the experimental observaalthough 〈1012〉f1011g and 〈3032〉f1013g
havetwin S1).
boundaries{1013}(TBs)
in Mg–0.2
atomictions
using first-principles calculations (fig. S1)
also been observed (8–13). The formability,yield% Gd [(C) and (G)] andandcontinuum
estimates and the impact of thestrength, and tension–compression yield-strength
Mg–0.8 atomic % Gd
solutesegregation on mechanical properties using
asymmetry of wrought Mg products are (E)allsolid
in- solution
alloys.
F, and H)compression
Close-ups
tests. Alloy compositions, the preptimately related to twinning; hence, there(D,haveof (C), (E), andaration(G), sche-and testing conditions and characteribeen considerable efforts to gain a fundamental
matically illustrated inunderstanding of the nucleation, growth, andther- zations, and the details of the computations are(I to K). In (B) and (I) to
mal stability of such deformation twins (K),andatoms
of in available
the A layer in the supplementary materials.

An example of outputs

such as twin and grain boundaries
tical role in plastic deformation andy in controlling the formability andproperties of many engineering manotable examples are lightweight(Mg) alloys, which have received
attention for applications leading
iency and green environment (6).
ommonly used metals such as tizirconium (Zr), and zinc (Zn), Mg
onal structure with fewer slip sysose of cubic materials. To readily
oducts requires the activation ofMaterials Engineering, Monash University,
ustralia. 2Department of Mechanical and Aerog, Monash University, Victoria 3800, Australia.
for Electron Microscopy, Monash University,
ustralia.
author. E-mail: jianfeng.nie@monash.edu

www.sciencemag.org

SCIENCEare blue (in the paper
plane) or purple (out of
paper
plane)2013
and yelVOL 340 the24MAY
low (in) or orange (out) in
the B layer. Sample details
are available in table S1.

Microstructural examination of the deformed
samples of all alloys indicated the existence ofmany twins—generally f1012g, but f1011g andf1013g were also present in samples subjected

957

10

Materials Modelling
Development of physically based constitutive models• Phenomenological Models– Large number of fit
parameters– Limited predictive
capability• Physically based Models
Ø Small number ofadjustable parameters
Ø Excellent predictive
capabilities

11Materials Modelling
Process optimisation

Extrusion

Qform 8 Extrusion,www.qform3d.com

Forging12

Materials modeling
Extrusion• Optimisation of extrusion process– Increase productivity– Improve die life
– Quality of the product surface– Different materials (Al, Mg)

13

Definition of Additive Manufacturing• A process of joining materials to make objects from 3D model data,
usually layer upon layer, as opposed to subtractive manufacturingmethodologies.
• Synonyms: additive fabrication, additive processes, additivetechniques, additive layer manufacturing, layer manufacturing, andfreeform fabrication
Designation: F2792 − 12aStandard Terminology for

Additive Manufacturing Technologies1,2This standard is issued under the fixed designation F2792; the number immediately following the designation indicates the year ooriginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.

14

RCAM
Swinburne AMDC

Anatomics

AmaeroMCAMCSIRO Lab22
Renishaw

The Melbourne 3D
Ecosystem
examples

Chisholm
Tasman 3D

MetamorphCG
Objective 3D

Monash Centre for Additive Manufacturing
Prof Xinhua Wu
EOS M280 (x2)
• 400 W fibre laser• Max build: ~ 250 x
250 x 300 mm3• Ni, Ti, Al alloy andsteel powders
Concept Laser X1000R
LaserCUSING®
• 1000 W fibre laser• Largest in world: 400
x 600 x 500 mm3• Ni, Ti, Al alloy andsteel powders

Trumpf TLC 7040 DLD• 4 kW Disk Laser• 5 axis + rotation• 4000 mm x 1500 mm chamber• Programmable spot size (0.2-6 mm)• Blown powder mixing capabilities 16• Local shielding to 10 ppm O2

Design for Additive Manufacturing

Increased'part'complexity

Reduced'part'mass

Credit: Chris Davies,Xinhua Wu, Lee Djumas and Marten Jurg

19

The promise of design

The promise of design

20Design for Additive Manufacturing

Compressor production

Compressor'case'study
Department of Mechanical and Aerospace Engineering

Redesign'#1
Department of Mechanical and Aerospace Engineering

Credit: Chris Davies

21Design for Additive Manufacturing•••

A357 aluminium cast alloy– Al, Si (6.5% - 7.5%), Mg(0.4% - 0.7%)
structural durability, corrosion
resistanceT6 heat treatment (Cast alloy)

Printed compressor redesign
Department of Mechanical and Aerospace Engineering

Credit: Chris Davies and Heng Rao

22

Selective Laser Melting of Aluminium Alloy A357
Density measurement

Rao, S Giet, K Yang, X Wu, CHJ Davies, Materials & Design 109, 334-346, (2016)23

The microstructure & molten pool morphology
of as-SLMed specimen built at 200°C

Rao, S Giet, K Yang, X Wu, CHJ Davies, Materials & Design 109, 334-346, (2016)24

Tensile testing
Influence of SLM process and post heat treatment
Vertical direction

Horizontal direction
As-SLMedDAAs-SLMed

SR & SHTed & Ageing
DA

SHTed & AgeingSR
SR & Ageing

SR & SHTed & Ageing
SHTed & AgeingSR

SR & Ageing

Rao, S Giet, K Yang, X Wu, CHJ Davies, Materials & Design 109, 334-346, (2016)25

Selective Laser Melting of Aluminium Alloy A357
Summary• Optimised SLM process parameters based on density measurement;• Influence of SLM process and post heat treatment on the
microstructure and mechanical properties;• Mechanical property difference in relation to the directionality.

Rao, S Giet, K Yang, X Wu, CHJ Davies, Materials & Design 109, 334-346, (2016)26

Selective Laser Melting
SLM Surface Finish• Highly complex geometries
possible• Near fully dense components(>99.9%)• High value proposition

Credit: Marten Jurg

27

Selective Laser Melting
SLM Surface Finish••••

SLM surface a limiting factor
Some improvement possible
through parameter development
Adhered powder and melt poolfluctuation remain an issue
Surface roughness ∝ angle• Typical Ra 10-60µm

As built surface (vertical)

Credit: Marten Jurg

28

Non-Contact Polishing
Chemical Polishing•

Roughness results in poor
fatigue performance & reduces
effective specific strength• Fatigue crack initiation result of
surface roughness• In simple cases machining
applicable à Complex
geometry prohibitive• Only non-contact methods
applicable•

Titanium alloys corrosion
resistant – limited chemicaltreatment options• Hydrofluoric acid solutions
proven & effective

Marten Jurg, W. Yan, A. Molotnikov, unpublished29

Non-Contact Polishing
HF-HNO3 Polishing

Solution Trials:(a) As-built(b) 10% HF(c) 5% HF + 5% HNO3(d) 5% HF + 10% HNO3
10 minute immersion

Marten Jurg, W. Yan, A. Molotnikov, unpublished30

Non-Contact Polishing
Initial Roughness Reduction••

5% HF and 10% nearstoichiometric optimum –greatest roughness reduction
Very aggressive, greatest
material reduction

Marten Jurg, W. Yan, A. Molotnikov, unpublished31

Non-Contact Polishing
Design Methodology

1. Initial designed geometry
2. As-built geometry
3. Chemically polished result

Credit: Marten Jurg

32

Design for Surface Quality
Design Example• Desired final Ra <6µm
• Desired thickness 1mm• Solution: 5% HF & 10%
HNO3• 3.5 minutes @ 63µm/min =220µm• Design thickness 1440µm

Marten Jurg, W. Yan, A. Molotnikov, unpublished33

Biomedical applications

SURGEON

PLANNING

FEEDBACKCUSTOM DRILL GUIDEFOR ACCURATE DRILLINGCUSTOMISED S

CEMENTED XLPE LINERFOR OPTIMAL

Custom Triflange Shell
HA Coating with Silver Ions
10th July 2015

Acusure Ag® Technology Clinical Case

STERILE TRIAL

USED FOR SIZING & FIT

141-02-0061 Rev A

SURGEON

FEEDBACKSTERILE TRIAL

USED FOR SIZING & FIT

141-02-006

CEMENTED XLPE LINER+ SILVER IONS FOR ANTI-INFECTIONCUSTOMISED SCREW TRAJECTORYCEMENTED XLPE LINERPLANNING

STERILE PACKED IMPLANT
Ti6Al4V WITH HA COATING

4W

FOR OPTIMAL BONE PURCHASECUSTOM DRILL GUIDEFOR ACCURATE DRILLINGSTERILE PACKED IMPLANT
Ti6Al4V WITH HA COATING+ SILVER IONS FOR ANTI-INFECTIONCUSTOMISED SCREW TRAJECTORYFOR OPTIMAL BONE PURCHASEPOST OP

34

Biomedical applications
EXAMPLE Case study: Thumb Phalangeoctahedral
Credit: Ezgi Onal

35

Biomedical applications

•

•
•

•
•

New generation of metallic
orthopaedic implants with
tailored mechanical andbiological properties
Design of functionally gradedstructures
Cell behaviour with Cell line
MG-63 cell line (humanosteoblast cells)
Mechanical Characterization,
Simulation..

Credit: Ezgi Onal, Marten Jurg

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Five symposia focusing onMaterial Science andEngineering– Additive manufacturing– Corrosion– Light metals design– Composite materials– Fatigue and Fracture
Abstract submission: open
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Thank you for your attention!
Questions?
Andrey Molotnikov
Department of Materials Science and Engineering, Monash University
Contact: andrey.molotnikov@monash.edu