Selective Laser Melting

Selective Laser Melting
Developemts in SLM Equipment
and
d Processes
P
Dr Chris Sutcliffe R+D Director MTT Technologies
Group
Outline
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Introduction
SLM process
Typical characteristics
Various applications
Validation
F t
Future
platforms
l tf
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Locations
SLM Technology Center - Stone - United Kingdom
MTT Technologies
Whitebridge Way,
Whitebridge Park, Stone,
Staffordshire ST15 8LQ.
England
Tel: +44 (0)1785 815651
Fax: +44 (0)1785 812115
Locations
SLM Technology Center - Lübeck - Germany
MTT Technologies
Roggenhorster Strasse 9 c
D- 23556 Lübeck
Germany
Tel. +49 451/16082- 0
Fax.+49 451/16082 – 250
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SLM timeline
1995-1998
1995
1998
1998-2002
200220042004
2006 2008-
Basic Research F&S and Fraunhofer
ILT, University of Liverpool, University of
Texas
F&S Research leading to IP
F&S / MCP partner to develop, produce
and market the MCP Realizer
L
Launch
h off SLM R
Realizer
li
250
Launch of SLM Realizer 100
MTT/3DS partner to launch the
machines in the USA
SLM timeline
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SLM timeline
SLM process characteristics
• SLM is a cyclic process consisting of
– The application of thin powder layer
– exposure of the powder bed to laser beam
– lowering of the build platform
• Typical deposition rates of 5 – 30 cm³/h
• Typical powder particle size of between 10 and 50µm
• Laser powers of 200W and up to 400W (more of this
later)
• High
Hi h degree
d
off geometric
t i freedom
f d
similar
i il to
t SLA
• Fully automated one-step manufacturing (more of this
later)
• Ability to process reactive powders
• Very good levels of powder recyclability
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SLM process characteristics
Properties of typical parts
Surfaces
Strength
Accuracy
Rz  30 µm
Typically as good
as parent
± 25µm in 100 mm
Residual Stress
Density
Hardness
Preheated powder
up to 99.9 %
up to 54 HRC
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Typical parts
Ti Al6 V4
Inconel 625
1.4404
Al Si12 Mg
Typical uses
Heat sinks have been
designed and tested
for avionics cooling
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Typical uses
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Material:
1.2344
1 2344 tool steel
Dimensions:
170 x 46 x 18 [mm]
Layer thickness:
75 µm
Build time:
48 hours
Post treatment:
Manual polishing
Typical uses
• Considerable reduction
of cycle time
• Ideal design of size,
form and function of
cooling channels
• Quality improvement of
injection moulding
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Typical uses
• Mounting of four prefabricated cores on building
platform
• Precise individual
positioning of layer data to
mounted cores
• Economic hybrid
manufacturing
• Interface between Rapid
Manufacturing /
Conventional Tooling
Typical uses
• Up to 80 parts can be produced
in one run
• Customised parts can be
produced
• Very good surface finish in many
materials including CoCr,
CoCrMb, CpTi, Ti6Al4V and Ti6
Al4Nb
• Noble metals can be produced
• Low cost equipment is entering
the market
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Not so typical uses
Trabecular lower jaw implant
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Dense skull plate
Patient
P ti t specific
ifi geometries
ti
Specialist alloysTiAl6Nb7 in this case
Incorporation of surgical fixtures
Structured bone integration surfaces
Bone-Implant modulus matching
Not so typical uses
Source: Royal Perth Hospital, Australia
• Following a severe climbing accident
th patient
the
ti t was given
i
a THR which
hi h
was revised a number of times until
further revision was impossible
• 3D X-ray and computer tomography
allowed analysis of existing patient
bone
• Models were made of the geometry
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Customised SLM implants
Source: Royal Perth Hospital, Australia
• Cage designed to fit
bone and give proper
screw placement
• Results :minimum
removal of healthy bone
structure and reduction
of operation time
Customised SLM implants
Source: Royal Perth Hospital, Australia
• Analysis of 3d data set,
automatical generation of
pp structures
support
• SLM building of the cage
• with 0.05 mm thin layers
(TiAl6Nb7 or TiAl6V4)
• Finish of the cage
• (removal of supports)
• SLM + Finish < 2 days
• Courier cage to Perth
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Customised SLM implants
Source: Royal Perth Hospital, Australia
• Analysis and sterilisation of
built prostheses
• Preparation of the patient
• No fitting required during
operation due to custom
cage
• Insertion and screwing of the
cage
g made of TiAl6Nb7
• Operation time reduced to 2
h compared to 3 h with
standard prostheses
Smart structures
Density gain by
improved melting
strategy, D>99,8%
Helium leakage
test fulfilled up to
6x10-10 mbar
UHV compatible!
Material: 1.2344 tool steel
2 mm
• density gain by
improved melting
strategy,
D>99.9%
• helium leak test
fulfilled up to
6x10-10 mbar
• UHV compatible
• simultaneous
growth of dense
and porous
regions
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Smart structures
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Lightweight parts
Medical implants
Thermal management parts
Substitution of solid mass to
boost production
Engineered materials
Actuation
SOME
Smart EXAMPLES
structures
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Current materials
Material name
Material type
Typical applications
Stainless Steel
1.4404 (316L)
stainless
t i l
steel
t l
functional prototypes
Tool Steel
1.2344 (H13)
tool steel
Injection moulding tooling; functional
prototypes
CpTi
Commercially
Pure Titanium
Implants and medical devices
Ti64
Ti6Al4V
Implants and high performance
functional components
Ti6Al7Nb
Ti6Al7Nb
Implantable devices
Aluminium
Aluminum
Silicon Alloy
Functional prototypes and series
parts;
Cobalt Chrome
CoCrMo
superalloy
Functional prototypes and series
parts; medical, dental
Previous equipment
SLM 100
• Build volume:
• 125 mm Ø x 70 mm
• Layer thickness:
• 20 µm – 50 µm
• Fiber Laser 50 W or
100 W
30 100 µm
• Spot size: 30–
• Build speed: up to 70
tooth caps per shift
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Previous equipment
• Build volume 250 x
250 x 210mm
• Build speed: 5 cm3 –
30 cm3 per h
• Layer thickness: 30
µm – 100 µm
• Fiber Laser:100 W –
400 W
W, cw
• Laser spot size: 80
µm – 250 µm
Current
equipment
Future equipment?
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Custom build volumes
Thinner layer thickness 10 µm – 100 µm
Higher laser power 100 W – 1kW W, cw
Smaller spot size 50 µm – 2500 µm
Smater materials delivery
Better build atmospheres (sub 100ppm O2)
Paletised substrates and removable build units
Rugedised for the shop floor
Simple controlled user interfaces
Beam monitoring (now please)
Powder handling
HAZOP as standard
Verifification as standard
Data logging as standard
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Current
equipment
Future machine
SLM XXX
So
what?
Future
machine SLM XXX
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Validation
Validation Documentation Relationships and Sequences
User requirement specification
Functional Specification
Design specification
Performance qualification
Operational qualification
Installation qualification
Acceptance testing and commissioning
•
The problem is that few if any of our RM
machines have been fully validated for full production
of parts...this is particularly true if one considers
highly stressed or sensitive environments parts
Likely issues- data
Is the design correct and controlled
• Does it comply with specifications, regulations and standards
• Was the movement of the design into the manufacturing phase monitored
• Were typical
yp
manufacturing
gp
protocols followed
Did you check the CAD data
• Are you sure you are making the right thing and the correct revision
• What if you are making customised components
• Have you taken steps to identify parts
Did you check the manufacturing data
• The data not just for the overall geometry but also for the layer data must be checked at the very
minimum you must have a level of confidence that it is correct
• It will be one of the first things a accident investigator will ask
Are your processes robust
• Was it sliced at the right layer thickness have the correct processing parameters been assigned
• Are the shop floor practices correct were the protocols followed
Are the above documented and portable
• Do you have an RM/PLM system in place
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Likely issues- machine
Material properties
•Variation in material properties in the x/y/z direction is not acceptable full stop…lets not even bother having
the argument I don’t care if you think you can design for it…you can’t.
Property variation on a machine
•This is not acceptable the only property variation on a machine that is acceptable is random variation and this
should be minimised.
Parameter variation between machines
•All machines of a particular design must have the same machine parameters how else can you procreate and
maintain validation.
Temporal Instability
•Machines must be stable over time and they must be able to detect when they are outside limits…assuming
those limits have been defined
Machine reliability
•Will your machine stand up to production
•Will it do its job day in day out for 10 plus years
Is the user interface simple enough
•I want to drag someone in off the streets and get them to press go I do not want to employ PhD’s to work in
my factory
Collection and storage of manufacturing data
•Is the manufacturing data logged
•Is it stored (75 years!)
Some Examples
The tensile strengths of
samples are shown
across 4 builds you can
see the same
characteristics on each
build. It is clear this is
NOT a random process
variable…do you accept
the parts…what if you
part spans
p
p
the whole
bed…how do you design
that out…
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Some Examples
The compressive strength
of samples are shown
across 4 builds on two
different machines at the
same machine settings you
can see one build is
significantly weaker than
the other. …do you accept
the machines knowing full
well that you will have to
validate them separately
Some Examples
EVERY LAYER PLEASE…its
not good enough to build
test samples by each part
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Some Examples
Thought I’d better put some stuff in
on lasers
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The Future for Additive Manufacturing
Did I say I was going to give you a look at the future
• Sorry to disappoint it seems I’m
I m not quite as clever as I thought! …here
here
are some guesses
RM/PLM/MRP/whatever 3 letter acronym you care to choose
• Data handling and portability of this data is key
Material handling
• Come on powder filled workspaces must be stopped…contamination of
us and our parts is unacceptable
Machine performance
• Stronger faster more repeatable and whilst your about it make them
easier to use
• Make them validatable please
Can we do it now?
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THANKS FOR LISTENING
I was going to write some
conclusions but to be honneset I
guessed either you’d have seen
enough of me by now or I’d have run
out of time.
If you need any further information
contact me on.
csutcliffe@mtt-group.com
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