170614 Progress Update WP1 (Laura Cordova Gonzalez)

1. POWDER REUSE FOR ADDITIVE MANUFACTURING
Laura Cordova, Mónica Campos*, Tiedo Tinga
* Universidad Carlos III de Madrid

2. 17/07/2017l.cordovagonzalez@utwente.nl 2
AGENDA
• UPDATE
• INTRODUCTION
• RESULTS & DISCUSSION
• CONCLUSIONS
• NEXT STEPS

3. UPDATE
3

4. 17/07/2017l.cordovagonzalez@utwente.nl 4
UPDATE
• VI Powder metallurgy Conference. Ciudad Real, Spain (6 - 9 June 2017).
Oral presentation and paper submitted: “Powder Characterization and
Optimization for Additive Manufacturing” Laura Cordova1, Mónica
Campos2, Tiedo Tinga1
• EURO PM2017 Conference. Milan, Italy (1 - 5 October 2017). Oral
presentation and paper submitted: “Assessment of Moisture Content and
Its Influence on Laser Beam Melting Feedstock” Laura Cordova1, Mónica
Campos2, Tiedo Tinga1
• Collaboration between University of Twente – University Charles III of
Madrid – IMDEA Materials Institute
1University of Twente (Drienerlolaan 5, 7522 NB Enschede, Netherlands)
2University Charles III of Madrid (Avda. Universidad, 30. 28911 Leganés, Madrid)

5. INTRODUCTION
5

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WHY USE ADDITIVE MANUFACTURING?
TECHNICAL POINT OF VIEW
 Weight reduction though topological optimization
 Relative high complex parts
 No need for specific tooling
 Waste reduction
Metal powder Powder Bed Fusion

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WHY INVESTIGATE POWDER REUSE?
 Waste / Cost reduction: Reusing the powder makes the Additive
Manufacturing process cheaper and more sustainable
 Process repeatability: Powder feedstock and process parameters
determine the predictability
 Parts reliability: Mechanical properties are compromised if the metal
powder does not meet a minimum quality

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POWDER REUSE IN POWDER BED SYSTEMS
Sieve Fill the container
… and continue the process replacing the used powder with new one
Collect powder
Repeat

9. 17/07/2017l.cordovagonzalez@utwente.nl 9
STUDIED POWDER MATERIALS
Nomenclature Alloy system Supplier Machine hours
Inconel 718 Ni, Cr, Fe, Nb+Ta, Mo Oerlikon +++
Ti6Al4V Ti, Al, V LPW Technology +++
Scalmalloy Al, Mg, Sc Airbus APWorks +
AlSi10Mg Al, Si, Mg LPW ++
Virgin
Powders
Re-Used
Powders

10. 17/07/2017l.cordovagonzalez@utwente.nl 10
METAL POWDER CHARACTERIZATION METHODOLOGY
…FOR ADDITIVE MANUFACTURING
1 2 3 4
Distribution size and shape allows to
predict the layer spreading and to
decrease porosity in the final builds.
The powder must have no contamination to
ensure optimal final properties, and
minimum internal porosity for an
homogeneous energy distribution along the
powder bed

11. RESULTS & DISCUSSION
11

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RESULTS & DISCUSSION
Size Distribution
Shape
Composition
Internal Pores
Virgin
Powders
Re-used
Powders

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MORPHOLOGY - SIZE
PARTICLE SIZE DISTRIBUTION
0 20 40 60 80 100
0
20
40
60
80
100
Virgin
Buffer
Volume(%)
Size (µm)
0 20 40 60 80 100
0
20
40
60
80
100
Volume(%)
Size (µm)
Virgin
Buffer
0 20 40 60 80 100
0
20
40
60
80
100
Virgin
Buffer
Size (m)
Volume(%)
0 20 40 60 80 100
0
20
40
60
80
100
Virgin
Buffer
Volume(%)
Size (µm)
Inconel 718
1

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MORPHOLOGY - SIZE
PARTICLE SIZE DISTRIBUTION
0 20 40 60 80 100
0
20
40
60
80
100
Virgin
Buffer
Volume(%)
Size (µm)
0 20 40 60 80 100
0
20
40
60
80
100
Volume(%)
Size (µm)
Virgin
Buffer
0 20 40 60 80 100
0
20
40
60
80
100
Virgin
Buffer
Size (m)
Volume(%)
0 20 40 60 80 100
0
20
40
60
80
100
Virgin
Buffer
Volume(%)
Size (µm)
0 20 40 60 80 100
0
20
40
60
80
100
Virgin
Buffer
Volume(%)
Size (µm)
0 20 40 60 80 100
0
20
40
60
80
100
Volume(%)
Size (µm)
Virgin
Buffer
0 20 40 60 80 100
0
20
40
60
80
100
Virgin
Buffer
Size (m)
Volume(%)
0 20 40 60 80 100
0
20
40
60
80
100
Virgin
Buffer
Volume(%)
Size (µm)
0 20 40 60 80 100
0
20
40
60
80
100
Virgin
Buffer
Volume(%)
Size (µm)
0 20 40 60 80 100
0
20
40
60
80
100
Volume(%)
Size (µm)
Virgin
Buffer
0 20 40 60 80 100
0
20
40
60
80
100
Virgin
Buffer
Size (m)
Volume(%)
0 20 40 60 80 100
0
20
40
60
80
100
Virgin
Buffer
Volume(%)
Size (µm)
Inconel 718 Ti6Al4V
AlSi10Mg Scalmalloy
0 20 40 60 80 100
0
20
40
60
80
100
Virgin
Buffer
Volume(%)
Size (µm)
0 20 40 60 80 100
0
20
40
60
80
100Volume(%)
Size (µm)
Virgin
Buffer
0 20 40 60 80 100
0
20
40
60
80
100
Virgin
Buffer
Size (m)
Volume(%)
0 20 40 60 80 100
0
20
40
60
80
100
Virgin
Buffer
Volume(%)
Size (µm)
1

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MORPHOLOGY - SHAPE
VIRGIN AND RE-USED FEEDSTOCK
Inconel 718
Virgin Re-used
2

16. Ti6Al4V
17/07/2017l.cordovagonzalez@utwente.nl 16
MORPHOLOGY - SHAPE
VIRGIN AND RE-USED FEEDSTOCK
Virgin
2
Re-used

17. AlSi10Mg
17/07/2017l.cordovagonzalez@utwente.nl 17
MORPHOLOGY - SHAPE
VIRGIN AND RE-USED FEEDSTOCK
Virgin
2
Re-used

18. Scalmalloy
17/07/2017l.cordovagonzalez@utwente.nl 18
MORPHOLOGY - SHAPE
VIRGIN AND RE-USED FEEDSTOCK
Virgin
2
Re-used

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MORPHOLOGY - SHAPE
STATISTICAL ANALYSIS
0,70 0,75 0,80 0,85 0,90 0,95 1,00
0,70
0,75
0,80
0,85
0,90
0,95
1,00
Inconel 718
Ti6Al4V
AlSi10Mg
Scalmalloy
fshape
fcircle
𝑓𝑠ℎ𝑎𝑝𝑒 =
𝑚𝑖𝑛𝐷
𝑚𝑎𝑥𝐷
; 𝑓𝑠 ∈ ℚ 0 < 𝑓𝑠 < 1 𝑓𝑐𝑖𝑟𝑐𝑢𝑙𝑎𝑟 =
4𝜋𝐴
𝑃2
; 𝑓𝑐 ∈ ℚ 0 < 𝑓𝑐 < 1
2

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SURFACE AREA
BET METHOD
34 35 36 37 38 39
0,00
0,02
0,04
0,06
0,08
0,10
0,12
0,14
0,16
0,18
Inconel 718 virgin
Ti6Al4V virgin
AlSi10Mg virgin
Scalmalloy virgin
Inconel 718 re-used
Ti6Al4V re-used
AlSi10Mg re-used
Scalmalloy re-used
Surfacearea(m2
/g)
d50 (m)
2

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PHYSICAL PROPERTIES
DENSITY AND FLOWABILITY
Density
Material
ρpycnometer
(g/cm3)
Inconel 718 8.26
Ti6Al4V 4.38
Scalmalloy 2.68
AlSi10Mg 2.65
Virgin Buffer
10
20
30
40
70
80
90
100
Hall(s)
Inconel 718
Ti6Al4V
AlSi10Mg
Scalmalloy
Flowability
Re-used

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COMPOSITION - CHEMICAL
BUFFER MATERIAL: CONTAMINATION
Nitrogen content ~ 8wt%
Inconel 718
Ti6Al4V
3

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COMPOSITION – INTERNAL POROSITY
VIRGIN POWDER
Inconel 718 Ti6Al4V
AlSi10Mg Scalmalloy
4

24. CONCLUSIONS
24

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CONCLUSIONS
 Particle size distribution: Tends to increase with the build jobs
 Morphology: Small changes due to particles sintering and material
sparks
 Composition: there is a risk of contamination when using different
materials in a printer
 Flowability: influenced by the change in morphology, PSD and internal
porosity
 Physical and chemical changes in the reused powder should be
monitored
 Virgin powder is usually added to replace the used material,
therefore feedstock is renewed after a while

26. NEXT STEPS
26

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NEXT STEPS
A- MOISTURE ANALYSIS AND B- MECHANICAL PROPERTIES COMPARISON
 Morphology
 Composition (EDX and LECO)
 Moisture content and Flowability (Hall flowmeter and NLR tool)
 Tensile test ex-situ and in-situ
 Al alloys: AlSi10Mg & Scalmalloy - Dried powders
 Fractography (fracture surfaces)
 Crack propagation
 Electron backscatter diffraction (EBSD)
A
B

28. THANKS FOR YOUR ATTENTION!