Polymer Powders for Laser Sintering - ETH Z · ©2018 inspire AG Agenda - Additive Manufacturing...

©2018 inspire AG

Polymer Powders for Laser Sintering

Manfred Schmid, inspire icams

[email protected]

©2018 inspire AG

Agenda

- Additive Manufacturing and Laser Sintering (LS)

- Market for Polymer Powders

- Essential Powder Properties

- Polyamide 12 (PA12) for LS

- Processing of PA12 (commercial materials)

- Properties influencing process and parts

©2018 inspire AG

Introduction – inspire AG

Competence centre for the Swiss Industry regarding production technique and tooling. Founded on an initiative of ETH-Zürich and machine building industry. Approved as ETH-research annex institute (non-profit foundation).

ETH

inspire Industry

SME

Universities of applied science

Basic R&D Application driven

R&D Technology

Development Product development

Inspire, icams is working with Additive Manufacturing since 20 years

©2018 inspire AG

Introduction – Additive Manufacturing

©2018 inspire AG

Additive Manufacturing – state of the art

Source: Gartner

©2018 inspire AG

Introduction – Laser Sintering (LS)

Invented from Carl Deckard (1986 Univ. Austin (TX))

©2018 inspire AG

Introduction LS powders

©2018 inspire AG

PA12 unfilled

85%

PA12 filled 10%

PA11

others


©2018 inspire AG


Polymer Powders for Laser Sintering

Duraform® PA / Orgasol® invent smooth

©2018 inspire AG

An: Energy per unit area (or volume considering layer thickness)

)( ThicknessLayerSpeedScanSpaceScan

PowerLaserAN

PA 12 Used range:

100 ~ 200 J/cm3

Introduction LS process

©2018 inspire AG

work on DTM 2500plus for best processing, part details and good productivity

part bed temp: 175 C

laser power: 38 W

hatch distance: 0.25 mm

Laser speed: 10 m/s

An = 15 x 10-3 J/mm2

part bed temp: 164 C

laser power: 48 W

hatch distance: 0.15 mm

Laser speed: 10 m/s

An = 32 x 10-3 J/mm2

> < > =

LS process – building parts

©2018 inspire AG

Polymer powders for Laser Sintering


©2018 inspire AG

LS process – mechanical properties

Tensile tests with parts in X-, Z-direction

Charpy tests with parts in X-, Z-direction

Duraform® PA

175 C / 38 W / 0.25 mm

An = 15 x 10-3 J/mm2

Orgasol® invent smooth

164 C / 48 W / 0.15 mm

An = 32 x 10-3 J/mm2

©2018 inspire AG

LS process – mechanical properties

Duraform® PA Orgasol® invent smooth

values from MDS – 3DS inspire values MDS - Arkema inspire values

build direction X Z X Z X Z X Z

Young‘s

modulus

ISO

-52

7

MPa 1586 --- 1677 ± 41

1800 --- 1500 ± 25

max. Tensile

Strength MPa 43 --- 47.6

± 1.5 45 --- 51.7

± 0.7

Elongation

at Break % 14 --- 6.6

± 0.7 20 --- 12.0

± 0.4

Charpy

unnotched

ISO

19

7

1e

U

kJ/m2 --- --- 32.3 ± 2.6

34 --- 34.6 ± 2.0

Charpy

notched

ISO

19

7

1e

A kJ/m2

--- --- 2.0

± 0.5 --- --- 2.6

± 0.5

pronounced loss of mechanical properties in Z-direction for Orgasol® invent


values from MDS – 3DS inspire values MDS - Arkema inspire values

build direction X Z X Z X Z X Z

Young‘s

modulus

ISO

-52

7

MPa 1586 --- 1677 ± 41

1611 ± 61

1800 --- 1500 ± 25

1580 ± 21

max. Tensile

Strength MPa 43 --- 47.6

± 1.5

40.6 ± 3.4

45 --- 51.7 ± 0.7

29.3 ± 3.6

Elongation

at Break % 14 --- 6.6

± 0.7

3.7 ± 0.6

20 --- 12.0 ± 0.4

1.9 ± 0.3

Charpy

unnotched

ISO

19

7

1e

U

kJ/m2 --- --- 32.3 ± 2.6

10.2 ± 2.0

34 --- 34.6 ± 2.0

2.8 ± 0.7

Charpy

notched

ISO

19

7

1e

A kJ/m2

--- --- 2.0

± 0.5

2.1 ± 0.1

--- --- 2.6 ± 0.5

1.3 ± 0.2

©2018 inspire AG

LS process – surface characterisation

GelSight® for fast and reliable surface characterisation in mm- and µm-range

Duraform® PA


©2018 inspire AG

LS process – surface characterisation

top surface bottom surface upright surface

Dura

form

® P

A

Org

asol®

inv s

mooth

MountainsMap® Imaging Topography 7.3.7690

Orgasol Flat Bottomface

Surface Investigation Gelsight Magnification 3xPrimary surface; S1-nesting index (ni) = 0.008 mm

SF surface; F-operator = poly. degree 6; S1 = 0.008 mm

0 1 2 3 4 5 6 7 mm

mm

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

µm

0

10

20

30

40

50

60

70

80

90

I SO 25178

Height Parameters

Sq 7.67 µm

Ssk 0.410

Sku 5.34

Sz 97.1 µm

Sa 5.96 µm

Spatial Parameters

Sal 0.163 mm

Str 0.923

Std 50.7 °

Hybrid Parameters

Sdq 0.403

Sdr 6.47 %

Feature Parameters

Spd 32.7 1/mm²

S10z 64.3 µm

Other 3D Parameters

Miscellaneous

Sdar 40.2 mm²

Spar 37.8 mm²

I SO 12781

Flatness Parameters

FLTt 28.5 µm

FLTp 18.3 µm

FLTv 10.2 µm

FLTq 3.37 µm

1

10

100

1000

10000

100000

0.01 0.1 1 mm

I nformation

Method Enclosing boxes

Parameters Value

Fractal dimension 2.39

Scale of analysis

Num

ber

of

encl

osi

ng b

oxes

0°

10°

20°

30°

40°

50°

60°70°

80°90°100°110°

120°

130°

140°

150°

160°

170°

180°

Parameters Value Unit

Isotropy 92.3 %

First Direction 33.8 °

Second Direction 90.0 °

Third Direction 0.202 °

µm

0.000

97.146

24.286

48.573

72.859

0 20 40 60 80 100 %

0 5 10 15 20 25 %


Orgasol Lying Topface



0 1 2 3 4 5 6 7 mm

mm

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

µm

0

50

100

I SO 25178

Height Parameters

Sq 16.7 µm

Ssk 0.399

Sku 3.64

Sz 148 µm

Sa 13.0 µm

Spatial Parameters

Sal 0.142 mm

Str 0.871

Std 84.7 °

Hybrid Parameters

Sdq 0.532

Sdr 10.6 %

Feature Parameters

Spd 13.8 1/mm²

S10z 113 µm

Other 3D Parameters

Miscellaneous

Sdar 41.8 mm²

Spar 37.8 mm²

I SO 12781

Flatness Parameters

FLTt 37.7 µm

FLTp 21.3 µm

FLTv 16.4 µm

FLTq 6.04 µm

10

100

1000

10000

100000

0.01 0.1 1 mm

I nformation


Parameters Value


Scale of analysis

Num

ber

of

encl

osi

ng b

oxes

0°

10°

20°

30°

40°

50°

60°70°

80°90°100°110°

120°

130°

140°

150°

160°

170°

180°


Isotropy 87.1 %



Third Direction 116 °

µm

0.000

147.644

36.911

73.822

110.733

0 20 40 60 80 100 %

0 5 10 15 %


Orgasol Standing



0 1 2 3 4 5 6 7 mm

mm

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

µm

0

50

100

150

I SO 25178

Height Parameters

Sq 20.1 µm

Ssk -0.105

Sku 2.76

Sz 150 µm

Sa 16.3 µm

Spatial Parameters

Sal 0.113 mm

Str 0.0448

Std 90.0 °

Hybrid Parameters

Sdq 0.546

Sdr 10.9 %

Feature Parameters

Spd 11.5 1/mm²

S10z 96.8 µm

Other 3D Parameters

Miscellaneous

Sdar 41.9 mm²

Spar 37.8 mm²

I SO 12781

Flatness Parameters

FLTt 44.4 µm

FLTp 19.7 µm

FLTv 24.7 µm

FLTq 9.14 µm

10

100

1000

10000

100000

0.01 0.1 1 mm

I nformation


Parameters Value


Scale of analysis

Num

ber

of

encl

osi

ng b

oxes

0°

10°

20°

30°

40°

50°

60°70°

80°90°100°110°

120°

130°

140°

150°

160°

170°

180°


Isotropy 4.48 %




µm

0.000

150.182

37.546

75.091

112.637

0 20 40 60 80 100 %

0 2 4 6 8 10 12 %MountainsMap® Imaging Topography 7.3.7690

PA12 Lying Bottomface



0 1 2 3 4 5 6 7 mm

mm

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

µm

0

50

100

I SO 25178

Height Parameters

Sq 17.8 µm

Ssk -0.295

Sku 3.04

Sz 143 µm

Sa 14.2 µm

Spatial Parameters

Sal 0.142 mm

Str 0.866

Std 86.2 °

Hybrid Parameters

Sdq 0.568

Sdr 11.7 %

Feature Parameters

Spd 15.2 1/mm²

S10z 117 µm

Other 3D Parameters

Miscellaneous

Sdar 42.2 mm²

Spar 37.8 mm²

I SO 12781

Flatness Parameters

FLTt 41.1 µm

FLTp 20.3 µm

FLTv 20.8 µm

FLTq 6.60 µm

10

100

1000

10000

100000

0.01 0.1 1 mm

I nformation


Parameters Value


Scale of analysis

Num

ber

of

encl

osi

ng b

oxes

0°

10°

20°

30°

40°

50°

60°70°

80°90°100°110°

120°

130°

140°

150°

160°

170°

180°


Isotropy 86.6 %


Second Direction 146 °


µm

0.000

142.804

35.701

71.402

107.103

0 20 40 60 80 100 %

0 5 10 15 %


PA12 Lying Topface



0 1 2 3 4 5 6 7 mm

mm

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

µm

0

50

100

150

I SO 25178

Height Parameters

Sq 19.6 µm

Ssk -0.026

Sku 3.12

Sz 172 µm

Sa 15.6 µm

Spatial Parameters

Sal 0.175 mm

Str 0.887

Std 55.3 °

Hybrid Parameters

Sdq 0.552

Sdr 11.0 %

Feature Parameters

Spd 10.6 1/mm²

S10z 147 µm

Other 3D Parameters

Miscellaneous

Sdar 41.9 mm²

Spar 37.8 mm²

I SO 12781

Flatness Parameters

FLTt 48.0 µm

FLTp 24.2 µm

FLTv 23.9 µm

FLTq 8.48 µm

10

100

1000

10000

100000

0.01 0.1 1 mm

I nformation


Parameters Value


Scale of analysis

Num

ber

of

encl

osi

ng b

oxes

0°

10°

20°

30°

40°

50°

60°70°

80°90°100°110°

120°

130°

140°

150°

160°

170°

180°


Isotropy 88.7 %




µm

0.000

172.000

43.000

86.000

129.000

0 20 40 60 80 100 %

0 5 10 15 %


PA12 standing part (90deg)



0 1 2 3 4 5 6 7 mm

mm

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

µm

0

50

100

150

I SO 25178

Height Parameters

Sq 24.3 µm

Ssk -0.0963

Sku 2.98

Sz 197 µm

Sa 19.4 µm

Spatial Parameters

Sal 0.155 mm

Str 0.0413

Std 3.00 °

Hybrid Parameters

Sdq 0.604

Sdr 13.1 %

Feature Parameters

Spd 8.36 1/mm²

S10z 150 µm

Other 3D Parameters

Miscellaneous

Sdar 42.7 mm²

Spar 37.8 mm²

I SO 12781

Flatness Parameters

FLTt 70.3 µm

FLTp 37.0 µm

FLTv 33.2 µm

FLTq 11.1 µm

10

100

1000

10000

100000

0.01 0.1 1 mm

I nformation


Parameters Value


Scale of analysis

Num

ber

of

encl

osi

ng b

oxes

0°

10°

20°

30°

40°

50°

60°70°

80°90°100°110°

120°

130°

140°

150°

160°

170°

180°


Isotropy 4.13 %




µm

0.000

196.787

49.197

98.394

147.591

0 20 40 60 80 100 %

0 5 10 15 %

Sq = 19.0 μm

Sa = 15.6 μm

Sq = 16.7 μm

Sa = 13.0 μm

Sq = 17.8 μm

Sa = 14.2 μm

Sq = 24.3 μm

Sa = 19.4 μm

Sq = 7.7 μm

Sa = 6.0 μm

Sq = 20.1 μm

Sa = 16.3 μm

Sa and Sq are the Average Roughness and Root Mean Square

Roughness are evaluated over the complete 3D surface respectively.

©2018 inspire AG



Summary 1

©2018 inspire AG

Arkema


3D Systems

Duraform® PA

Evonik (Vestosint®) Arkema (Orgasol®)

Production: Precipitation Production: Polymerisation

LS Materials – powder production


µm

DuraForm® PA

µm

©2018 inspire AG

Eρ = LP / HS*v (J/mm2)

∑Porosität (SLS) = 4% - 6%

Orgasol® i.s.

Duraform® PA

LS parts – microstructure and porosity

©2018 inspire AG

LS Materials – thermal behavior

melting

crystallisation

pro

cess

win

dow

Dtmax =4ºC 97% area Dtmax =10ºC

©2018 inspire AG

C

H O

N

(CH2)11

Lauryllactam

+ H2O

n

PA 12 (open chain ends)

H2N COOH

n

PA 12 (blocked chain ends)

X X

LS Materials – molecular properties

polymerisation of polyamide 12 (PA12)


Duraform® PA

post condensation during SLS processing

increasing chain length

increasing melt viscosity

= reactive end groups -NH2 and -COOH MVR values (235 C / 2.16 kg):

Orgasol® IS:

remain at about 15 cm3/10 min

Duraform® PA:

reduction 60 20 cm3/10 min

©2018 inspire AG

Chemical equilibrium depends on Δp and T

SLS provides best conditions for ‘successful’ post condensation

T > 100°C; dry N2 atmosphere drying chamber!

H2O

(CH2)11

n

OH C

O

H

H

N (CH2)11

m

OH C

O

H

H

N

(CH2)11

n+m

OH C

O

H

H

N +

+

T, t, ΔpH2O Kp,T = [chain(m+n)] H2O

[chain(m)] [chain(n)]


©2018 inspire AG

mirror Laser

SLS building chamber

powder

new part

top layer

3rd layer

2nd layer NH2

COOH

NH2

CONH

COOH CONH

NH2

COOH

Inter-layer bonding intra-layer bonding

low melt viscosity

at process start

post condensation

of powder (aging)


unwanted

©2018 inspire AG


production precipitation direct polymerisation

Particle shape „potato“

compromise regarding

flowability

spherical

more detailed parts

better part surfaces

Thermal situation larger Sintering window

easier processing

crystal size and structure!

needs more stable temp.

situation during processing

thermal problems

Powder distribution broad (bimodal) narrow

high powder flowability

better powder density

PA12 chain ends

(termination)

open

easy flowing melt

enhanced properties due

to „post condensation“

blocked

less powder „aging“

(economy)

mechanical

properties

more homogenous in all

directions

pronounced drop in z-

direction

Summary 2

Polymer Powders for Laser Sintering - ETH Z · ©2018 inspire AG Agenda - Additive Manufacturing...

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