Ralph Davidovits

Prof. Christine PélegrisAxel Compere

Indirect 3D-printing of MK-750-based

geopolymer ceramic

Poly(sialate-siloxo) type K-PSS

2016

3D Printing Equipments at the Campus

Stratasys Object30Photopolymer technology

Polypropylene resin

High resolution: 0,028 mm

3DSystems ProJet® CJP 460PlusFull-color 3D printer

2-part materials a core and a colored binder

Good resolution: 0,1 mm

Gypsum 3D printerFast prototyping first generation printer

Gypsum powder hardened with a resin

Medium resolution: 0,3 mm

Low cost

Used for foundry prototyping

Envisiontec Perfactory MicroPhotopolymer technology

High resolution: 0,03 mm

Know-how before 3D and after 3D

Requirements for 3D-printing of MK-750-based geopolymer ceramic

High Fluidity

Good mechanical strength

Easy process

Exempt of air/gaz bubbles

Initial geopolymer preparation process

Metakaolin

Potassium silicate

Filler

Cast the resin

Hardening

Binder

6 Steps in Geopolymer ProcessingAlkalination

Depolymerization of silicates

Gel formation of oligo-sialates

Polycondensation

Reticulation networking

Geopolymer solidification

Mixing (K-Na) silicate and metakaolin

Mixing time and mixing method

Facultative rest period

Starting to harden

Hardening

Testing of 10 commercial metakaolins

Imerys - Newchem - BASF - Argeco

Dehydroxylation of Kaolinite: 2 mechanisms

Calcination at 750°C for MK-750

Al (V) most reactive

Making of metakaolin MK-750

Industrial processing metakaolin MK-750

Credits Imerys

Reactivity test, observing exothermicity see: J. Davidovits, Geopolymer Chemistry and Applications, Chapter 8.

0

27,5

55

82,5

110

0 18 35 53 70

Blank Metaver N Metaver MMetaver I Argical M1000 MetamaxPowerPozz white Argical M1200S Metaver SFMK Red Clay Metastar 501

Testing of 10 commercial metakaolinsT°C

Time (min.)

Exothermicity, reactivity

Oven temperature 80°C

Blank

Metaver SF

Argical M1200S

Metastar 501

PowerPozz

Metamax

Metaver M

Argical M1000

Metaver N

Metaver I

MK-red clay

2016

Fluidity

FluidityTi

me

(sec

onds

)

0

27,5

55

82,5

110

66,33

18,2129,37

101,45

4,92

M1000 M1200 Metamax PowerPoz Metaver SF

2016

Viscosity

ViscosityVi

scos

ity

(cP)

0

2250

4500

6750

9000

4600

12611860

8900

300

M1000 M1200 Metamax PowerPoz Metaver SF

2016

Testing of 6 commercial SiO2 fillers

Silmer, CMMP, Sibelco…

SiO2, Cristobalite, Opal CT, Quartz, ZirconSilicon based, aluminum based, or silico-aluminum based

Compressive and tensile strength

Mineralogy is important for selecting the right material

No inert fillers

Example with quartz

Surface ReactivityTe

nsile

(M

Pa)

0

1,1

2,2

3,3

4,4

StandardSand

SibelcoSand

Influence of fillers

Filler typesTe

nsile

(M

pa)

0

2,5

5

7,5

10

SiO2 =50 micronsSiO2 0-120 micronsZircon < 220 microns

M1200 Metamax PowerPoz Metaver SF

d502016

Testing of 6 commercial additives

Woellner

Betolin plasticizer, wetting agent, hydrophobic…

Additives

Tim

e (s

econ

ds)

0

45

90

135

180

Wetting Hydrophobic Plasticizer

Fluidity

Requirements for 3D-printing of geopolymer ceramic

Easy process: UV photosensitive organic polymer 3D-print

Geopolymer ceramic with:

High Fluidity

Good mechanical strength: tensile 8-9 MPa

Exempt of air/gaz bubbles (additives)

Optimizing the process

Mixing time Mixing method

Resting time ?

Get rid of bubbles / gaz

Setting time Setting temperature

Metakaolin

Potassium silicate

Filler

Cast the resin

Hardening

Geopolymer preparation process

Binder

160 trials carried out in 9 weeks !

Successful Making of 3D-geopolymer ceramic

MK-750 K-silicate Mixing

1h to 24h of rest

1 to 2 % additive

SiO2 filler 75 %

Injection in 3D-mould

Setting at 80°C

Remove the mould

Successful Making of 3D-geopolymer ceramic

Successful manufacture of a complex 3D shape with a low temperature setting geopolymer ceramic

75 MPa compressive strength 7,5 MPa tensile strength

Ceramic Precision / Exactness Easy Process

Acknowledgements

Imerys for Argical M1000 and M1200S metakaolins

Newchem and BASF for other metakaolins

Woellner for Geosil Potassium Silicate and Betolin additives

Silmer for SiO2 fillers, Farsil, Minigrain, Granublanc

CMMP for zircon sand