Powde r flowability Unia xia l c o mpre ssio n te st 1 c 1 : - - PowerPoint PPT Presentation

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Powde r flowability Unia xia l c o mpre ssio n te st 1 c 1 : - - PowerPoint PPT Presentation

Apr 03, 2024 1.02k likes •1.34k views

Powde r flowability at low str e sse s: ball inde ntation Co lin Ha re De partme nt o f Che mic al and Pro c e ss E ng ine e ring , Unive rsity o f Surre y Powde r flowability Unia xia l c o mpre ssio n te st 1 c 1 : pr e -c

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SLIDE 1

Powde r flowability at low str e sse s: ball inde ntation

Co lin Ha re

De partme nt o f Che mic al and Pro c e ss E ng ine e ring , Unive rsity o f Surre y

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SLIDE 2
  • Unia xia l c o mpre ssio n te st

Powde r flowability

2

σ1 σc

σ1

: pr e -c o nso lidatio n str e ss

σc

: unc o nfine d yie ld str e ss = flo w func tio n, ffc

[1} Sc hulze , D., 2007 “Po wd e rs a nd b ulk so lid s: b e ha vio ur, c ha ra c te riza tio n, sto ra g e a nd flo w”, Spring e r

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SLIDE 3

F lowability me asur e me nt

  • Mo re c o mmo nly me a sure d with she a r c e lls

3

σn τ σ1 σ τ σ1 σc

[1} Sc hulze , D., 2007 “Po wd e rs a nd b ulk so lid s: b e ha vio ur, c ha ra c te riza tio n, sto ra g e a nd flo w”, Spring e r

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SLIDE 4
  • Ba ll inde nta tio n2
  • E

la stic a lly de fo rming re g io n pro vide s a dditio na l c o nstra int:

Pr

  • pose d me thod

4

F

max

c

σ

. C H=

( )

2 max max

h Rh 2

π

F A F H

− = =

[2] Ha ssa npo ur, A., Gha d iri, M., 2007 “Cha ra c te risa tio n o f flo w o f lo o se ly c o mpa c te d c o he sive po wd e rs b y b a ll ind e nta tio n”, Partic le & Partic le Syste ms Charac te rizatio n 24, 117-123

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SLIDE 5

Ball inde ntation

  • Ro utine ly use d fo r c ha ra c te rising ha rdne ss o f c o ntinuum so lids
  • C is kno wn fo r me ta ls (~3)3
  • C c a n b e c a lc ula te d fro m ma te ria l pro pe rtie s fo r o rg a nic s & po lyme rs4
  • I

nde nta tio n pro c e dure ha s b e e n e sta b lishe d 5:

  • I

nde nte r size to b e use d fo r a g ive n pa rtic le size

  • Minimum a mo unt o f po wde r ne e de d
  • Be d d ia me te r
  • Be d he ig ht
  • T
  • wha t de pth the inde nt sho uld b e ma de

5

[3] T a b o r, D., 1951 “T he ha rd ne ss o f me ta ls”, Clare ndo n Pre ss [4] Jo hnso n, K .L ., 1985 “Co nta c t me c ha nic s”, Camb ridg e Unive rsity Pre ss [5] Za fa r, U., Ha re , C., Ha ssa npo ur, A., Gha d iri, M., 2017 “Ba ll ind e nta tio n o n po wd e r b e d s fo r a sse ssing flo wa b ility: Ana lysis o f o pe ra tio n wind o w”, Po wde r T e c hno lo g y 310, 300-306.

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SLIDE 6

Inde nte r size

Minimum:

6

0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5 10 15 20 25 30 35 Har dne ss (kPa)

Di/ Dp

[5] Za fa r, U., Ha re , C., Ha ssa npo ur, A., Gha d iri, M., 2017 “Ba ll ind e nta tio n o n po wd e r b e d s fo r a sse ssing flo wa b ility: Ana lysis o f o pe ra tio n wind o w”, Po wde r T e c hno lo g y 310, 300-306.

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SLIDE 7

Be d he ight

Minimum amount of powde r

Be d diame te r

7

1 2 3 4 5 6 7 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Har dne ss (kPa) Di/ Dd

2 4 6 8 10 12 14 25 50 75 100 125 150 175

Har dne ss (kPa) Be d he ight/ Par tic le diame te r

[5] Za fa r, U., Ha re , C., Ha ssa npo ur, A., Gha d iri, M., 2017 “Ba ll ind e nta tio n o n po wd e r b e d s fo r a sse ssing flo wa b ility: Ana lysis o f o pe ra tio n wind o w”, Po wde r T e c hno lo g y 310, 300-306.

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SLIDE 8

Inde ntation de pth

8

5 10 15 20 25 30 35 0.2 0.4 0.6 0.8 1

h/ R

i

Har dne ss (kPa)

[5] Za fa r, U., Ha re , C., Ha ssa npo ur, A., Gha d iri, M., 2017 “Ba ll ind e nta tio n o n po wd e r b e d s fo r a sse ssing flo wa b ility: Ana lysis o f o pe ra tio n wind o w”, Po wde r T e c hno lo g y 310, 300-306.

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SLIDE 9

9

  • I

nde nte r dia me te r ≥ 17 d p

  • Be d dia me te r ≥ 1.5 DI

nd

  • Be d he ig ht ≥ 40 d p
  • Dime nsio nle ss pe ne tra tio n de pth (h/ R

i) ≥ 0.4

Inde ntation pr

  • c e dur

e

Size d50 (μm) Diame te r (mm) Be d he ight (mm) Be d Volume (mm 3) Inde nte r Be d

50 0.85 1.7 2 5 100 1.7 3.4 4 40 200 3.4 6.8 8 300 500 8.5 17 20 4500

[5] Za fa r, U., Ha re , C., Ha ssa npo ur, A., Gha d iri, M., 2017 “Ba ll ind e nta tio n o n po wd e r b e d s fo r a sse ssing flo wa b ility: Ana lysis o f o pe ra tio n wind o w”, Po wde r T e c hno lo g y 310, 300-306.

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SLIDE 10

10

  • Ge ne ra lly we wa nt to kno w the unc o nfine d yie ld stre ss
  • Ne e d to kno w c o nstra int fa c to r
  • Ho w do e s c o nstra int fa c to r va ry with pa rtic le pro pe rtie s?
  • Ca n she a r c e ll da ta b e re lia b ly e xtra po la te d to lo w stre ss?

Mate r ials

  • I

nde nta tio n te ste d fo r wide ra ng e o f po wde rs

  • Sila nise d g la ss b e a ds (va rying size distrib utio ns)
  • F
  • o d po wde rs – swe e te ne r, ma ize sta rc h, pe a pro te in
  • I

no rg a nic po wde rs – lime sto ne , tita nia , ta lc , c o ppe r

Me thods

  • F

T 4 she a r c e ll

  • Ba ll inde nta tio n

De te r mining c onstr aint fac tor

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SLIDE 11

0.5 1 1.5 2 2.5 3 3.5 2 4 6 8 10 12

Unc onfine d yie ld str e ngth (kPa) Major pr inc ipal str e ss (kPa) 45-53 μm 53-63 μm 63-75 μm 75-90 μm 90-106 μm

11

Unc onfine d Yie ld Str e ngth

ffc =1 ffc =2 ffc =4 ffc =10

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SLIDE 12

1 2 3 4 5 6 7 2 4 6 8 10 12

Har dne ss (kPa) Major pr inc ipal str e ss (kPa) 45-53 μm 53-63 μm 63-75 μm 75-90 μm 90-106 μm

12

Har dne ss

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SLIDE 13

13

Constr aint fac tor

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SLIDE 14

0.0 0.5 1.0 1.5 2.0 2.5 3.0 2 4 6 8 10 12

Constr aint fac tor Major pr inc ipal str e ss (kPa) 63-75 μm 53-90 μm 45-106 μm 63-75 μm + 10% <25 μm

14

Size distr ibution e ffe c t

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SLIDE 15

15

Adhe sion to the piston

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SLIDE 16

16

L

  • w str

e ss be haviour

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SLIDE 17

17

Compar ison of te c hnique s

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SLIDE 18

18

She ar ing at low str e sse s

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SLIDE 19

19

F

  • od powde r

s – she ar c e ll

ffc =1 ffc =2 ffc =4 ffc =10

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SLIDE 20

20

Constr aint fac tor

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SLIDE 21

21

Slip- stic k be haviour : pe a pr

  • te in
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SLIDE 22

22

Slip- stic k be haviour : pe a pr

  • te in
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SLIDE 23

23

Slip- stic k: str ain r ate e ffe c t

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SLIDE 24

0.5 1 1.5 2 2.5 3 2 4 6 8 10 12 14

Unc onfine d yie ld str e ngth (kPa) Major pr inc ipal str e ss (kPa) ma ize sta rc h ind ma ize sta rc h

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 0.5 1 1.5 2

Unc onfine d yie ld str e ngth (kPa) Major Pr inc ipal Str e ss (kPa) she a r c e ll b a ll ind e nta tio n

24

Compar ison of te c hnique s - maize

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SLIDE 25

25

She ar ing at low str e sse s

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SLIDE 26

5 10 15 20 25 30 35 5 10 15 20 25

Har dne ss (kPa) Major pr inc ipal str e ss (kPa) tita nia ta lc lime sto ne c o ppe r

26

Inor ganic powde r s

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SLIDE 27

27

Inor ganic powde r s

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SLIDE 28

28

  • F

lo wa b ility c a nno t b e e a sily me a sure d a t lo w stre sse s using she a r c e lls

  • T

a rg e t stre sse s o fte n no t o b ta ine d

  • De te rmine d yie ld lo c us ma y b e inc o nsiste nt
  • Ba ll inde nta tio n c a n pro vide re pro duc ib le me a sure me nts o f flo wa b ility a t

lo w stre sse s

  • Re q uire s c o nstra int fa c to r to b e kno wn (o r de te rmine d)
  • Co nstra int fa c to r fo und to b e inde pe nde nt o f a pplie d stre ss
  • T

ho ug h va rie s (~ 2 – 6) fo r diffe re nt ma te ria ls

  • Re duc e s slig htly with d 50, tho ug h inc re a se s with fine s a dditio n
  • Se ve ra l po wde rs e xhib it sha rp re duc tio n in she a r stre ss a t lo we r stre sse s
  • Be ha vio ur a t hig he r stre sse s c a nno t b e re lia b ly e xtra po la te d

Conc lusions

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SLIDE 29

F utur e wor k

  • DE

M will b e use d to a na lyse C a t lo w stre sse s

  • And influe nc e o f pa rtic le sha pe o n C
  • E

xpe rime nta lly a sse ss de pe nde nc y o f C o n surfa c e e ne rg y

  • A ra ng e o f c o a ting s a pplie d to d iffe re nt b a tc he s
  • I

nve stig a te inde nta tio n a t hig h-stra in ra te s

  • Optimisa tio n o f she a r c e ll pro c e dure a t lo w stre sse s
  • Numb e r o f pre -she a r ste ps a pplie d
  • De fine d e nd po int – i.e a c c e pta b le de via tio n to de fine ste a dy sta te
  • Re q uire d a g re e me nt b e twe e n c o nse c utive pre -she a rs

29

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SLIDE 30

30

Ac knowle dge me nts

Collabor ator s

  • Dr Uma ir Za fa r
  • Dr Ma ssih Pa sha
  • Mr Ale x Sta vro u
  • Pro f. Mo jta b a Gha diri
  • Dr Ali Ha ssa npo ur
  • Mr T

im F re e ma n

  • Dr Ma rty Murta g h