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Lehigh University Lehigh University Lehigh Preserve Lehigh Preserve US-Japan Winter School Semester Length Glass Courses and Glass Schools Winter 1-1-2008 Lecture 9, Part 4: Nucleation, growth and transparent glass- Lecture 9, Part 4: Nucleation, growth and transparent glass- ceramics - Transparent glass ceramics ceramics - Transparent glass ceramics Edgar Dutra Zanotto Federal University of Sao Carlos, Brazil Follow this and additional works at: https://preserve.lehigh.edu/imi-tll-courses-usjapanwinterschool Part of the Materials Science and Engineering Commons Recommended Citation Recommended Citation Zanotto, Edgar Dutra, "Lecture 9, Part 4: Nucleation, growth and transparent glass-ceramics - Transparent glass ceramics" (2008). US-Japan Winter School. 27. https://preserve.lehigh.edu/imi-tll-courses-usjapanwinterschool/27 This Video is brought to you for free and open access by the Semester Length Glass Courses and Glass Schools at Lehigh Preserve. It has been accepted for inclusion in US-Japan Winter School by an authorized administrator of Lehigh Preserve. For more information, please contact [email protected].
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Page 1: Nucleation, growth and transparent glass-ceramics - CORE

Lehigh University Lehigh University

Lehigh Preserve Lehigh Preserve

US-Japan Winter School Semester Length Glass Courses and Glass Schools

Winter 1-1-2008

Lecture 9, Part 4: Nucleation, growth and transparent glass-Lecture 9, Part 4: Nucleation, growth and transparent glass-

ceramics - Transparent glass ceramics ceramics - Transparent glass ceramics

Edgar Dutra Zanotto Federal University of Sao Carlos, Brazil

Follow this and additional works at: https://preserve.lehigh.edu/imi-tll-courses-usjapanwinterschool

Part of the Materials Science and Engineering Commons

Recommended Citation Recommended Citation Zanotto, Edgar Dutra, "Lecture 9, Part 4: Nucleation, growth and transparent glass-ceramics - Transparent glass ceramics" (2008). US-Japan Winter School. 27. https://preserve.lehigh.edu/imi-tll-courses-usjapanwinterschool/27

This Video is brought to you for free and open access by the Semester Length Glass Courses and Glass Schools at Lehigh Preserve. It has been accepted for inclusion in US-Japan Winter School by an authorized administrator of Lehigh Preserve. For more information, please contact [email protected].

Page 2: Nucleation, growth and transparent glass-ceramics - CORE

Transparent Transparent glass glass -- ceramicsceramicsEdgar D. Zanotto

Vitreous Materials Lab

Federal University of São Carlos, Brazil

www.lamav.ufscar.br

Presented at the IMI-NFG US-Japan Winter School , Jan 14, 2008 and Reproduced by the International Materials Institute for Glass for use by the glass research community; Available at: www.lehigh.edu/imi

Page 3: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Page 4: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

OUTLINEIntroduction to glass-ceramicsBrief literature review on TGCPotential applications of TGCConditions for transparencyMature TGC – nanocrystalsNew TGC: Properties

Sintered aluminate GC Opt & MechIR transmitting CG Opt & MechCe: YAG GC for lighting OptLaser crystallized GC OptPTR GC Opt & MechLGHC GC Opt & Mech

Surprise....Conclusions

Page 5: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Glass-ceramic synthesis

Entropy vs. T plotHeat-treatment plot

Page 6: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

INTRODUCTIONINTRODUCTION

GLASS-CERAMICS

controlledcontrolledvolumevolume

crystallizationcrystallization

null porositynull porosity

designeddesignedmicrostructuresmicrostructures::size & shape & size & shape &

uniformuniform grain size, grain size, % % crystallinitycrystallinity, ,

etc. etc.

reproducible reproducible propertiesproperties

optical transparencyoptical transparency

high thermal and chemical stability

tougher than glasses

interesting electricalproperties

Page 7: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

INTRODUCTIONINTRODUCTION

Applications of transparent glass-ceramics

Cooking wareFire resistant platesSecurity windows Telescope mirrors…

saturable absorber media; illumination devices using IR; heat-resistant materials that absorb UV,that reflect infrared and are transparent to visible light; that absorb UV and fluoresce in red/IR;second harmonics generating; substrates for LCD devices; optical amplifiers for up-conver; substrates for arrayed waveguide grating (AWG);radiation sources of lamps; Laser pumps; Laser media; Materials for precision photolithography; ring laser gyroscopes; solar collectors; printed optical circuits; etc.

OpticalOptical((potentialpotential))

Thermo-mechanical

Page 8: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

The inventor of GLASS-CERAMICS

S.D. Stookey discovering GC in the middle 1950s

Page 9: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

LITERATURE REVIEW- PIONEERS OF TGC

STOOKEY,S.D. V Int. Congress on Glass, pp. V/1-8 1959

BORRELLI, N.F. ELECTRO-OPTIC EFFECT IN TRANSPARENT NIOBATE GLASS-CERAMIC SYSTEMSJournal of Applied Physics, 38 (11): 4243 1967

BEALL, G.H.; DUKE, D.A.TRANSPARENT GLASS-CERAMICSJournal of Materials Science, 4 (4): 340 1969

Recent articles in the next slide

Page 10: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

LITERATURE REVIEW (TGC title )YEAR 112 ISI papers1967 1 1969 21978 31982 31984 21985 21986 51987 31988 21993 21994 21995 41996 51998 81999 52000 72001 92002 112003 52004 20

2005 52006 5

Derwent II~90 patents

CorningSchottNipponOthers

0

5

10

15

20

25

1960 1980 2000 2020

30 years

Page 11: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Crystalline phases in TGC

Β−quartz ssΒ-eucriptiteMulliteSpinelWillemiteGhaniteForsteriteβ-BBOLiNbO3NaNbO3PbF2LaF3ZnOEtc.

Most TGC havenanosize crystals &small crystallizedvolume fraction(~ 50% or less)

Page 12: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

THEORYTHEORY

Light attenuation atomic absorption (β)

scattering (S)+ surface reflection (R)

2

2

11

))(exp()1(

⎟⎠⎞

⎜⎝⎛

+−

=

+−−=

nnR

xSRII o β

Reflection losses (%)

02468

1012

1 1.2 1.4 1.6 1.8 2

n

R

scattered lightIncidentlight

reflected light

fluorescence

Transmittedlight

reflected light

Io

Page 13: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

crystal size << crystal size << wavelength of lightwavelength of light

nnglassglass ≅≅ nncrystalcrystal

Basic requirementsBasic requirements

Transparent glassTransparent glass--ceramicsceramics

ConditionsConditions for for transparencytransparency

low birefringence

Page 14: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Examples of commercially mature

TGC

Page 15: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Corning’s VISION

Page 16: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

VLT 8.2 m Zerodur mirror on its way to ParanalObservatory, Chile, Dec. 97/ Schott

Page 17: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

ROBAX – SchottNEOCERAM – NIPPONKERAGLASS- Corning/ St. Gobain CERAN- Schott

.

Page 18: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

NEWTRANSPARENT GC

(yet on the development stage)

Page 19: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Bulk glasses and ultrahard nanoceramics based on alumina and rare-earth oxides by A. Rosenflanz et al. Nature 430, 761 - 764 (August 2004).

a, b: no dopants; c 5wt% Nd2O3; d 5wt% Eu2O3; e 5wt% Er2O3. All except b were hot-pressed at 905 °C at 34 MPa for 360 s.

Material b was hot-pressed for 1,200 s inducing partial crystallization, giving the opalescent appearance.

2 mm tick

50-90% Al2O3

Nd Eu Er

IR transparent

Page 20: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

High alumina glasses and GC

.Hardness against Al2O3 content. High-alumina glasses and glass-ceramics surpass other oxides : BeO, MgO, Y2O3, ZrO2, TiO2, Y3Al5O12, Corning 9606 and 9608 GC, and are comparable to pure a-Al2O3 and b-Si3N4.

These compositions were crystallized directly from the melt during slow cooling.

Ultra hard

Page 21: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

IR transmitting chalco-sulfide glass-ceramics

Ge-Sb-S-Cs-Cl glass withCsCl crystals

X. Zhang et. al. , J. Non-crystalline Solids 337 (2004) 130Lab. glasses and ceramics, University of Rennes, France

Page 22: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Typical microstructure of IR glass-ceramics

Zhang et. al.

100nm CsClcrystals

Page 23: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

IR transmission versus crystallinity

0102030405060708090

100

0.5 1.0 1.5 2.0 2.5 3.0

Wavelength (µm)

Tra

nsm

issi

on (%

)

0 hour3 H7 H23 H31 H73 H144 H246 H

Zhang et. al.

0102030405060708090

100

0 1 2 3 4 5 6 7 8 9 10 11 12Wavelength (µm)

Tran

smis

sion

(%) sample A

sample B

sample A sample B

Page 24: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.brJacques Lucas

Night vision

Page 25: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Resistance to fracture propagation

10 µm 10 µm

Zhang et. al.

GC Glass

Page 26: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Glass-Ceramic for Solid State Lighting - White LED

Ce:YAG-GC

Setsuhisa TanabeKyoto University, Kyoto, Japan

Shunsuke Fujita, Akihiko Sakamoto, Shigeru YamamotoNippon Electric Glass, Otsu, Japan

Presented at the ACerS meeting, Baltimore, April 2005

Page 27: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Solid-State Lighting (future)

Promise of LEDs for illuminationEfficiency Life

Incadescent Light Bulb 16 lm / W 1000hFluorescent Lamp 80 lm / W 10,000hToday’s white LED 60 lm / W 20,000hFuture white LED 200 lm / W 100,000h

Efficiently bright, broad spectrum, long-lifetime…

S. Tanabe et al.

Page 28: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

As-made Cerammed

SEM0

1000

2000

3000

4000

5000

6000

7000

10 20 30 40 50 60

2θ  /  °

inte

nsity

 / 

cps

XRDYAG

60% Crystalinity

(wt%)

YAG20μm

1cm

YAG-GC from glass- microstructure

S. Tanabe et al.

Page 29: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

380 480 580 680 780

wavelength / nm

inte

nsity

/ar

b.un

it

EmissionEmission

t = 0.5mmt = 0.5mmTransmissionTransmission

Moderate transmission of blueModerate transmission of blueYellow fluorescenceYellow fluorescence

a) Ce:YAG GC

a) b)

b) White light emission from Ce:YAG G.C.

10mm 10mm

White lightWhite light

Excitation (460nm)Excitation (460nm)

Transmission.Transmission. EmissionEmission

Ce:YAG G.C.Ce:YAG G.C.

(540nm)(540nm)

Page 30: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Laser crystallization in Nagaoka

Takayuki Komatsu & collaborators(Benino, Ihara, Fujiwara, et al.)

Department of ChemistryNagaoka University of TechnologyJapan

Example: Example: ApplAppl. Phys. . Phys. LettLett., 82 (2003) 892, 83 (2003) 2796., 82 (2003) 892, 83 (2003) 2796..

Page 31: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Laser crystallization in glassLaser crystallization in glass

RareRare--earth (Samarium) atom heat processingearth (Samarium) atom heat processing1. CW 1. CW Nd:YAGNd:YAG laser irradiation to Smlaser irradiation to Sm22OO33 or Dyor Dy22OO33 containing glassescontaining glasses2. Absorption and non2. Absorption and non--radiativeradiative relaxationrelaxation

Irradiated region is heatedIrradiated region is heated Crystallization Crystallization

○○ SmSm22OO33--BaOBaO--BB22OO33 →→ ββ--BaBBaB22OO44○○ SmSm22OO33--BiBi22OO33--BB22OO33 →→ SmSmxxBiBi11--xxBOBO33○○ SmSm22OO33--MoOMoO33--BB22OO33 →→ ββ’’--SmSm22(MoO(MoO44))33○○ SmSm22OO33--KK22OO--PP22OO55 →→ KSm(POKSm(PO33))44

Writing of nonlinear optical/ferroelectric crystal dots and lineWriting of nonlinear optical/ferroelectric crystal dots and liness

Polarization optical microscopePolarization optical microscope

SmSm22OO33--BiBi22OO33--BB22OO33 glassglassSmSmxxBiBi11--xxBOBO33 crystalcrystal

Power: 0.66WPower: 0.66WScanning speed: 10Scanning speed: 10μμm/sm/s

NagaokaNagaoka

20,000 J/cm2

Page 32: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

10Sm10Sm22OO33.35Bi.35Bi22OO33.55B.55B22OO3 glass3 glass

Tg=474Tg=474ooC, C, TxTx=574=574ooCC

Temp. < Temp. < TTxx

crystalcrystal

Refractive index changeRefractive index change

Temp. >> Temp. >> TTxx

5050μμmm

0.6 W0.6 W

0.66 W0.66 W

0.9 W0.9 W

0.8 W0.8 W

SmSmxxBiBi11--xxBOBO33

J. Am. Ceram. Soc. 88 (2005) 989

Komatsu

Page 33: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Laser crystallization in São Carlos

C. A. C. Feitosa, L. J. Q. Maia, A. L. Martinez, A. C. Hernandes, Valmor R. Mastelaro,

IFQSC, University ofSão Paulo, São Carlos, Brazil

Page 34: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

40BaO - 45B2O3 - 15 TiO2 (BBT)

Microstructures from two crystallization processes

BBT GC in resistive furnace at 620oC.

BBT glass after irradiation with CO2 laser (λ= 10.6 μm) 4 min, 40 W/cm2.

= 10,000 J/cm2

Glass at 300oC (Tg = 580 oC)

Mastelaro et. al.

Page 35: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Surface crystallization of BBT glass

5 μm

20 μm

200 μm

10 20 30 40 50 60

Vidros 4% e 15%

# (006)

* (009)* (006)

* (003)

# (006)# (104) 15% de TiO2

4% de TiO2

* BaTi(BO3)2

# β-BBO

Inte

nsid

ade

(u.a

.)

2 θ Graus

It is possible to producepolicrystalline lines.

Details; crystals within the lineand diffraction pattern

Mastelaro et. al.

Page 36: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Laser beamNd:YAG (λ = 1064 nm)

SecondSecond harmonicharmonic generationgeneration

SHG in partially crystallized BBT glass

Mastelaro et. al.

Page 37: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

PTR GlassesOxy fluor bromide glasses

CompositionMajor: SiO2, Na2O, ZnO, Al2O3

Minor: K2O, F, Br

Dopants (~200 ppm): Ag, Ce, Sb, Sn

Impurities ( < 2 ppm): transition metals

S.D. Stookey et al. (1954) – Corning, USAL.B. Glebov et al. (1990) - Vavilov SOI, Russia + Creol/ UCF, USA

Page 38: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Ce3+

Ce4+

e-

PTR glass is a F-Br sodium-zinc-aluminum-silicate glass doped with Ag, Ce, Sn and Sb

Current technology at UCF/CREOL - optical quality PTR glasses with aperture up to 50 mm.

Page 39: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Ce3+

Ce4+

e-

Mechanism of photo-thermo-crystallization

Ce3+

Ce4+

e-hν

Ag+ Ag0

UVexcitation

Photoionization

Valence change

ElectronTrapping

Valence change

LatentImage

Ag0

Ag0

kT

Ag0

Ag0

Ag0

Ag0

Ag0

kT kT

kT kT

kT

Ag0 Ag0

Ag0 Ag0

Silver atomsdiffusion

Growth of Silvernanocrystal

Ag0

Ag0

kT

Ag0

Ag0

Ag0

Ag0

Ag0

kT kT

kT kT

kT

Ag0 Ag0

Ag0 Ag0

Silver atomsdiffusion

Growth of Silvernanocrystal

Na+ F -

Na+

Na+ F -F

-

Na+Na+ F -

Na+F -F

-

F -

kT

Na+

kT

Na+

kT

F -

kTAg0 Ag0

Ag0 Ag0

Silvernucleationcenter

Sodiumfluoridecrystal

3D image (hologram) of object is transformedto the phase pattern (refractive index variations)caused by selective NaF crystal distribution in accordance with the UV intensity distribution in glass interior.

Page 40: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

PTRG (only the active ions are shown) Proposed mechanism of photo induced

crystallization.

Page 41: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

University of Central FloridaSchool of Optics - CREOL Laboratory of Photo-Induced Processes Ce3+

Ce4+

e-

Absorption spectrum of photo-thermo-refractive glass

No detectable absorption in the range of 1 μmAbsorption of hydroxyl in the range of 4 μm

0

0.5

1

1.5

2

0 1000 2000 3000 4000

Wavelength, nm

Abs

orpt

ion,

cm-1 COIL

Nd, Yb, Er1-1.6 μm

DF3.6-4.2 μm

HF2.7 μm

Page 42: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

PTR glasses

Creol’s PTRGHologram

Corning’s Fotalite

Leon Glebov et. al.

S.D. Stookey et. al.

Page 43: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

LARGE GRAIN, HIGHLY CRYSTALLINE, HIGHLY TRANSPARENT GC

T. Berthier, V.M. Fokin, E.D. ZanottoLaMav- Federal University São Carlos, Brazil

Vlad Fokin ThianaBerthier

Page 44: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

STRATEGYSTRATEGY

New type of transparent glass-ceramic

Simultaneous compositional variation

small or large grain size high crystallizedvolume fraction

of solid solution crystals and glassy matrix

decreases Δn

Page 45: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

OPTICAL PROPERTIESOPTICAL PROPERTIES

200 nm – 1100 nm

Estimated parameters (P1 and P2): P1 = (1-R)2

P2 = (β+S)( )xPP

II

210

exp −=

Transmittance measured for different sample thicknesses

Crystal morphology

Grain size

Degree of crystallinity OM

TransmissionSpectra

Page 46: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

MICROSTRUCTURESMICROSTRUCTURES

The crystals are solid solutions: TA4+2xAE4-x[GF6O18] (0 ≤ x ≤ 1)

T = trace element

A = alkali

AE = alkaline earth

GF = Si, P, B

Their morphology can vary from

J,J, spherical tospherical to V8V8, , cubiccubic

Page 47: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

TRANSMITTANCETRANSMITTANCE

Distinct crystal shapes Different transmittances

Best transmittance Cubic crystals

V8, cubic 5-6 μmJ, spherical 7-8 μm

Morphology

crystal/crystal Interfaces are

quite different for spherical and cubic crystals

Page 48: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

TRANSMITTANCETRANSMITTANCE

Crystal size

Importance ofthermal history

* Same crystalline fractionAffects P2

I(λ) dependence

glass J, spherical crystals, ~42% crystallizedGrain size

Page 49: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

TRANSMITTANCETRANSMITTANCE

glass V8glass V8, cubic crystals (3, cubic crystals (3--5 5 μμm)m)Degree of crystallinity

Glass V8 & T6, maximumtransmission for ~ 95-97% OM crystallinity

Page 50: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Glass GC 97% crystallinity 50% crystallinity

The beasts! Transparencyof 4 mm thick specimens

Page 51: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

DISCUSSIONDISCUSSION

alkali content in crystals

30% > glassy matrix

EDS measurements

5 10 15 20 25 30 351.54

1.56

1.58

1.60

1.62

1.64

2

1

glass phase

crystal

n

Alkali oxide, wt%

0,0 0,2 0,4 0,6 0,8 1,010

12

14

16

18

CA, a

t%

α

crystals glassy matrix

Page 52: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

DISCUSSIONDISCUSSION

Main reasons for improvedtransparency in these new TGC

Simultaneous variations of theglass-matrix and s/s-crystal compositions

during crystallization

refractive indexesof crystal and glass

verge

reducedcrystal / glass

interface

High crytallizedfraction

Page 53: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Mechanical behaviour ofHCHTGC

A new, specially designed, method of impact testing!

Page 54: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Impact testing of glassCourtesy of Leo Siiman, Creol/ UCF

Page 55: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Don’t try thisexperiment in your

lab!

Page 56: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Kic versus volume fraction crystallized

23

21

016.0

c

FHEKIC ⎟

⎠⎞

⎜⎝⎛=

c

Anstis

Eglass71 GPa

⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎠⎞

⎜⎝⎛=

−−

φφaH

EH

alkic

52

21

035,0

Nihara

φ~3, a,l,c [um]

Average grain sizefrom 3 to 6 um

Ecr ~105

0 20 40 60 80 100

0.5

1.0

1.5

Kic

(MP

a. m

1/2 )

Fr. cristalizada (%)

Kic Anstis Kic Niihara kic Anstis (Thiana) Kic Niihara (Thiana)

Page 57: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

Why do the transparencyand impact strength drop

significantly for > 97% crystallinity?

Page 58: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

SPONTANEOUS CRACKING for > 97% crystallinity!

accelerated 300X

.

Page 59: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

CONCLUSIONSCONCLUSIONS

New

type of TGC

- highly transparent in the visible ~ 90% for 1mm

- nm to μm grain size

- up to 97% crystallized volume fraction

- chemical durability OK

- good mechanical properties, which canprobably be much improved by ion-exchange.

- can be drawn into fibers

- luminescence ? doping with Cr and

RE ions should be tested...

Page 60: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

On the origem of misterious biomorphsand geoglyphs in Nazca, Peru, 200 B.C.

.

Page 61: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br300 300 μμmm

SmSm22OO33--BiBi22OO33--BB22OO33 glassglassSmSmxxBiBi11--xxBOBO3 3 crystalcrystal

CrystalsCrystals

Bird in Bird in NazcaNazca, Peru, Peru

SHGSHG

Courtesy ofT. Komatsu

Page 62: Nucleation, growth and transparent glass-ceramics - CORE

Vitreous Materials Lab – www.lamav.ufscar.br

VITREOUS MATERIALS LAB, UFSCar, São CarlosBRAZIL

Thank you!