O56-THERMODYNAMIC PROPERTIES AND PHASE EQUILIBRIA IN …tofa2010/Apresentacoes_TOFA2010/O56... ·...

THERMODYNAMIC PROPERTIES AND PHASE EQUILIBRIA IN THE TERNARY Ag-Sn-Sb SYSTEM

TOFA 2010DISCUSSION MEETING ON THERMODYNAMICS OF ALLOYSPORTO, PORTUGAL12-16 SEPTEMBER 2010

12-16 September 2010 TOFA 2010 - PORTO 1

Joanna Łapsa, Bogusław Onderka

Laboratory of Physical Chemistry and Electrochemistry, Faculty of Non-Ferrous Metals, AGH University of Science and Technology,

30 Mickiewicza Ave., 30-059 Kraków, Poland

Keywords: thermodynamics, ternary system, silver alloys, galvanic cell, e.m.f.

Motivation:

The meso-scale approach in frame COST Action MP0602:Investigation of Pb-free replacements for high-Pb solders for high-temperature applications.

� Tasks:Determination of the thermodynamic properties of ternaryDetermination of the thermodynamic properties of ternaryAg-Sn-Sb alloys.

�Methods:Electrochemical studies (E.M.F – components activity in liquidsolution), CALPHAD method (optimization of ternary systems -the set of model parameters)


, J/

mol

-1000

0

1000

2000

Concentration dependence of ∆HM of liquid Ag-Sb

Probability of propagation of such characteristic over all systemconcentrations.

The enthalpy of mixing, ∆HM,

of liquid Ag-Sb solutions

Ag SbXSb

0.0 0.2 0.4 0.6 0.8 1.0

∆∆ ∆∆HM

, J/

mol

-5000

-4000

-3000

-2000

-1000

Hultgren - 1248 KPredel - 1273 KCastanet - 1300 KCalculated


of liquid Ag-Sb solutions

at 12480C, 12730C and 1300 K.

Temperature dependence of ∆HM of liquid Ag-Sn

Integral enthalpy of mixing

H.Flandorfer et al., J. Non-Crystalline Solids, 354, 2953–2972 (2008)

in liquid Ag-Sn solutions


Ag

Experimental enthalpy of mixing for liquid Ag-Sb-Snalloys

Gather, B; Schroter, P; Blachnik, R, The Enthalpies of Mixing in the Liquid State of the Ternary Systems Ag-In-Sn, Ag-Sn-Sb, Ag-In-Sb and In-Pb-Sb, Z. Metallkd. , 78(4), 280-285 Apr. (1987)


Ag

Sn

Schematic representation of experimental cross-sections of Ag-Sb-Sn diagram

AgSb


Experimental method

The galvanic cell e.m.f. measurements of liquid Ag-Sb- Snalloys

Kanthal+Re, Ag-Sb-Sn, SnO 2 | Yttria Stabilized Zirconia | Ni+NiO, Pt

• experimental temperature range: 973-1223 Kframed by liquid solution existence and of the possible evaporation of more volatile components


Schematic representation of the sample electrodecompositions in the Ag-Sb-Sn diagram

• three cross-sections with constant Ag/Sb ratio equal to:


to: 1/3, 1 and 3/1

•• tin compositions ranging

every 10%, from 10% up to 80 at.% Sn.

Gas inlet

Gas outlet

O-ring

CapillaryAl 2O3 Scheme of an experimental assembly

EMF method of galvanic cell with YSZ electrolyte

Filter

Quartz tube

TermocouplePt/PtRh10

Resistancefurnace

Scheme of a galvanic cell

Electrolyte YSZ

Temperature controller

Ar

Data acquisitionsystem


YSZelectrolyte

(-)Kanthal, Re Ag-Sb-Sn(l),SnO 2(s) ZrO2-Y2O3 Ni(s), NiO(s) Pt (+)

Schematic representation of solid electrolyte cell

(+) 2 NiO 2 Ni + O 2 – 4e-

(-) Sn + O2 SnO2 + 4e-

Ni+NiO(s)powdermixture

Rhenium tip

Kanthalwire

Pt wire

SnO2 pellet

Ag-Sb-Snliquid alloy

2

2

=ref

O

O

RTE ln

4F

P

P

2

refOP 2OP


The check of tie line status

(1)

Sb2O3

O

SnO2

2 x y

yx Me O Me O

2+ =

2

0, ln ln

2x yf Me O OMeay

G x RT RT p∆ = ⋅ + ⋅

aMe - activity of metal which

2 2 33SnO 4Sb 2Sb O 3Sn+ ⇔ +Cu

SnSb

Ag

Schematic representationof Ag-Sb-Sn-O system


aMe - activity of metal whichforms MexOy oxide

(2)

Sn + O2 = SnO2 (3)

from standard Gibbs energy change of reaction (1) and

Total galvanic cell reaction

relation between e.m.f. of concentration cell and Sn activity:

2 2

0 reff,SnO Sn O4F E G RT ln a RTln p− ⋅ = ∆ − −


Ni+NiO reference state and the check of tie line status

700-950 0C

2Ni + O2 = 2NiO

Sb2O3

Sn + O2 = SnO2

4/3Sb + O2 = 2/3Sb2O3


10-12

10-16

Exchange reaction test

2 2 33SnO 4Sb 2Sb O 3Sn+ ⇔ + (2)


Thermal equilibration: 24 hours

• I sample at 8000C

• II sample at 9000C

Point and area analysis EDX analysis of metallic part of Sb+SnO2 sample

The check of tie line status - results

8000C


9000C

The check of tie line status - results

XRD analysis of powder part Sb+SnO2 sample

SnO2

SnO2SnO2


SnO2SnO2

Thermodynamic equilibrium in Sb-Sn-O

Stability of stannic oxide(SnO2)and stannous oxide(SnO)


At 1346 K liquid tin is inequilibrium with solid SnO2and liquid SnO. [83Kar]

1346I.Karakaya ,W.T.Thompson,Can. Metall. Quart. 22 (1983), 61

Sn + O2 = SnO2 (3)

2 2

0 reff,SnO Sn O4F E G RT ln a RT ln p− = ∆ − −

Tin activity determination

2− += +2

0 0f,NiO f, SnO

Sn

∆G ∆G Fln aRT

ERT

So the tin activity can be determined from relation:


AuthorsExper.

methodTemp.

range (K)kJ mol -1

Belford, Alcock e.m.f. 770-987 -586.5 + 0.2156·T ± 1.2

Palamutcu e.m.f. 823-1023 -575.9 + 0.2053·T

Onishi et al. e.m.f. 1173-1373 -563.6 + 0.1960·T

Ramanarayanan, Rapp

e.m.f. 940-1173 -575.1 + 0.207·T

02∆∆∆∆ ( , ),fG SnO c

Test of measurements accuracy (quality)Experimental results of determination of standard SnO 2 Gibbs free energy of formation

Petot-Ervas, et al. e.m.f. 773-1380 -576.3 + 0.2070·T ± 0.4

Seetharaman,Staffansson e.m.f. 990-1371 -575.07 + 0.2074·T ± 0.9

Iwase et al. e.m.f. 1023-1273 -578.8 + 0.2088·T ± 0.8

Kammel et al. e.m.f. 973-1273 -576.6 + 0.2087·T

Panek, Fitzner e.m.f. 950-1173 -578.5 + 0.2056·T

Kurchania, Kale e.m.f. 823-1273 -579.6 + 0.2070·T ± 1.0

Kopyto, Onderka e.m.f. 973-1325 -570.4 + 0.2013·T ± 0.9

This work e.m.f. 973-1223 -567.9 + 0.2003·T ± 1.0


-330

-310

-290

-270

kJ·m

ol-1

)

Test of measurements accuracy (quality)The comparison of the literature data of standard G ibbs energy of SnO 2 formation with present one.

for reaction:

2

0f,SnOG ( 1) 567.9 0.2003 T, kJ / mol∆ ± = − + ⋅

-430

-410

-390

-370

-350

600 700 800 900 1000 1100 1200 1300 1400 1500

Belford and Alcock

Petot-Evans et al.

Seetharaman andSteffanssonOishi et al.

Matsushita and Goto

Present work

T, K

∆G0 f,

SnO

2,(k

J·m

olfor reaction:

Sn(l) + O2(g) = SnO2(s)


Time-dependent e.m.f. curve recorded by data acquisition system

750

800

850

900

950

e.m

.f., m

V

xAg/xSb = 1/3, xSn = 0.5

880

700

0 10 20 30 40 50Time, hours

760

800

840

880

25 25.5 26 26.5 27

e.m

.f, m

V

Time, hoursOne cycle 4-5 days

Horizontal parts represent equilibrium e.m.f. values


Plot of E.M.F. vs. T for different tin compositions


Summary of e.m.f. vs. temperature data for different Sn concentrations in Ag-Sb-Sn liquid alloys

XSn

E0, E, VAg/Sb = 1 Ag/Sb = 1/3 Ag/Sb = 3/1

a b⋅⋅⋅⋅103 σσσσ a b⋅⋅⋅⋅103 σσσσ a b⋅⋅⋅⋅103 σσσσ

1.0 0.2627 -0.0810 ± 2.1 0.2627 -0.0810 ± 2.1 0.2627 -0.0810 ± 2.1

0.8 0.2612 -0.0856 ± 0.4 0.2595 -0.0848 ± 0.8


0.7 0.2543 -0.0828 ± 0.9 0.2566 -0.0849 ± 0.8

0.6 0.2410 -0.0753 ± 0.8 0.2668 -0.0985 ± 1.9 0.2529 -0.0859 ± 0.8

0.5 0.2574 -0.0945 ± 0.8 0.2329 -0.0754 ± 0.7 0.2375 -0.0784 ± 0.9

0.4 0.2426 -0.0881 ± 0.8 0.2307 -0.0797 ± 1.0 0.2388 -0.0850 ± 0.5

0.3 0.2666 -0.1165 ± 0.6 0.2485 -0.0999 ± 0.8

0.2 0.2722 -0.1331 ± 0.6 0.2656 -0.1249 ± 1.5

Temperature dependence of a Sn in liquid Ag-Sb-Snalloys vs. Sn composition


�- W.Gierlotka, Y-C.Huang, S-W.Chen, Phase Equilibria of Sn-Sb-Ag Ternary System(II):Calculation,Met.Mater.Trans.A, 39A, 3199 (2008)

�- C-S.Oh, J-H.Shim, B-J.Lee, D.N.Lee, A thermodynamic study on the Ag-Sb-Sn system, J.Alloys Comp.,238, 155-166 (1996)




�- C-S.Oh, J-H.Shim, B-J.Lee, D.N.Lee, A thermodynamic study on the Ag-Sb-Sn system, J.Alloys Comp.,238, 155-166 (1996)

No significant temperature dependenceof a tin activity



The derived tin activities in liquid Ag-Sb-Sn alloys show negative deviation from Raoult’s law in experimental composition range.

Obtained activities and, consequently, chemical potentials are new new experimental informationexperimental information to be used in phase diagram calculations.

Conclusions:

experimental informationexperimental information to be used in phase diagram calculations.

The thermodynamic data of the liquid phase in Ag-Sn-Sb system will give us the missing information about the three component interactions in such a melt and the chance to correct the system assessment.


Thank you for your attention


0 0 0m Ag Ag Bi Bi Sn Sn

exAg Ag Bi Bi Sn Sn m

G x G x G x G

RT(x lnx x lnx x lnx ) G

= + +

+ + + +

2 3i jex exx x

G G x x x L

= ⋅ + ⋅ ∑∑

Liquid phase - regular solution model

m i,j Ag Sb Sn AgSbSni 1 j i 1 i,j j,i

G G x x x LV V= = +

= ⋅ + ⋅

∑∑

0

ex k ki,j i j i j

k

G x x L(x x )=

= ⋅ ⋅ −∑ i j j ii,j j,i

1 x x 1 x xV V

2 2

+ − + −= =

i, j = Ag, Sb, Sn

For atmospheric pressure

M.Batzill , U.Diebold, The surface and materials science of tin oxide, Progress in SurfaceScience 79, 47–154 (2005)[160] L. Luxmann, R. Dobner, Metall (Berlin) 34 (1980) 821.

S. Cahen, N. David, J. M. Fiorani, A. Maître, M. Vilasi , Thermodynamic modellingS. Cahen, N. David, J. M. Fiorani, A. Maître, M. Vilasi , Thermodynamic modellingof the O–Sn system, Thermoch. Acta, 403(2), 275-285 (2003)

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