Silver - Bismuth - Thallium

Hans Leo Lukas

Introduction

The complete system was obtained by a computer optimization [76Zim1, 76Zim2], using thermodyamic and phase diagram data of the ternary system, DTA measurements of ternary liquidus temperatures and calorimetric measurements of heats of mixing of the ternary melt. The calculation was refined using new coefficients of the binary Bi-Tl system [78Kri].



Binary Systems

The liquidus of the system Ag-Tl [76Zim2] (Fig. 1) and some phase boundaries of the system Tl-Bi [78Kri] (Fig. 2) are slightly different from those assumed by [H]. For Ag-Bi the diagram of [H] is accepted.

Solid Phases

Except for the (Ag) solid solution in equilibrium with liquid, the extension into the ternary system is very small (see Table 1).

Invariant Equilibria

Invariant equilibria are given in Table 2 and Fig. 3.

Liquidus Surface

The liquidus surface is given in Fig. 4.

Isothermal Sections

The isothermal section at 200C is given in Fig. 5.

References

[76Zim1] B. ZIMMERMANN, "Rechnerische und Experimentelle Optimierung von Binären und Ternären Systemen aus Ag, Bi, Pb and Tl", Thesis, Universität Stuttgart, Germany (1976) (Equi. Diagram, Thermodyn., Experimental, #, 95)

[76Zim2] B. ZIMMERMANN, E.-TH. HENIG and H.L. LUKAS, "Das System Ag-Bi-Tl, Berechnet aus den Optimierten Binären Randsystemen", Z. Metallkde., 67, 815-820 (1976) (Equi. Diagram, Thermodyn., Experimental, #, *, 13)

[78Kri] H. KRIEG, "Experimentelle und Rechnerische Bestimmung des Systems Bi-Pb-Tl", Diplomarbeit, Universität Stuttgart (1978) (Equi. Diagram, Experimental, 13)

Table 1: Solid Phases

Phase / 

Temperature Range (°C)

Pearson 

Symbol/ 

Prototype

Lattice Parameters (pm) Comments
(Ag) cF4 

Cu

a = 408.62 pure element 25C [P]
(Bi) hR2 

As

a = 454.6 

c = 1186.2

pure element 25C [P]
(Tl)(h) cI2 

W

a = 388.2 pure element 262C [P]
(Tl)(r) hP2 

Mg

a = 345.66 

c = 552.48

pure element 18C [P]
Tl3Bi cF4 

Cu

a = 491.4 at 79.9 at.% Tl [P]
Tl2Bi3 hP3 

B2Al

a = 566.3 

c = 337.8

[P]

Table 2: Invariant Equilibria

T (C) 

Reaction

Type Phase Composition (at.%) 

Ag Bi Tl

289.3 

L+Tl3Bi (Ag)+(Tl)(h)

U1

(Ag) 

(Tl)(h) 

Tl3Bi

2.3 5.8 91.9 

95.5 0.0 4.5 

0.0 6.0 94.0 

0.0 7.5 92.5

197.3 

L (Ag)+(Bi)+Tl2Bi3

E1

(Ag) 

(Bi) 

Tl2Bi3

2.2 75.0 22.8 

99.7 0.2 0.1 

0.0 100.0 0.0 

0.0 69.4 30.6

187.8 

L (Ag)+Tl3Bi+Tl2Bi3

E2

(Ag) 

Tl3Bi 

Tl2Bi3

1.1 46.8 52.1 

99.6 0.1 0.3 

0.0 40.5 59.5 

0.0 55.1 44.9

144 

(Tl)(h) Tl(r)+Tl3Bi(Ag)

D1 (Tl)(h) 

(Tl)(r) 

Tl3Bi 

(Ag)

0.0 2.3 97.9 

0.0 1.3 98.7 

0.0 5.3 94.7 

100.0 0.0 0.0