PI-7

Experimental Study of the System Sn-Ti-Zn to 600^oC.

Dobrev E.S.^1,2, Vassilev G.P.¹, Tedenac J-C²

¹Faculté of Chemistry, Université of Sofia, 1 James Bourchier front, 1164 Sofia, Bulgaria B L.P.M.C., ²Université Montpellier II, Pl. E Bataillon, 34095 Montpellier, France

The compounds formation and stoichiometry in the system Sn-Ti-Zn have been studied at 600^oC, using optical, scanning electron microscopy, X-ray analysis and EMPA. The homogeneity ranges for the ternary extensions of the binary compounds Ti₆Sn₅, Ti₃Sn, Ti₂Sn, TiZn3, TiZn₅ have been defined. The compound Ti₆Sn₅ dissolves the highest content of the correspondent ternary element (6.9 at. % Zn), while TiZn₃ – 2 at. % Sn. The zinc solubility into the Ti-Sn compounds is probably due to the feeble difference between the electronegativities and the atomic radii of Ti and Zn. The ternary solution of Sn and Zn in aTi contains approx. 6 at. % Sn and 5 at. % Zn. The largest titanium concentration (1.5 at. % Ti) in the liquid phase is registered in binary Ti-Zn dendrites. New formerly unknown ternary compound having the formula Ti₅Sn₄Zn₁₁ has been found. An isothermal section at 600^oC including this phase has been constructed.