CHEMICAL INTERACTION BETWEEN CARBON AND TITANIUM DISSOLVED IN LIQUID-TIN - CRYSTAL-STRUCTURE AND REACTIVITY OF TI2SNC WITH AL

Chemical interaction between carbon and titanium dissolved in liquid t in was studied at temperatures higher than 1000 degrees C. The phase e quilibria in the ternary system graphite-titanium-tin were investigate d by thermal analysis, metallography, X-ray diffraction and electron m icroprobe analysis. The isothermal section at 1200 degrees C is propos ed. At this temperature, carbon can react to yield a binary phase, TIG , or a ternary phase, Ti2SnC. The structure of Ti2SnC is proposed on t he basis of powder diffraction X-ray data (space group: P6(3)/m.m.c, h exagonal axes a = 0.31626 nm, c = 1.36789 nm). Some experiments realiz ed by immersion of T300 fibres in Sn-Ti alloys show that the chemical reaction leads to either a single layer of TiC or a double-layer, TiC- Ti2SnC. The results demonstrate that the ternary phase is not stable i n liquid aluminium. (C) 1998 Elsevier Science S.A. All rights reserved .