Influence of Tin on the Structure and Properties of As-Cast Ti-Rich Ti—Si Alloys.

Abstract By the methods of DTA, X-ray diffraction, metallography and microprobe analysis, phase equilibria in the Ti-corner (more than 50 at.% Ti) of the Ti–Si–Sn system were studied. The solidus projection and the melting diagram (solidus+liquidus) were constructed. A new ternary compound T of composition Ti5Si1.2–1.6Sn1.8–1.4 was found to form with the crystal structure of W5Si3-type. The ternary eutectic equilibrium L↔〈β-Ti〉+〈Ti5Si3〉+〈Ti3Sn〉 was established to occur at 1460 °C with the composition of the invariant point E at ∼77Ti–9Si–14Sn. Microhardness measurements were carried out for the primary grains of the alloys with 5 at.% Si.