Co-In-Sb Ternary System (I): Isothermal Sections and Liquidus Projection

Abstract

The Co-In-Sb ternary system has thermoelectric application interests. Co-In-Sb ternary alloys are prepared in this study. Their equilibrium phases at 1123.15 K and 923.15 K (850 °C and 650 °C) as well as their primary solidification phases and univariant reaction temperatures are determined. The isothermal sections at 1123.15 K and 923.15 K (850 °C and 650 °C) and the liquidus projection of the Co-In-Sb ternary system are determined based on the ternary experimental results, the phase diagrams of its three constituent binary systems, and the limited phase equilibria literature. No ternary compounds are found. The phase relationships at both 1123.15 K and 923.15 K (850 °C and 650 °C) are the same. There are five phases, seven two-phase regions, and three tie-triangles which are Co-CoSb-liquid, CoSb-CoSb2-liquid, and CoSb2-CoSb3-liquid. In the liquidus projection, there are nine primary solidification phase regions, Co, CoSb, CoSb2, CoSb3, Sb, InSb, In, CoIn2, and CoIn3. There are seven invariant reactions which are two Class I, four Class II, and one Class III.