Phase equilibria in the Co–Ti–V system at 873 K

• The 873 K isothermal section of Co–Ti–V ternary system is determined.
• Nine three-phase equilibria are experimentally measured.
• All of Co–V and Co–Ti binary phases show large ternary solubility.
• The maximum solid solubility of Ti, Co, V in binary phases is determined.

The isothermal section of the Co–Ti–V ternary system at 873 K has been investigated by means of diffusion triple together with electron probe microanalysis technique. Series of tie lines and tie-triangles have been determined and the isothermal section at 873 K has been established, and nine three-phase fields have been figured out. It is found that VCo3, VCo, TiCo3, TiCo2(h), TiCo2(c) and TiCo have range of homogeneity at 873 K, and the V3Co and Ti2Co are line compounds. The solid solubility of Ti in VCo3, VCo and V3Co is about 5.2 at.% Ti, 8.8 at.% Ti and 6.9 at.% Ti, and that of V in TiCo3, TiCo2(h), TiCo2(c), TiCo and Ti2Co is about 6.1 at.% V, 3.7 at.% V, 3.0 at.% V, 9.3 at.% V and 6.6 at.% V, respectively.