Determination of the CoTi congruent melting point and thermodynamic reassessment of the Co-Ti system

New experimental results and a thermodynamic re-evaluation of the Co-Ti system are presented. Using differential thermal analysis (DTA) and a visual observation-of-melting (VOM) technique, the ≈220 K inconsistency in melting temperature in the literature for the B2 (CoTi) phase is resolved. The congruent melting point is determined to be 1776±5 K. The revised B2 melting temperature, along with other critically reviewed thermochemical and phase-equilibria data from the literature, are used to reassess the thermodynamic description of the Co-Ti system. As a result, a self-consistent set of optimized Gibbs-energy expressions for all CoTi phases is obtained.