The Cr–Ti system was investigated by several experimental methods and first-principles calculations. The thermodynamic activity of the body-centered cubic solid solution was measured by Knudsen effusion mass spectrometry. The stability of all three polymorphic structures of the Laves phase (C14, C15, and C36) was determined by differential thermal analysis, and the equilibrium tie-lines with the solid solution were obtained by combining results from diffusion couples and equilibrated alloys. The enthalpy of formation of the Laves phases with the corresponding end-members were calculated using density functional theory and the obtained values were integrated in the models. The experimental and computed data available in the literature was reviewed and the binary system was assessed by the Calphad method. The present evaluation results in an improved thermodynamic description, which can describe the experimentally observed activity in a large temperature range. The temperatures of the invariant reactions between the C15 and the C36 phase with the Cr-rich and the Ti-rich bcc solid solution were significantly modified. The difference of the temperature of transformation between the C15 and the C36 polytypes on both sides of the Laves phase is much smaller than reported previously.

通过多种实验方法和第一性原理计算对 Cr-Ti 体系进行了研究。通过努森流出质谱法测量体心立方固溶体的热力学活性。通过差热分析确定了Laves 相的所有三种多晶型结构（C 14、C 15 和C 36）的稳定性，并通过结合扩散偶和平衡合金的结果获得了固溶体的平衡联络线。使用密度泛函理论计算具有相应端元的 Laves 相的形成焓，并将获得的值集成到模型中。回顾了文献中可用的实验和计算数据，并通过 Calphad 方法评估了二元系统。目前的评估结果是改进的热力学描述，可以描述在大温度范围内实验观察到的活性。C 15 和C 36 相与富Cr和富Ti bcc固溶体之间的不变反应温度被显着改变。Laves相两侧的C 15 和C 36 多型体之间的转变温度差异比之前报道的要小得多。