The phase equilibria at 1000 °C of the Co-V-Ga ternary system and composition dependence of martensitic transformation characteristics in Co₂VGa Heusler alloys are investigated. Firstly, the results show that six three-phase regions and three ternary compounds are identified in the isothermal section. The CoVGa compound is discovered with a composition range of 43.0–46.2 at.% V and 27.3–31.4 at.% Ga. Secondly, according to the obtained phase equilibria, the martensitic transformation characteristics depending on composition for those alloys that locate the Co₂VGa Heusler phase region are investigated. The results confirm that the Co₂VGa Heusler phase exists in a wide composition range (about 39.7–66.5 at.% Co, 4.8–40.0 at.% V, and 15.0–31.2 at.% Ga). Furthermore, the critical compositions with the martensitic transformation temperature close to room temperature are determined, in which those alloys (50.8–58.5 at.% Co, 20.2–33.0 at.% V, and 15.2–21.5 at.% Ga) show the martensite structure at room temperature. Thirdly, based on the phase equilibria and the composition dependence of martensitic transformation characteristics, a Co₅₅V₂₄Ga₂₁ shape memory alloy is designed. Its microstructure, reversible martensitic transformation, and shape memory effect are investigated. Full shape recovery of about 2.6% is obtained. The present obtained results may provide useful information for composition designation and the estimation of martensitic transformation temperatures of Co-V-Ga Heusler shape memory alloys.

研究了 Co-V-Ga 三元体系在 1000 °C 时的相平衡以及 Co ₂ VGa Heusler 合金中马氏体转变特性的成分依赖性。首先，结果表明，在等温剖面中识别出六个三相区和三个三元化合物。发现的 CoVGa 化合物的成分范围为 43.0-46.2 at.% V 和 27.3-31.4 at.% Ga。其次，根据获得的相平衡，马氏体转变特征取决于那些定位 Co _{2 的}合金的成分研究了 VGA Heusler 相区。结果证实 Co ₂VGa Heusler 相存在于很宽的组成范围内（约 39.7–66.5 at.% Co、4.8–40.0 at.% V 和 15.0–31.2 at.% Ga）。此外，确定了马氏体转变温度接近室温的临界成分，其中这些合金（50.8-58.5 at.% Co、20.2-33.0 at.% V 和 15.2-21.5 at.% Ga）显示马氏体室温下的结构。第三，基于相平衡和马氏体转变特性的成分依赖性，Co ₅₅ V ₂₄ Ga ₂₁设计了形状记忆合金。研究了其微观结构、可逆马氏体转变和形状记忆效应。获得约 2.6% 的完全形状恢复。目前获得的结果可为 Co-V-Ga Heusler 形状记忆合金的成分指定和马氏体转变温度的估计提供有用的信息。