基于ProCAST有限元仿真平台，开展了TC18钛合金泵体真空凝壳铸造工艺优化研究。通过构建合金牛顿 流体本构模型，量化分析了TC18与TC4钛合金的流变特性差异，确定TC18优化浇注温度为1770℃。 建立了泵体三 维流-固耦合模型，并系统对比传统顶注式与改进底注式浇注系统的熔体充型行为及凝固特征。 结果表明，优化浇注系 统后有效抑制了金属液紊流（流速降幅达38.6%），促使缩松缩孔体积分数降低74.3%；同时二次枝晶间距缩减21.4%， 关键部位抗拉强度提升15.5%。 X射线探伤与拉伸试验验证了模拟结果的可靠性。

On the basis of the ProCAST finite element simulation platform, the TC18 titanium alloy pump vacuum condensing shell casting process was optimized. The difference in rheological properties between the TC18 and TC4 titanium alloys was quantitatively analysed by constructing a Newtonian fluid constitutive model, and the optimal pouring temperature of TC18 was determined to be 1 770 ℃. A three-dimensional fluid-solid coupling model of the pump body was established, and the filling behavior and solidification characteristics of the melt were systematically compared between the traditional top pouring system and the improved bottom pouring system. The results show that the turbulent flow of liquid metal (the flow rate decreases by 38.6%) is effectively restrained after the pouring system is optimized, and the volume fraction of shrinkage porosity is reduced by 74.3%. Moreover, the secondary dendrite spacing is reduced by 21.4%, and the tensile strength of key parts is increased by 15.5%. The reliability of the simulation results is verified via X-ray flaw detection and tensile tests.