ZTi60钛合金大型构件熔模精铸工艺及组织性能研究

Study on the Investment Casting Process,Microstructure and Mechanical Properties of Large-sized Structural Components in ZTi60 Titanium Alloy

针对ZTi60钛合金大型构件熔模精铸件研制周期长、风险大和成本高的问题,开展了大型构件缩比件的熔模铸造工艺和组织性能研究,为大型构件工艺设计和优化提供技术支持和试验验证。基于ZTi60合金特点,设计缩比件的铸造工艺参数,并使用计算机软件对浇注系统进行设计和模拟验证优化。此外,对单铸试棒进行不同参数热等静压实验以确定最佳热等静压工艺,对结构复杂难焊位置进一步加大补焊难度后试验ZTi60可焊性,取样测试不同位置的微观组织、化学成分和力学性能。结果表明,铸件浇注成形完整,表面无明显缺陷;热等静压后疏松和缩孔压实,密集气孔得到有效改善,且铸件具有良好的可焊性;铸件各部位化学成分相同、组织相同但晶粒度差异较大,力学性能均高于性能指标。

To address the problems of a long development period,high risk and high cost,the investment casting process and microstructure properties of large component reduction parts of ZTi60 titanium alloy were studied to provide technical support and test verification for the process design and optimization of large components.On the basis of the characteristics of the ZTi60 alloy,the casting process parameters of the reduced parts were designed,and the pouring system was designed and simulated via computer software.In addition,a hot isostatic pressing test with different parameters was carried out on a single casting test rod to determine the best hot isostatic pressing process for ZTi60 castings.The weldability of ZTi60 was tested after further increasing the difficulty of welding in the difficult position of the complex structure,and the microstructure,chemical composition and mechanical properties at different positions were tested.The results show that the casting is complete,and no obvious defects are observed on the surface of the casting.After hot isostatic pressing,the dense porosity is effectively improved,and the casting has good weldability.The chemical composition and structure of each part of the casting are uniform,whereas the grain size varies significantly.The mechanical properties are greater than the performance indices.