As an excellent structural material,
titanium alloy has high specific strength, low density and good corrosion resistance, so it is widely used in aerospace, ships, automobiles and other fields. As a medium strength α+β titanium alloy, ZTC4 is a widely used and mature casting titanium alloy, which is suitable for the preparation of static aerospace structural parts under high stress. Precision casting can mass produce components with accurate size and complex shape at a lower cost, such castings have good overall structure and high reliability, and can solve the difficulties of titanium alloy component forming and high cost at the same time, so it has been an important direction of titanium alloy casting industry research.
Numerical simulation of titanium shaped parts processing can quantitatively describe complex problems. Numerical solidification analysis based on actual physical process has gradually become an important means to predict and improve the internal quality of castings. Through numerical simulation analysis of the temperature field, flow field and defect distribution of alloy casting process, the limitations of over-relying on production experience and trial and error to improve the pouring process, long research and development cycle and high cost in traditional industrial production are broken through, and the comprehensive properties of materials can be significantly improved. Therefore, this study first analyzed the structural characteristics of the casting, and then used ProCAST software to simulate the vacuum investment casting process of titanium alloy castings to clarify the flow state, solidification characteristics and defect distribution of the alloy liquid during the pouring process, and based on this, carried out iterative optimization to obtain the Z-optimal process parameters. Using the new process for trial production, Z finally obtained qualified casting inspection.
Therefore, the conclusion of titanium alloy processing workpiece manufacturers:
(1) ProCAST software was used to conduct vacuum investment casting numerical simulation for thin wall parts cast of ZTC4 titanium alloy, evaluate the initial casting process, and obtain the defect distribution law of the structural parts and the design criteria of casting system.
(2) Reverse engineering means and finite element analysis method were used to optimize the casting scheme, and casting/riser was added to the original casting process to obtain the Z-optimal casting process, which solved the problem that the bearing plate area of the casting in the original process was prone to shrinkage and porosity. The test results of the trial-made parts prepared by the optimized scheme show that the internal quality of the castings is good, there is no porosity and shrinkage hole defects, and the process stability is high.
(3) The numerical simulation results are highly consistent with the results of non-destructive testing, which provides a reliable basis and analysis method for the development of similar titanium alloy castings and the optimization of pouring process, and lays a foundation for the improvement of precision casting technology for similar special-shaped thin-wall parts.
