Abstract:
Aiming at the problems of many internal defects and low molding quality of cast titanium alloy impeller blades, By designed two casting systems, the finite element method is used to numerically simulate the gating system.. The design optimization of casting system was studied during the casting and solidification process. The effects of flow field, temperature field and shrinkage were carried out on the basis of optimal design, and the microstructure and mechanical properties of the casting were tested and analyzed. The results showed that under the condition of vacuum precipitating temperature of 400 ℃, pouring temperature of 1730 ℃, pouring time of 8 s, the bottom injection have good filling and solidification quality, and there is no defect inside the casting; The top-injection structure is filled with a disordered flow field, and there is a gas-filling phenomenon. Concurrently, there are many internal defects in the casting. Therefore, the pouring system of the bottom-injecting multi-risk structure is superior to the top-injection structure. Simultaneously,the castings microstructure is density, The yield strength, elongation and microhardness are 785.5 MPa, 25.5% and 301.67 HBW.The mechanical properties are good, the surface precision is high, meet the requirements of high quality titanium alloy castings
