SiC陶瓷/K4169合金复合铸件铸造过程的数值模拟研究

Numerical Simulation Research on Casting Process of SiC Ceramic/K4169 Alloy Composite Casting

摘要:

铸造一体化成形技术有助于制备大尺寸、复杂结构的陶瓷/金属复合构件,具有重要的理论意义和应用价值。本文基于有限元方法,针对SiC陶瓷/K4169合金复合铸件,探究铸造充型过程的流场,陶瓷-金属的热交互作用以及凝固过程中复合铸件热应力、残余应力的产生与分布特性。结果表明,金属液充型过程在内浇口处出现不稳定流动；陶瓷在接触金属液后,表面温度陡升,且在陶瓷内部形成20-30℃/mm的温度梯度；铸造热应力呈现出先降低后升高的趋势；残余应力集中在陶瓷和金属界面,且较大应力在陶瓷一侧,陶瓷端残余应力峰值在距离界面2-3mm处。

Abstract:

Foundry integral forming technology is helpful to fabricate large size and complex structure ceramic/metal composite components, which has important theoretical significance and application value. In this paper, based on the finite element method, the flow field of SiC ceramic /K4169 alloy composite castings during filling process, the thermal interaction between ceramic and metal, the generation and distribution characteristics of thermal stress and residual stress in the solidification process were investigated. The results show that unstable flow occurs at the inner gate during the filling process. The surface temperature of the ceramic rises sharply after contacting the metal liquid, and a temperature gradient of 20-30℃/mm is generated inside the ceramic. The casting thermal stress decreases first and then increases. And the residual stress is concentrated on the interface between the ceramic and the metal, and the greater stress is on the ceramic side. Futhermore, the peak value of the residual stress is 2-3mm away from the interface.