铝合金半固态触变充型模拟技术研究

Simulation Study of Flow Characteristics of Semisolid Slurry Filling for Aluminium Alloy

通过计算和理论推导相结合的方法建立了耦合半固态铝合金表观粘度的触变充型模拟的三维数学模型 ,确定了边界条件和初始条件 ,模拟对比分析了半固态充型及液态充型流动特征。模拟结果表明了半固态充型和液态充型具有不同特征 ,半固态充型过程具有层流流动特征 ,液态充型流动基本呈现紊流特征 ,容易导致铸件出现气孔及氧化夹杂等缺陷。

Our simulation study aims at comparing flow characteristics of semi-solid slurry filling with those of liquid filling for aluminium alloy. Section 1 reviews relevant information in Ref.7, which takes into consideration apparent viscosity for semisolid alloy. Section 2 discusses the basic equations of semisolid filling. Section 3 discusses the initial conditions and boundary conditions of semisolid filling. Section 4 gives the simulation study of flow characteristics of semisolid slurry filling and liquid filling for aluminium alloy. Simulation results show that the semisolid filling process has laminar flow characteristics and liquid filling process has turbulent flow characteristics. Turbulent flow of liquid aluminium alloy can easily cause gas cavity and oxidation mixture defects in castings.