镁合金离心铸造工艺数值模拟研究

Numerical Simulation of Centrifugal Casting Process for Magnesium Alloy

为研究镁合金在卧式离心铸造条件下的流动性,以AZ31B镁合金为对象,采用有限元数值模拟,探究了不同初始条件下离心铸造的温度场和压力场的分布,分析了从浇注到凝固过程中的流动和温度变化情况。结果表明,受流动、旋转和回流等影响,温度场存在小范围波动,总体趋势是浇注后温度短时间内上升,然后逐渐下降直至凝固。分析了铸型内壁压力场分布,发现随着浇注过程进行,内表面压力由负压逐渐增大至平稳值,且随温度变化不大,随离心转速的增大而增大。

In order to understand the macroscopic flow of magnesium alloy in horizontal centrifugal casting,Az31B magnesium alloy was simulated by means of finite element method to explore the distribution of temperature field and pressure field of centrifugal casting under different initial conditions.The flow and temperature changes from pouring to solidification were analyzed.It is found that the temperature field is fluctuated in a small range under the influence of flow,rotation and backflow.The general trend is that the temperature is increased in a short time after pouring,and then gradually decreased until solidification.The pressure field distribution of inner wall of centrifugal cylinder was analyzed.It is found that the inner surface pressure is increased gradually from negative pressure to stable value with pouring,and its change can be neglected with the temperature,while increased with the increase of centrifugal speed.