半固态镁合金压铸充型过程的数值模拟研究

在考虑半固态AZ91D镁合金充型过程的压力和速度变化特征的基础上,建立了模拟计算所需要的表观黏度数学模型。采用ProCAST软件,对半固态镁合金压铸充型过程进行模拟,预测卷气、夹杂物产生的可能性,以便优化其工艺参数和工艺方案。结果表明,与全液态镁合金充型过程相比,半固态金属充型平稳,模具寿命长,铸件质量好;改变内浇道和溢流槽的设置位置和数量,还可有效地减少铸件本身内部杂质,提高铸件质量。

Mold filling process of semi-solid Mg alloy in die casting by numerical simulation

Mold filling process of semi-solid Mg alloy in die castings is a transient process with various fluid viscosities.Based on the variation characteristics of filling pressure and velocity during mold filling process of semi-solid AZ91D alloy,a mathematical model of apparent viscosity for numerical calculation is established.The mold filling process of semi-solid Mg alloy in die castings is simulated by employing ProCAST and the possibility of involved gas and inclusions is predicted.The best technique is determined through optimizing the process parameters.Simulation results demonstrate that the filling process of semi-solid Mg alloy is more stable than that of liquid Mg alloy,and therefore,the service life of dies can be prolonged and the quality of the castings can be improved.Furthermore,changing the location and numbers of ingates can effectively reduce the inclusions in castings and thereby improve casting qualities.