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根据热溶质在凝固过程中传输原理,通过计算机建立A偏析成形过程的数值模型,得到温度场和浓度场与固相分值的耦合关系;再利用计算机进行数值模拟计算A偏析在合金溶液凝固成形的演化过程,并且分析研究了A偏析的成形位置及其变形程度受浮力数值的影响。结果表明,侧向凝固过程中,溶质浓度与温度的变化均对流体密度产生影响,且该影响因素互相抑制。当膨胀系数α或浮力比F较小时,在凝固侧较近区形成A偏析;随着膨胀系数α或浮力比F的增大,A偏析向凝固中心处移动,偏析程度较小,可提高铸件的力学性能与使用性能。
According to the transmission principle of hot solute in the process of solidification, a numerical model of A segregation forming process was established by computer, and the coupling relationship between temperature field and concentration field and solid fraction was obtained. Then the numerical simulation of A segregation was performed in alloy solution solidification The evolution of A-segregation and its deformation degree are analyzed by the buoyancy values. The results show that the changes of solute concentration and temperature have an impact on the fluid density in the lateral solidification process, and the influencing factors inhibit each other. When the coefficient of expansion α or buoyancy ratio F is smaller, A segregation occurs in the vicinity of the solidification side. As the coefficient of expansion α or buoyancy ratio F increases, segregation of A moves to the center of the solidification and the degree of segregation is small, The mechanical properties and the use of performance.