金属熔滴与基板碰撞变形的数值模拟

为了保证熔滴沉积增材制造工艺中熔滴间的良好结合及成型精度,对熔滴与基板碰撞后的变形及凝固过程进行数值模拟研究.采用两相流模型,结合自由表面跟踪算法和凝固界面跟踪算法,建立了熔滴变形及凝固的耦合计算模型并求解.分析计算结果表明熔滴温度场变化与形态变形过程相吻合;熔滴与基板的接触部分瞬时就发生了凝固,因此凝固层半径和熔滴外...

Numerical simulation of a metal drop in impinging on substrate

To obtain good fusion and precision of drops during drop deposition increasing material manufacturing,the drop deformation and solidification after impinging on the substrate was simulated.Two phase flow model,combining with free surface tracking algorithm and solidification interface tracking algorithm,was adapted to built up the coupled calculating models for drop deformation and solidification.The results show that the temperature transformation of the drop agrees well with the shape deformation,and the part contacting with the substrate solidifies instantaneously as the drop impinges on the substrate.The solidification layer radius equals to the drop radius,and the effect of the impinging velocity on solidification is more than that of the temperature.A concept of semi-solidification was proposed,and the time,radius and thickness of frozen layer for semi-solidification drop were calcutlated.The fusion was in the good conditon when the former drop was in semi-solidification state.