建立了等离子熔积成形过程移动热源和动质传热的三维有限元数学模型,进行了该过程温度场的模拟分析.模拟结果表明,等离子熔积成形的温度场具有时空交变与不均匀分布的特性,随着熔积层数的增加,零件温度均匀化程度提高,冷却速度下降;但随着冷却速度下降,易产生流淌,影响成形性.最后通过对温度场的实验测定,模拟结果与实验结果基本符合,证明了熔积成形模拟计算模型的合理性.
A FEM model of plasma powder deposition manufacturing (PPDM) was presented in consideration of the moving heat source and dynamic transfer process. The three-dimension numerical analysis of the temperature field was carried out. The results showed that the temperature field changed rapidly with time and space in the PPDM process. With the increase of the deposited height, the temperature field tended to be uniform, reducing the cooling rate. The formability would be influenced with the reduction of the cooling rate. An experiment was carried out to measure the temperature field of PPDM and verified the temperature field simulated by the developed software. The result showed the effectiveness of the simulation model.