Heat Transfer to the Wire Based on Multiphysics Model for Wire Arc Additive Manufacturing

The dynamic melting process of wire is less discussed in the wire arc additive manufacturing (WAAM) process, while it is a precondition of precision forming and automatic control. Based on the combination of electric field, magnetic field, temperature field, and flow field, a 3-D Multiphysics model is established for the WAAM to study the dynamic heat-transfer process from arc to wire. The heat-transfer characteristics between plasma arc and solid wire are demonstrated, and the heating and melting process of wire is displayed. Detailed research is made to explore the heat-transfer mechanism at various conditions, in which wire diameter, welding current, wire feeding angle, and wire material are chosen as influencing factors. It shows the maximum heat flux density on the upper surface of the wire increases positively to the wire feeding angle. The variation of the above technological conditions causes a big difference in heat transfer in the wire. The model is useful for predicting the wire melting process with various conditions and provides theoretical guidance for optimizing the WAAM process, which has good potential in engineering applications.