Additive Manufacturing With Metallic Wire Using a Coaxial Fed Microwave Plasma Jet

A new direct energy deposition process using an atmospheric plasma jet in the microwave (MW) frequency range at 2.45 GHz is shown in this work. This new technology, taking advantage of the potential-free nature of MW plasma, is able to process a wide range of materials from metals to ceramics, as well as in wire or powder state. Due to the innovative design, a coaxial material feed directly into the plasma is possible. The system layout is described, including the design for the individual components. Based on fluid dynamics simulations, the optimum operating point is calculated and compared with the measurements. This is followed by the metrological characterization of 2-D and 3-D welding tests with lateral-fed metal wire, in which good results are obtained. Further on welding test are described, using a coaxial powder feed. After creating weld beads, 3-D structures are generated and analyzed. It is shown that MW plasma can be used to additively manufacture conductive and nonconductive materials.