Ti60 合金磁场辅助 TIG 电弧熔粉增材制造工艺

To solve the problems of low density and difficulty in wire fabrication in the additive manufacturing of Ti60 high-temperature titanium alloy, the magnetic field-assisted TIG arc powder fusion additive manufacturing method was adopted, and related process studies were conducted. The results show that during the conventional TIG arc powder fusion additive manufacturing process, the powder easily flies off the substrate under the action of arc force, producing severe spatter. However, applying a transverse magnetic field changes the arc morphology and its leading arc force, significantly suppressing spatter generation. In addition, the effect of current on the macroscopic forming of the weld bead is investigated. It is found that with the increase of current, the melting width and penetration depth of the weld bead increase significantly; the uniformity of the weld bead improves obviously, and the spheroidized metal decreases substantially. The unique powder melting and droplet transfer processes of this method are captured with a high-speed camera. The powder undergoes a process of droplet formation, droplet growth, and droplet transfer different from that of wire. The additively manufactured Ti60 alloy wall specimens exhibit high strength and excellent plasticity. The average transverse tensile strength is 1 047.0 MPa, and the elongation after fracture is 14.1%; the longitudinal tensile strength is 1 036.9 MPa, and the elongation after fracture is 15.4%. Their excellent mechanical properties are mainly attributed to the fine α + β basketweave microstructure and the small aspect ratio of α laths. Highlights: (1) By applying a magnetic field to regulate arc characteristics, powder spatter during the TIG arc powder fusion additive manufacturing process was reduced. (2) The effect of current on the macroscopic forming of the weld bead and the unique powder melting process were investigated. (3) The Ti60 alloy with excellent strength and plasticity was obtained by subsequent weld bead heat treatment to promote martensite decomposition.