Abstract
? 2022 Elsevier B.V.Using an arc heat source, the filling ratio of Ti6Al4V and Inconel 625 wires was controlled to manufacture a TiNi gradient material using wire arc additive manufacturing (WAAM). The effects of wire filling ratio on the microstructure of the deposition layer were studied through X-ray diffraction (XRD), scanning electron microscope (SEM), and differential scanning colorimetry (DSC). The mechanical performance was evaluated using compression, Vickers hardness, and surface wear testing. The results show that increasing the ratio of Inconel 625 filling wire can form Ti2Ni and TiNi strengthening phases in the deposition layer. The Ti2Ni and TiNi phases are evenly distributed over the region owing to the stirring of the molten pool by the arc, which improves the compression and surface wear performance of the WAAM parts. When the Inconel 625 wire filling ratio is 35%, the Vickers hardness reaches 600 HV and the compression strength increases to 2.15 GPa. However, excessive Ti2Ni phase will reduce toughness. As an Inconel 625 wire filling ratio lower than 35% can achieve a well-performing structure, five kinds of wire filling ratios were chosen to fabricate different gradient materials, and the microstructure, elemental distribution, phase composition, and mechanical properties were analyzed thoroughly.
NSTL
Elsevier