Effect of diameter and content of zirconium dioxide on the microstructure and mechanical properties of the TC17 titanium alloy repaired by wire arc additive manufacture

Abstract

Wire arc additive manufacturing (WAAM) has many advantages of high efficiency and low cost to repair blades or blisk made of titanium alloy. In this work, different contents and sizes of ZrO2 particles were added in the single-layer deposition and the multi-layer deposition fabricated by the WAAM technology to investigate the microstructure and mechanical properties of the repaired TC17 titanium alloy. Results show that the content and size of ZrO2 particles have a great influence on the geometry shape and β grain morphology. Especially, the deposition height (dH) increased and the deposition width (dW) decreased with the increased content of 75 µm ZrO2 under the direct current arc. The silicides are promoted to form with the addition of ZrO2, and more silicides tend to precipitate between the heat affected bands (HABands). The addition of ZrO2 can extremely increase the ultimate strength and make the plasticity meet the standard requirements. Especially, the ultimate strength of the multi-layer deposition with 0.5 wt% +50 nm ZrO2 was highest, 1116 MPa, which is 100 MPa higher than that of the deposition without ZrO2 addition. Meanwhile, the strength of the multi-layer deposition with the addition of 1 wt%+ 75 µm ZrO2 have less of an uplifting effect compared with that of 0.5 wt%+ 75 µm ZrO2.