Abstract
Titanium alloys manufactured via additive manufacturing are suffering from coarse columnar grains due to the insufficient spontaneous nucleation rate during solidification. In this study, a newly designed Ti–2Fe-0.1B alloy with higher nucleating agent were introduced and manufactured by laser melting deposition method. The manufactured part is presenting a fully equiaxed grain morphology with 779 MPa on ultimate tensile strength. In order to reveal the mechanism of equiaxed grain formation and its influence on mechanical properties, a comprehensive study of microstructure evolution was carried out on Ti–2Fe-0.1B alloy manufactured via casting, forging and laser melting deposition. The results indicate that cooling speed are playing an important role on TiB morphology and Ti–2Fe-0.1B grain size simultaneously. The TiB formed from fast cooling speed are presenting a 3D quasi-network structure and improves the ultimate tensile strength of laser melting deposited part by 1.7 and 1.5 times when compared with casting and forging parts correspondingly. The study reveals that B addition is a sufficient method to control equiaxed grain formation in additive manufacturing of Ti–Fe alloy and promotes B addition as grain morphology controlling method in other additive manufactured titanium alloys in future.
Original language | English |
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Article number | 108854 |
Journal | Composites Part B: Engineering |
Volume | 216 |
DOIs | |
State | Published - 1 Jul 2021 |
Externally published | Yes |
Keywords
- Additive manufacturing
- Boron
- CTE transition
- Equiaxed grain
- Titanium alloy
- Ti–Fe