Control of TRIP in Ti-1023 Through Powder Bed Fusion-laser Beam Parameter Selection and Thermal Cycling
Christopher Jasien, Colorado School of Mines
The continued development of metal additive manufacturing (AM) has expanded the metallic alloys for which these processes can be applied. However, non-equilibrium conditions, such as rapid cooling, inherent in AM have presented difficulties in producing strong, crack-free parts. A subset of titanium alloys can mitigate these problems by undergoing a solid-state phase transformation in order to better accommodate deformation. This mechanism is typically referred to as transformation induced plasticity (TRIP) and also results in better combinations of strength and ductility compared to conventional deformation via slip. In order to better understand what controls and affects this TRIP behavior during AM processing, simulated powder bed fusion-laser beam (PBF-LB) of the β-titanium alloy Ti-10V-2Fe-3Al (weight percent) (Ti-1023) was performed at the Advanced Photon Source at Argonne National Laboratory under varying processing conditions. TRIP was observed in all experiments in varying degrees and locations. Residual stress distribution and grain orientation were identified as the two main factors controlling the TRIP behavior of this alloy during AM. These factors suggest that through site-specific processing possible with AM, Ti-1023 microstructures can be designed in situ to contain regions that deform by either TRIP or slip, creating parts with unique combinations of mechanical properties.
Authors: Chris Jasien1, Alec Saville1, Jonas Klemm-Toole1, Kamal Fezzaa2, Kester Clarke1, Amy Clarke1
1Colorado School of Mines, USA
2Advanced Photon Source, Argonne National Laboratory, USA
Abstract Author(s): (see above entries)