Microstructural Refinement via High Deposition Rate Wire-Arc Directed Energy Deposited Ti-6Al-4V Using Cold Metal Transfer Technology

Activity: Talk or presentation / LecturePresentation at a scientific conference / workshop

Description

Wire-arc directed energy deposition (waDED) of Ti-alloys via the the novel cold metal transfer (CMT) technique with a novel welding characteristic offers significant cost reduction with higher production rates for 3D printing large-scale aerospace components. However, additive manufacturing (AM) processes with high-speed deposition rates involve complex thermo-mechanical profiles that promote heterogeneous microstructures and anisotropic mechanical properties within Ti-alloy builds.
This work seeks to comprehensively understand the microstructure evolution during CMT of a critical Ti-6Al-4V alloy and its capability to address material processing challenges. Here, CMT successfully stirs the melt pool and limits the epitaxial growth of the β-phase grains. Further, the unique thermal profile of the process refines both α- and β-phase microstructures and promotes the partitioning of alloying elements. Microstructure refinement unlocks more isotropic mechanical response when compared to other AM techniques. The chemical partitioning results in variations in α-lath size and local mechanical heterogeneities. However, it has a negligible effect on the overall mechanical performance of the as-build Ti-6Al-4V alloy. These findings showcase the potential of CMT to become a preferred processing route for manufacturing large-scale engineering parts for future aerospace applications and beyond.
Period30 Jun 2020
Event titleAsia-Pacific Conference on Additive Manufacturing
Event typeConference

Research Field

  • Wire-Based Additive Manufacturing