Role of thermo-mechanical gyrations on the α/β interface stability in a Ti6Al4V AM alloy

Fluctuating energy distributions experienced during Additive Manufacturing yield an evolution of spatial and temporal transients within a part. In general, the in-situ monitoring of these transients is near to impossible during manufacturing. In order to then gain perspective into the impact on these localized thermo-mechanical transients on the interface stability, rapid thermo-mechanical reversals with known boundary conditions are imposed on an AM Ti6Al4V alloy which resulted in a phase transformation leading to an increased beta phase stability. Our goal with this study is to comprehend the kinetics of this phase transformation with concepts of stored energy due to plastic strain accumulation and diffusion kinetics. Atom Probe Tomography is employed to study the partitioning of the solute elements across the interface. As expected, the thermo-mechanically cycled samples showed a reduced Vanadium concentration across the beta phase. This concentration profile across the interface, alongside a full-width-half-max analysis, provided insight on the potential phase transformation kinetics involved in the alpha -> beta transformation subject to thermo-mechanical gyrations. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

Fluctuating energy distributions during Additive Manufacturing cause spatial and temporal transients within a part. Researchers imposed rapid thermo-mechanical reversals on an AM Ti6Al4V alloy to study the impact of localized thermo-mechanical transients on interface stability, leading to increased beta phase stability. Atom Probe Tomography was used to analyze the partitioning of solute elements across the interface.