Rapid thermokinetics driven nanoscale vanadium clustering within martensite laths in laser powder bed fused additively manufactured Ti6Al4V

Abstract

This paper reports the computational approach adopted for thermo-diffusion kinetics to rationalize homogenously distributed nanoscale vanadium-rich clusters formed within the martensite laths of Ti6Al4V alloy printed using laser powder bed fusion at an energy density of 52.08J/mm3. The computations were conducted using a finite element method based thermal model, which predicted extremely rapid thermokinetics associated with the thermal cycles experienced at any given location of LPBF-printed Ti6Al4V. The numerically estimated effective V diffusion length of 6.61 nm indicated kinetic-limited diffusion resulting in V nano-clusters and are in good agreement with the atom probe tomography data giving a value of half the inter-cluster spacing of 7 nm.