Authors:
Quentin Gaillard (École des Mines de Saint-Étienne, France),
Xavier Boulnat (Institut national des sciences appliquées de Lyon, France),
Sylvain Dancette (Institut national des sciences appliquées de Lyon, France),
Christophe Desrayaud (Ecole des Mines de Saint-Étienne, France)
Abstract:
L-PBF made Ti-6Al-4V parts show a fine martensitic microstructure and significant residual stresses that are disastrous for their mechanical performance. Consequently, post-processing heat treatments are necessary to relieve the internal stresses and lead to a microstructure adequate for the mechanical requirements. Due to the various powder compositions and processing parameters, there is a large scattering of properties of as-built and stress-relieved parts. As such, this study aims at quantifying the link between interstitials (oxygen, nitrogen) contents and the transition temperatures (martensite decomposition, beta transus) of as-built parts and as-atomized pre-alloyed powders as a reference. To do so, high-temperature X-Ray diffraction, differential scanning calorimetry and electron microscopy were performed. This insight provides a guide for designing post-processing heat treatments of Ti-6Al-4V as-built parts.
DOI:
https://doi.org/10.59499/WP225371951