Artículos de revistas
Ductility Improvement Due To Martensite α' Decomposition In Porous Ti-6al-4v Parts Produced By Selective Laser Melting For Orthopedic Implants.
Registro en:
Journal Of The Mechanical Behavior Of Biomedical Materials. v. 54, p. 149-158, 2016-Feb.
1878-0180
10.1016/j.jmbbm.2015.09.020
26458113
Autor
Sallica-Leva, E
Caram, R
Jardini, A L
Fogagnolo, J B
Institución
Resumen
Ti-6Al-4V parts obtained by selective laser melting typically have an acicular α' martensitic microstructure whose ductility is low. Thus, post-heat treatments are useful for increasing ductility. In this work, the effects of sub-β-transus heat treatments on the mechanical properties of Ti-6Al-4V parts with porous structures are correlated with martensite α' phase decomposition. The precipitation of β phase and the gradual transformation of α' into α phase by the diffusion of excess vanadium from α' to β phase are proposed to be the main events of martensite α' phase decomposition in parts fabricated by selective laser melting. The heat treatment performed at 650°C for 1h produced no microstructural changes, but the samples treated for at the same temperature 2h showed a fine precipitation of β phase along the α' needle boundaries. The heat treatment performed at 800°C for 1 or 2h produced a fine α+β microstructure, in which β phase are present as particles fewer in number and larger in size, when compared with the ones present in the sample heat-treated at 650°C for 2h. Heat-treatment of the parts at 800°C for 2h proved to be the best condition, which improved the ductility of the samples while only slightly reducing their strength. 54 149-158