title: Effects of build orientation and element partitioning on microstructure and mechanical properties of biomedical Ti-6Al-4V alloy produced by laser sintering.
abstract: Direct Metal Laser Sintering (DMLS) technology was used to produce tensile and flexural samples based on the Ti-6Al-4V biomedical composition. Tensile samples were produced in three different orientations in order to investigate the effect of building direction on the mechanical behavior. On the other hand, flexural samples were submitted to thermal treatments to simulate the firing cycle commonly used to veneer metallic devices with ceramics in dental applications. Roughness and hardness measurements as well as tensile and flexural mechanical tests were performed to study the mechanical response of the alloy while X-ray diffraction (XRD), electron microscopy (SEM, TEM, STEM) techniques and microanalysis (EDX) were used to investigate sample microstructure. Results evidenced a difference in the mechanical response of tensile samples built in orthogonal directions. In terms of microstructure, samples not submitted to the firing cycle show a single phase acicular α' (hcp) structure typical of metal parts subject to high cooling rates. After the firing cycle, samples show a reduction of hardness and strength due to the formation of laths of the β (bcc) phase at the boundaries of the primary formed α' plates as well as to lattice parameters variation of the hcp phase. Element partitioning during the firing cycle gives rise to high concentration of V atoms (up to 20wt%) at the plate boundaries where the β phase preferentially forms.
authors.affiliation: Dipartimento SIMAU, Università Politecnica delle Marche, 60131 Ancona, Italy. Electronic address: p.mengucci@univpm.it.
authors.forename: P
authors.initials: P
authors.lastname: Mengucci
authors.affiliation: Dipartimento DIEF, Università di Modena e Reggio Emilia, Via Vivarelli 10, 41125 Modena, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Gatto
authors.affiliation: Dipartimento DIEF, Università di Modena e Reggio Emilia, Via Vivarelli 10, 41125 Modena, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Bassoli
authors.affiliation: Dipartimento DIEF, Università di Modena e Reggio Emilia, Via Vivarelli 10, 41125 Modena, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Denti
authors.affiliation: Dipartimento DISCO, Università Politecnica delle Marche, 60131 Ancona, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Fiori
authors.affiliation: Dipartimento DISCO, Università Politecnica delle Marche, 60131 Ancona, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Girardin
authors.affiliation: Dipartimento SIMAU, Università Politecnica delle Marche, 60131 Ancona, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Bastianoni
authors.affiliation: International Centre of Electron Microscopy for Material Science & Faculty of Metals Engineering and Industrial Computer Science, AGH University of Science and Technology, Al. A. Mickiewicza 30, 30-059 Kraków, Poland.
authors.forename: B
authors.initials: B
authors.lastname: Rutkowski
authors.affiliation: International Centre of Electron Microscopy for Material Science & Faculty of Metals Engineering and Industrial Computer Science, AGH University of Science and Technology, Al. A. Mickiewicza 30, 30-059 Kraków, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Czyrska-Filemonowicz
authors.affiliation: Dipartimento SIMAU, Università Politecnica delle Marche, 60131 Ancona, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Barucca
mesh_terms: D000497:Alloys; D007834:Lasers; D008422:Materials Testing; D013718:Tensile Strength; D014025:Titanium / Q000032:analysis*; D014961:X-Ray Diffraction
chemical_list: D000497:Alloys; C031462:titanium alloy (TiAl6V4); D014025:Titanium
keywords: Element partitioning; Heat treatments; Laser sintering; Mechanical properties; Structure characterization; Ti alloys