title: Microstructures and mechanical properties of Co-29Cr-6Mo alloy fabricated by selective laser melting process for dental applications.
abstract: The selective laser melting (SLM) process was applied to a Co-29Cr-6Mo alloy, and its microstructure, mechanical properties, and metal elution were investigated to determine whether the fabrication process is suitable for dental applications. The microstructure was evaluated using scanning electron microscopy with energy-dispersed X-ray spectroscopy (SEM-EDS), X-ray diffractometry (XRD), and electron back-scattered diffraction pattern analysis. The mechanical properties were evaluated using a tensile test. Dense builds were obtained when the input energy of the laser scan was higher than 400 J mm⁻³, whereas porous builds were formed when the input energy was lower than 150 J mm⁻³. The microstructure obtained was unique with fine cellular dendrites in the elongated grains parallel to the building direction. The γ phase was dominant in the build and its preferential <001> orientation was confirmed along the building direction, which was clearly observed for the builds fabricated at lower input energy. Although the mechanical anisotropy was confirmed in the SLM builds due to the unique microstructure, the yield strength, UTS, and elongation were higher than those of the as-cast alloy and satisfied the type 5 criteria in ISO22764. Metal elution from the SLM build was smaller than that of the as-cast alloy, and thus, the SLM process for the Co-29Cr-6Mo alloy is a promising candidate for fabricating dental devices.
authors.affiliation: Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takaichi
authors.lastname: Suyalatu
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakamoto
authors.forename: Natsuka
authors.initials: N
authors.lastname: Joko
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Nomura
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Tsutsumi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Migita
authors.forename: Hisashi
authors.initials: H
authors.lastname: Doi
authors.forename: Shingo
authors.initials: S
authors.lastname: Kurosu
authors.forename: Akihiko
authors.initials: A
authors.lastname: Chiba
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Wakabayashi
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Igarashi
authors.forename: Takao
authors.initials: T
authors.lastname: Hanawa
mesh_terms: D003764:Dental Materials / Q000032:analysis / Q000138:chemical synthesis* / Q000528:radiation effects*; D006244:Hardness; D006361:Heating / Q000379:methods*; D007834:Lasers; D008422:Materials Testing; D011829:Radiation Dosage; D013499:Surface Properties; D013718:Tensile Strength; D014800:Vitallium / Q000138:chemical synthesis* / Q000528:radiation effects*
chemical_list: D003764:Dental Materials; D014800:Vitallium